gd_gd2.c

PHP v6.0 For Linux 运行环境：Win9X/ WinME/ WinNT/ Win2K/ WinXP

/*
   * gd_gd2.c
   *
   * Implements the I/O and support for the GD2 format.
   *
   * Changing the definition of GD2_DBG (below) will cause copious messages
   * to be displayed while it processes requests.
   *
   * Designed, Written & Copyright 1999, Philip Warner.
   *
 */

#include <stdio.h>
#include <errno.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>
#include "gd.h"
#include "gdhelpers.h"

#include <zlib.h>

#define TRUE 1
#define FALSE 0

/* 2.11: not part of the API, as the save routine can figure it out
 *	from im->trueColor, and the load routine doesn't need to tell
 *	the end user the saved format. NOTE: adding 2 is assumed
 *	to result in the correct format value for truecolor!
*/
#define GD2_FMT_TRUECOLOR_RAW 3
#define GD2_FMT_TRUECOLOR_COMPRESSED 4

#define gd2_compressed(fmt) (((fmt) == GD2_FMT_COMPRESSED) || ((fmt) == GD2_FMT_TRUECOLOR_COMPRESSED))
#define gd2_truecolor(fmt) (((fmt) == GD2_FMT_TRUECOLOR_RAW) || ((fmt) == GD2_FMT_TRUECOLOR_COMPRESSED))

/* Use this for commenting out debug-print statements. */
/* Just use the first '#define' to allow all the prints... */
/* #define GD2_DBG(s) (s) */
#define GD2_DBG(s)

typedef struct
{
	int offset;
	int size;
} t_chunk_info;

extern int _gdGetColors(gdIOCtx * in, gdImagePtr im, int gd2xFlag);
extern void _gdPutColors(gdImagePtr im, gdIOCtx * out);

/* */
/* Read the extra info in the gd2 header. */
/* */
static int _gd2GetHeader(gdIOCtxPtr in, int *sx, int *sy, int *cs, int *vers, int *fmt, int *ncx, int *ncy, t_chunk_info ** chunkIdx)
{
	int i;
	int ch;
	char id[5];
	t_chunk_info *cidx;
	int sidx;
	int nc;

	GD2_DBG(php_gd_error("Reading gd2 header info"));

	for (i = 0; i < 4; i++) {
		ch = gdGetC(in);
		if (ch == EOF) {
			goto fail1;
		}
		id[i] = ch;
	}
	id[4] = 0;

	GD2_DBG(php_gd_error("Got file code: %s", id));

	/* Equiv. of 'magick'.  */
	if (strcmp(id, GD2_ID) != 0) {
		GD2_DBG(php_gd_error("Not a valid gd2 file"));
		goto fail1;
	}

	/* Version */
	if (gdGetWord(vers, in) != 1) {
		goto fail1;
	}
	GD2_DBG(php_gd_error("Version: %d", *vers));

	if ((*vers != 1) && (*vers != 2)) {
		GD2_DBG(php_gd_error("Bad version: %d", *vers));
		goto fail1;
	}

	/* Image Size */
	if (!gdGetWord(sx, in)) {
		GD2_DBG(php_gd_error("Could not get x-size"));
		goto fail1;
	}
	if (!gdGetWord(sy, in)) {
		GD2_DBG(php_gd_error("Could not get y-size"));
		goto fail1;
	}
	GD2_DBG(php_gd_error("Image is %dx%d", *sx, *sy));

	/* Chunk Size (pixels, not bytes!) */
	if (gdGetWord(cs, in) != 1) {
		goto fail1;
	}
	GD2_DBG(php_gd_error("ChunkSize: %d", *cs));

	if ((*cs < GD2_CHUNKSIZE_MIN) || (*cs > GD2_CHUNKSIZE_MAX)) {
		GD2_DBG(php_gd_error("Bad chunk size: %d", *cs));
		goto fail1;
	}

	/* Data Format */
	if (gdGetWord(fmt, in) != 1) {
		goto fail1;
	}
	GD2_DBG(php_gd_error("Format: %d", *fmt));

	if ((*fmt != GD2_FMT_RAW) && (*fmt != GD2_FMT_COMPRESSED) && (*fmt != GD2_FMT_TRUECOLOR_RAW) && (*fmt != GD2_FMT_TRUECOLOR_COMPRESSED)) {
		GD2_DBG(php_gd_error("Bad data format: %d", *fmt));
		goto fail1;
	}

	/* # of chunks wide */
	if (gdGetWord(ncx, in) != 1) {
		goto fail1;
	}
	GD2_DBG(php_gd_error("%d Chunks Wide", *ncx));

	/* # of chunks high */
	if (gdGetWord(ncy, in) != 1) {
		goto fail1;
	}
	GD2_DBG(php_gd_error("%d Chunks vertically", *ncy));

	if (gd2_compressed(*fmt)) {
		nc = (*ncx) * (*ncy);
		GD2_DBG(php_gd_error("Reading %d chunk index entries", nc));
		sidx = sizeof(t_chunk_info) * nc;
		if (sidx <= 0) {
			goto fail1;
		}
		cidx = gdCalloc(sidx, 1);
		for (i = 0; i < nc; i++) {
			if (gdGetInt(&cidx[i].offset, in) != 1) {
				goto fail1;
			}
			if (gdGetInt(&cidx[i].size, in) != 1) {
				goto fail1;
			}
		}
		*chunkIdx = cidx;
	}

	GD2_DBG(php_gd_error("gd2 header complete"));

	return 1;

fail1:
	return 0;
}

static gdImagePtr _gd2CreateFromFile (gdIOCtxPtr in, int *sx, int *sy, int *cs, int *vers, int *fmt, int *ncx, int *ncy, t_chunk_info ** cidx)
{
	gdImagePtr im;

	if (_gd2GetHeader (in, sx, sy, cs, vers, fmt, ncx, ncy, cidx) != 1) {
		GD2_DBG(php_gd_error("Bad GD2 header"));
		goto fail1;
	}

	if (gd2_truecolor(*fmt)) {
		im = gdImageCreateTrueColor(*sx, *sy);
	} else {
		im = gdImageCreate(*sx, *sy);
	}
	if (im == NULL) {
		GD2_DBG(php_gd_error("Could not create gdImage"));
		goto fail1;
	}

	if (!_gdGetColors(in, im, (*vers) == 2)) {
		GD2_DBG(php_gd_error("Could not read color palette"));
		goto fail2;
	}
	GD2_DBG(php_gd_error("Image palette completed: %d colours", im->colorsTotal));

	return im;

fail2:
	gdImageDestroy(im);
	return 0;

fail1:
	return 0;
}

static int _gd2ReadChunk (int offset, char *compBuf, int compSize, char *chunkBuf, uLongf * chunkLen, gdIOCtx * in)
{
	int zerr;

	if (gdTell(in) != offset) {
		GD2_DBG(php_gd_error("Positioning in file to %d", offset));
		gdSeek(in, offset);
	} else {
		GD2_DBG(php_gd_error("Already Positioned in file to %d", offset));
	}

	/* Read and uncompress an entire chunk. */
	GD2_DBG(php_gd_error("Reading file"));
	if (gdGetBuf(compBuf, compSize, in) != compSize) {
		return FALSE;
	}
	GD2_DBG(php_gd_error("Got %d bytes. Uncompressing into buffer of %d bytes", compSize, (int)*chunkLen));
	zerr = uncompress((unsigned char *) chunkBuf, chunkLen, (unsigned char *) compBuf, compSize);
	if (zerr != Z_OK) {
		GD2_DBG(php_gd_error("Error %d from uncompress", zerr));
		return FALSE;
	}
	GD2_DBG(php_gd_error("Got chunk"));

	return TRUE;
}

gdImagePtr gdImageCreateFromGd2 (FILE * inFile)
{
	gdIOCtx *in = gdNewFileCtx(inFile);
	gdImagePtr im;

	im = gdImageCreateFromGd2Ctx(in);

	in->gd_free(in);

	return im;
}

gdImagePtr gdImageCreateFromGd2Ptr (int size, void *data)
{
	gdImagePtr im;
	gdIOCtx *in = gdNewDynamicCtxEx(size, data, 0);
	im = gdImageCreateFromGd2Ctx(in);
	in->gd_free(in);

	return im;
}

gdImagePtr gdImageCreateFromGd2Ctx (gdIOCtxPtr in)
{
	int sx, sy;
	int i;
	int ncx, ncy, nc, cs, cx, cy;
	int x, y, ylo, yhi, xlo, xhi;
	int vers, fmt;
	t_chunk_info *chunkIdx = NULL;	/* So we can gdFree it with impunity. */
	unsigned char *chunkBuf = NULL;	/* So we can gdFree it with impunity. */
	int chunkNum = 0;
	int chunkMax = 0;
	uLongf chunkLen;
	int chunkPos = 0;
	int compMax = 0;
	int bytesPerPixel;
	char *compBuf = NULL;		/* So we can gdFree it with impunity. */

	gdImagePtr im;

	/* Get the header */
	if (!(im = _gd2CreateFromFile(in, &sx, &sy, &cs, &vers, &fmt, &ncx, &ncy, &chunkIdx))) {
		 return 0;
	}

	bytesPerPixel = im->trueColor ? 4 : 1;
	nc = ncx * ncy;

	if (gd2_compressed(fmt)) {
		/* Find the maximum compressed chunk size. */
		compMax = 0;
		for (i = 0; (i < nc); i++) {
			if (chunkIdx[i].size > compMax) {
				compMax = chunkIdx[i].size;
			}
		}
		compMax++;

		/* Allocate buffers */
		chunkMax = cs * bytesPerPixel * cs;
		if (chunkMax <= 0) {
			return 0;
		}
		chunkBuf = gdCalloc(chunkMax, 1);
		compBuf = gdCalloc(compMax, 1);

		GD2_DBG(php_gd_error("Largest compressed chunk is %d bytes", compMax));
	}

	/* Read the data... */
	for (cy = 0; (cy < ncy); cy++) {
		for (cx = 0; (cx < ncx); cx++) {
			ylo = cy * cs;
			yhi = ylo + cs;
			if (yhi > im->sy) {
				yhi = im->sy;
			}

			GD2_DBG(php_gd_error("Processing Chunk %d (%d, %d), y from %d to %d", chunkNum, cx, cy, ylo, yhi));

			if (gd2_compressed(fmt)) {
				chunkLen = chunkMax;

				if (!_gd2ReadChunk(chunkIdx[chunkNum].offset, compBuf, chunkIdx[chunkNum].size, (char *) chunkBuf, &chunkLen, in)) {
					GD2_DBG(php_gd_error("Error reading comproessed chunk"));
					goto fail2;
				}

				chunkPos = 0;
			}

			for (y = ylo; (y < yhi); y++) {
				xlo = cx * cs;
				xhi = xlo + cs;
				if (xhi > im->sx) {
					xhi = im->sx;
				}

				if (!gd2_compressed(fmt)) {
					for (x = xlo; x < xhi; x++) {
						if (im->trueColor) {
							if (!gdGetInt(&im->tpixels[y][x], in)) {
								im->tpixels[y][x] = 0;
							}
						} else {
							int ch;
							if (!gdGetByte(&ch, in)) {
								ch = 0;
							}
							im->pixels[y][x] = ch;
						}
					}
				} else {
					for (x = xlo; x < xhi; x++) {
						if (im->trueColor) {
							/* 2.0.1: work around a gcc bug by being verbose. TBB */
							int a = chunkBuf[chunkPos++] << 24;
							int r = chunkBuf[chunkPos++] << 16;
							int g = chunkBuf[chunkPos++] << 8;
							int b = chunkBuf[chunkPos++];
							im->tpixels[y][x] = a + r + g + b;
						} else {
							im->pixels[y][x] = chunkBuf[chunkPos++];
						}
					}
				}
			}
			chunkNum++;
		}
	}

	GD2_DBG(php_gd_error("Freeing memory"));

	if (chunkBuf) {
		gdFree(chunkBuf);
	}
	if (compBuf) {
		gdFree(compBuf);
	}
	if (chunkIdx) {
		gdFree(chunkIdx);
	}

	GD2_DBG(php_gd_error("Done"));

	return im;

fail2:
	gdImageDestroy(im);
	if (chunkBuf) {
		gdFree(chunkBuf);
	}
	if (compBuf) {
		gdFree(compBuf);
	}
	if (chunkIdx) {
		gdFree(chunkIdx);
	}

	return 0;
}

gdImagePtr gdImageCreateFromGd2PartPtr (int size, void *data, int srcx, int srcy, int w, int h)
{
	gdImagePtr im;
	gdIOCtx *in = gdNewDynamicCtxEx(size, data, 0);
	im = gdImageCreateFromGd2PartCtx(in, srcx, srcy, w, h);
	in->gd_free(in);

	return im;
}

gdImagePtr gdImageCreateFromGd2Part (FILE * inFile, int srcx, int srcy, int w, int h)
{
	gdImagePtr im;
	gdIOCtx *in = gdNewFileCtx(inFile);

	im = gdImageCreateFromGd2PartCtx(in, srcx, srcy, w, h);

	in->gd_free(in);

	return im;
}

gdImagePtr gdImageCreateFromGd2PartCtx (gdIOCtx * in, int srcx, int srcy, int w, int h)
{
	int scx, scy, ecx, ecy, fsx, fsy;
	int nc, ncx, ncy, cs, cx, cy;