2 * doc.c - Contains the short and long descriptions of all the documentation
3 * sections in the Glk spec, as well as the GtkDoc comments for symbols
4 * defined only in glk.h.
9 * @short_description: How to terminate a Glk program cleanly
10 * @include: libchimara/glk.h
12 * A Glk program usually ends when the end of the glk_main() function is
13 * reached. You can also terminate it earlier.
17 * SECTION:glk-interrupt
18 * @short_description: Specifying an interrupt handler for cleaning up critical
20 * @include: libchimara/glk.h
22 * Most platforms have some provision for interrupting a program —
23 * <keycombo action="simul"><keycap function="command">command</keycap>
24 * <keycap>period</keycap></keycombo> on the Macintosh, <keycombo
25 * action="simul"><keycap function="control">control</keycap><keycap>C</keycap>
26 * </keycombo> in Unix, possibly a window manager item, or other possibilities.
27 * This can happen at any time, including while execution is nested inside one
28 * of your own functions, or inside a Glk library function.
30 * If you need to clean up critical resources, you can specify an interrupt
36 * @short_description: Yielding time to the operating system
37 * @include: libchimara/glk.h
39 * Many platforms have some annoying thing that has to be done every so often,
40 * or the gnurrs come from the voodvork out and eat your computer.
42 * Well, not really. But you should call glk_tick() every so often, just in
43 * case. It may be necessary to yield time to other applications in a
44 * cooperative-multitasking OS, or to check for player interrupts in an infinite
50 * @short_description: Basic types used in Glk
51 * @include: libchimara/glk.h
53 * For simplicity, all the arguments used in Glk calls are of a very few types.
56 * <term>32-bit unsigned integer</term>
57 * <listitem><para>Unsigned integers are used wherever possible, which is
58 * nearly everywhere. This type is called #glui32.</para></listitem>
61 * <term>32-bit signed integer</term>
62 * <listitem><para>This type is called #glsi32. Rarely used.</para>
66 * <term>References to library objects</term>
67 * <listitem><para>These are pointers to opaque C structures; each library
68 * will use different structures, so you can not and should not try to
69 * manipulate their contents. See <link
70 * linkend="chimara-Opaque-Objects">Opaque Objects</link>.</para></listitem>
73 * <term>Pointer to one of the above types</term>
74 * <listitem><para>Pointer to a structure which consists entirely of the
75 * above types.</para></listitem>
78 * <term><type>unsigned char</type></term>
79 * <listitem><para>This is used only for Latin-1 text characters; see
80 * <link linkend="chimara-Character-Encoding">Character Encoding</link>.
84 * <term>Pointer to <type>char</type></term>
85 * <listitem><para>Sometimes this means a null-terminated string; sometimes
86 * an unterminated buffer, with length as a separate #glui32 argument. The
87 * documentation says which.</para></listitem>
90 * <term>Pointer to <type>void</type></term>
91 * <listitem><para>When nothing else will do.</para></listitem>
97 * SECTION:glk-opaque-objects
98 * @short_description: Complex objects in Glk
99 * @include: libchimara/glk.h
101 * Glk keeps track of a few classes of special objects. These are opaque to your
102 * program; you always refer to them using pointers to opaque C structures.
104 * Currently, these classes are:
107 * <term>Windows</term>
108 * <listitem><para>Screen panels, used to input or output information.
112 * <term>Streams</term>
113 * <listitem><para>Data streams, to which you can input or output text.
115 * <note><para>There are file streams and window streams, since you can
116 * output data to windows or files.</para></note>
120 * <term>File references</term>
121 * <listitem><para>Pointers to files in permanent storage.</para>
122 * <note><para>In Unix a file reference is a pathname; on the Mac, an
123 * <type>FSSpec</type>. Actually there's a little more information included,
124 * such as file type and whether it is a text or binary file.</para></note>
128 * <term>Sound channels</term>
129 * <listitem><para>Audio output channels.</para>
130 * <note><para>Not all Glk libraries support sound.</para></note>
136 * Note that there may be more object classes in future versions of the Glk API.
139 * When you create one of these objects, it is always possible that the creation
140 * will fail (due to lack of memory, or some other OS error.) When this happens,
141 * the allocation function will return %NULL (0) instead of a valid pointer. You
142 * should always test for this possibility.
144 * %NULL is never the identifier of any object (window, stream, file reference,
145 * or sound channel). The value %NULL is often used to indicate <quote>no
146 * object</quote> or <quote>nothing</quote>, but it is not a valid reference. If
147 * a Glk function takes an object reference as an argument, it is illegal to
148 * pass in %NULL unless the function definition says otherwise.
150 * The <filename class="headerfile">glk.h</filename> file defines types
151 * #winid_t, #strid_t, #frefid_t, #schanid_t to store references. These are
152 * pointers to struct #glk_window_struct, #glk_stream_struct,
153 * #glk_fileref_struct, and #glk_schannel_struct respectively. It is, of course,
154 * illegal to pass one kind of pointer to a function which expects another.
157 * This is how you deal with opaque objects from a C program. If you are using
158 * Glk through a virtual machine, matters will probably be different. Opaque
159 * objects may be represented as integers, or as VM objects of some sort.
161 * <refsect2 id="chimara-Rocks"><!-- Indeed it does. -->
162 * <title>Rocks</title>
164 * Every one of these objects (window, stream, file reference, or sound channel)
165 * has a <quote>rock</quote> value. This is simply a 32-bit integer value which
166 * you provide, for your own purposes, when you create the object.
168 * <note><para>The library — so to speak — stuffs this value under a
169 * rock for safe-keeping, and gives it back to you when you ask for it.
171 * <note><para>If you don't know what to use the rocks for, provide 0 and forget
172 * about it.</para></note>
174 * <refsect2 id="chimara-Iterating-Through-Opaque-Objects">
175 * <title>Iteration Through Opaque Objects</title>
177 * For each class of opaque objects, there is an iterate function, which you can
178 * use to obtain a list of all existing objects of that class. It takes the form
180 * <replaceable>CLASS</replaceable>id_t glk_<replaceable>CLASS</replaceable>_iterate(<replaceable>CLASS</replaceable>id_t <parameter>obj</parameter>, #glui32 *<parameter>rockptr</parameter>);
182 * ...where <code><replaceable>CLASS</replaceable></code> represents one of the
183 * opaque object classes.
186 * So, at the current time, these are the functions glk_window_iterate(),
187 * glk_stream_iterate(), glk_fileref_iterate(), and glk_schannel_iterate().
188 * There may be more classes in future versions of the spec; they all behave
192 * Calling <code>glk_<replaceable>CLASS</replaceable>_iterate(%NULL, r)</code>
193 * returns the first object; calling
194 * <code>glk_<replaceable>CLASS</replaceable>_iterate(obj, r)</code> returns
195 * the next object, until there aren't any more, at which time it returns %NULL.
198 * The @rockptr argument is a pointer to a location; whenever
199 * <code>glk_<replaceable>CLASS</replaceable>_iterate()</code> returns an
200 * object, the object's rock is stored in the location <code>(*@rockptr)</code>.
201 * If you don't want the rocks to be returned, you may set @rockptr to %NULL.
204 * You usually use this as follows:
206 * obj = glk_<replaceable>CLASS</replaceable>_iterate(NULL, NULL);
208 * /* ...do something with obj... *<!-- -->/
209 * obj = glk_<replaceable>CLASS</replaceable>_iterate(obj, NULL);
214 * If you create or destroy objects inside this loop, obviously, the results are
215 * unpredictable. However it is always legal to call
216 * <code>glk_<replaceable>CLASS</replaceable>_iterate(obj, r)</code> as long as
217 * @obj is a valid object id, or %NULL.
220 * The order in which objects are returned is entirely arbitrary. The library
221 * may even rearrange the order every time you create or destroy an object of
222 * the given class. As long as you do not create or destroy any object, the rule
223 * is that <code>glk_<replaceable>CLASS</replaceable>_iterate(obj, r)</code> has
224 * a fixed result, and iterating through the results as above will list every
225 * object exactly once.
231 * SECTION:glk-gestalt
232 * @short_description: Testing Glk's capabilities
233 * @include: libchimara/glk.h
235 * The <quote>gestalt</quote> mechanism (cheerfully stolen from the Mac OS) is a
236 * system by which the Glk API can be upgraded without making your life
237 * impossible. New capabilities (graphics, sound, or so on) can be added without
238 * changing the basic specification. The system also allows for
239 * <quote>optional</quote> capabilities — those which not all Glk library
240 * implementations will support — and allows you to check for their
241 * presence without trying to infer them from a version number.
243 * The basic idea is that you can request information about the capabilities of
244 * the API, by calling the gestalt functions.
248 * SECTION:glk-character-input
249 * @short_description: Waiting for a single keystroke
250 * @include: libchimara/glk.h
252 * You can request that the player hit a single key. See <link
253 * linkend="chimara-Character-Input-Events">Character Input Events</link>.
255 * If you use the basic text API, the character code which is returned can be
256 * any value from 0 to 255. The printable character codes have already been
257 * described. The remaining codes are typically control codes: <keycombo
258 * action="simul"><keycap function="control">control</keycap>
259 * <keycap>A</keycap></keycombo> to <keycombo action="simul"><keycap
260 * function="control">control</keycap><keycap>Z</keycap></keycombo> and a few
263 * There are also a number of special codes, representing special keyboard
264 * keys, which can be returned from a char-input event. These are represented
265 * as 32-bit integers, starting with 4294967295 (0xFFFFFFFF) and working down.
266 * The special key codes are defined in the <filename
267 * class="headerfile">glk.h</filename> file. They include one code for <keycap
268 * function="enter">return</keycap> or <keycap function="enter">enter</keycap>,
269 * one for <keycap function="delete">delete</keycap> or <keycap
270 * function="backspace">backspace</keycap>, twelve function keys, and one code
271 * for any key which has no Latin-1 or special code. The full list of key codes
274 * Various implementations of Glk will vary widely in which characters the
275 * player can enter. The most obvious limitation is that some characters are
276 * mapped to others. For example, most keyboards return a <keycombo
277 * action="simul"><keycap function="control">control</keycap><keycap>I</keycap>
278 * </keycombo> code when the <keycap function="tab">tab</keycap> key is
279 * pressed. The Glk library, if it can recognize this at all, will generate a
280 * <keysym>%keycode_Tab</keysym> event (value 0xFFFFFFF7) when this occurs.
281 * Therefore, for these keyboards, no keyboard key will generate a <keycombo
282 * action="simul"><keycap function="control">control</keycap><keycap>I</keycap>
283 * </keycombo> event (value 9.) The Glk library will probably map many of the
284 * control codes to the other special keycodes.
287 * On the other hand, the library may be very clever and discriminate between
288 * <keycap>tab</keycap> and <keycombo action="simul"><keycap
289 * function="control">control</keycap><keycap>I</keycap></keycombo>. This is
290 * legal. The idea is, however, that if your program asks the player to
291 * <quote><computeroutput>press the <keycap function="tab">tab</keycap>
292 * key</computeroutput></quote>, you should check for a
293 * <keysym>%keycode_Tab</keysym> event as opposed to a <keycombo
294 * action="simul"><keycap function="control">control</keycap>
295 * <keycap>I</keycap></keycombo> event.
298 * Some characters may not be enterable simply because they do not exist.
301 * Not all keyboards have a <keycap function="home">home</keycap> or <keycap
302 * function="end">end</keycap> key. A pen-based platform may not recognize
303 * any control characters at all.
306 * Some characters may not be enterable because they are reserved for the
307 * purposes of the interface. For example, the Mac Glk library reserves the
308 * <keycap function="tab">tab</keycap> key for switching between different Glk
309 * windows. Therefore, on the Mac, the library will never generate a
310 * <keysym>%keycode_Tab</keysym> event or a <keycombo action="simul">
311 * <keycap function="control">control</keycap><keycap>I</keycap></keycombo>
315 * Note that the linefeed or <keycombo action="simul"><keycap
316 * function="control">control</keycap><keycap>J</keycap></keycombo>
317 * character, which is the only printable control character, is probably not
318 * typable. This is because, in most libraries, it will be converted to
319 * <keysym>%keycode_Return</keysym>. Again, you should check for
320 * <keysym>%keycode_Return</keysym> if your program asks the player to
321 * <quote><computeroutput>press the <keycap function="enter">return</keycap>
322 * key</computeroutput></quote>.
326 * The <keycap function="delete">delete</keycap> and <keycap
327 * function="backspace">backspace</keycap> keys are merged into a single
328 * keycode because they have such an astonishing history of being confused in
329 * the first place... this spec formally waives any desire to define the
330 * difference. Of course, a library is free to distinguish <keycap
331 * function="delete">delete</keycap> and <keycap
332 * function="backspace">backspace</keycap> during line input. This is when it
333 * matters most; conflating the two during character input should not be a
337 * You can test for this by using the %gestalt_CharInput selector.
340 * Glk porters take note: it is not a goal to be able to generate every
341 * single possible key event. If the library says that it can generate a
342 * particular keycode, then game programmers will assume that it is
343 * available, and ask players to use it. If a <keysym>%keycode_Home</keysym>
344 * event can only be generated by typing <keycombo action="seq"><keycap
345 * function="escape">escape</keycap><keycombo action="simul"><keycap
346 * function="control">control</keycap><keycap>A</keycap></keycombo>
347 * </keycombo>, and the player does not know this, the player will be lost
348 * when the game says <quote><computeroutput>Press the <keycap
349 * function="home">home</keycap> key to see the next
350 * hint.</computeroutput></quote> It is better for the library to say that it
351 * cannot generate a <keysym>%keycode_Home</keysym> event; that way the game
352 * can detect the situation and ask the user to type <keycap>H</keycap>
356 * Of course, it is better not to rely on obscure keys in any case. The arrow
357 * keys and <keycap function="enter">return</keycap> are nearly certain to be
358 * available; the others are of gradually decreasing reliability, and you
359 * (the game programmer) should not depend on them. You must be certain to
360 * check for the ones you want to use, including the arrow keys and <keycap
361 * function="enter">return</keycap>, and be prepared to use different keys in
362 * your interface if %gestalt_CharInput says they are not available.
368 * @short_description: Changing the case of strings
369 * @include: libchimara/glk.h
371 * Glk has functions to manipulate the case of both Latin-1 and Unicode strings.
372 * One Latin-1 lowercase character corresponds to one uppercase character, and
373 * vice versa, so the Latin-1 functions act on single characters. The Unicode
374 * functions act on whole strings, since the length of the string may change.
378 * SECTION:glk-window-opening
379 * @short_description: Creating new windows and closing them
380 * @include: libchimara/glk.h
382 * You can open a new window using glk_window_open() and close it again using
383 * glk_window_close().
387 * SECTION:glk-window-constraints
388 * @short_description: Manipulating the size of a window
389 * @include: libchimara/glk.h
391 * There are library functions to change and to measure the size of a window.
395 * SECTION:glk-window-types
396 * @short_description: Blank, pair, text grid, text buffer, and graphics windows
397 * @include: libchimara/glk.h
399 * A technical description of all the window types, and exactly how they behave.
403 * SECTION:glk-echo-streams
404 * @short_description: Creating a copy of a window's output
405 * @include: libchimara/glk.h
407 * Every window has an associated window stream; you print to the window by
408 * printing to this stream. However, it is possible to attach a second stream to
409 * a window. Any text printed to the window is also echoed to this second
410 * stream, which is called the window's <quote>echo stream.</quote>
412 * Effectively, any call to glk_put_char() (or the other output commands) which
413 * is directed to the window's window stream, is replicated to the window's echo
414 * stream. This also goes for the style commands such as glk_set_style().
416 * Note that the echoing is one-way. You can still print text directly to the
417 * echo stream, and it will go wherever the stream is bound, but it does not
418 * back up and appear in the window.
420 * An echo stream can be of any type, even another window's window stream.
423 * This would be somewhat silly, since it would mean that any text printed to
424 * the window would be duplicated in another window. More commonly, you would
425 * set a window's echo stream to be a file stream, in order to create a
426 * transcript file from that window.
429 * A window can only have one echo stream. But a single stream can be the echo
430 * stream of any number of windows, sequentially or simultaneously.
432 * If a window is closed, its echo stream remains open; it is not automatically
436 * Do not confuse the window's window stream with its echo stream. The window
437 * stream is <quote>owned</quote> by the window, and dies with it. The echo
438 * stream is merely temporarily associated with the window.
441 * If a stream is closed, and it is the echo stream of one or more windows,
442 * those windows are reset to not echo anymore. (So then calling
443 * glk_window_get_echo_stream() on them will return %NULL.)
447 * SECTION:glk-window-other
448 * @short_description: Miscellaneous functions for windows
449 * @include: libchimara/glk.h
451 * This section contains functions for windows that don't fit anywhere else.
456 * @short_description: Waiting for events
457 * @include: libchimara/glk.h
459 * As described in <link linkend="chimara-Your-Programs-Main-Function">Your
460 * Program's Main Function</link>, all player input is handed to your program by
461 * the glk_select() call, in the form of events. You should write at least one
462 * event loop to retrieve these events.
466 * SECTION:glk-character-input-events
467 * @short_description: Events representing a single keystroke
468 * @include: libchimara/glk.h
470 * You can request character input from text buffer and text grid windows. See
471 * %evtype_CharInput. There are separate functions for requesting Latin-1 input
472 * and Unicode input; see %gestalt_Unicode.
476 * SECTION:glk-line-input-events
477 * @short_description: Events representing a line of user input
478 * @include: libchimara/glk.h
480 * You can request line input from text buffer and text grid windows. See
481 * %evtype_LineInput. There are separate functions for requesting Latin-1 input
482 * and Unicode input; see %gestalt_Unicode.
486 * SECTION:glk-timer-events
487 * @short_description: Events sent at fixed intervals
488 * @include: libchimara/glk.h
490 * You can request that an event be sent at fixed intervals, regardless of what
491 * the player does. Unlike input events, timer events can be tested for with
492 * glk_select_poll() as well as glk_select().
494 * It is possible that the library does not support timer events. You can check
495 * this with the %gestalt_Timer selector.
499 * SECTION:glk-streams
500 * @short_description: Input and output abstractions
501 * @include: libchimara/glk.h
503 * All character output in Glk is done through streams. Every window has an
504 * output stream associated with it. You can also write to files on disk; every
505 * open file is represented by an output stream as well.
507 * There are also input streams; these are used for reading from files on disk.
508 * It is possible for a stream to be both an input and an output stream.
511 * Player input is done through line and character input events, not streams.
512 * This is a small inelegance in theory. In practice, player input is slow and
513 * things can interrupt it, whereas file input is immediate. If a network
514 * extension to Glk were proposed, it would probably use events and not
515 * streams, since network communication is not immediate.
518 * It is also possible to create a stream that reads or writes to a buffer in
521 * Finally, there may be platform-specific types of streams, which are created
522 * before your program starts running.
525 * For example, a program running under Unix may have access to standard input
526 * as a stream, even though there is no Glk call to explicitly open standard
527 * input. On the Mac, data in a Mac resource may be available through a
528 * resource-reading stream.
531 * You do not need to worry about the origin of such streams; just read or write
532 * them as usual. For information about how platform-specific streams come to
533 * be, see <link linkend="chimara-Startup-Options">Startup Options</link>.
535 * A stream is opened with a particular file mode, see the
536 * <code>filemode_</code> constants below.
538 * For information on opening streams, see the discussion of each specific type
539 * of stream in <link linkend="chimara-The-Types-of-Streams">The Types of
540 * Streams</link>. Remember that it is always possible that opening a stream
541 * will fail, in which case the creation function will return %NULL.
543 * Each stream remembers two character counts, the number of characters printed
544 * to and read from that stream. The write-count is exactly one per
545 * glk_put_char() call; it is figured before any platform-dependent character
549 * For example, if a newline character is converted to
550 * linefeed-plus-carriage-return, the stream's count still only goes up by
551 * one; similarly if an accented character is displayed as two characters.
554 * The read-count is exactly one per glk_get_char_stream() call, as long as the
555 * call returns an actual character (as opposed to an end-of-file token.)
557 * Glk has a notion of the <quote>current (output) stream</quote>. If you print
558 * text without specifying a stream, it goes to the current output stream. The
559 * current output stream may be %NULL, meaning that there isn't one. It is
560 * illegal to print text to stream %NULL, or to print to the current stream when
563 * If the stream which is the current stream is closed, the current stream
569 * @short_description: Printing to streams
570 * @include: libchimara/glk.h
572 * You can print Latin-1 and Unicode characters, null-terminated strings, or
573 * buffers to any stream. The characters will be converted into the appropriate
574 * format for that stream.
579 * @short_description: Reading from streams
580 * @include: libchimara/glk.h
582 * You can read Latin-1 or Unicode characters, buffers, or whole lines from any
583 * stream. The characters will be converted into the form in which you request
588 * SECTION:glk-closing-streams
589 * @short_description: Closing streams and retrieving their character counts
590 * @include: libchimara/glk.h
592 * When you close a Glk stream, you have the opportunity to examine the
593 * character counts — the number of characters written to or read from the
598 * SECTION:glk-stream-positions
599 * @short_description: Moving the read/write mark
600 * @include: libchimara/glk.h
602 * You can set the position of the read/write mark in a stream.
605 * Which makes one wonder why they're called <quote>streams</quote> in the
606 * first place. Oh well.
612 * @short_description: Changing the appearance of printed text
613 * @include: libchimara/glk.h
615 * You can send style-changing commands to an output stream. After a style
616 * change, new text which is printed to that stream will be given the new style,
617 * whatever that means for the stream in question. For a window stream, the text
618 * will appear in that style. For a memory stream, style changes have no effect.
619 * For a file stream, if the machine supports styled text files, the styles may
620 * be written to the file; more likely the style changes will have no effect.
622 * Styles are exclusive. A character is shown with exactly one style, not a
623 * subset of the possible styles.
626 * Note that every stream and window has its own idea of the <quote>current
627 * style.</quote> Sending a style command to one window or stream does not
631 * Except for a window's echo stream; see <link
632 * linkend="chimara-Echo-Streams">Echo Streams</link>.
635 * The styles are intended to distinguish meaning and use, not formatting. There
636 * is no standard definition of what each style will look like. That is left up
637 * to the Glk library, which will choose an appearance appropriate for the
638 * platform's interface and the player's preferences.
640 * There are currently eleven styles defined. More may be defined in the future.
642 * Styles may be distinguished on screen by font, size, color, indentation,
643 * justification, and other attributes. Note that some attributes (notably
644 * justification and indentation) apply to entire paragraphs. If possible and
645 * relevant, you should apply a style to an entire paragraph — call
646 * glk_set_style() immediately after printing the newline at the beginning of
647 * the text, and do the same at the end.
650 * For example, %style_Header may well be centered text. If you print
651 * <quote>Welcome to Victim (a short interactive mystery)</quote>, and only the
652 * word <quote>Victim</quote> is in the %style_Header, the center-justification
653 * attribute will be lost. Similarly, a block quote is usually indented on both
654 * sides, but indentation is only meaningful when applied to an entire line or
655 * paragraph, so block quotes should take up an entire paragraph. Contrariwise,
656 * %style_Emphasized need not be used on an entire paragraph. It is often used
657 * for single emphasized words in normal text, so you can expect that it will
658 * appear properly that way; it will be displayed in italics or underlining,
659 * not center-justified or indented.
663 * Yes, this is all a matter of mutual agreement between game authors and game
664 * players. It's not fixed by this specification. That's natural language for
670 * SECTION:glk-stylehints
671 * @short_description: Setting style hints
672 * @include: libchimara/glk.h
674 * There are no guarantees of how styles will look, but you can make
677 * Initially, no hints are set for any window type or style. Note that having no
678 * hint set is not the same as setting a hint with value 0.
680 * These functions do <emphasis>not</emphasis> affect
681 * <emphasis>existing</emphasis> windows. They affect the windows which you
682 * create subsequently. If you want to set hints for all your game windows, call
683 * glk_stylehint_set() before you start creating windows. If you want different
684 * hints for different windows, change the hints before creating each window.
687 * This policy makes life easier for the interpreter. It knows everything about
688 * a particular window's appearance when the window is created, and it doesn't
689 * have to change it while the window exists.
692 * Hints are hints. The interpreter may ignore them, or give the player a choice
693 * about whether to accept them. Also, it is never necessary to set hints. You
694 * don't have to suggest that %style_Preformatted be fixed-width, or
695 * %style_Emphasized be boldface or italic; they will have appropriate defaults.
696 * Hints are for situations when you want to <emphasis>change</emphasis> the
697 * appearance of a style from what it would ordinarily be. The most common case
698 * when this is appropriate is for the styles %style_User1 and %style_User2.
700 * There are currently ten style hints defined. More may be defined in the
703 * Again, when passing a style hint to a Glk function, any value is actually
704 * legal. If the interpreter does not recognize the stylehint value, it will
707 * This policy allows for the future definition of style hints without breaking
713 * SECTION:glk-stream-types
714 * @short_description: Window, memory, and file streams
715 * @include: libchimara/glk.h
717 * <refsect2 id="chimara-Window-Streams"><title>Window Streams</title>
719 * Every window has an output stream associated with it. This is created
720 * automatically, with %filemode_Write, when you open the window. You get it
721 * with glk_window_get_stream().
723 * A window stream cannot be closed with glk_stream_close(). It is closed
724 * automatically when you close its window with glk_window_close().
726 * Only printable characters (including newline) may be printed to a window
727 * stream. See <link linkend="chimara-Character-Encoding">Character
731 * <refsect2 id="chimara-Memory-Streams"><title>Memory Streams</title>
733 * You can open a stream which reads from or writes to a space in memory. See
734 * glk_stream_open_memory() and glk_stream_open_memory_uni(). When opening a
735 * memory stream, you specify a buffer to which the stream's output will be
736 * written, and its length @buflen.
738 * When outputting, if more than @buflen characters are written to the stream,
739 * all of them beyond the buffer length will be thrown away, so as not to
740 * overwrite the buffer. (The character count of the stream will still be
741 * maintained correctly. That is, it will count the number of characters written
742 * into the stream, not the number that fit into the buffer.)
744 * If the buffer is %NULL, or for that matter if @buflen is zero, then
745 * <emphasis>everything</emphasis> written to the stream is thrown away. This
746 * may be useful if you are interested in the character count.
748 * When inputting, if more than @buflen characters are read from the stream, the
749 * stream will start returning -1 (signalling end-of-file.) If the buffer is
750 * %NULL, the stream will always return end-of-file.
752 * The data is written to the buffer exactly as it was passed to the printing
753 * functions (glk_put_char(), etc.); input functions will read the data exactly
754 * as it exists in memory. No platform-dependent cookery will be done on it.
757 * You can write a disk file in text mode, but a memory stream is effectively
758 * always in binary mode.
761 * Whether reading or writing, the contents of the buffer are undefined until
762 * the stream is closed. The library may store the data there as it is written,
763 * or deposit it all in a lump when the stream is closed. It is illegal to
764 * change the contents of the buffer while the stream is open.
767 * <refsect2 id="chimara-File-Streams"><title>File Streams</title>
769 * You can open a stream which reads from or writes to a disk file. See
770 * glk_stream_open_file() and glk_stream_open_file_uni().
772 * The file may be written in text or binary mode; this is determined by the
773 * file reference you open the stream with. Similarly, platform-dependent
774 * attributes such as file type are determined by the file reference. See <link
775 * linkend="chimara-File-References">File References</link>.
781 * SECTION:glk-stream-other
782 * @short_description: Miscellaneous functions for streams
783 * @include: libchimara/glk.h
785 * This section includes functions for streams that don't fit anywhere else.
789 * SECTION:glk-fileref
790 * @short_description: A platform-independent way to refer to disk files
791 * @include: libchimara/glk.h
793 * You deal with disk files using file references. Each fileref is an opaque C
794 * structure pointer; see <link linkend="chimara-Opaque-Objects">Opaque
797 * A file reference contains platform-specific information about the name and
798 * location of the file, and possibly its type, if the platform has a notion of
799 * file type. It also includes a flag indication whether the file is a text file
803 * Note that this is different from the standard C I/O library, in which you
804 * specify text or binary mode when the file is opened.
807 * A fileref does not have to refer to a file which actually exists. You can
808 * create a fileref for a nonexistent file, and then open it in write mode to
811 * You always provide a usage argument when you create a fileref. The usage is a
812 * mask of constants (see below) to indicate the file type and the mode (text or
813 * binary.) These values are used when you create a new file, and also to filter
814 * file lists when the player is selecting a file to load.
816 * In general, you should use text mode if the player expects to read the file
817 * with a platform-native text editor; you should use binary mode if the file is
818 * to be read back by your program, or if the data must be stored exactly. Text
819 * mode is appropriate for %fileusage_Transcript; binary mode is appropriate for
820 * %fileusage_SavedGame and probably for %fileusage_InputRecord. %fileusage_Data
821 * files may be text or binary, depending on what you use them for.
825 * SECTION:glk-fileref-types
826 * @short_description: Four different ways to create a file reference
827 * @include: libchimara/glk.h
829 * There are four different functions for creating a fileref, depending on how
830 * you wish to specify it. Remember that it is always possible that a fileref
831 * creation will fail and return %NULL.
835 * SECTION:glk-fileref-other
836 * @short_description: Miscellaneous functions for file references
837 * @include: libchimara/glk.h
839 * This section includes functions for file references that don't fit anywhere
844 * SECTION:dispatch-interrogating
845 * @short_description: Finding out what functions the Glk library exports
846 * @include: libchimara/glk.h, libchimara/gi_dispa.h
848 * These are the ancilliary functions that let you enumerate.
852 * SECTION:dispatch-dispatching
853 * @short_description: Dispatching the call to the Glk library
854 * @include: libchimara/glk.h, libchimara/gi_dispa.h
858 * SECTION:dispatch-prototypes
859 * @short_description: Querying Glk function prototypes
860 * @include: libchimara/glk.h, libchimara/gi_dispa.h
862 * There are many possible ways to set up a #gluniversal_t array, and it's
863 * illegal to call gidispatch_call() with an array which doesn't match the
864 * function. Furthermore, some references are passed in, some passed out, and
865 * some both. How do you know how to handle the argument list?
867 * One possibility is to recognize each function selector, and set up the
868 * arguments appropriately. However, this entails writing special code for each
869 * Glk function; which is exactly what we don't want to do.
871 * Instead, you can call gidispatch_prototype().
875 * SECTION:dispatch-library-functions
876 * @short_description: Platform-dependent dispatch layer functions
877 * @include: libchimara/glk.h, libchimara/gi_dispa.h
879 * Ideally, the three layers — program, dispatch layer, Glk library
880 * — would be completely modular; each would refer only to the layers
881 * beneath it. Sadly, there are a few places where the library must notify the
882 * program that something has happened. Worse, these situations are only
883 * relevant to programs which use the dispatch layer, and then only some of
886 * Since C is uncomfortable with the concept of calling functions which may not
887 * exist, Glk handles this with call-back function pointers. The program can
888 * pass callbacks in to the library; if it does, the library will call them, and
889 * if not, the library doesn't try.
891 * These callbacks are optional, in the sense that the program may or may not
892 * set them. However, any library which wants to interoperate with the dispatch
893 * layer must <emphasis>allow</emphasis> the program to set them; it is the
894 * program's choice. The library does this by implementing
895 * <code>set_registry functions</code> — the functions to which the
896 * program passes its callbacks.
899 * Even though these callbacks and the functions to set them are declared in
900 * <filename class="headerfile">gi_dispa.h</filename>, they are not defined in
901 * <filename>gi_dispa.c</filename>. The dispatch layer merely coordinates
902 * them. The program defines the callback functions; the library calls them.
907 * SECTION:blorb-program
908 * @short_description: How to use the Blorb layer in your program
909 * @include: libchimara/glk.h, libchimara/gi_blorb.h
911 * If you wish your program to load its resources from a Blorb file, you need to
912 * find and open that file in your startup code. (See <link
913 * linkend="chimara-Startup-Options">Startup Options</link>.) Each platform will
914 * have appropriate functions available for finding startup data. Be sure to
915 * open the file in binary mode, not text mode. Once you have opened the file as
916 * a Glk stream, pass it to giblorb_set_resource_map().
918 * If you do not call giblorb_set_resource_map() in your startup code, or if it
919 * fails, the library is left to its own devices for finding resources. Some
920 * libraries may try to load resources from individual files —
921 * <filename>PIC1</filename>, <filename>PIC2</filename>,
922 * <filename>PIC3</filename>, and so on. (See the Blorb specification for more
923 * on this approach.) Other libraries will not have any other loading mechanism
924 * at all; no resources will be available.
928 * SECTION:blorb-layer
929 * @short_description: The platform-independent functions in the Blorb layer
930 * @include: libchimara/glk.h, libchimara/gi_blorb.h
932 * These are the functions which are implemented in
933 * <filename>gi_blorb.c</filename>. They will be compiled into the library, but
934 * they are the same on every platform. In general, only the library needs to
935 * call these functions. The Glk program should allow the library to do all the
940 * SECTION:blorb-errors
941 * @short_description: Error codes returned by the Blorb layer functions
942 * @include: libchimara/glk.h, libchimara/gi_blorb.h
944 * All Blorb layer functions, including giblorb_set_resource_map(), return the
945 * following error codes.
949 * SECTION:glkext-startup
950 * @short_description: Parsing startup options
951 * @include: libchimara/glk.h, libchimara/glkstart.h
953 * This section describes an extension to Glk for parsing command-line startup
954 * options. It was written by Andrew Plotkin for the Glk libraries CheapGlk and
957 * When you compile a Glk program, you may define a function called
958 * glkunix_startup_code(), and an array <code>glkunix_arguments[]</code>. These
959 * set up various Unix-specific options used by the Glk library. There is a
960 * sample <quote><filename>glkstart.c</filename></quote> file included in this
961 * package; you should modify it to your needs.
963 * |[ extern #glkunix_argumentlist_t glkunix_arguments[]; ]|
965 * The <code>glkunix_arguments[]</code> array is a list of command-line
966 * arguments that your program can accept. The library will sort these out of
967 * the command line and pass them on to your code.
971 * SECTION:glkext-unix
972 * @short_description: Unix-specific functions
973 * @include: libchimara/glk.h, libchimara/glkstart.h
975 * This section describes an extension to Glk for various Unix functions. It was
976 * written by Andrew Plotkin for the Glk libraries CheapGlk and GlkTerm.
978 * You can put other startup code in glkunix_startup_code(). This should
979 * generally be limited to finding and opening data files. There are a few Unix
980 * Glk library functions which are convenient for this purpose.
983 /*---------------- TYPES AND CONSTANTS FROM GLK.H ----------------------------*/
988 * A 32-bit unsigned integer type, used wherever possible in Glk.
994 * A 32-bit signed integer type, rarely used.
998 * GLK_MODULE_UNICODE:
1000 * If this preprocessor symbol is defined, so are all the Unicode functions and
1001 * constants (see %gestalt_Unicode). If not, not.
1007 * Opaque structure representing a Glk window. It has no user-accessible
1014 * Opaque structure representing an input or output stream. It has no
1015 * user-accessible members.
1021 * Opaque structure representing a file reference. It has no user-accessible
1028 * For an example of the gestalt mechanism, consider the selector
1029 * %gestalt_Version. If you do
1032 * res = #glk_gestalt(#gestalt_Version, 0);
1034 * <code>res</code> will be set to a 32-bit number which encodes the version of
1035 * the Glk spec which the library implements. The upper 16 bits stores the major
1036 * version number; the next 8 bits stores the minor version number; the low 8
1037 * bits stores an even more minor version number, if any.
1040 * So the version number 78.2.11 would be encoded as 0x004E020B.
1043 * The current Glk specification version is 0.7.0, so this selector will return
1048 * res = #glk_gestalt_ext(#gestalt_Version, 0, NULL, 0);
1050 * does exactly the same thing. Note that, in either case, the second argument
1051 * is not used; so you should always pass 0 to avoid future surprises.
1055 * gestalt_CharInput:
1057 * If you set <code>ch</code> to a character code, or a special code (from
1058 * 0xFFFFFFFF down), and call
1061 * res = #glk_gestalt(#gestalt_CharInput, ch);
1063 * then <code>res</code> will be %TRUE (1) if that character can be typed by
1064 * the player in character input, and %FALSE (0) if not. See <link
1065 * linkend="chimara-Character-Input">Character Input</link>.
1069 * gestalt_LineInput:
1071 * If you set <code>ch</code> to a character code, and call
1074 * res = #glk_gestalt(#gestalt_LineInput, ch);
1076 * then <code>res</code> will be %TRUE (1) if that character can be typed by the
1077 * player in line input, and %FALSE (0) if not. Note that if <code>ch</code> is
1078 * a nonprintable Latin-1 character (0 to 31, 127 to 159), then this is
1079 * guaranteed to return %FALSE. See <link linkend="chimara-Line-Input">Line
1084 * gestalt_CharOutput:
1086 * If you set <code>ch</code> to a character code (Latin-1 or higher), and call
1089 * res = #glk_gestalt_ext(#gestalt_CharOutput, ch, &len, 1);
1091 * then <code>res</code> will be one of %gestalt_CharOutput_CannotPrint,
1092 * %gestalt_CharOutput_ExactPrint, or %gestalt_CharOutput_ApproxPrint (see
1095 * In all cases, <code>len</code> (the #glui32 value pointed at by the third
1096 * argument) will be the number of actual glyphs which will be used to represent
1097 * the character. In the case of %gestalt_CharOutput_ExactPrint, this will
1098 * always be 1; for %gestalt_CharOutput_CannotPrint, it may be 0 (nothing
1099 * printed) or higher; for %gestalt_CharOutput_ApproxPrint, it may be 1 or
1100 * higher. This information may be useful when printing text in a fixed-width
1104 * As described in <link linkend="chimara-Other-API-Conventions">Other API
1105 * Conventions</link>, you may skip this information by passing %NULL as the
1106 * third argument in glk_gestalt_ext(), or by calling glk_gestalt() instead.
1109 * This selector will always return %gestalt_CharOutput_CannotPrint if
1110 * <code>ch</code> is an unprintable eight-bit character (0 to 9, 11 to 31, 127
1114 * Make sure you do not get confused by signed byte values. If you set a
1115 * <quote><type>char</type></quote> variable <code>ch</code> to 0xFE, the
1116 * small-thorn character (þ), and then call
1117 * |[ res = #glk_gestalt(#gestalt_CharOutput, ch); ]|
1118 * then (by the definition of C/C++) <code>ch</code> will be sign-extended to
1119 * 0xFFFFFFFE, which is not a legitimate character, even in Unicode. You
1121 * |[ res = #glk_gestalt(#gestalt_CharOutput, (unsigned char)ch); ]|
1125 * Unicode includes the concept of non-spacing or combining characters, which
1126 * do not represent glyphs; and double-width characters, whose glyphs take up
1127 * two spaces in a fixed-width font. Future versions of this spec may
1128 * recognize these concepts by returning a <code>len</code> of 0 or 2 when
1129 * %gestalt_CharOutput_ExactPrint is used. For the moment, we are adhering to
1130 * a policy of <quote>simple stuff first</quote>.
1135 * gestalt_CharOutput_CannotPrint:
1137 * When the %gestalt_CharOutput selector returns this for a character, the
1138 * character cannot be meaningfully printed. If you try, the player may see
1139 * nothing, or may see a placeholder.
1143 * gestalt_CharOutput_ApproxPrint:
1145 * When the %gestalt_CharOutput selector returns this for a character, the
1146 * library will print some approximation of the character. It will be more or
1147 * less right, but it may not be precise, and it may not be distinguishable from
1148 * other, similar characters. (Examples:
1149 * <quote><computeroutput>ae</computeroutput></quote> for the one-character
1150 * <quote>æ</quote> ligature,
1151 * <quote><computeroutput>e</computeroutput></quote> for
1152 * <quote>è</quote>, <quote><computeroutput>|</computeroutput></quote>
1153 * for a broken vertical bar (¦).)
1157 * gestalt_CharOutput_ExactPrint:
1159 * When the %gestalt_CharOutput selector returns this for a character, the
1160 * character will be printed exactly as defined.
1166 * The basic text functions will be available in every Glk library. The Unicode
1167 * functions may or may not be available. Before calling them, you should use
1168 * the following gestalt selector:
1171 * res = #glk_gestalt(#gestalt_Unicode, 0);
1174 * This returns 1 if the Unicode functions are available. If it returns 0, you
1175 * should not try to call them. They may print nothing, print gibberish, or
1176 * cause a run-time error. The Unicode functions include
1177 * glk_buffer_to_lower_case_uni(), glk_buffer_to_upper_case_uni(),
1178 * glk_buffer_to_title_case_uni(), glk_put_char_uni(), glk_put_string_uni(),
1179 * glk_put_buffer_uni(), glk_put_char_stream_uni(), glk_put_string_stream_uni(),
1180 * glk_put_buffer_stream_uni(), glk_get_char_stream_uni(),
1181 * glk_get_buffer_stream_uni(), glk_get_line_stream_uni(),
1182 * glk_request_char_event_uni(), glk_request_line_event_uni(),
1183 * glk_stream_open_file_uni(), glk_stream_open_memory_uni().
1185 * If you are writing a C program, there is an additional complication. A
1186 * library which does not support Unicode may not implement the Unicode
1187 * functions at all. Even if you put gestalt tests around your Unicode calls,
1188 * you may get link-time errors. If the
1189 * <filename class="headerfile">glk.h</filename> file is so old that it does not
1190 * declare the Unicode functions and constants, you may even get compile-time
1193 * To avoid this, you can perform a preprocessor test for the existence of
1194 * #GLK_MODULE_UNICODE.
1200 * You can test whether the library supports timer events:
1201 * |[ res = #glk_gestalt(#gestalt_Timer, 0); ]|
1202 * This returns 1 if timer events are supported, and 0 if they are not.
1208 * No event. This is a placeholder, and glk_select() never returns it.
1214 * An event that repeats at fixed intervals. See <link
1215 * linkend="chimara-Timer-Events">Timer Events</link>.
1221 * A keystroke event in a window. See <link
1222 * linkend="chimara-Character-Input-Events">Character Input Events</link>.
1224 * If a window has a pending request for character input, and the player hits a
1225 * key in that window, glk_select() will return an event whose type is
1226 * %evtype_CharInput. Once this happens, the request is complete; it is no
1227 * longer pending. You must call glk_request_char_event() or
1228 * glk_request_char_event_uni() if you want another character from that window.
1230 * In the event structure, @win tells what window the event came from. @val1
1231 * tells what character was entered; this will be a character code, or a special
1232 * keycode. (See <link linkend="chimara-Character-Input">Character
1233 * Input</link>.) If you called glk_request_char_event(), @val1 will be in
1234 * 0..255, or else a special keycode. In any case, @val2 will be 0.
1240 * A full line of input completed in a window. See <link
1241 * linkend="chimara-Line-Input-Events">Line Input Events</link>.
1243 * If a window has a pending request for line input, and the player hits
1244 * <keycap>enter</keycap> in that window (or whatever action is appropriate to
1245 * enter his input), glk_select() will return an event whose type is
1246 * %evtype_LineInput. Once this happens, the request is complete; it is no
1247 * longer pending. You must call glk_request_line_event() if you want another
1248 * line of text from that window.
1250 * In the event structure, @win tells what window the event came from. @val1
1251 * tells how many characters were entered. @val2 will be 0. The characters
1252 * themselves are stored in the buffer specified in the original
1253 * glk_request_line_event() or glk_request_line_event_uni() call.
1255 * <note><para>There is no null terminator stored in the buffer.</para></note>
1257 * It is illegal to print anything to a window which has line input pending.
1260 * This is because the window may be displaying and editing the player's
1261 * input, and printing anything would make life unnecessarily complicated for
1267 * evtype_MouseInput:
1269 * A mouse click in a window. See <link
1270 * linkend="chimara-Mouse-Input-Events">Mouse Input Events</link>.
1276 * An event signalling that the sizes of some windows have changed.
1278 * Some platforms allow the player to resize the Glk window during play. This
1279 * will naturally change the sizes of your windows. If this occurs, then
1280 * immediately after all the rearrangement, glk_select() will return an event
1281 * whose type is %evtype_Arrange. You can use this notification to redisplay the
1282 * contents of a graphics or text grid window whose size has changed.
1285 * The display of a text buffer window is entirely up to the library, so you
1286 * don't need to worry about those.
1289 * In the event structure, @win will be %NULL if all windows are affected. If
1290 * only some windows are affected, @win will refer to a window which contains
1291 * all the affected windows. @val1 and @val2 will be 0.
1294 * You can always play it safe, ignore @win, and redraw every graphics and
1298 * An arrangement event is guaranteed to occur whenever the player causes any
1299 * window to change size, as measured by its own metric.
1302 * Size changes caused by you — for example, if you open, close, or
1303 * resize a window — do not trigger arrangement events. You must be
1304 * aware of the effects of your window management, and redraw the windows that
1309 * It is possible that several different player actions can cause windows to
1310 * change size. For example, if the player changes the screen resolution, an
1311 * arrangement event might be triggered. This might also happen if the player
1312 * changes his display font to a different size; the windows would then be
1313 * different <quote>sizes</quote> in the metric of rows and columns, which is
1314 * the important metric and the only one you have access to.
1317 * Arrangement events, like timer events, can be returned by glk_select_poll().
1318 * But this will not occur on all platforms. You must be ready to receive an
1319 * arrangement event when you call glk_select_poll(), but it is possible that it
1320 * will not arrive until the next time you call glk_select().
1323 * This is because on some platforms, window resizing is handled as part of
1324 * player input; on others, it can be triggered by an external process such as
1332 * An event signalling that graphics windows must be redrawn.
1334 * On platforms that support graphics, it is possible that the contents of a
1335 * graphics window will be lost, and have to be redrawn from scratch. If this
1336 * occurs, then glk_select() will return an event whose type is %evtype_Redraw.
1338 * In the event structure, @win will be %NULL if all windows are affected. If
1339 * only some windows are affected, @win will refer to a window which contains
1340 * all the affected windows. @val1 and @val2 will be 0.
1343 * You can always play it safe, ignore @win, and redraw every graphics window.
1346 * Affected windows are already cleared to their background color when you
1347 * receive the redraw event.
1349 * Redraw events can be returned by glk_select_poll(). But, like arrangement
1350 * events, this is platform-dependent. See %evtype_Arrange.
1352 * For more about redraw events and how they affect graphics windows, see <link
1353 * linkend="chimara-Graphics-Windows">Graphics Windows</link>.
1357 * evtype_SoundNotify:
1359 * On platforms that support sound, you can request to receive an
1360 * %evtype_SoundNotify event when a sound finishes playing. See <link
1361 * linkend="chimara-Playing-Sounds">Playing Sounds</link>.
1367 * On platforms that support hyperlinks, you can request to receive an
1368 * %evtype_Hyperlink event when the player selects a link. See <link
1369 * linkend="chimara-Accepting-Hyperlink-Events">Accepting Hyperlink
1375 * @type: the event type
1376 * @win: the window that spawned the event, or %NULL
1377 * @val1: information, the meaning of which depends on the type of event
1378 * @val2: more information, the meaning of which depends on the type of event
1380 * The event structure is self-explanatory. @type is the event type. The window
1381 * that spawned the event, if relevant, is in @win. The remaining fields contain
1382 * more information specific to the event.
1384 * The event types are described below. Note that %evtype_None is zero, and the
1385 * other values are positive. Negative event types (0x80000000 to 0xFFFFFFFF)
1386 * are reserved for implementation-defined events.
1392 * Represents any key that has no Latin-1 or special code.
1398 * Represents the <keycap function="left">left arrow</keycap> key.
1404 * Represents the <keycap function="right">right arrow</keycap> key.
1410 * Represents the <keycap function="up">up arrow</keycap> key.
1416 * Represents the <keycap function="down">down arrow</keycap> key.
1422 * Represents the <keycap function="enter">return</keycap> or <keycap
1423 * function="enter">enter</keycap> keys.
1429 * Represents the <keycap function="delete">delete</keycap> or <keycap
1430 * function="backspace">backspace</keycap> keys.
1436 * Represents the <keycap function="escape">escape</keycap> key.
1442 * Represents the <keycap function="tab">tab</keycap> key.
1448 * Represents the <keycap function="pageup">page up</keycap> key.
1454 * Represents the <keycap function="pagedown">page down</keycap> key.
1460 * Represents the <keycap function="home">home</keycap> key.
1466 * Represents the <keycap function="end">end</keycap> key.
1472 * Represents the <keycap>F1</keycap> key.
1478 * Represents the <keycap>F2</keycap> key.
1484 * Represents the <keycap>F3</keycap> key.
1490 * Represents the <keycap>F4</keycap> key.
1496 * Represents the <keycap>F5</keycap> key.
1502 * Represents the <keycap>F6</keycap> key.
1508 * Represents the <keycap>F7</keycap> key.
1514 * Represents the <keycap>F8</keycap> key.
1520 * Represents the <keycap>F9</keycap> key.
1526 * Represents the <keycap>F10</keycap> key.
1532 * Represents the <keycap>F11</keycap> key.
1538 * Represents the <keycap>F12</keycap> key.
1544 * This value is equal to the number of special keycodes. The last keycode is
1547 * <alt>(0x100000000 - <keysym>keycode_MAXVAL</keysym>)</alt>
1548 * <mathphrase>(0x100000000 - <keysym>keycode_MAXVAL</keysym>)</mathphrase>
1556 * The style of normal or body text. A new window or stream always starts with
1557 * %style_Normal as the current style.
1563 * Text which is emphasized.
1567 * style_Preformatted:
1569 * Text which has a particular arrangement of characters.
1571 * This style, unlike the others, does have a standard appearance; it will
1572 * always be a fixed-width font. This is a concession to practicality. Games
1573 * often want to display maps or diagrams using character graphics, and this is
1574 * the style for that.
1581 * Text which introduces a large section. This is suitable for the title of an
1582 * entire game, or a major division such as a chapter.
1588 * Text which introduces a smaller section within a large section.
1590 * In a Colossal-Cave-style game, this is suitable for the name of a room (when
1591 * the player looks around.)
1598 * Text which warns of a dangerous condition, or one which the player should pay
1605 * Text which notifies of an interesting condition.
1607 * This is suitable for noting that the player's score has changed.
1614 * Text which forms a quotation or otherwise abstracted text.
1620 * Text which the player has entered. You should generally not use this style at
1621 * all; the library uses it for text which is typed during a line-input request.
1622 * One case when it is appropriate for you to use %style_Input is when you are
1623 * simulating player input by reading commands from a text file.
1629 * This style has no particular semantic meaning. You may define a meaning
1630 * relevant to your own work, and use it as you see fit.
1636 * Another style available for your use.
1642 * The number of styles defined in this library.
1647 * @readcount: Number of characters read from the stream.
1648 * @writecount: Number of characters printed to the stream, including ones that
1651 * If you are interested in the character counts of a stream (see <link
1652 * linkend="chimara-Streams">Streams</link>), then you can pass a pointer to
1653 * #stream_result_t as an argument of glk_stream_close() or glk_window_close().
1654 * The structure will be filled with the stream's final character counts.
1660 * A constant representing all window types, which may be used as the @wintype
1661 * argument in glk_stylehint_set().
1667 * A pair window is completely filled by the two windows it contains. It
1668 * supports no input and no output, and it has no size.
1670 * You cannot directly create a pair window; one is automatically created
1671 * every time you split a window with glk_window_open(). Pair windows are
1672 * always created with a rock value of 0.
1674 * You can close a pair window with glk_window_close(); this also closes every
1675 * window contained within the pair window.
1677 * It is legal to split a pair window when you call glk_window_open().
1683 * A blank window is always blank. It supports no input and no output. (You
1684 * can call glk_window_get_stream() on it, as you can with any window, but
1685 * printing to the resulting stream has no effect.) A blank window has no
1686 * size; glk_window_get_size() will return (0,0), and it is illegal to set a
1687 * window split with a fixed size in the measurement system of a blank window.
1690 * A blank window is not the same as there being no windows. When Glk starts
1691 * up, there are no windows at all, not even a window of the blank type.
1696 * wintype_TextBuffer:
1698 * A text buffer window contains a linear stream of text. It supports output;
1699 * when you print to it, the new text is added to the end. There is no way for
1700 * you to affect text which has already been printed. There are no guarantees
1701 * about how much text the window keeps; old text may be stored forever, so
1702 * that the user can scroll back to it, or it may be thrown away as soon as it
1703 * scrolls out of the window.
1706 * Therefore, there may or may not be a player-controllable scroll bar or
1707 * other scrolling widget.
1710 * The display of the text in a text buffer is up to the library. Lines will
1711 * probably not be broken in the middles of words — but if they are, the
1712 * library is not doing anything illegal, only ugly. Text selection and copying
1713 * to a clipboard, if available, are handled however is best on the player's
1714 * machine. Paragraphs (as defined by newline characters in the output) may be
1718 * You should not, in general, fake this by printing spaces before each
1719 * paragraph of prose text. Let the library and player preferences handle
1720 * that. Special cases (like indented lists) are of course up to you.
1723 * When a text buffer is cleared (with glk_window_clear()), the library will do
1724 * something appropriate; the details may vary. It may clear the window, with
1725 * later text appearing at the top — or the bottom. It may simply print
1726 * enough blank lines to scroll the current text out of the window. It may
1727 * display a distinctive page-break symbol or divider.
1729 * The size of a text buffer window is necessarily imprecise. Calling
1730 * glk_window_get_size() will return the number of rows and columns that would
1731 * be available <emphasis>if</emphasis> the window was filled with
1732 * <quote>0</quote> (zero) characters in the <quote>normal</quote> font.
1733 * However, the window may use a non-fixed-width font, so that number of
1734 * characters in a line could vary. The window might even support
1735 * variable-height text (say, if the player is using large text for emphasis);
1736 * that would make the number of lines in the window vary as well.
1738 * Similarly, when you set a fixed-size split in the measurement system of a
1739 * text buffer, you are setting a window which can handle a fixed number of rows
1740 * (or columns) of <quote>0</quote> characters. The number of rows (or
1741 * characters) that will actually be displayed depends on font variances.
1743 * A text buffer window supports both character and line input, but not mouse
1746 * In character input, there will be some visible signal that the window is
1747 * waiting for a keystroke. (Typically, a cursor at the end of the text.) When
1748 * the player hits a key in that window, an event is generated, but the key is
1749 * <emphasis>not</emphasis> printed in the window.
1751 * In line input, again, there will be some visible signal. It is most common
1752 * for the player to compose input in the window itself, at the end of the text.
1753 * (This is how IF story input usually looks.) But it's not strictly required.
1754 * An alternative approach is the way MUD clients usually work: there is a
1755 * dedicated one-line input window, outside of Glk's window space, and the user
1756 * composes input there.
1759 * If this approach is used, there will still be some way to handle input from
1760 * two windows at once. It is the library's responsibility to make this
1761 * available to the player. You only need request line input and wait for the
1765 * When the player finishes his line of input, the library will display the
1766 * input text at the end of the buffer text (if it wasn't there already.) It
1767 * will be followed by a newline, so that the next text you print will start a
1768 * new line (paragraph) after the input.
1770 * If you call glk_cancel_line_event(), the same thing happens; whatever text
1771 * the user was composing is visible at the end of the buffer text, followed by
1778 * A text grid contains a rectangular array of characters, in a fixed-width
1779 * font. Its size is the number of columns and rows of the array.
1781 * A text grid window supports output. It maintains knowledge of an output
1782 * cursor position. When the window is opened, it is filled with blanks (space
1783 * characters), and the output cursor starts in the top left corner —
1784 * character (0,0). If the window is cleared with glk_window_clear(), the window
1785 * is filled with blanks again, and the cursor returns to the top left corner.
1787 * When you print, the characters of the output are laid into the array in
1788 * order, left to right and top to bottom. When the cursor reaches the end of a
1789 * line, it goes to the beginning of the next line. The library makes no attempt
1790 * to wrap lines at word breaks.
1793 * Note that printing fancy characters may cause the cursor to advance more
1794 * than one position per character. (For example, the <quote>æ</quote>
1795 * ligature may print as two characters.) See <link
1796 * linkend="chimara-Output">Output</link>, for how to test this situation.
1799 * You can set the cursor position with glk_window_move_cursor().
1801 * When a text grid window is resized smaller, the bottom or right area is
1802 * thrown away, but the remaining area stays unchanged. When it is resized
1803 * larger, the new bottom or right area is filled with blanks.
1806 * You may wish to watch for %evtype_Arrange events, and clear-and-redraw your
1807 * text grid windows when you see them change size.
1810 * Text grid window support character and line input, as well as mouse input (if
1811 * a mouse is available.)
1813 * Mouse input returns the position of the character that was touched, from
1816 * <alt>(width-1,height-1)</alt>
1817 * <mathphrase>(width - 1, height - 1)</mathphrase>
1821 * Character input is as described in the previous section.
1823 * Line input is slightly different; it is guaranteed to take place in the
1824 * window, at the output cursor position. The player can compose input only to
1825 * the right edge of the window; therefore, the maximum input length is
1827 * <alt>(windowwidth - 1 - cursorposition)</alt>
1828 * <mathphrase>(windowwidth - 1 - cursorposition)</mathphrase>
1830 * . If the maxlen argument of glk_request_line_event() is smaller than this,
1831 * the library will not allow the input cursor to go more than maxlen characters
1832 * past its start point.
1835 * This allows you to enter text in a fixed-width field, without the player
1836 * being able to overwrite other parts of the window.
1839 * When the player finishes his line of input, it will remain visible in the
1840 * window, and the output cursor will be positioned at the beginning of the
1841 * <emphasis>next</emphasis> row. Again, if you glk_cancel_line_event(), the
1842 * same thing happens.
1848 * A graphics window contains a rectangular array of pixels. Its size is the
1849 * number of columns and rows of the array.
1851 * Each graphics window has a background color, which is initially white. You
1852 * can change this; see <link
1853 * linkend="chimara-Graphics-in-Graphics-Windows">Graphics in Graphics
1856 * When a text grid window is resized smaller, the bottom or right area is
1857 * thrown away, but the remaining area stays unchanged. When it is resized
1858 * larger, the new bottom or right area is filled with the background color.
1861 * You may wish to watch for %evtype_Arrange events, and clear-and-redraw your
1862 * graphics windows when you see them change size.
1865 * In some libraries, you can receive a graphics-redraw event (%evtype_Redraw)
1866 * at any time. This signifies that the window in question has been cleared to
1867 * its background color, and must be redrawn. If you create any graphics
1868 * windows, you <emphasis>must</emphasis> handle these events.
1871 * Redraw events can be triggered when a Glk window is uncovered or made
1872 * visible by the platform's window manager. On the other hand, some Glk
1873 * libraries handle these problem automatically — for example, with a
1874 * backing store — and do not send you redraw events. On the third hand,
1875 * the backing store may be discarded if memory is low, or for other reasons
1876 * — perhaps the screen's color depth has changed. So redraw events are
1877 * always a possibility, even in clever libraries. This is why you must be
1878 * prepared to handle them.
1880 * However, you will not receive a redraw event when you create a graphics
1881 * window. It is assumed that you will do the initial drawing of your own
1882 * accord. You also do not get redraw events when a graphics window is
1883 * enlarged. If you ordered the enlargement, you already know about it; if the
1884 * player is responsible, you receive a window-arrangement event, which covers
1888 * For a description of the drawing functions that apply to graphics windows,
1889 * see <link linkend="chimara-Graphics-in-Graphics-Windows">Graphics in Graphics
1892 * Graphics windows support no text input or output.
1894 * Not all libraries support graphics windows. You can test whether Glk graphics
1895 * are available using the gestalt system. In a C program, you can also test
1896 * whether the graphics functions are defined at compile-time. See <link
1897 * linkend="chimara-Testing-for-Graphics-Capabilities">Testing for Graphics
1898 * Capabilities</link>.
1901 * As with all windows, you should also test for %NULL when you create a
1909 * When calling glk_window_open() with this @method, the new window will be
1910 * to the left of the old one which was split.
1916 * When calling glk_window_open() with this @method, the new window will be
1917 * to the right of the old one which was split.
1923 * When calling glk_window_open() with this @method, the new window will be
1924 * above the old one which was split.
1930 * When calling glk_window_open() with this @method, the new window will be
1931 * below the old one which was split.
1935 * winmethod_DirMask:
1937 * Bitwise AND this value with a window splitting method argument to find
1938 * whether the split is %winmethod_Left, %winmethod_Right, %winmethod_Above, or
1945 * When calling glk_window_open() with this @method, the new window will be
1946 * a fixed size. (See glk_window_open()).
1950 * winmethod_Proportional:
1952 * When calling glk_window_open() with this @method, the new window will be
1953 * a given proportion of the old window's size. (See glk_window_open()).
1957 * winmethod_DivisionMask:
1959 * Bitwise AND this value with a window splitting method argument to find
1960 * whether the new window has %winmethod_Fixed or %winmethod_Proportional.
1966 * Any other kind of file (preferences, statistics, arbitrary data.)
1970 * fileusage_SavedGame:
1972 * A file which stores game state.
1976 * fileusage_Transcript:
1978 * A file which contains a stream of text from the game (often an echo stream
1983 * fileusage_InputRecord:
1985 * A file which records player input.
1989 * fileusage_TextMode:
1991 * The file contents will be transformed to a platform-native text file as they
1992 * are written out. Newlines may be converted to linefeeds or
1993 * linefeed-plus-carriage-return combinations; Latin-1 characters may be
1994 * converted to native character codes. When reading a file in text mode, native
1995 * line breaks will be converted back to newline (0x0A) characters, and native
1996 * character codes may be converted to Latin-1.
1999 * Line breaks will always be converted; other conversions are more
2000 * questionable. If you write out a file in text mode, and then read it back
2001 * in text mode, high-bit characters (128 to 255) may be transformed or lost.
2003 * <note><title>Chimara</title>
2005 * Text mode files in Chimara are in UTF-8, which is GTK+'s native file
2011 * fileusage_BinaryMode:
2013 * The file contents will be stored exactly as they are written, and read back
2014 * in the same way. The resulting file may not be viewable on platform-native
2015 * text file viewers.
2019 * fileusage_TypeMask:
2021 * Bitwise AND this value with a file usage argument to find whether the file
2022 * type is %fileusage_SavedGame, %fileusage_Transcript, %fileusage_InputRecord,
2023 * or %fileusage_Data.
2032 * Corresponds to mode <code>"w"</code> in the stdio library, using fopen().
2042 * Corresponds to mode <code>"r"</code> in the stdio library, using fopen().
2047 * filemode_ReadWrite:
2049 * Both an input and an output stream.
2052 * Corresponds to mode <code>"r+"</code> in the stdio library, using fopen().
2057 * filemode_WriteAppend:
2059 * An output stream, but the data will added to the end of whatever already
2060 * existed in the destination, instead of replacing it.
2063 * Corresponds to mode <code>"a"</code> in the stdio library, using fopen().
2070 * In glk_stream_set_position(), signifies that @pos is counted in characters
2071 * after the beginning of the file.
2077 * In glk_stream_set_position(), signifies that @pos is counted in characters
2078 * after the current position (moving backwards if @pos is negative.)
2084 * In glk_stream_set_position(), signifies that @pos is counted in characters
2085 * after the end of the file. (@pos should always be zero or negative, so that
2086 * this will move backwards to a position within the file.
2090 * stylehint_Indentation:
2092 * How much to indent lines of text in the given style. May be a negative
2093 * number, to shift the text out (left) instead of in (right). The exact metric
2094 * isn't precisely specified; you can assume that +1 is the smallest indentation
2095 * possible which is clearly visible to the player.
2099 * stylehint_ParaIndentation:
2101 * How much to indent the first line of each paragraph. This is in addition to
2102 * the indentation specified by %stylehint_Indentation. This too may be
2103 * negative, and is measured in the same units as %stylehint_Indentation.
2107 * stylehint_Justification:
2109 * The value of this hint must be one of the constants
2110 * %stylehint_just_LeftFlush, %stylehint_just_LeftRight (full justification),
2111 * %stylehint_just_Centered, or %stylehint_just_RightFlush.
2117 * How much to increase or decrease the font size. This is relative; 0 means the
2118 * interpreter's default font size will be used, positive numbers increase it,
2119 * and negative numbers decrease it. Again, +1 is the smallest size increase
2120 * which is easily visible.
2122 * The amount of this increase may not be constant. +1 might increase an
2123 * 8-point font to 9-point, but a 16-point font to 18-point.
2130 * The value of this hint must be 1 for heavy-weight fonts (boldface), 0 for
2131 * normal weight, and -1 for light-weight fonts.
2135 * stylehint_Oblique:
2137 * The value of this hint must be 1 for oblique fonts (italic), or 0 for normal
2142 * stylehint_Proportional:
2144 * The value of this hint must be 1 for proportional-width fonts, or 0 for
2149 * stylehint_TextColor:
2151 * The foreground color of the text. This is encoded in the 32-bit hint value:
2152 * the top 8 bits must be zero, the next 8 bits are the red value, the next 8
2153 * bits are the green value, and the bottom 8 bits are the blue value. Color
2154 * values range from 0 to 255.
2156 * So 0x00000000 is black, 0x00FFFFFF is white, and 0x00FF0000 is bright red.
2161 * stylehint_BackColor:
2163 * The background color behind the text. This is encoded the same way as
2164 * %stylehint_TextColor.
2168 * stylehint_ReverseColor:
2170 * The value of this hint must be 0 for normal printing (%stylehint_TextColor on
2171 * %stylehint_BackColor), or 1 for reverse printing (%stylehint_BackColor on
2172 * %stylehint_TextColor).
2174 * Some libraries may support this hint but not the %stylehint_TextColor and
2175 * %stylehint_BackColor hints. Other libraries may take the opposite tack;
2176 * others may support both, or neither.
2181 * stylehint_NUMHINTS:
2183 * The number of style hints defined in this library.
2187 * stylehint_just_LeftFlush:
2189 * A value for %stylehint_Justification representing left-justified text.
2193 * stylehint_just_LeftRight:
2195 * A value for %stylehint_Justification representing fully justified text.
2199 * stylehint_just_Centered:
2201 * A value for %stylehint_Justification representing centered text.
2205 * stylehint_just_RightFlush:
2207 * A value for %stylehint_Justification representing right-justified text.
2210 /*---------- TYPES, FUNCTIONS AND CONSTANTS FROM GI_DISPA.H ------------------*/
2213 * gidispatch_count_classes:
2215 * Returns the number of opaque object classes used by the library. You will
2216 * need to know this if you want to keep track of opaque objects as they are
2217 * created; see <link linkend="gidispatch-set-object-registry">Opaque Object
2220 * As of Glk API 0.7.0, there are four classes: windows, streams, filerefs, and
2221 * sound channels (numbered 0, 1, 2, and 3 respectively.)
2223 * Returns: Number of opaque object classes used by the library.
2227 * gidispatch_count_intconst:
2229 * Returns the number of integer constants exported by the library.
2231 * Returns: Number of integer constants exported by the library.
2235 * gidispatch_get_intconst:
2236 * @index: Unique integer index of the integer constant.
2238 * Returns a structure describing an integer constant which the library exports.
2239 * These are, roughly, all the constants defined in the <filename
2240 * class="headerfile">glk.h</filename> file. @index can range from 0 to
2241 * <inlineequation><mathphrase>N - 1</mathphrase><alt>N -
2242 * 1</alt></inlineequation>, where N is the value returned by
2243 * gidispatch_count_intconst().
2245 * Returns: A #gidispatch_intconst_t structure describing the integer constant.
2249 * gidispatch_intconst_t:
2250 * @name: Symbolic name of the integer constant.
2251 * @val: Value of the integer constant.
2253 * This structure simply contains a string and a value. The string is a
2254 * symbolic name of the value, and can be re-exported to anyone interested in
2255 * using Glk constants.
2259 * gidispatch_count_functions:
2261 * Returns the number of functions exported by the library.
2263 * Returns: Number of functions exported by the library.
2267 * gidispatch_get_function:
2268 * @index: Unique integer index of the function.
2270 * Returns a structure describing a Glk function. @index can range from 0 to
2271 * <inlineequation><mathphrase>N - 1</mathphrase><alt>N -
2272 * 1</alt></inlineequation>, where N is the value returned by
2273 * gidispatch_count_functions().
2275 * Returns: A #gidispatch_function_t structure describing the function.
2279 * gidispatch_function_t:
2280 * @id: Dispatch selector of the function.
2281 * @fnptr: Pointer to the function.
2282 * @name: Name of the function, without the <code>glk_</code> prefix.
2284 * The @id field is a selector — a numeric constant used to refer to the
2285 * function in question. @name is the function name, as it is given in the
2286 * <filename class="headerfile">glk.h</filename> file, but without the
2287 * <quote><code>glk_</code></quote> prefix. And @fnptr is the address of the
2291 * This is included because it might be useful, but it is not recommended. To
2292 * call an arbitrary Glk function, you should use gidispatch_call().
2295 * See <link linkend="chimara-Table-of-Selectors">Table of Selectors</link> for
2296 * the selector definitions. See <link
2297 * linkend="chimara-Dispatching">Dispatching</link> for more about calling Glk
2298 * functions by selector.
2302 * gidispatch_get_function_by_id:
2305 * Returns a structure describing the Glk function with selector @id. If there
2306 * is no such function in the library, this returns %NULL.
2308 * Returns: a #gidispatch_function_t structure, or %NULL.
2313 * @funcnum: Selector of the function to call.
2314 * @numargs: Length of @arglist.
2315 * @arglist: List of arguments to pass to the function.
2317 * @funcnum is the function number to invoke; see <link
2318 * linkend="chimara-Table-of-Selectors">Table of Selectors</link>. @arglist is
2319 * the list of arguments, and @numargs is the length of the list.
2321 * The arguments are all stored as #gluniversal_t objects.
2322 * </para><refsect3 id="chimara-Basic-Types"><title>Basic Types</title><para>
2323 * Numeric arguments are passed in the obvious way — one argument per
2324 * #gluniversal_t, with the @uint or @sint field set to the numeric value.
2325 * Characters and strings are also passed in this way — #char<!---->s in
2326 * the @uch, @sch, or @ch fields (depending on whether the #char is signed) and
2327 * strings in the @charstr field. Opaque objects (windows, streams, etc) are
2328 * passed in the @opaqueref field (which is <code>void*</code>, in order to
2329 * handle all opaque pointer types.)
2331 * However, pointers (other than C strings), arrays, and structures complicate
2332 * life. So do return values.
2333 * </para></refsect3>
2334 * <refsect3 id="chimara-References"><title>References</title><para>
2335 * A reference to a numeric type or object reference — that is,
2336 * <code>#glui32*</code>, <code>#winid_t*</code>, and so on — takes
2337 * <emphasis>one or two</emphasis> #gluniversal_t objects. The first is a flag
2338 * indicating whether the reference argument is %NULL or not. The @ptrflag field
2339 * of this #gluniversal_t should be %FALSE if the reference is %NULL, and %TRUE
2340 * otherwise. If %FALSE, that is the end of the argument; you should not use a
2341 * #gluniversal_t to explicitly store the %NULL reference. If the flag is %TRUE,
2342 * you must then put a #gluniversal_t storing the base type of the reference.
2344 * For example, consider a hypothetical function, with selector
2345 * <code>0xABCD</code>:
2347 * void glk_glomp(#glui32 num, #winid_t win, #glui32 *numref, #strid_t *strref);
2353 * #strid_t gamefile;
2354 * glk_glomp(5, mainwin, &value, &gamefile);
2357 * To perform this through gidispatch_call(), you would do the following:
2359 * #gluniversal_t arglist[6];
2360 * arglist[0].uint = 5;
2361 * arglist[1].opaqueref = mainwin;
2362 * arglist[2].ptrflag = TRUE;
2363 * arglist[3].uint = value;
2364 * arglist[4].ptrflag = TRUE;
2365 * arglist[5].opaqueref = gamefile;
2366 * #gidispatch_call(0xABCD, 6, arglist);
2367 * value = arglist[3].uint;
2368 * gamefile = arglist[5].opaqueref;
2371 * Note that you copy the value of the reference arguments into and out of
2372 * @arglist. Of course, it may be that glk_glomp() only uses these as pass-out
2373 * references or pass-in references; if so, you could skip copying in or out.
2375 * For further examples:
2377 * glk_glomp(7, mainwin, NULL, NULL);
2379 * #gluniversal_t arglist[4];
2380 * arglist[0].uint = 7;
2381 * arglist[1].opaqueref = mainwin;
2382 * arglist[2].ptrflag = FALSE;
2383 * arglist[3].ptrflag = FALSE;
2384 * #gidispatch_call(0xABCD, 4, arglist);
2388 * glk_glomp(13, NULL, NULL, &gamefile);
2390 * #gluniversal_t arglist[5];
2391 * arglist[0].uint = 13;
2392 * arglist[1].opaqueref = NULL;
2393 * arglist[2].ptrflag = FALSE;
2394 * arglist[3].ptrflag = TRUE;
2395 * arglist[4].opaqueref = gamefile;
2396 * #gidispatch_call(0xABCD, 5, arglist);
2397 * gamefile = arglist[4].opaqueref;
2401 * glk_glomp(17, NULL, &value, NULL);
2403 * #gluniversal_t arglist[5];
2404 * arglist[0].uint = 17;
2405 * arglist[1].opaqueref = NULL;
2406 * arglist[2].ptrflag = TRUE;
2407 * arglist[3].uint = value;
2408 * arglist[4].ptrflag = FALSE;
2409 * #gidispatch_call(0xABCD, 5, arglist);
2410 * value = arglist[3].uint;
2413 * As you see, the length of @arglist depends on how many of the reference
2414 * arguments are %NULL.
2415 * </para></refsect3>
2416 * <refsect3 id="chimara-Structures"><title>Structures</title><para>
2417 * A structure pointer is represented by a single @ptrflag, possibly followed by
2418 * a sequence of #gluniversal_t objects (one for each field of the structure.)
2419 * Again, if the structure pointer is non-%NULL, the @ptrflag should be %TRUE
2420 * and be followed by values; if not, the @ptrflag should be %NULL and stands
2423 * For example, the function glk_select() can be invoked as follows:
2426 * #gluniversal_t arglist[5];
2427 * arglist[0].ptrflag = TRUE;
2428 * #gidispatch_call(0x00C0, 5, arglist);
2429 * ev.type = arglist[1].uint;
2430 * ev.win = arglist[2].opaqueref;
2431 * ev.val1 = arglist[3].uint;
2432 * ev.val2 = arglist[4].uint;
2435 * Since the structure passed to glk_select() is a pass-out reference (the entry
2436 * values are ignored), you don't need to fill in <code>arglist[1..4]</code>
2437 * before calling gidispatch_call().
2440 * Theoretically, you would invoke <code>#glk_select(%NULL)</code> by setting'
2441 * <code>arglist[0].ptrflag</code> to %FALSE, and using a one-element @arglist
2442 * instead of five-element. But it's illegal to pass %NULL to glk_select(). So
2443 * you cannot actually do this.
2444 * </para></note></para></refsect3>
2445 * <refsect3 id="chimara-Arrays"><title>Arrays</title><para>
2446 * In the Glk API, an array argument is always followed by a numeric argument
2447 * giving the array's length. These two C arguments are a single logical
2448 * argument, which is represented by <emphasis>one or three</emphasis>
2449 * #gluniversal_t objects. The first is a @ptrflag, indicating whether the
2450 * argument is %NULL or not. The second is a pointer, stored in the @array
2451 * field. The third is the array length, stored in the @uint field. And again,
2452 * if the @ptrflag is %NULL, the following two are omitted.
2454 * For example, the function glk_put_buffer() can be invoked as follows:
2458 * #glk_put_buffer(buf, len);
2460 * #gluniversal_t arglist[3];
2461 * arglist[0].ptrflag = TRUE;
2462 * arglist[1].array = buf;
2463 * arglist[2].uint = len;
2464 * #gidispatch_call(0x0084, 3, arglist);
2467 * Since you are passing a C char array to gidispatch_call(), the contents will
2468 * be read directly from that. There is no need to copy data into @arglist, as
2469 * you would for a basic type.
2471 * If you are implementing a VM whose native representation of char arrays is
2472 * more complex, you will have to do more work. You should allocate a C char
2473 * array, copy your characters into it, make the call, and then free the array.
2476 * glk_put_buffer() does not modify the array passed to it, so there is no
2477 * need to copy the characters out.
2478 * </para></note></para></refsect3>
2479 * <refsect3 id="chimara-Return-Values"><title>Return Values</title><para>
2480 * The return value of a function is not treated specially. It is simply
2481 * considered to be a pass-out reference argument which may not be %NULL. It
2482 * comes after all the other arguments of the function.
2484 * For example, the function glk_window_get_rock() can be invoked as follows:
2488 * rock = #glk_window_get_rock(win);
2490 * #gluniversal_t arglist[3];
2491 * arglist[0].opaqueref = win;
2492 * arglist[1].ptrflag = TRUE;
2493 * #gidispatch_call(0x0021, 3, arglist);
2494 * rock = arglist[2].uint;
2496 * </para></refsect3><para>
2501 * @uint: Stores a #glui32.
2502 * @sint: Stores a #glsi32.
2503 * @opaqueref: Stores a #winid_t, #strid_t, #frefid_t, or #schanid_t.
2504 * @uch: Stores an #unsigned #char.
2505 * @sch: Stores a #signed #char.
2506 * @ch: Stores a #char with the default signedness.
2507 * @charstr: Stores a %NULL-terminated string.
2508 * @array: Stores a pointer to an array, and should be followed by another
2509 * #gluniversal_t with the array length stored in the @uint member.
2510 * @ptrflag: If %FALSE, represents an opaque reference or array that is %NULL,
2511 * in which case it represents the entire argument. If %TRUE, should be followed
2512 * by another #gluniversal_t with the pointer in its @opaqueref or @array field.
2514 * This is a union, encompassing all the types that can be passed to Glk
2519 * gidispatch_prototype:
2520 * @funcnum: A selector for the function to be queried.
2522 * This returns a string which encodes the proper argument list for the given
2523 * function. If there is no such function in the library, this returns %NULL.
2525 * The prototype string for the glk_glomp() function described above would be:
2526 * <code>"4IuQa&Iu&Qb:"</code>. The <code>"4"</code> is the number of
2527 * arguments (including the return value, if there is one, which in this case
2528 * there isn't.) <code>"Iu"</code> denotes an unsigned integer;
2529 * <code>"Qa"</code> is an opaque object of class 0 (window).
2530 * <code>"&Iu"</code> is a <emphasis>reference</emphasis> to an unsigned
2531 * integer, and <code>"&Qb"</code> is a reference to a stream. The colon at
2532 * the end terminates the argument list; the return value would follow it, if
2535 * Note that the initial number (<code>"4"</code> in this case) is the number of
2536 * logical arguments, not the number of #gluniversal_t objects which will be
2537 * passed to gidispatch_call(). The glk_glomp() call uses anywhere from four to
2538 * six #gluniversal_t objects, as demonstrated above.
2540 * The basic type codes:
2543 * <term><code>Iu, Is</code></term>
2544 * <listitem><para>Unsigned and signed 32-bit integer.</para></listitem>
2547 * <term><code>Cn, Cu, Cs</code></term>
2548 * <listitem><para>Character, #unsigned #char, and #signed #char.</para>
2549 * <note><para>Of course <code>Cn</code> will be the same as either
2550 * <code>Cu</code> or <code>Cs</code>, depending on the platform. For this
2551 * reason, Glk avoids using it, but it is included here for completeness.
2556 * <term><code>S</code></term>
2557 * <listitem><para>A C-style string (null-terminated array of #char). In Glk,
2558 * strings are always treated as read-only and used immediately; the library
2559 * does not retain a reference to a string between Glk calls. A Glk call that
2560 * wants to use writable char arrays will use an array type
2561 * (<code>"#C"</code>), not string (<code>"S"</code>).</para></listitem>
2564 * <term><code>U</code></term>
2565 * <listitem><para>A zero-terminated array of 32-bit integers. This is
2566 * primarily intended as a Unicode equivalent of <code>"S"</code>. Like
2567 * <code>"S"</code> strings, <code>"U"</code> strings are read-only and used
2568 * immediately. A Glk call that wants to use writable Unicode arrays will use
2569 * an array type (<code>"#Iu"</code>) instead of <code>"U"</code>.</para>
2573 * <term><code>F</code></term>
2574 * <listitem><para>A floating-point value. Glk does not currently use
2575 * floating-point values, but we might as well define a code for them.</para>
2579 * <term><code>Qa, Qb, Qc...</code></term>
2580 * <listitem><para>A reference to an opaque object. The second letter
2581 * determines which class is involved. (The number of classes can be gleaned
2582 * from gidispatch_count_classes(); see <link
2583 * linkend="chimara-Interrogating-the-Interface">Interrogating the
2584 * Interface</link>).</para>
2586 * If Glk expands to have more than 26 classes, we'll think of something.
2587 * </para></note></listitem>
2590 * Any type code can be prefixed with one or more of the following characters
2591 * (order does not matter):
2594 * <term><code>&</code></term>
2595 * <listitem><para>A reference to the type; or, if you like, a variable passed
2596 * by reference. The reference is passed both in and out, so you must copy the
2597 * value in before calling gidispatch_call() and copy it out afterward.</para>
2601 * <term><code><</code></term>
2602 * <listitem><para>A reference which is pass-out only. The initial value is
2603 * ignored, so you only need copy out the value after the call.</para>
2607 * <term><code>></code></term>
2608 * <listitem><para>A reference which is pass-in only.</para>
2610 * This is not generally used for simple types, but is useful for structures
2612 * </para></note></listitem>
2615 * <term><code>+</code></term>
2616 * <listitem><para>Combined with <code>"&"</code>, <code>"<"</code>, or
2617 * <code>">"</code>, indicates that a valid reference is mandatory; %NULL
2618 * cannot be passed.</para>
2620 * Note that even though the @ptrflag #gluniversal_t for a <code>"+"</code>
2621 * reference is always %TRUE, it cannot be omitted.
2622 * </para></note></listitem>
2625 * <term><code>:</code></term>
2626 * <listitem><para>The colon separates the arguments from the return value, or
2627 * terminates the string if there is no return value. Since return values are
2628 * always non-%NULL pass-out references, you may treat <code>":"</code> as
2629 * equivalent to <code>"<+"</code>. The colon is never combined with any
2630 * other prefix character.</para></listitem>
2633 * <term><code>[...]</code></term>
2634 * <listitem><para>Combined with <code>"&"</code>, <code>"<"</code>, or
2635 * <code>">"</code>, indicates a structure reference. Between the brackets
2636 * is a complete argument list encoding string, including the number of
2639 * For example, the prototype string for glk_select() is
2640 * <code>"1<+[4IuQaIuIu]:"</code> — one argument, which is a
2641 * pass-out non-%NULL reference to a structure, which contains four
2644 * <para>Currently, structures in Glk contain only basic types.</para>
2648 * <term><code>#</code></term>
2649 * <listitem><para>Combined with <code>"&"</code>, <code>"<"</code>, or
2650 * <code>">"</code>, indicates an array reference. As described above, this
2651 * encompasses up to three #gluniversal_t objects — @ptrflag, pointer,
2652 * and integer length.</para>
2654 * Depending on the design of your program, you may wish to pass a pointer
2655 * directly to your program's memory, or allocate an array and copy the
2656 * contents in and out. See <link linkend="chimara-Arrays">Arrays</link>.
2657 * </para></note></listitem>
2660 * <term><code>!</code></term>
2661 * <listitem><para>Combined with <code>"#"</code>, indicates that the
2662 * array is retained by the library. The library will keep a reference to the
2663 * array; the contents are undefined until further notice. You should not use
2664 * or copy the contents of the array out after the call, even for
2665 * <code>"&#!"</code> or <code>"<#!"</code> arrays. Instead, do
2666 * it when the library releases the array.</para>
2668 * For example, glk_stream_open_memory() retains the array that you pass it,
2669 * and releases it when the stream is closed. The library can notify you
2670 * automatically when arrays are retained and released; see <link
2671 * linkend="gidispatch-set-retained-registry">Retained Array
2673 * </para></note></listitem>
2677 * Returns: A string which encodes the prototype of the specified Glk function.
2681 * gidisp_Class_Window:
2683 * Represents a #winid_t opaque object.
2687 * gidisp_Class_Stream:
2689 * Represents a #strid_t opaque object.
2693 * gidisp_Class_Fileref:
2695 * Represents a #frefid_t opaque object.
2699 * gidisp_Class_Schannel:
2701 * Represents a #schanid_t opaque object.
2705 * gidispatch_rock_t:
2706 * @num: Space for storing an integer.
2707 * @ptr: Space for storing a pointer.
2709 * You can store any value you want in this object; return it from your object
2710 * registry and retained array registry callbacks, and the library will stash it
2711 * away. You can retrieve it with gidispatch_get_objrock().
2714 /*---------- TYPES, FUNCTIONS AND CONSTANTS FROM GI_BLORB.H ------------------*/
2719 * An integer type that can hold the Blorb error codes.
2729 * giblorb_err_CompileTime:
2731 * Something is compiled wrong in the Blorb layer.
2735 * giblorb_err_Alloc:
2737 * Memory could not be allocated.
2738 * <note><title>Chimara</title>
2740 * The Blorb layer in the Chimara library should not return this error code;
2741 * instead, the program aborts if memory allocation fails, in keeping with
2749 * Data could not be read from the file.
2753 * giblorb_err_NotAMap:
2755 * The map parameter is invalid.
2759 * giblorb_err_Format:
2761 * The Blorb file is corrupted or invalid.
2765 * giblorb_err_NotFound:
2767 * The requested data could not be found.
2771 * giblorb_method_DontLoad:
2773 * Pass this to giblorb_load_chunk_by_type(), giblorb_load_chunk_by_number(), or
2774 * giblorb_load_resource() to obtain information about a chunk without actually
2779 * giblorb_method_Memory:
2781 * Pass this to giblorb_load_chunk_by_type(), giblorb_load_chunk_by_number(), or
2782 * giblorb_load_resource() to load a chunk into memory.
2786 * giblorb_method_DontLoad:
2788 * Pass this to giblorb_load_chunk_by_type(), giblorb_load_chunk_by_number(), or
2789 * giblorb_load_resource() to get the position in the Blorb file at which the
2790 * chunk data starts.
2796 * Resource usage constant representing a sound file.
2802 * Resource usage constant representing an executable program.
2808 * Resource usage constant representing an image file.
2812 * giblorb_ID_Copyright:
2814 * Resource usage constant representing the copyright message (date and holder,
2815 * without the actual copyright symbol). There should only be one such chunk per
2822 * Resource usage constant representing the name of the author or creator of the
2823 * file. This could be a login name on multi-user systems, for example. There
2824 * should only be one such chunk per file.
2830 * Resource usage constant representing any textual annotation that the user or
2831 * writing program sees fit to include.
2837 * Holds the complete description of an open Blorb file. This type is opaque for
2838 * normal interpreter use.
2844 * Holds information about a chunk loaded from a Blorb file, and the method of
2845 * accessing the chunk data. See giblorb_load_chunk_by_type() and
2846 * giblorb_load_chunk_by_number().
2850 * giblorb_create_map:
2851 * @file: An input stream pointing to a Blorb file.
2852 * @newmap: Return location for a Blorb resource map.
2854 * Reads Blorb data out of a Glk stream. It does not load every resource at
2855 * once; instead, it creates a map in memory which makes it easy to find
2856 * resources. A pointer to the map is stored in @newmap. This is an opaque
2857 * object; you pass it to the other Blorb-layer functions.
2859 * Returns: a Blorb error code.
2863 * giblorb_destroy_map:
2864 * @map: A Blorb resource map to deallocate.
2866 * Deallocates @map and all associated memory. This does
2867 * <emphasis>not</emphasis> close the original stream.
2869 * Returns: a Blorb error code.
2873 * giblorb_load_chunk_by_type:
2874 * @map: The Blorb resource map to load a chunk from.
2875 * @method: The loading method to use, one of %giblorb_method_DontLoad,
2876 * %giblorb_method_Memory, or %giblorb_method_FilePos.
2877 * @res: Return location for the result.
2878 * @chunktype: The type of chunk to load.
2879 * @count: The chunk number of type @chunktype to load.
2881 * Loads a chunk of a given type. The @count parameter distinguishes between
2882 * chunks of the same type. If @count is zero, the first chunk of that type is
2883 * loaded, and so on.
2885 * To load a chunk of an IFF FORM type (such as AIFF), you should pass in the
2886 * form type, rather than FORM.
2888 * This introduces a slight ambiguity — you cannot distiguish between a
2889 * FORM AIFF chunk and a non-FORM chunk of type AIFF. However, the latter is
2890 * almost certainly a mistake.
2893 * The returned data is written into @res, according to @method.
2895 * The <structfield>chunknum</structfield> field is filled in with the number of
2896 * the chunk. (This value can then be passed to giblorb_load_chunk_by_number()
2897 * or giblorb_unload_chunk().) The <structfield>length</structfield> field is
2898 * filled in with the length of the chunk in bytes. The
2899 * <structfield>chunktype</structfield> field is the chunk's type, which of
2900 * course will be the type you asked for.
2902 * If you specify %giblorb_method_DontLoad, no data is actually loaded in. You
2903 * can use this if you are only interested in whether a chunk exists, or in the
2904 * <structfield>chunknum</structfield> and <structfield>length</structfield>
2907 * If you specify %giblorb_method_FilePos,
2908 * <structfield>data.startpos</structfield> is filled in with the file position
2909 * of the chunk data. You can use glk_stream_set_position() to read the data
2912 * If you specify %giblorb_method_Memory, <structfield>data.ptr</structfield> is
2913 * filled with a pointer to allocated memory containing the chunk data. This
2914 * memory is owned by the map, not you. If you load the chunk more than once
2915 * with %giblorb_method_Memory, the Blorb layer is smart enough to keep just one
2916 * copy in memory. You should not deallocate this memory yourself; call
2917 * giblorb_unload_chunk() instead.
2919 * Returns: a Blorb error code.
2923 * giblorb_load_chunk_by_number:
2924 * @map: The Blorb resource map to load a chunk from.
2925 * @method: The loading method to use, one of %giblorb_method_DontLoad,
2926 * %giblorb_method_Memory, or %giblorb_method_FilePos.
2927 * @res: Return location for the result.
2928 * @chunknum: The chunk number to load.
2930 * This is similar to giblorb_load_chunk_by_type(), but it loads a chunk with a
2931 * given chunk number. The type of the chunk can be found in the
2932 * <structfield>chunktype</structfield> field of #giblorb_result_t. You can get
2933 * the chunk number from the <structfield>chunknum</structfield> field, after
2934 * calling one of the other load functions.
2936 * Returns: a Blorb error code.
2940 * giblorb_unload_chunk:
2941 * @map: The Blorb resource map to unload a chunk from.
2942 * @chunknum: The chunk number to unload.
2944 * Frees the chunk data allocated by %giblorb_method_Memory. If the given chunk
2945 * has never been loaded into memory, this has no effect.
2947 * Returns: a Blorb error code.
2951 * giblorb_load_resource:
2952 * @map: The Blorb resource map to load a resource from.
2953 * @method: The loading method to use, one of %giblorb_method_DontLoad,
2954 * %giblorb_method_Memory, or %giblorb_method_FilePos.
2955 * @res: Return location for the result.
2956 * @usage: The type of data resource to load.
2957 * @resnum: The resource number to load.
2959 * Loads a resource, given its usage and resource number. Currently, the three
2960 * usage values are %giblorb_ID_Pict (images), %giblorb_ID_Snd (sounds), and
2961 * %giblorb_ID_Exec (executable program). See the Blorb specification for more
2962 * information about the types of data that can be stored for these usages.
2964 * Note that a resource number is not the same as a chunk number. The resource
2965 * number is the sound or image number specified by a Glk program. Chunk number
2966 * is arbitrary, since chunks in a Blorb file can be in any order. To find the
2967 * chunk number of a given resource, call giblorb_load_resource() and look in
2968 * <structfield>res.chunknum</structfield>.
2970 * Returns: a Blorb error code.
2974 * giblorb_count_resources:
2975 * @map: The Blorb resource map in which to count the resources.
2976 * @usage: The type of data resource to count.
2977 * @num: Return location for the number of chunks of @usage.
2978 * @min: Return location for the lowest resource number of @usage.
2979 * @max: Return location for the highest resource number of @usage.
2981 * Counts the number of chunks with a given usage (image, sound, or executable.)
2982 * The total number of chunks of that usage is stored in @num. The lowest and
2983 * highest resource number of that usage are stored in @min and @max. You can
2984 * leave any of the three pointers %NULL if you don't care about that
2987 * Returns: a Blorb error code.
2990 /*--------------------TYPES AND CONSTANTS FROM GLKSTART.H---------------------*/
2993 * glkunix_argumentlist_t:
2995 * In each entry, name is the option as it would appear on the command line
2996 * (including the leading dash, if any.) The desc is a description of the
2997 * argument; this is used when the library is printing a list of options. And
2998 * argtype is one of the following constants:
3002 * <term>%glkunix_arg_NoValue</term>
3003 * <listitem><para>The argument appears by itself.</para></listitem>
3006 * <term>%glkunix_arg_ValueFollows</term>
3007 * <listitem><para>The argument must be followed by another argument (the
3008 * value).</para></listitem>
3011 * <term>%glkunix_arg_ValueCanFollow</term>
3012 * <listitem><para>The argument may be followed by a value, optionally. (If the
3013 * next argument starts with a dash, it is taken to be a new argument, not the
3014 * value of this one.)</para></listitem>
3017 * <term>%glkunix_arg_NumberValue</term>
3018 * <listitem><para>The argument must be followed by a number, which may be the
3019 * next argument or part of this one. (That is, either <quote><code>-width
3020 * 20</code></quote> or <quote><code>-width20</code></quote> will be accepted.)
3021 * </para></listitem>
3024 * <term>%glkunix_arg_End</term>
3025 * <listitem><para>The <code>glkunix_arguments[]</code> array must be
3026 * terminated with an entry containing this value.</para></listitem>
3030 * To accept arbitrary arguments which lack dashes, specify a name of
3031 * <code>""</code> and an argtype of %glkunix_arg_ValueFollows.
3033 * If you don't care about command-line arguments, you must still define an
3034 * empty arguments list, as follows:
3036 * #glkunix_argumentlist_t glkunix_arguments[] = {
3037 * { NULL, #glkunix_arg_End, NULL }
3041 * Here is a more complete sample list:
3043 * #glkunix_argumentlist_t glkunix_arguments[] = {
3044 * { "", #glkunix_arg_ValueFollows, "filename: The game file to load." },
3045 * { "-hum", #glkunix_arg_ValueFollows, "-hum NUM: Hum some NUM." },
3046 * { "-bom", #glkunix_arg_ValueCanFollow, "-bom [ NUM ]: Do a bom (on
3047 * the NUM, if given)." },
3048 * { "-goo", #glkunix_arg_NoValue, "-goo: Find goo." },
3049 * { "-wob", #glkunix_arg_NumberValue, "-wob NUM: Wob NUM times." },
3050 * { NULL, #glkunix_arg_End, NULL }
3053 * This would match the arguments <quote><code>thingfile -goo -wob8 -bom -hum
3054 * song</code></quote>.
3056 * After the library parses the command line, it does various occult rituals of
3057 * initialization, and then calls glkunix_startup_code().
3059 * |[ int glkunix_startup_code(#glkunix_startup_t *data); ]|
3061 * This should return %TRUE if everything initializes properly. If it returns
3062 * %FALSE, the library will shut down without ever calling your glk_main()
3067 * glkunix_startup_t:
3069 * The fields are a standard Unix <code>(argc, argv)</code> list, which contain
3070 * the arguments you requested from the command line. In deference to custom,
3071 * <code>argv[0]</code> is always the program name.
3077 * Terminates a list of #glkunix_argumentlist_t.
3081 * glkunix_arg_ValueFollows:
3083 * Indicates an argument which must be followed by a value, as the next
3088 * glkunix_arg_NoValue:
3090 * Indicates an argument which occurs by itself, without a value.
3094 * glkunix_arg_ValueCanFollow:
3096 * Indicates an argument which may be followed by a value, or may occur by
3101 * glkunix_arg_NumberValue:
3103 * Indicates an argument which must be followed by a numerical value, either as
3104 * the next argument or tacked onto the end of this argument.
projects / rodin / chimara.git / blob