1177 lines
33 KiB
C
1177 lines
33 KiB
C
#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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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 "gd_errors.h"
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/* JCE: Arrange HAVE_LIBPNG so that it can be set in gd.h */
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#ifdef HAVE_LIBPNG
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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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/**
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* File: PNG IO
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*
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* Read and write PNG images.
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*/
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#ifdef PNG_SETJMP_SUPPORTED
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typedef struct _jmpbuf_wrapper {
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jmp_buf jmpbuf;
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}
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jmpbuf_wrapper;
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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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gd_error_ex(GD_WARNING, "gd-png: fatal libpng error: %s\n", msg);
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jmpbuf_ptr = png_get_error_ptr (png_ptr);
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if (jmpbuf_ptr == NULL) { /* we are completely hosed now */
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gd_error_ex(GD_ERROR, "gd-png: EXTREMELY fatal error: jmpbuf unrecoverable; terminating.\n");
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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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static void gdPngWarningHandler (png_structp png_ptr, png_const_charp msg)
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{
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gd_error_ex(GD_WARNING, "gd-png: libpng warning: %s", msg);
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}
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#endif
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static void
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gdPngReadData (png_structp png_ptr, png_bytep data, png_size_t length)
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{
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int check;
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check = gdGetBuf (data, length, (gdIOCtx *) png_get_io_ptr (png_ptr));
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if (check != (int)length) {
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png_error(png_ptr, "Read Error: truncated data");
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}
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}
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static void
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gdPngWriteData (png_structp png_ptr, png_bytep data, png_size_t length)
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{
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gdPutBuf (data, length, (gdIOCtx *) 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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(void)png_ptr;
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}
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/*
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Function: gdImageCreateFromPng
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<gdImageCreateFromPng> is called to load images from PNG format
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files. Invoke <gdImageCreateFromPng> with an already opened
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pointer to a FILE containing the desired
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image. <gdImageCreateFromPng> returns a <gdImagePtr> to the new
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image, or NULL if unable to load the image (most often because the
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file is corrupt or does not contain a PNG
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image). <gdImageCreateFromPng> does not close the file. You can
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inspect the sx and sy members of the image to determine its
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size. The image must eventually be destroyed using
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gdImageDestroy().
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If the PNG image being loaded is a truecolor image, the resulting
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gdImagePtr will refer to a truecolor image. If the PNG image being
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loaded is a palette or grayscale image, the resulting gdImagePtr
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will refer to a palette image. gd retains only 8 bits of
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resolution for each of the red, green and blue channels, and only
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7 bits of resolution for the alpha channel. The former restriction
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affects only a handful of very rare 48-bit color and 16-bit
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grayscale PNG images. The second restriction affects all
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semitransparent PNG images, but the difference is essentially
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invisible to the eye. 7 bits of alpha channel resolution is, in
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practice, quite a lot.
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Variants:
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<gdImageCreateFromPngPtr> creates an image from PNG data (i.e. the
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contents of a PNG file) already in memory.
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<gdImageCreateFromPngCtx> reads in an image using the functions in
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a <gdIOCtx> struct.
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<gdImageCreateFromPngSource> is similar to
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<gdImageCreateFromPngCtx> but uses the old <gdSource> interface.
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It is *obsolete*.
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Parameters:
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infile - The input FILE pointer.
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Returns:
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A pointer to the new image or NULL if an error occurred.
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Example:
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(start code)
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gdImagePtr im;
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... inside a function ...
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FILE *in;
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in = fopen("mypng.png", "rb");
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im = gdImageCreateFromPng(in);
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fclose(in);
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// ... Use the image ...
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gdImageDestroy(im);
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(end code)
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*/
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BGD_DECLARE(gdImagePtr) 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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if (in == NULL) return NULL;
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im = gdImageCreateFromPngCtx (in);
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in->gd_free (in);
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return im;
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}
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/*
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Function: gdImageCreateFromPngPtr
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See <gdImageCreateFromPng>.
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*/
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BGD_DECLARE(gdImagePtr) gdImageCreateFromPngPtr (int size, void *data)
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{
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gdImagePtr im;
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gdIOCtx *in = gdNewDynamicCtxEx (size, data, 0);
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if(!in)
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return 0;
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im = gdImageCreateFromPngCtx (in);
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in->gd_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
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* "PNG: The Definitive Guide" (http://www.libpng.org/pub/png/book/).
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*/
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/*
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Function: gdImageCreateFromPngCtx
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See <gdImageCreateFromPng>.
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*/
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BGD_DECLARE(gdImagePtr) gdImageCreateFromPngCtx (gdIOCtx * infile)
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{
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png_byte sig[8];
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#ifdef PNG_SETJMP_SUPPORTED
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jmpbuf_wrapper jbw;
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#endif
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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, w, h, res_x, res_y;
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int bit_depth, color_type, interlace_type, unit_type;
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int num_palette = 0, 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 = NULL;
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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 (sig, 0, sizeof (sig));
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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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if (gdGetBuf (sig, 8, infile) < 8) {
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return NULL;
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}
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if (png_sig_cmp(sig, 0, 8) != 0) { /* bad signature */
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return NULL; /* bad signature */
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}
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#ifdef PNG_SETJMP_SUPPORTED
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png_ptr = png_create_read_struct (PNG_LIBPNG_VER_STRING, &jbw, gdPngErrorHandler, gdPngWarningHandler);
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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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gd_error("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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gd_error("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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*/
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/* setjmp() must be called in every non-callback function that calls a
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* PNG-reading libpng function. We must reset it everytime we get a
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* new allocation that we save in a stack variable.
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*/
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#ifdef PNG_SETJMP_SUPPORTED
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if (setjmp(jbw.jmpbuf)) {
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gd_error("gd-png error: setjmp returns error condition 1\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, &interlace_type, NULL, NULL);
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if ((color_type == PNG_COLOR_TYPE_RGB) || (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
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|| color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
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im = gdImageCreateTrueColor ((int) width, (int) height);
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} else {
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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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gd_error("gd-png error: cannot allocate gdImage struct\n");
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goto error;
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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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}
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/* setjmp() must be called in every non-callback function that calls a
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* PNG-reading libpng function. We must reset it everytime we get a
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* new allocation that we save in a stack variable.
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*/
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#ifdef PNG_SETJMP_SUPPORTED
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if (setjmp(jbw.jmpbuf)) {
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gd_error("gd-png error: setjmp returns error condition 2\n");
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goto error;
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}
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#endif
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#ifdef PNG_pHYs_SUPPORTED
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/* check if the resolution is specified */
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if (png_get_valid(png_ptr, info_ptr, PNG_INFO_pHYs)) {
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if (png_get_pHYs(png_ptr, info_ptr, &res_x, &res_y, &unit_type)) {
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switch (unit_type) {
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case PNG_RESOLUTION_METER:
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im->res_x = DPM2DPI(res_x);
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im->res_y = DPM2DPI(res_y);
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break;
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}
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}
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}
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#endif
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switch (color_type) {
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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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gd_error("gd-png color_type is palette, colors: %d\n", 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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/* 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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*/
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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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im->alpha[i] = gdAlphaMax - (trans[i] >> 1);
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if ((trans[i] == 0) && (firstZero)) {
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/* 2.0.5: long-forgotten patch from Wez Furlong */
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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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/* 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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gd_error("gd-png error: cannot allocate gray palette\n");
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goto error;
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}
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palette_allocated = TRUE;
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if (bit_depth < 8) {
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num_palette = 1 << bit_depth;
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for (i = 0; i < 256; ++i) {
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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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} else {
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num_palette = 256;
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for (i = 0; i < 256; ++i) {
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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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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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}
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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_GRAY_ALPHA:
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png_set_gray_to_rgb(png_ptr);
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// fall through
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// Keep above comment, gcc recognizes it and silent its warning about fall through case here
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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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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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}
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break;
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default:
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gd_error("gd-png color_type is unknown: %d\n", color_type);
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goto error;
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}
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/* enable the interlace transform if supported */
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#ifdef PNG_READ_INTERLACING_SUPPORTED
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(void)png_set_interlace_handling(png_ptr);
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#endif
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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 (overflow2(rowbytes, height))
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goto error;
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image_data = (png_bytep) gdMalloc (rowbytes * height);
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if (!image_data) {
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gd_error("gd-png error: cannot allocate image data\n");
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goto error;
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}
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if (overflow2(height, sizeof (png_bytep)))
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goto error;
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row_pointers = (png_bytepp) gdMalloc (height * sizeof (png_bytep));
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if (!row_pointers) {
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gd_error("gd-png error: cannot allocate row pointers\n");
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goto error;
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}
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/* setjmp() must be called in every non-callback function that calls a
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* PNG-reading libpng function. We must reset it everytime we get a
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* new allocation that we save in a stack variable.
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*/
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#ifdef PNG_SETJMP_SUPPORTED
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if (setjmp(jbw.jmpbuf)) {
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gd_error("gd-png error: setjmp returns error condition 3\n");
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goto error;
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}
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#endif
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/* set the individual row_pointers to point at the correct offsets */
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for (h = 0; h < height; ++h) {
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row_pointers[h] = image_data + h * 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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im->colorsTotal = num_palette;
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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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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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open[i] = 1;
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}
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}
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/* 2.0.12: Slaven Rezic: palette images are not the only images
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with a simple transparent color setting */
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im->transparent = transparent;
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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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|
case PNG_COLOR_TYPE_RGB:
|
|
for (h = 0; h < height; h++) {
|
|
int boffset = 0;
|
|
for (w = 0; w < width; w++) {
|
|
register png_byte r = row_pointers[h][boffset++];
|
|
register png_byte g = row_pointers[h][boffset++];
|
|
register png_byte b = row_pointers[h][boffset++];
|
|
im->tpixels[h][w] = gdTrueColor (r, g, b);
|
|
}
|
|
}
|
|
break;
|
|
|
|
case PNG_COLOR_TYPE_GRAY_ALPHA:
|
|
case PNG_COLOR_TYPE_RGB_ALPHA:
|
|
for (h = 0; h < height; h++) {
|
|
int boffset = 0;
|
|
for (w = 0; w < width; w++) {
|
|
register png_byte r = row_pointers[h][boffset++];
|
|
register png_byte g = row_pointers[h][boffset++];
|
|
register png_byte b = row_pointers[h][boffset++];
|
|
|
|
/* gd has only 7 bits of alpha channel resolution, and
|
|
* 127 is transparent, 0 opaque. A moment of convenience,
|
|
* a lifetime of compatibility.
|
|
*/
|
|
|
|
register png_byte a = gdAlphaMax - (row_pointers[h][boffset++] >> 1);
|
|
im->tpixels[h][w] = gdTrueColorAlpha(r, g, b, a);
|
|
}
|
|
}
|
|
break;
|
|
default:
|
|
if (!im->trueColor) {
|
|
/* Palette image, or something coerced to be one */
|
|
for (h = 0; h < height; ++h) {
|
|
for (w = 0; w < width; ++w) {
|
|
register png_byte idx = row_pointers[h][w];
|
|
im->pixels[h][w] = idx;
|
|
open[idx] = 0;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
#ifdef DEBUG
|
|
if (!im->trueColor) {
|
|
for (i = num_palette; i < gdMaxColors; ++i) {
|
|
if (!open[i]) {
|
|
fprintf (stderr,
|
|
"gd-png warning: image data references out-of-range"
|
|
" color index (%d)\n", i);
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
done:
|
|
if (palette_allocated) {
|
|
gdFree (palette);
|
|
}
|
|
if (image_data)
|
|
gdFree(image_data);
|
|
if (row_pointers)
|
|
gdFree(row_pointers);
|
|
|
|
return im;
|
|
|
|
error:
|
|
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
|
|
if (im) {
|
|
gdImageDestroy(im);
|
|
im = NULL;
|
|
}
|
|
goto done;
|
|
}
|
|
|
|
|
|
/*
|
|
Function: gdImagePngEx
|
|
|
|
<gdImagePngEx> outputs the specified image to the specified file in
|
|
PNG format. The file must be open for writing. Under MSDOS and all
|
|
versions of Windows, it is important to use "wb" as opposed to
|
|
simply "w" as the mode when opening the file, and under Unix there
|
|
is no penalty for doing so. <gdImagePngEx> does not close the file;
|
|
your code must do so.
|
|
|
|
In addition, <gdImagePngEx> allows the level of compression to be
|
|
specified. A compression level of 0 means "no compression." A
|
|
compression level of 1 means "compressed, but as quickly as
|
|
possible." A compression level of 9 means "compressed as much as
|
|
possible to produce the smallest possible file." A compression level
|
|
of -1 will use the default compression level at the time zlib was
|
|
compiled on your system.
|
|
|
|
Variants:
|
|
|
|
<gdImagePng> is equivalent to calling <gdImagePngEx> with
|
|
compression of -1.
|
|
|
|
<gdImagePngCtx> and <gdImagePngCtxEx> write via a <gdIOCtx>
|
|
instead of a file handle.
|
|
|
|
<gdImagePngPtr> and <gdImagePngPtrEx> store the image file to
|
|
memory.
|
|
|
|
Parameters:
|
|
|
|
im - the image to write
|
|
outFile - the output FILE* object.
|
|
level - compression level: 0 -> none, 1-9 -> level, -1 -> default
|
|
|
|
Returns:
|
|
|
|
Nothing.
|
|
|
|
Example:
|
|
(start code)
|
|
|
|
gdImagePtr im;
|
|
int black, white;
|
|
FILE *out;
|
|
|
|
im = gdImageCreate(100, 100); // Create the image
|
|
white = gdImageColorAllocate(im, 255, 255, 255); // Alloc background
|
|
black = gdImageColorAllocate(im, 0, 0, 0); // Allocate drawing color
|
|
gdImageRectangle(im, 0, 0, 99, 99, black); // Draw rectangle
|
|
out = fopen("rect.png", "wb"); // Open output file (binary)
|
|
gdImagePngEx(im, out, 9); // Write PNG, max compression
|
|
fclose(out); // Close file
|
|
gdImageDestroy(im); // Destroy image
|
|
|
|
(end code)
|
|
*/
|
|
BGD_DECLARE(void) gdImagePngEx (gdImagePtr im, FILE * outFile, int level)
|
|
{
|
|
gdIOCtx *out = gdNewFileCtx (outFile);
|
|
if (out == NULL) return;
|
|
gdImagePngCtxEx (im, out, level);
|
|
out->gd_free (out);
|
|
}
|
|
|
|
/*
|
|
Function: gdImagePng
|
|
|
|
Equivalent to calling <gdImagePngEx> with compression of -1.
|
|
|
|
Parameters:
|
|
|
|
im - the image to save.
|
|
outFile - the output FILE*.
|
|
|
|
Returns:
|
|
|
|
Nothing.
|
|
*/
|
|
BGD_DECLARE(void) gdImagePng (gdImagePtr im, FILE * outFile)
|
|
{
|
|
gdIOCtx *out = gdNewFileCtx (outFile);
|
|
if (out == NULL) return;
|
|
gdImagePngCtxEx (im, out, -1);
|
|
out->gd_free (out);
|
|
}
|
|
|
|
static int _gdImagePngCtxEx(gdImagePtr im, gdIOCtx * outfile, int level);
|
|
|
|
/*
|
|
Function: gdImagePngPtr
|
|
|
|
Equivalent to calling <gdImagePngPtrEx> with compression of -1.
|
|
|
|
See <gdImagePngEx> for more information.
|
|
|
|
Parameters:
|
|
|
|
im - the image to save.
|
|
size - Output: size in bytes of the result.
|
|
|
|
Returns:
|
|
|
|
A pointer to memory containing the image data or NULL on error.
|
|
|
|
*/
|
|
BGD_DECLARE(void *) gdImagePngPtr (gdImagePtr im, int *size)
|
|
{
|
|
void *rv;
|
|
gdIOCtx *out = gdNewDynamicCtx (2048, NULL);
|
|
if (out == NULL) return NULL;
|
|
if (!_gdImagePngCtxEx (im, out, -1)) {
|
|
rv = gdDPExtractData (out, size);
|
|
} else {
|
|
rv = NULL;
|
|
}
|
|
out->gd_free (out);
|
|
return rv;
|
|
}
|
|
|
|
/*
|
|
Function: gdImagePngPtrEx
|
|
|
|
Identical to <gdImagePngEx> except that it returns a pointer to a
|
|
memory area with the PNG data. This memory must be freed by the
|
|
caller when it is no longer needed. **The caller must invoke
|
|
gdFree(), not free()**
|
|
|
|
The 'size' parameter receives the total size of the block of
|
|
memory.
|
|
|
|
See <gdImagePngEx> for more information.
|
|
|
|
Parameters:
|
|
|
|
im - the image to save.
|
|
size - Output: size in bytes of the result.
|
|
level - compression level: 0 -> none, 1-9 -> level, -1 -> default
|
|
|
|
Returns:
|
|
|
|
A pointer to memory containing the image data or NULL on error.
|
|
|
|
*/
|
|
BGD_DECLARE(void *) gdImagePngPtrEx (gdImagePtr im, int *size, int level)
|
|
{
|
|
void *rv;
|
|
gdIOCtx *out = gdNewDynamicCtx (2048, NULL);
|
|
if (out == NULL) return NULL;
|
|
if (!_gdImagePngCtxEx (im, out, level)) {
|
|
rv = gdDPExtractData (out, size);
|
|
} else {
|
|
rv = NULL;
|
|
}
|
|
out->gd_free (out);
|
|
return rv;
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
Function: gdImagePngCtx
|
|
|
|
Equivalent to calling <gdImagePngCtxEx> with compression of -1.
|
|
See <gdImagePngEx> for more information.
|
|
|
|
Parameters:
|
|
|
|
im - the image to save.
|
|
outfile - the <gdIOCtx> to write to.
|
|
|
|
Returns:
|
|
|
|
Nothing.
|
|
|
|
*/
|
|
BGD_DECLARE(void) gdImagePngCtx (gdImagePtr im, gdIOCtx * outfile)
|
|
{
|
|
/* 2.0.13: 'return' here was an error, thanks to Kevin Smith */
|
|
gdImagePngCtxEx (im, outfile, -1);
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
Function: gdImagePngCtxEx
|
|
|
|
Outputs the given image as PNG data, but using a <gdIOCtx> instead
|
|
of a file. See <gdIamgePnEx>.
|
|
|
|
Parameters:
|
|
|
|
im - the image to save.
|
|
outfile - the <gdIOCtx> to write to.
|
|
level - compression level: 0 -> none, 1-9 -> level, -1 -> default
|
|
|
|
Returns:
|
|
|
|
Nothing.
|
|
|
|
*/
|
|
BGD_DECLARE(void) gdImagePngCtxEx (gdImagePtr im, gdIOCtx * outfile, int level)
|
|
{
|
|
_gdImagePngCtxEx(im, outfile, level);
|
|
}
|
|
|
|
/* This routine is based in part on code from Dale Lutz (Safe Software Inc.)
|
|
* and in part on demo code from Chapter 15 of "PNG: The Definitive Guide"
|
|
* (http://www.libpng.org/pub/png/book/).
|
|
*/
|
|
/* returns 0 on success, 1 on failure */
|
|
static int _gdImagePngCtxEx(gdImagePtr im, gdIOCtx * outfile, int level)
|
|
{
|
|
int i, j, bit_depth = 0, interlace_type;
|
|
int width = im->sx;
|
|
int height = im->sy;
|
|
int colors = im->colorsTotal;
|
|
int *open = im->open;
|
|
int mapping[gdMaxColors]; /* mapping[gd_index] == png_index */
|
|
png_byte trans_values[256];
|
|
png_color_16 trans_rgb_value;
|
|
png_color palette[gdMaxColors];
|
|
png_structp png_ptr;
|
|
png_infop info_ptr;
|
|
png_bytep *row_pointers = NULL;
|
|
volatile int transparent = im->transparent;
|
|
volatile int remap = FALSE;
|
|
#ifdef PNG_SETJMP_SUPPORTED
|
|
jmpbuf_wrapper jbw;
|
|
#endif
|
|
int ret = 0;
|
|
|
|
/* width or height of value 0 is invalid in IHDR;
|
|
see http://www.w3.org/TR/PNG-Chunks.html */
|
|
if (width == 0 || height ==0) return 1;
|
|
|
|
#ifdef PNG_SETJMP_SUPPORTED
|
|
png_ptr = png_create_write_struct (PNG_LIBPNG_VER_STRING,
|
|
&jbw, gdPngErrorHandler,
|
|
gdPngWarningHandler);
|
|
#else
|
|
png_ptr = png_create_write_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
|
|
#endif
|
|
if (png_ptr == NULL) {
|
|
gd_error("gd-png error: cannot allocate libpng main struct\n");
|
|
return 1;
|
|
}
|
|
|
|
info_ptr = png_create_info_struct (png_ptr);
|
|
if (info_ptr == NULL) {
|
|
gd_error("gd-png error: cannot allocate libpng info struct\n");
|
|
png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
|
|
return 1;
|
|
}
|
|
|
|
#ifdef PNG_SETJMP_SUPPORTED
|
|
if (setjmp(jbw.jmpbuf)) {
|
|
gd_error("gd-png error: setjmp returns error condition\n");
|
|
png_destroy_write_struct (&png_ptr, &info_ptr);
|
|
|
|
if (row_pointers) {
|
|
for (i = 0; i < height; ++i)
|
|
gdFree(row_pointers[i]);
|
|
gdFree(row_pointers);
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
#endif
|
|
|
|
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. */
|
|
|
|
/* Faster if this is uncommented, but may produce larger truecolor files.
|
|
Wait for gdImagePngCtxEx. */
|
|
#if 0
|
|
png_set_filter (png_ptr, 0, PNG_FILTER_NONE);
|
|
#endif
|
|
|
|
/* 2.0.12: this is finally a parameter */
|
|
png_set_compression_level (png_ptr, level);
|
|
|
|
#ifdef PNG_pHYs_SUPPORTED
|
|
/* 2.1.0: specify the resolution */
|
|
png_set_pHYs(png_ptr, info_ptr, DPI2DPM(im->res_x), DPI2DPM(im->res_y),
|
|
PNG_RESOLUTION_METER);
|
|
#endif
|
|
|
|
/* 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 == 0) {
|
|
gd_error("gd-png error: no colors in palette\n");
|
|
ret = 1;
|
|
goto bail;
|
|
}
|
|
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)) {
|
|
/* 2.0.9: fixed by Thomas Winzig */
|
|
trans_rgb_value.red = gdTrueColorGetRed (im->transparent);
|
|
trans_rgb_value.green = gdTrueColorGetGreen (im->transparent);
|
|
trans_rgb_value.blue = gdTrueColorGetBlue (im->transparent);
|
|
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] >> 6));
|
|
}
|
|
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) {
|
|
/* Andrew Hull: >> 6, not >> 7! (gd 2.0.5) */
|
|
trans_values[j] = 255 -
|
|
((im->alpha[i] << 1) + (im->alpha[i] >> 6));
|
|
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) {
|
|
/* performance optimizations by Phong Tran */
|
|
int channels = im->saveAlphaFlag ? 4 : 3;
|
|
/* Our little 7-bit alpha channel trick costs us a bit here. */
|
|
unsigned char *pOutputRow;
|
|
int **ptpixels = im->tpixels;
|
|
int *pThisRow;
|
|
unsigned char a;
|
|
int thisPixel;
|
|
png_bytep *prow_pointers;
|
|
int saveAlphaFlag = im->saveAlphaFlag;
|
|
if (overflow2(sizeof (png_bytep), height)) {
|
|
ret = 1;
|
|
goto bail;
|
|
}
|
|
/* Need to use calloc so we can clean it up sanely in the error handler. */
|
|
row_pointers = gdCalloc(height, sizeof (png_bytep));
|
|
if (row_pointers == NULL) {
|
|
gd_error("gd-png error: unable to allocate row_pointers\n");
|
|
ret = 1;
|
|
goto bail;
|
|
}
|
|
prow_pointers = row_pointers;
|
|
for (j = 0; j < height; ++j) {
|
|
if (overflow2(width, channels) || ((*prow_pointers =
|
|
(png_bytep) gdMalloc (width * channels)) == NULL)) {
|
|
gd_error("gd-png error: unable to allocate rows\n");
|
|
for (i = 0; i < j; ++i)
|
|
gdFree (row_pointers[i]);
|
|
/* 2.0.29: memory leak TBB */
|
|
gdFree(row_pointers);
|
|
ret = 1;
|
|
goto bail;
|
|
}
|
|
pOutputRow = *prow_pointers++;
|
|
pThisRow = *ptpixels++;
|
|
for (i = 0; i < width; ++i) {
|
|
thisPixel = *pThisRow++;
|
|
*pOutputRow++ = gdTrueColorGetRed (thisPixel);
|
|
*pOutputRow++ = gdTrueColorGetGreen (thisPixel);
|
|
*pOutputRow++ = gdTrueColorGetBlue (thisPixel);
|
|
|
|
if (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 (thisPixel);
|
|
/* Andrew Hull: >> 6, not >> 7! (gd 2.0.5) */
|
|
*pOutputRow++ = 255 - ((a << 1) + (a >> 6));
|
|
}
|
|
}
|
|
}
|
|
|
|
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;
|
|
if (overflow2(sizeof (png_bytep), height)) {
|
|
ret = 1;
|
|
goto bail;
|
|
}
|
|
row_pointers = gdMalloc (sizeof (png_bytep) * height);
|
|
if (row_pointers == NULL) {
|
|
gd_error("gd-png error: unable to allocate row_pointers\n");
|
|
ret = 1;
|
|
goto bail;
|
|
}
|
|
for (j = 0; j < height; ++j) {
|
|
if ((row_pointers[j] = (png_bytep) gdMalloc (width)) == NULL) {
|
|
gd_error("gd-png error: unable to allocate rows\n");
|
|
for (i = 0; i < j; ++i)
|
|
gdFree (row_pointers[i]);
|
|
/* TBB: memory leak */
|
|
gdFree (row_pointers);
|
|
ret = 1;
|
|
goto bail;
|
|
}
|
|
for (i = 0; i < width; ++i)
|
|
row_pointers[j][i] = mapping[im->pixels[j][i]];
|
|
}
|
|
|
|
png_write_image (png_ptr, row_pointers);
|
|
|
|
for (j = 0; j < height; ++j)
|
|
gdFree (row_pointers[j]);
|
|
gdFree (row_pointers);
|
|
|
|
png_write_end (png_ptr, info_ptr);
|
|
} 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 */
|
|
bail:
|
|
png_destroy_write_struct (&png_ptr, &info_ptr);
|
|
return ret;
|
|
}
|
|
|
|
#else /* !HAVE_LIBPNG */
|
|
|
|
static void _noPngError(void)
|
|
{
|
|
gd_error("PNG image support has been disabled\n");
|
|
}
|
|
|
|
BGD_DECLARE(gdImagePtr) gdImageCreateFromPng (FILE * inFile)
|
|
{
|
|
ARG_NOT_USED(inFile);
|
|
_noPngError();
|
|
return NULL;
|
|
}
|
|
|
|
BGD_DECLARE(gdImagePtr) gdImageCreateFromPngPtr (int size, void *data)
|
|
{
|
|
ARG_NOT_USED(size);
|
|
ARG_NOT_USED(data);
|
|
return NULL;
|
|
}
|
|
|
|
BGD_DECLARE(gdImagePtr) gdImageCreateFromPngCtx (gdIOCtx * infile)
|
|
{
|
|
ARG_NOT_USED(infile);
|
|
return NULL;
|
|
}
|
|
|
|
BGD_DECLARE(void) gdImagePngEx (gdImagePtr im, FILE * outFile, int level)
|
|
{
|
|
ARG_NOT_USED(im);
|
|
ARG_NOT_USED(outFile);
|
|
ARG_NOT_USED(level);
|
|
_noPngError();
|
|
}
|
|
|
|
BGD_DECLARE(void) gdImagePng (gdImagePtr im, FILE * outFile)
|
|
{
|
|
ARG_NOT_USED(im);
|
|
ARG_NOT_USED(outFile);
|
|
_noPngError();
|
|
}
|
|
|
|
BGD_DECLARE(void *) gdImagePngPtr (gdImagePtr im, int *size)
|
|
{
|
|
ARG_NOT_USED(im);
|
|
ARG_NOT_USED(size);
|
|
return NULL;
|
|
}
|
|
|
|
BGD_DECLARE(void *) gdImagePngPtrEx (gdImagePtr im, int *size, int level)
|
|
{
|
|
ARG_NOT_USED(im);
|
|
ARG_NOT_USED(size);
|
|
ARG_NOT_USED(level);
|
|
return NULL;
|
|
}
|
|
|
|
BGD_DECLARE(void) gdImagePngCtx (gdImagePtr im, gdIOCtx * outfile)
|
|
{
|
|
ARG_NOT_USED(im);
|
|
ARG_NOT_USED(outfile);
|
|
_noPngError();
|
|
}
|
|
|
|
BGD_DECLARE(void) gdImagePngCtxEx (gdImagePtr im, gdIOCtx * outfile, int level)
|
|
{
|
|
ARG_NOT_USED(im);
|
|
ARG_NOT_USED(outfile);
|
|
ARG_NOT_USED(level);
|
|
_noPngError();
|
|
}
|
|
|
|
#endif /* HAVE_LIBPNG */
|