X-Git-Url: https://git.stderr.nl/gitweb?a=blobdiff_plain;f=interpreters%2Ffrotz%2Fquetzal.c;fp=interpreters%2Ffrotz%2Fquetzal.c;h=e41a57b577a759238a23ce2fb75bb2ca77661d90;hb=b1f1dc50b22b30c4d7176e1ff7c0805e80fe0724;hp=0000000000000000000000000000000000000000;hpb=50176172d18ae72d019181725c5629d45d21c548;p=projects%2Fchimara%2Fchimara.git

diff --git a/interpreters/frotz/quetzal.c b/interpreters/frotz/quetzal.c
new file mode 100644
index 0000000..e41a57b
--- /dev/null
+++ b/interpreters/frotz/quetzal.c
@@ -0,0 +1,539 @@
+/* quetzal.c  - Saving and restoring of Quetzal files.
+ *	Written by Martin Frost <mdf@doc.ic.ac.uk>
+ *
+ * This file is part of Frotz.
+ *
+ * Frotz is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * Frotz is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+#include "frotz.h"
+#include "glk.h"
+#include "glkio.h"
+
+#define get_c fgetc
+#define put_c fputc
+
+typedef unsigned long zlong;
+
+/*
+ * This is used only by save_quetzal. It probably should be allocated
+ * dynamically rather than statically.
+ */
+
+static zword frames[STACK_SIZE/4+1];
+
+/*
+ * ID types.
+ */
+
+#define makeid(a,b,c,d) ((zlong) (((a)<<24) | ((b)<<16) | ((c)<<8) | (d)))
+
+#define ID_FORM makeid ('F','O','R','M')
+#define ID_IFZS makeid ('I','F','Z','S')
+#define ID_IFhd makeid ('I','F','h','d')
+#define ID_UMem makeid ('U','M','e','m')
+#define ID_CMem makeid ('C','M','e','m')
+#define ID_Stks makeid ('S','t','k','s')
+#define ID_ANNO makeid ('A','N','N','O')
+
+/*
+ * Various parsing states within restoration.
+ */
+
+#define GOT_HEADER	0x01
+#define GOT_STACK	0x02
+#define GOT_MEMORY	0x04
+#define GOT_NONE	0x00
+#define GOT_ALL		0x07
+#define GOT_ERROR	0x80
+
+/*
+ * Macros used to write the files.
+ */
+
+#define write_byte(fp,b) (put_c (b, fp) != EOF)
+#define write_bytx(fp,b) write_byte (fp, (b) & 0xFF)
+#define write_word(fp,w) \
+    (write_bytx (fp, (w) >>  8) && write_bytx (fp, (w)))
+#define write_long(fp,l) \
+    (write_bytx (fp, (l) >> 24) && write_bytx (fp, (l) >> 16) && \
+     write_bytx (fp, (l) >>  8) && write_bytx (fp, (l)))
+#define write_chnk(fp,id,len) \
+    (write_long (fp, (id))      && write_long (fp, (len)))
+#define write_run(fp,run) \
+    (write_byte (fp, 0)         && write_byte (fp, (run)))
+
+/* Read one word from file; return TRUE if OK. */
+static bool read_word (FILE *f, zword *result)
+{
+    int a, b;
+
+    if ((a = get_c (f)) == EOF) return FALSE;
+    if ((b = get_c (f)) == EOF) return FALSE;
+
+    *result = ((zword) a << 8) | (zword) b;
+    return TRUE;
+}
+
+/* Read one long from file; return TRUE if OK. */
+static bool read_long (FILE *f, zlong *result)
+{
+    int a, b, c, d;
+
+    if ((a = get_c (f)) == EOF) return FALSE;
+    if ((b = get_c (f)) == EOF) return FALSE;
+    if ((c = get_c (f)) == EOF) return FALSE;
+    if ((d = get_c (f)) == EOF) return FALSE;
+
+    *result = ((zlong) a << 24) | ((zlong) b << 16) |
+	      ((zlong) c <<  8) |  (zlong) d;
+    return TRUE;
+}
+
+/*
+ * Restore a saved game using Quetzal format. Return 2 if OK, 0 if an error
+ * occurred before any damage was done, -1 on a fatal error.
+ */
+
+zword restore_quetzal (FILE *svf, FILE *stf, int blorb_ofs)
+{
+    zlong ifzslen, currlen, tmpl;
+    zlong pc;
+    zword i, tmpw;
+    zword fatal = 0;	/* Set to -1 when errors must be fatal. */
+    zbyte skip, progress = GOT_NONE;
+    int x, y;
+
+    /* Check it's really an `IFZS' file. */
+    if (!read_long (svf, &tmpl)
+	|| !read_long (svf, &ifzslen)
+	|| !read_long (svf, &currlen))				return 0;
+    if (tmpl != ID_FORM || currlen != ID_IFZS)
+    {
+	print_string ("This is not a saved game file!\n");
+	return 0;
+    }
+    if ((ifzslen & 1) || ifzslen<4) /* Sanity checks. */	return 0;
+    ifzslen -= 4;
+
+    /* Read each chunk and process it. */
+    while (ifzslen > 0)
+    {
+	/* Read chunk header. */
+	if (ifzslen < 8) /* Couldn't contain a chunk. */	return 0;
+	if (!read_long (svf, &tmpl)
+	    || !read_long (svf, &currlen))			return 0;
+	ifzslen -= 8;	/* Reduce remaining by size of header. */
+
+	/* Handle chunk body. */
+	if (ifzslen < currlen) /* Chunk goes past EOF?! */	return 0;
+	skip = currlen & 1;
+	ifzslen -= currlen + (zlong) skip;
+
+	switch (tmpl)
+	{
+	    /* `IFhd' header chunk; must be first in file. */
+	    case ID_IFhd:
+		if (progress & GOT_HEADER)
+		{
+		    print_string ("Save file has two IFZS chunks!\n");
+		    return fatal;
+		}
+		progress |= GOT_HEADER;
+		if (currlen < 13
+		    || !read_word (svf, &tmpw))			return fatal;
+		if (tmpw != h_release)
+		    progress = GOT_ERROR;
+
+		for (i=H_SERIAL; i<H_SERIAL+6; ++i)
+		{
+		    if ((x = get_c (svf)) == EOF)		return fatal;
+		    if (x != zmp[i])
+			progress = GOT_ERROR;
+		}
+
+		if (!read_word (svf, &tmpw))			return fatal;
+		if (tmpw != h_checksum)
+		    progress = GOT_ERROR;
+
+		if (progress & GOT_ERROR)
+		{
+		    print_string ("File was not saved from this story!\n");
+		    return fatal;
+		}
+		if ((x = get_c (svf)) == EOF)			return fatal;
+		pc = (zlong) x << 16;
+		if ((x = get_c (svf)) == EOF)			return fatal;
+		pc |= (zlong) x << 8;
+		if ((x = get_c (svf)) == EOF)			return fatal;
+		pc |= (zlong) x;
+		fatal = -1;	/* Setting PC means errors must be fatal. */
+		SET_PC (pc);
+
+		for (i=13; i<currlen; ++i)
+		    (void) get_c (svf);	/* Skip rest of chunk. */
+		break;
+	    /* `Stks' stacks chunk; restoring this is quite complex. ;) */
+	    case ID_Stks:
+		if (progress & GOT_STACK)
+		{
+		    print_string ("File contains two stack chunks!\n");
+		    break;
+		}
+		progress |= GOT_STACK;
+
+		fatal = -1;	/* Setting SP means errors must be fatal. */
+		sp = stack + STACK_SIZE;
+
+		/*
+		 * All versions other than V6 may use evaluation stack outside
+		 * any function context. As a result a faked function context
+		 * will be present in the file here. We skip this context, but
+		 * load the associated stack onto the stack proper...
+		 */
+		if (h_version != V6)
+		{
+		    if (currlen < 8)				return fatal;
+		    for (i=0; i<6; ++i)
+			if (get_c (svf) != 0)			return fatal;
+		    if (!read_word (svf, &tmpw))		return fatal;
+		    if (tmpw > STACK_SIZE)
+		    {
+			print_string ("Save-file has too much stack (and I can't cope).\n");
+			return fatal;
+		    }
+		    currlen -= 8;
+		    if (currlen < tmpw*2)			return fatal;
+		    for (i=0; i<tmpw; ++i)
+			if (!read_word (svf, --sp))		return fatal;
+		    currlen -= tmpw*2;
+		}
+
+		/* We now proceed to load the main block of stack frames. */
+		for (fp = stack+STACK_SIZE, frame_count = 0;
+		     currlen > 0;
+		     currlen -= 8, ++frame_count)
+		{
+		    if (currlen < 8)				return fatal;
+		    if (sp - stack < 4)	/* No space for frame. */
+		    {
+			print_string ("Save-file has too much stack (and I can't cope).\n");
+			return fatal;
+		    }
+
+		    /* Read PC, procedure flag and formal param count. */
+		    if (!read_long (svf, &tmpl))		return fatal;
+		    y = (int) (tmpl & 0x0F);	/* Number of formals. */
+		    tmpw = y << 8;
+
+		    /* Read result variable. */
+		    if ((x = get_c (svf)) == EOF)		return fatal;
+
+		    /* Check the procedure flag... */
+		    if (tmpl & 0x10)
+		    {
+			tmpw |= 0x1000;	/* It's a procedure. */
+			tmpl >>= 8;	/* Shift to get PC value. */
+		    }
+		    else
+		    {
+			/* Functions have type 0, so no need to or anything. */
+			tmpl >>= 8;	/* Shift to get PC value. */
+			--tmpl;		/* Point at result byte. */
+			/* Sanity check on result variable... */
+			if (zmp[tmpl] != (zbyte) x)
+			{
+			    print_string ("Save-file has wrong variable number on stack (possibly wrong game version?)\n");
+			    return fatal;
+			}
+		    }
+		    *--sp = (zword) (tmpl >> 9);	/* High part of PC */
+		    *--sp = (zword) (tmpl & 0x1FF);	/* Low part of PC */
+		    *--sp = (zword) (fp - stack - 1);	/* FP */
+
+		    /* Read and process argument mask. */
+		    if ((x = get_c (svf)) == EOF)		return fatal;
+		    ++x;	/* Should now be a power of 2 */
+		    for (i=0; i<8; ++i)
+			if (x & (1<<i))
+			    break;
+		    if (x ^ (1<<i))	/* Not a power of 2 */
+		    {
+			print_string ("Save-file uses incomplete argument lists (which I can't handle)\n");
+			return fatal;
+		    }
+		    *--sp = tmpw | i;
+		    fp = sp;	/* FP for next frame. */
+
+		    /* Read amount of eval stack used. */
+		    if (!read_word (svf, &tmpw))		return fatal;
+
+		    tmpw += y;	/* Amount of stack + number of locals. */
+		    if (sp - stack <= tmpw)
+		    {
+			print_string ("Save-file has too much stack (and I can't cope).\n");
+			return fatal;
+		    }
+		    if (currlen < tmpw*2)			return fatal;
+		    for (i=0; i<tmpw; ++i)
+			if (!read_word (svf, --sp))		return fatal;
+		    currlen -= tmpw*2;
+		}
+		/* End of `Stks' processing... */
+		break;
+	    /* Any more special chunk types must go in HERE or ABOVE. */
+	    /* `CMem' compressed memory chunk; uncompress it. */
+	    case ID_CMem:
+		if (!(progress & GOT_MEMORY))	/* Don't complain if two. */
+		{
+		    (void) fseek (stf, blorb_ofs, SEEK_SET);
+		    i=0;	/* Bytes written to data area. */
+		    for (; currlen > 0; --currlen)
+		    {
+			if ((x = get_c (svf)) == EOF)		return fatal;
+			if (x == 0)	/* Start run. */
+			{
+			    /* Check for bogus run. */
+			    if (currlen < 2)
+			    {
+				print_string ("File contains bogus `CMem' chunk.\n");
+				for (; currlen > 0; --currlen)
+				    (void) get_c (svf);	/* Skip rest. */
+				currlen = 1;
+				i = 0xFFFF;
+				break; /* Keep going; may be a `UMem' too. */
+			    }
+			    /* Copy story file to memory during the run. */
+			    --currlen;
+			    if ((x = get_c (svf)) == EOF)	return fatal;
+			    for (; x >= 0 && i<h_dynamic_size; --x, ++i)
+				if ((y = get_c (stf)) == EOF)	return fatal;
+				else
+				    zmp[i] = (zbyte) y;
+			}
+			else	/* Not a run. */
+			{
+			    if ((y = get_c (stf)) == EOF)	return fatal;
+			    zmp[i] = (zbyte) (x ^ y);
+			    ++i;
+			}
+			/* Make sure we don't load too much. */
+			if (i > h_dynamic_size)
+			{
+			    print_string ("warning: `CMem' chunk too long!\n");
+			    for (; currlen > 1; --currlen)
+				(void) get_c (svf);	/* Skip rest. */
+			    break;	/* Keep going; there may be a `UMem' too. */
+			}
+		    }
+		    /* If chunk is short, assume a run. */
+		    for (; i<h_dynamic_size; ++i)
+			if ((y = get_c (stf)) == EOF)		return fatal;
+			else
+			    zmp[i] = (zbyte) y;
+		    if (currlen == 0)
+			progress |= GOT_MEMORY;	/* Only if succeeded. */
+		    break;
+	    }
+		/* Fall right thru (to default) if already GOT_MEMORY */
+	    /* `UMem' uncompressed memory chunk; load it. */
+	    case ID_UMem:
+		if (!(progress & GOT_MEMORY))	/* Don't complain if two. */
+		{
+		    /* Must be exactly the right size. */
+		    if (currlen == h_dynamic_size)
+		    {
+			if (fread (zmp, currlen, 1, svf) == 1)
+			{
+			    progress |= GOT_MEMORY;	/* Only on success. */
+			    break;
+			}
+		    }
+		    else
+			print_string ("`UMem' chunk wrong size!\n");
+		    /* Fall into default action (skip chunk) on errors. */
+		}
+		/* Fall thru (to default) if already GOT_MEMORY */
+	    /* Unrecognised chunk type; skip it. */
+	    default:
+		(void) fseek (svf, currlen, SEEK_CUR);	/* Skip chunk. */
+		break;
+	}
+	if (skip)
+	    (void) get_c (svf);	/* Skip pad byte. */
+    }
+
+    /*
+     * We've reached the end of the file. For the restoration to have been a
+     * success, we must have had one of each of the required chunks.
+     */
+    if (!(progress & GOT_HEADER))
+	print_string ("error: no valid header (`IFhd') chunk in file.\n");
+    if (!(progress & GOT_STACK))
+	print_string ("error: no valid stack (`Stks') chunk in file.\n");
+    if (!(progress & GOT_MEMORY))
+	print_string ("error: no valid memory (`CMem' or `UMem') chunk in file.\n");
+
+    return (progress == GOT_ALL ? 2 : fatal);
+}
+
+/*
+ * Save a game using Quetzal format. Return 1 if OK, 0 if failed.
+ */
+
+zword save_quetzal (FILE *svf, FILE *stf, int blorb_ofs)
+{
+    zlong ifzslen = 0, cmemlen = 0, stkslen = 0;
+    zlong pc;
+    zword i, j, n;
+    zword nvars, nargs, nstk, *p;
+    zbyte var;
+    long cmempos, stkspos;
+    int c;
+
+    /* Write `IFZS' header. */
+    if (!write_chnk (svf, ID_FORM, 0))			return 0;
+    if (!write_long (svf, ID_IFZS))			return 0;
+
+    /* Write `IFhd' chunk. */
+    GET_PC (pc);
+    if (!write_chnk (svf, ID_IFhd, 13))			return 0;
+    if (!write_word (svf, h_release))			return 0;
+    for (i=H_SERIAL; i<H_SERIAL+6; ++i)
+	if (!write_byte (svf, zmp[i]))			return 0;
+    if (!write_word (svf, h_checksum))			return 0;
+    if (!write_long (svf, pc << 8)) /* Includes pad. */	return 0;
+
+    /* Write `CMem' chunk. */
+    if ((cmempos = ftell (svf)) < 0)			return 0;
+    if (!write_chnk (svf, ID_CMem, 0))			return 0;
+    (void) fseek (stf, blorb_ofs, SEEK_SET);
+    /* j holds current run length. */
+    for (i=0, j=0, cmemlen=0; i < h_dynamic_size; ++i)
+    {
+	if ((c = get_c (stf)) == EOF)			return 0;
+	c ^= (int) zmp[i];
+	if (c == 0)
+	    ++j;	/* It's a run of equal bytes. */
+	else
+	{
+	    /* Write out any run there may be. */
+	    if (j > 0)
+	    {
+		for (; j > 0x100; j -= 0x100)
+		{
+		    if (!write_run (svf, 0xFF))		return 0;
+		    cmemlen += 2;
+		}
+		if (!write_run (svf, j-1))		return 0;
+		cmemlen += 2;
+		j = 0;
+	    }
+	    /* Any runs are now written. Write this (nonzero) byte. */
+	    if (!write_byte (svf, (zbyte) c))		return 0;
+	    ++cmemlen;
+	}
+    }
+    /*
+     * Reached end of dynamic memory. We ignore any unwritten run there may be
+     * at this point.
+     */
+    if (cmemlen & 1)	/* Chunk length must be even. */
+	if (!write_byte (svf, 0))			return 0;
+
+    /* Write `Stks' chunk. You are not expected to understand this. ;) */
+    if ((stkspos = ftell (svf)) < 0)			return 0;
+    if (!write_chnk (svf, ID_Stks, 0))			return 0;
+
+    /*
+     * We construct a list of frame indices, most recent first, in `frames'.
+     * These indices are the offsets into the `stack' array of the word before
+     * the first word pushed in each frame.
+     */
+    frames[0] = sp - stack;	/* The frame we'd get by doing a call now. */
+    for (i = fp - stack + 4, n=0; i < STACK_SIZE+4; i = stack[i-3] + 5)
+	frames[++n] = i;
+
+    /*
+     * All versions other than V6 can use evaluation stack outside a function
+     * context. We write a faked stack frame (most fields zero) to cater for
+     * this.
+     */
+    if (h_version != V6)
+    {
+	for (i=0; i<6; ++i)
+	    if (!write_byte (svf, 0))			return 0;
+	nstk = STACK_SIZE - frames[n];
+	if (!write_word (svf, nstk))			return 0;
+	for (j=STACK_SIZE-1; j >= frames[n]; --j)
+	    if (!write_word (svf, stack[j]))		return 0;
+	stkslen = 8 + 2*nstk;
+    }
+
+    /* Write out the rest of the stack frames. */
+    for (i=n; i>0; --i)
+    {
+	p = stack + frames[i] - 4;	/* Points to call frame. */
+	nvars = (p[0] & 0x0F00) >> 8;
+	nargs =  p[0] & 0x00FF;
+	nstk  =  frames[i] - frames[i-1] - nvars - 4;
+	pc    =  ((zlong) p[3] << 9) | p[2];
+
+	switch (p[0] & 0xF000)	/* Check type of call. */
+	{
+	    case 0x0000:	/* Function. */
+		var = zmp[pc];
+		pc = ((pc + 1) << 8) | nvars;
+		break;
+	    case 0x1000:	/* Procedure. */
+		var = 0;
+		pc = (pc << 8) | 0x10 | nvars;	/* Set procedure flag. */
+		break;
+	    /* case 0x2000: */
+	    default:
+		runtime_error (ERR_SAVE_IN_INTER);
+		return 0;
+	}
+	if (nargs != 0)
+	    nargs = (1 << nargs) - 1;	/* Make args into bitmap. */
+
+	/* Write the main part of the frame... */
+	if (!write_long (svf, pc)
+	    || !write_byte (svf, var)
+	    || !write_byte (svf, nargs)
+	    || !write_word (svf, nstk))			return 0;
+
+	/* Write the variables and eval stack. */
+	for (j=0, --p; j<nvars+nstk; ++j, --p)
+	    if (!write_word (svf, *p))			return 0;
+
+	/* Calculate length written thus far. */
+	stkslen += 8 + 2 * (nvars + nstk);
+    }
+
+    /* Fill in variable chunk lengths. */
+    ifzslen = 3*8 + 4 + 14 + cmemlen + stkslen;
+    if (cmemlen & 1)
+	++ifzslen;
+    (void) fseek (svf,         4, SEEK_SET);
+    if (!write_long (svf, ifzslen))			return 0;
+    (void) fseek (svf, cmempos+4, SEEK_SET);
+    if (!write_long (svf, cmemlen))			return 0;
+    (void) fseek (svf, stkspos+4, SEEK_SET);
+    if (!write_long (svf, stkslen))			return 0;
+
+    /* After all that, still nothing went wrong! */
+    return 1;
+}