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754 lines
22 KiB
C
754 lines
22 KiB
C
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#ifdef HAVE_LIBPNG
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#include <stdio.h>
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#include <math.h>
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#include <string.h>
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#include <stdlib.h>
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#include "gd.h"
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#include "gdhelpers.h"
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#include "png.h" /* includes zlib.h and setjmp.h */
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#define TRUE 1
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#define FALSE 0
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/*---------------------------------------------------------------------------
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gd_png.c Copyright 1999 Greg Roelofs and Thomas Boutell
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The routines in this file, gdImagePng*() and gdImageCreateFromPng*(),
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are drop-in replacements for gdImageGif*() and gdImageCreateFromGif*(),
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except that these functions are noisier in the case of errors (comment
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out all fprintf() statements to disable that).
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GD 2.0 supports RGBA truecolor and will read and write truecolor PNGs.
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GD 2.0 supports 8 bits of color resolution per channel and
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7 bits of alpha channel resolution. Images with more than 8 bits
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per channel are reduced to 8 bits. Images with an alpha channel are
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only able to resolve down to '1/128th opaque' instead of '1/256th',
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and this conversion is also automatic. I very much doubt you can see it.
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Both tRNS and true alpha are supported.
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Gamma is ignored, and there is no support for text annotations.
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Last updated: 9 February 2001
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---------------------------------------------------------------------------*/
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#ifndef PNG_SETJMP_NOT_SUPPORTED
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typedef struct _jmpbuf_wrapper
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{
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jmp_buf jmpbuf;
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}
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jmpbuf_wrapper;
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static jmpbuf_wrapper gdPngJmpbufStruct;
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static void
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gdPngErrorHandler (png_structp png_ptr, png_const_charp msg)
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{
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jmpbuf_wrapper *jmpbuf_ptr;
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/* This function, aside from the extra step of retrieving the "error
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* pointer" (below) and the fact that it exists within the application
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* rather than within libpng, is essentially identical to libpng's
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* default error handler. The second point is critical: since both
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* setjmp() and longjmp() are called from the same code, they are
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* guaranteed to have compatible notions of how big a jmp_buf is,
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* regardless of whether _BSD_SOURCE or anything else has (or has not)
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* been defined. */
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fprintf (stderr, "gd-png: fatal libpng error: %s\n", msg);
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fflush (stderr);
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jmpbuf_ptr = png_get_error_ptr (png_ptr);
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if (jmpbuf_ptr == NULL)
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{ /* we are completely hosed now */
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fprintf (stderr,
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"gd-png: EXTREMELY fatal error: jmpbuf unrecoverable; terminating.\n");
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fflush (stderr);
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exit (99);
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}
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longjmp (jmpbuf_ptr->jmpbuf, 1);
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}
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#endif
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static void
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gdPngReadData (png_structp png_ptr,
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png_bytep data, png_size_t length)
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{
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gdGetBuf (data, length, (gdIOCtx *)
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png_get_io_ptr (png_ptr));
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}
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static void
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gdPngWriteData (png_structp png_ptr,
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png_bytep data, png_size_t length)
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{
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gdPutBuf (data, length, (gdIOCtx *)
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png_get_io_ptr (png_ptr));
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}
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static void
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gdPngFlushData (png_structp png_ptr)
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{
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}
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gdImagePtr
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gdImageCreateFromPng (FILE * inFile)
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{
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gdImagePtr im;
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gdIOCtx *in = gdNewFileCtx (inFile);
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im = gdImageCreateFromPngCtx (in);
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in->free (in);
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return im;
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}
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/* This routine is based in part on the Chapter 13 demo code in "PNG: The
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* Definitive Guide" (http://www.cdrom.com/pub/png/pngbook.html).
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*/
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gdImagePtr
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gdImageCreateFromPngCtx (gdIOCtx * infile)
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{
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png_byte sig[8];
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png_structp png_ptr;
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png_infop info_ptr;
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png_uint_32 width, height, rowbytes;
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int bit_depth, color_type, interlace_type;
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int num_palette, num_trans;
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png_colorp palette;
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png_color_16p trans_gray_rgb;
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png_color_16p trans_color_rgb;
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png_bytep trans;
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png_bytep image_data = NULL;
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png_bytepp row_pointers = NULL;
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gdImagePtr im = NULL;
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int i, j, *open;
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png_uint_32 ui, uj;
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volatile int transparent = -1;
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volatile int palette_allocated = FALSE;
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/* Make sure the signature can't match by dumb luck -- TBB */
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/* GRR: isn't sizeof(infile) equal to the size of the pointer? */
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memset (infile, 0, sizeof (infile));
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/* first do a quick check that the file really is a PNG image; could
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* have used slightly more general png_sig_cmp() function instead */
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gdGetBuf (sig, 8, infile);
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if (!png_check_sig (sig, 8))
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return NULL; /* bad signature */
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#ifndef PNG_SETJMP_NOT_SUPPORTED
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png_ptr = png_create_read_struct (PNG_LIBPNG_VER_STRING, &gdPngJmpbufStruct,
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gdPngErrorHandler, NULL);
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#else
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png_ptr = png_create_read_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
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#endif
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if (png_ptr == NULL)
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{
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fprintf (stderr, "gd-png error: cannot allocate libpng main struct\n");
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return NULL;
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}
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info_ptr = png_create_info_struct (png_ptr);
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if (info_ptr == NULL)
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{
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fprintf (stderr, "gd-png error: cannot allocate libpng info struct\n");
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png_destroy_read_struct (&png_ptr, NULL, NULL);
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return NULL;
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}
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/* we could create a second info struct here (end_info), but it's only
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* useful if we want to keep pre- and post-IDAT chunk info separated
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* (mainly for PNG-aware image editors and converters) */
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/* setjmp() must be called in every non-callback function that calls a
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* PNG-reading libpng function */
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#ifndef PNG_SETJMP_NOT_SUPPORTED
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if (setjmp (gdPngJmpbufStruct.jmpbuf))
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{
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fprintf (stderr, "gd-png error: setjmp returns error condition\n");
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png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
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return NULL;
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}
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#endif
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png_set_sig_bytes (png_ptr, 8); /* we already read the 8 signature bytes */
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png_set_read_fn (png_ptr, (void *) infile, gdPngReadData);
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png_read_info (png_ptr, info_ptr); /* read all PNG info up to image data */
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png_get_IHDR (png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
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&interlace_type, NULL, NULL);
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if ((color_type == PNG_COLOR_TYPE_RGB) ||
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(color_type == PNG_COLOR_TYPE_RGB_ALPHA))
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{
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im = gdImageCreateTrueColor ((int) width, (int) height);
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}
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else
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{
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im = gdImageCreate ((int) width, (int) height);
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}
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if (im == NULL)
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{
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fprintf (stderr, "gd-png error: cannot allocate gdImage struct\n");
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png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
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gdFree (image_data);
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gdFree (row_pointers);
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return NULL;
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}
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if (bit_depth == 16)
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png_set_strip_16 (png_ptr);
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else if (bit_depth < 8)
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png_set_packing (png_ptr); /* expand to 1 byte per pixel */
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switch (color_type)
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{
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case PNG_COLOR_TYPE_PALETTE:
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png_get_PLTE (png_ptr, info_ptr, &palette, &num_palette);
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#ifdef DEBUG
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fprintf (stderr, "gd-png color_type is palette, colors: %d\n",
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num_palette);
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#endif /* DEBUG */
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if (png_get_valid (png_ptr, info_ptr, PNG_INFO_tRNS))
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{
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/* gd 2.0: we support this rather thoroughly now. Grab the
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first fully transparent entry, if any, as the value of
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the simple-transparency index, mostly for backwards
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binary compatibility. The alpha channel is where it's
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really at these days. */
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int firstZero = 1;
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png_get_tRNS (png_ptr, info_ptr, &trans, &num_trans, NULL);
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for (i = 0; i < num_trans; ++i)
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{
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im->alpha[i] = gdAlphaMax - (trans[i] >> 1);
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if ((trans[i] == 0) && (firstZero))
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{
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transparent = i;
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firstZero = 0;
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}
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}
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}
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break;
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case PNG_COLOR_TYPE_GRAY:
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case PNG_COLOR_TYPE_GRAY_ALPHA:
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/* create a fake palette and check for single-shade transparency */
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if ((palette = (png_colorp) gdMalloc (256 * sizeof (png_color))) == NULL)
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{
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fprintf (stderr, "gd-png error: cannot allocate gray palette\n");
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png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
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return NULL;
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}
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palette_allocated = TRUE;
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if (bit_depth < 8)
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{
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num_palette = 1 << bit_depth;
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for (i = 0; i < 256; ++i)
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{
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j = (255 * i) / (num_palette - 1);
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palette[i].red = palette[i].green = palette[i].blue = j;
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}
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}
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else
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{
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num_palette = 256;
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for (i = 0; i < 256; ++i)
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{
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palette[i].red = palette[i].green = palette[i].blue = i;
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}
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}
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if (png_get_valid (png_ptr, info_ptr, PNG_INFO_tRNS))
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{
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png_get_tRNS (png_ptr, info_ptr, NULL, NULL, &trans_gray_rgb);
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if (bit_depth == 16) /* png_set_strip_16() not yet in effect */
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transparent = trans_gray_rgb->gray >> 8;
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else
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transparent = trans_gray_rgb->gray;
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/* Note slight error in 16-bit case: up to 256 16-bit shades
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* may get mapped to a single 8-bit shade, and only one of them
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* is supposed to be transparent. IOW, both opaque pixels and
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* transparent pixels will be mapped into the transparent entry.
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* There is no particularly good way around this in the case
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* that all 256 8-bit shades are used, but one could write some
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* custom 16-bit code to handle the case where there are gdFree
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* palette entries. This error will be extremely rare in
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* general, though. (Quite possibly there is only one such
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* image in existence.) */
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}
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break;
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case PNG_COLOR_TYPE_RGB:
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case PNG_COLOR_TYPE_RGB_ALPHA:
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/* gd 2.0: we now support truecolor. See the comment above
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for a rare situation in which the transparent pixel may not
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work properly with 16-bit channels. */
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if (png_get_valid (png_ptr, info_ptr, PNG_INFO_tRNS))
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{
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png_get_tRNS (png_ptr, info_ptr, NULL, NULL, &trans_color_rgb);
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if (bit_depth == 16) /* png_set_strip_16() not yet in effect */
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transparent = gdTrueColor (trans_color_rgb->red >> 8,
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trans_color_rgb->green >> 8,
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trans_color_rgb->blue >> 8);
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else
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transparent = gdTrueColor (trans_color_rgb->red,
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trans_color_rgb->green,
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trans_color_rgb->blue);
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}
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break;
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}
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png_read_update_info (png_ptr, info_ptr);
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/* allocate space for the PNG image data */
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rowbytes = png_get_rowbytes (png_ptr, info_ptr);
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if ((image_data = (png_bytep) gdMalloc (rowbytes * height)) == NULL)
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{
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fprintf (stderr, "gd-png error: cannot allocate image data\n");
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png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
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return NULL;
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}
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if ((row_pointers = (png_bytepp) gdMalloc (height * sizeof (png_bytep))) == NULL)
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{
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fprintf (stderr, "gd-png error: cannot allocate row pointers\n");
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png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
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gdFree (image_data);
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return NULL;
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}
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/* set the individual row_pointers to point at the correct offsets */
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for (uj = 0; uj < height; ++uj)
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{
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row_pointers[uj] = image_data + uj * rowbytes;
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}
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png_read_image (png_ptr, row_pointers); /* read whole image... */
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png_read_end (png_ptr, NULL); /* ...done! */
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if (!im->trueColor)
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{
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im->colorsTotal = num_palette;
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im->transparent = transparent;
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/* load the palette and mark all entries "open" (unused) for now */
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open = im->open;
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for (i = 0; i < num_palette; ++i)
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{
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im->red[i] = palette[i].red;
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im->green[i] = palette[i].green;
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im->blue[i] = palette[i].blue;
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open[i] = 1;
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}
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for (i = num_palette; i < gdMaxColors; ++i)
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{
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open[i] = 1;
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}
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}
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im->interlace = (interlace_type == PNG_INTERLACE_ADAM7);
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/* can't nuke structs until done with palette */
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png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
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switch (color_type)
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{
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case PNG_COLOR_TYPE_RGB:
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for (uj = 0; uj < height; uj++)
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{
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int boffset = 0;
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for (ui = 0; ui < width; ui++)
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{
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register png_byte r = row_pointers[uj][boffset++];
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register png_byte g = row_pointers[uj][boffset++];
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register png_byte b = row_pointers[uj][boffset++];
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im->tpixels[uj][ui] = gdTrueColor (r, g, b);
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}
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}
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break;
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case PNG_COLOR_TYPE_RGB_ALPHA:
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for (uj = 0; uj < height; uj++)
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{
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int boffset = 0;
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for (ui = 0; ui < width; ui++)
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{
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register png_byte r = row_pointers[uj][boffset++];
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register png_byte g = row_pointers[uj][boffset++];
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register png_byte b = row_pointers[uj][boffset++];
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/* gd has only 7 bits of alpha channel resolution, and
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127 is transparent, 0 opaque. A moment of convenience,
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a lifetime of compatibility. */
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register png_byte a = gdAlphaMax -
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(row_pointers[uj][boffset++] >> 1);
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im->tpixels[uj][ui] = gdTrueColorAlpha (r, g, b, a);
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}
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}
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break;
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default:
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/* Palette image, or something coerced to be one */
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for (uj = 0; uj < height; ++uj)
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{
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for (ui = 0; ui < width; ++ui)
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{
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register png_byte idx = row_pointers[uj][ui];
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im->pixels[uj][ui] = idx;
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open[idx] = 0;
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}
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}
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}
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#ifdef DEBUG
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if (!im->trueColor)
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{
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for (i = num_palette; i < gdMaxColors; ++i)
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{
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if (!open[i])
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{
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fprintf (stderr, "gd-png warning: image data references out-of-range"
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" color index (%d)\n", i);
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}
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}
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}
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#endif
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if (palette_allocated)
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gdFree (palette);
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gdFree (image_data);
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gdFree (row_pointers);
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return im;
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}
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void
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gdImagePng (gdImagePtr im, FILE * outFile)
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{
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gdIOCtx *out = gdNewFileCtx (outFile);
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gdImagePngCtx (im, out);
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out->free (out);
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}
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void *
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gdImagePngPtr (gdImagePtr im, int *size)
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{
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void *rv;
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gdIOCtx *out = gdNewDynamicCtx (2048, NULL);
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gdImagePngCtx (im, out);
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rv = gdDPExtractData (out, size);
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out->free (out);
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return rv;
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}
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/* This routine is based in part on code from Dale Lutz (Safe Software Inc.)
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* and in part on demo code from Chapter 15 of "PNG: The Definitive Guide"
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* (http://www.cdrom.com/pub/png/pngbook.html).
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*/
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void
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gdImagePngCtx (gdImagePtr im, gdIOCtx * outfile)
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{
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int i, j, bit_depth, interlace_type;
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int width = im->sx;
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int height = im->sy;
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int colors = im->colorsTotal;
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int *open = im->open;
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int mapping[gdMaxColors]; /* mapping[gd_index] == png_index */
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png_byte trans_values[256];
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png_color_16 trans_rgb_value;
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png_color palette[gdMaxColors];
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png_structp png_ptr;
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png_infop info_ptr;
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volatile int transparent = im->transparent;
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volatile int remap = FALSE;
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#ifndef PNG_SETJMP_NOT_SUPPORTED
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png_ptr = png_create_write_struct (PNG_LIBPNG_VER_STRING,
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&gdPngJmpbufStruct, gdPngErrorHandler, NULL);
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#else
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png_ptr = png_create_write_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
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#endif
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if (png_ptr == NULL)
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{
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fprintf (stderr, "gd-png error: cannot allocate libpng main struct\n");
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return;
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}
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info_ptr = png_create_info_struct (png_ptr);
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if (info_ptr == NULL)
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{
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fprintf (stderr, "gd-png error: cannot allocate libpng info struct\n");
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png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
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return;
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}
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#ifndef PNG_SETJMP_NOT_SUPPORTED
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if (setjmp (gdPngJmpbufStruct.jmpbuf))
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{
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fprintf (stderr, "gd-png error: setjmp returns error condition\n");
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png_destroy_write_struct (&png_ptr, &info_ptr);
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return;
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}
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#endif
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png_set_write_fn (png_ptr, (void *) outfile, gdPngWriteData, gdPngFlushData);
|
|
|
|
/* This is best for palette images, and libpng defaults to it for
|
|
palette images anyway, so we don't need to do it explicitly.
|
|
What to ideally do for truecolor images depends, alas, on the image.
|
|
gd is intentionally imperfect and doesn't spend a lot of time
|
|
fussing with such things. */
|
|
/* png_set_filter(png_ptr, 0, PNG_FILTER_NONE); */
|
|
|
|
/* may want to force maximum compression, but time penalty is large */
|
|
/* png_set_compression_level(png_ptr, Z_BEST_COMPRESSION); */
|
|
|
|
/* can set this to a smaller value without compromising compression if all
|
|
* image data is 16K or less; will save some decoder memory [min == 8] */
|
|
/* png_set_compression_window_bits(png_ptr, 15); */
|
|
|
|
if (!im->trueColor)
|
|
{
|
|
if (transparent >= im->colorsTotal ||
|
|
(transparent >= 0 && open[transparent]))
|
|
transparent = -1;
|
|
}
|
|
if (!im->trueColor)
|
|
{
|
|
for (i = 0; i < gdMaxColors; ++i)
|
|
mapping[i] = -1;
|
|
}
|
|
if (!im->trueColor)
|
|
{
|
|
/* count actual number of colors used (colorsTotal == high-water mark) */
|
|
colors = 0;
|
|
for (i = 0; i < im->colorsTotal; ++i)
|
|
{
|
|
if (!open[i])
|
|
{
|
|
mapping[i] = colors;
|
|
++colors;
|
|
}
|
|
}
|
|
if (colors < im->colorsTotal)
|
|
{
|
|
remap = TRUE;
|
|
}
|
|
if (colors <= 2)
|
|
bit_depth = 1;
|
|
else if (colors <= 4)
|
|
bit_depth = 2;
|
|
else if (colors <= 16)
|
|
bit_depth = 4;
|
|
else
|
|
bit_depth = 8;
|
|
}
|
|
interlace_type = im->interlace ? PNG_INTERLACE_ADAM7 : PNG_INTERLACE_NONE;
|
|
|
|
if (im->trueColor)
|
|
{
|
|
if (im->saveAlphaFlag)
|
|
{
|
|
png_set_IHDR (png_ptr, info_ptr, width, height, 8,
|
|
PNG_COLOR_TYPE_RGB_ALPHA, interlace_type,
|
|
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
|
|
}
|
|
else
|
|
{
|
|
png_set_IHDR (png_ptr, info_ptr, width, height, 8,
|
|
PNG_COLOR_TYPE_RGB, interlace_type,
|
|
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
png_set_IHDR (png_ptr, info_ptr, width, height, bit_depth,
|
|
PNG_COLOR_TYPE_PALETTE, interlace_type,
|
|
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
|
|
}
|
|
if (im->trueColor && (!im->saveAlphaFlag) && (transparent >= 0))
|
|
{
|
|
trans_rgb_value.red = gdTrueColorGetRed (im->trueColor);
|
|
trans_rgb_value.green = gdTrueColorGetGreen (im->trueColor);
|
|
trans_rgb_value.blue = gdTrueColorGetBlue (im->trueColor);
|
|
png_set_tRNS (png_ptr, info_ptr, 0, 0, &trans_rgb_value);
|
|
}
|
|
if (!im->trueColor)
|
|
{
|
|
/* Oy veh. Remap the PNG palette to put the
|
|
entries with interesting alpha channel
|
|
values first. This minimizes the size
|
|
of the tRNS chunk and thus the size
|
|
of the PNG file as a whole. */
|
|
int tc = 0;
|
|
int i;
|
|
int j;
|
|
int k;
|
|
for (i = 0; (i < im->colorsTotal); i++)
|
|
{
|
|
if ((!im->open[i]) &&
|
|
(im->alpha[i] != gdAlphaOpaque))
|
|
{
|
|
tc++;
|
|
}
|
|
}
|
|
if (tc)
|
|
{
|
|
#if 0
|
|
for (i = 0; (i < im->colorsTotal); i++)
|
|
{
|
|
trans_values[i] = 255 -
|
|
((im->alpha[i] << 1) +
|
|
(im->alpha[i] >> 7));
|
|
}
|
|
png_set_tRNS (png_ptr, info_ptr, trans_values, 256, NULL);
|
|
#endif
|
|
if (!remap)
|
|
{
|
|
remap = TRUE;
|
|
}
|
|
/* (Semi-)transparent indexes come up from the bottom
|
|
of the list of real colors; opaque
|
|
indexes come down from the top */
|
|
j = 0;
|
|
k = colors - 1;
|
|
for (i = 0; (i < im->colorsTotal); i++)
|
|
{
|
|
if (!im->open[i])
|
|
{
|
|
if (im->alpha[i] != gdAlphaOpaque)
|
|
{
|
|
trans_values[j] = 255 -
|
|
((im->alpha[i] << 1) +
|
|
(im->alpha[i] >> 7));
|
|
mapping[i] = j++;
|
|
}
|
|
else
|
|
{
|
|
mapping[i] = k--;
|
|
}
|
|
}
|
|
}
|
|
png_set_tRNS (png_ptr, info_ptr, trans_values, tc, NULL);
|
|
}
|
|
}
|
|
|
|
/* convert palette to libpng layout */
|
|
if (!im->trueColor)
|
|
{
|
|
if (remap)
|
|
for (i = 0; i < im->colorsTotal; ++i)
|
|
{
|
|
if (mapping[i] < 0)
|
|
continue;
|
|
palette[mapping[i]].red = im->red[i];
|
|
palette[mapping[i]].green = im->green[i];
|
|
palette[mapping[i]].blue = im->blue[i];
|
|
}
|
|
else
|
|
for (i = 0; i < colors; ++i)
|
|
{
|
|
palette[i].red = im->red[i];
|
|
palette[i].green = im->green[i];
|
|
palette[i].blue = im->blue[i];
|
|
}
|
|
png_set_PLTE (png_ptr, info_ptr, palette, colors);
|
|
}
|
|
|
|
/* write out the PNG header info (everything up to first IDAT) */
|
|
png_write_info (png_ptr, info_ptr);
|
|
|
|
/* make sure < 8-bit images are packed into pixels as tightly as possible */
|
|
png_set_packing (png_ptr);
|
|
|
|
/* This code allocates a set of row buffers and copies the gd image data
|
|
* into them only in the case that remapping is necessary; in gd 1.3 and
|
|
* later, the im->pixels array is laid out identically to libpng's row
|
|
* pointers and can be passed to png_write_image() function directly.
|
|
* The remapping case could be accomplished with less memory for non-
|
|
* interlaced images, but interlacing causes some serious complications. */
|
|
if (im->trueColor)
|
|
{
|
|
int channels = im->saveAlphaFlag ? 4 : 3;
|
|
/* Our little 7-bit alpha channel trick costs us a bit here. */
|
|
png_bytep *row_pointers;
|
|
row_pointers = gdMalloc (sizeof (png_bytep) * height);
|
|
if (row_pointers == NULL)
|
|
{
|
|
fprintf (stderr, "gd-png error: unable to allocate row_pointers\n");
|
|
}
|
|
for (j = 0; j < height; ++j)
|
|
{
|
|
int bo = 0;
|
|
if ((row_pointers[j] = (png_bytep) gdMalloc (width * channels)) == NULL)
|
|
{
|
|
fprintf (stderr, "gd-png error: unable to allocate rows\n");
|
|
for (i = 0; i < j; ++i)
|
|
gdFree (row_pointers[i]);
|
|
return;
|
|
}
|
|
for (i = 0; i < width; ++i)
|
|
{
|
|
unsigned char a;
|
|
row_pointers[j][bo++] = gdTrueColorGetRed (im->tpixels[j][i]);
|
|
row_pointers[j][bo++] = gdTrueColorGetGreen (im->tpixels[j][i]);
|
|
row_pointers[j][bo++] = gdTrueColorGetBlue (im->tpixels[j][i]);
|
|
if (im->saveAlphaFlag)
|
|
{
|
|
/* convert the 7-bit alpha channel to an 8-bit alpha channel.
|
|
We do a little bit-flipping magic, repeating the MSB
|
|
as the LSB, to ensure that 0 maps to 0 and
|
|
127 maps to 255. We also have to invert to match
|
|
PNG's convention in which 255 is opaque. */
|
|
a = gdTrueColorGetAlpha (im->tpixels[j][i]);
|
|
row_pointers[j][bo++] = 255 - ((a << 1) + (a >> 7));
|
|
}
|
|
}
|
|
}
|
|
|
|
png_write_image (png_ptr, row_pointers);
|
|
png_write_end (png_ptr, info_ptr);
|
|
|
|
for (j = 0; j < height; ++j)
|
|
gdFree (row_pointers[j]);
|
|
gdFree (row_pointers);
|
|
}
|
|
else
|
|
{
|
|
if (remap)
|
|
{
|
|
png_bytep *row_pointers;
|
|
row_pointers = gdMalloc (sizeof (png_bytep) * height);
|
|
if (row_pointers == NULL)
|
|
{
|
|
fprintf (stderr, "gd-png error: unable to allocate row_pointers\n");
|
|
}
|
|
for (j = 0; j < height; ++j)
|
|
{
|
|
if ((row_pointers[j] = (png_bytep) gdMalloc (width)) == NULL)
|
|
{
|
|
fprintf (stderr, "gd-png error: unable to allocate rows\n");
|
|
for (i = 0; i < j; ++i)
|
|
gdFree (row_pointers[i]);
|
|
return;
|
|
}
|
|
for (i = 0; i < width; ++i)
|
|
row_pointers[j][i] = mapping[im->pixels[j][i]];
|
|
}
|
|
|
|
png_write_image (png_ptr, row_pointers);
|
|
png_write_end (png_ptr, info_ptr);
|
|
|
|
for (j = 0; j < height; ++j)
|
|
gdFree (row_pointers[j]);
|
|
gdFree (row_pointers);
|
|
}
|
|
else
|
|
{
|
|
png_write_image (png_ptr, im->pixels);
|
|
png_write_end (png_ptr, info_ptr);
|
|
}
|
|
}
|
|
/* 1.6.3: maybe we should give that memory BACK! TBB */
|
|
png_destroy_write_struct (&png_ptr, &info_ptr);
|
|
}
|
|
|
|
|
|
#endif /* HAVE_LIBPNG */
|