X-Git-Url: https://git.stderr.nl/gitweb?a=blobdiff_plain;f=src%2Fgestalt.c;h=398aede093e5839e12fbeb1d6001dde22bddb706;hb=91214934fbcdfd363202a65c142194506604ff7b;hp=1bb7f7e9c5bda60308a37c6b10e818ac5609562a;hpb=be258466a9f733fda535554f9a5f24c5bf00d784;p=projects%2Fchimara%2Fchimara.git

diff --git a/src/gestalt.c b/src/gestalt.c
index 1bb7f7e..398aede 100644
--- a/src/gestalt.c
+++ b/src/gestalt.c
@@ -1,3 +1,4 @@
+#include <stddef.h> /* Surprisingly, the only symbol needed is NULL */
 #include "glk.h"
 
 /* Version of the Glk specification implemented by this library */
@@ -27,11 +28,37 @@ glk_gestalt(glui32 sel, glui32 val)
  * @sel: A selector, representing which capability to request information
  * about.
  * @val: Extra information, depending on the value of @sel.
- * @arr: Location of an array to store extra information in, or #NULL.
- * @arrlen: Length of @arr, or 0 if @arr is #NULL.
+ * @arr: Location of an array to store extra information in, or %NULL.
+ * @arrlen: Length of @arr, or 0 if @arr is %NULL.
  *
- * Calls the gestalt system to request information about selector @sel,
- * possibly returning information in @arr.
+ * Calls the gestalt system to request information about the capabilities of the
+ * API. The selector @sel tells which capability you are requesting information
+ * about; the other three arguments are additional information, which may or may
+ * not be meaningful. The @arr and @arrlen arguments of glk_gestalt_ext() are
+ * always optional; you may always pass %NULL and 0, if you do not want whatever
+ * information they represent. glk_gestalt() is simply a shortcut for this;
+ * <code>#glk_gestalt(x, y)</code> is exactly the same as 
+ * <code>#glk_gestalt_ext(x, y, %NULL, 0)</code>.
+ *
+ * The critical point is that if the Glk library has never heard of the selector
+ * @sel, it will return 0. It is <emphasis>always</emphasis> safe to call 
+ * <code>#glk_gestalt(x, y)</code> (or <code>#glk_gestalt_ext(x, y, %NULL, 
+ * 0)</code>). Even if you are using an old library, which was compiled before
+ * the given capability was imagined, you can test for the capability by calling
+ * glk_gestalt(); the library will correctly indicate that it does not support
+ * it, by returning 0.
+ *
+ * (It is also safe to call <code>#glk_gestalt_ext(x, y, z, zlen)</code> for an
+ * unknown selector <code>x</code>, where <code>z</code> is not %NULL, as long
+ * as <code>z</code> points at an array of at least <code>zlen</code> elements.
+ * The selector will be careful not to write beyond that point in the array, if
+ * it writes to the array at all.)
+ *
+ * (If a selector does not use the second argument, you should always pass 0; do
+ * not assume that the second argument is simply ignored. This is because the
+ * selector may be extended in the future. You will continue to get the current
+ * behavior if you pass 0 as the second argument, but other values may produce
+ * other behavior.)
  *
  * Returns: an integer, depending on what selector was called.
  */
@@ -44,6 +71,20 @@ glk_gestalt_ext(glui32 sel, glui32 val, glui32 *arr, glui32 arrlen)
 		case gestalt_Version:
 			return (MAJOR_VERSION << 16) + (MINOR_VERSION << 8) + SUB_VERSION;
 		
+		/* Which characters can the player type in line input? */
+		case gestalt_LineInput:
+			/* Does not accept control chars */
+			if( val < 32 || (val >= 127 && val <= 159) )
+				return 0;
+			return 1;
+			
+		/* Which characters can the player type in char input? */
+		case gestalt_CharInput:
+			/* Does not accept control chars or unknown */
+			if( val < 32 || (val >= 127 && val <= 159) || val == keycode_Unknown )
+				return 0;
+			return 1;
+		
 		/* Which characters can we print? */	
 		case gestalt_CharOutput:
 			/* All characters are printed as one character, in any case */
@@ -54,7 +95,26 @@ glk_gestalt_ext(glui32 sel, glui32 val, glui32 *arr, glui32 arrlen)
 				return gestalt_CharOutput_CannotPrint;
 			/* Can print all other Latin-1 characters */
 			return gestalt_CharOutput_ExactPrint;
+		
+		/* Unicode capabilities present */
+		case gestalt_Unicode:
+			return 1;
+
+		/* Timer capabilities present */
+		case gestalt_Timer:
+			return 1;
 			
+		/* Unsupported capabilities */
+		case gestalt_MouseInput:
+		case gestalt_Graphics:
+		case gestalt_DrawImage:
+		case gestalt_Sound:
+		case gestalt_SoundVolume:
+		case gestalt_SoundNotify:
+		case gestalt_Hyperlinks:
+		case gestalt_HyperlinkInput:
+		case gestalt_SoundMusic:
+		case gestalt_GraphicsTransparency:
 		/* Selector not supported */	
 		default:
 			return 0;