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#include "fitz.h"
#include "muxps.h"
#include <png.h>
/*
* PNG using libpng directly (no gs wrappers)
*/
struct xps_png_io_s
{
byte *ptr;
byte *lim;
};
static void
xps_png_read(png_structp png, png_bytep data, png_size_t length)
{
struct xps_png_io_s *io = png_get_io_ptr(png);
if (io->ptr + length > io->lim)
png_error(png, "Read Error");
memcpy(data, io->ptr, length);
io->ptr += length;
}
static png_voidp
xps_png_malloc(png_structp png, png_size_t size)
{
return fz_malloc(size);
}
static void
xps_png_free(png_structp png, png_voidp ptr)
{
fz_free(ptr);
}
/* This only determines if we have an alpha value */
int
xps_png_has_alpha(xps_context *ctx, byte *rbuf, int rlen)
{
png_structp png;
png_infop info;
struct xps_png_io_s io;
int has_alpha;
/*
* Set up PNG structs and input source
*/
io.ptr = rbuf;
io.lim = rbuf + rlen;
png = png_create_read_struct_2(PNG_LIBPNG_VER_STRING,
NULL, NULL, NULL,
ctx, xps_png_malloc, xps_png_free);
if (!png) {
fz_warn("png_create_read_struct");
return 0;
}
info = png_create_info_struct(png);
if (!info) {
fz_warn("png_create_info_struct");
return 0;
}
png_set_read_fn(png, &io, xps_png_read);
png_set_crc_action(png, PNG_CRC_WARN_USE, PNG_CRC_WARN_USE);
/*
* Jump to here on errors.
*/
if (setjmp(png_jmpbuf(png)))
{
png_destroy_read_struct(&png, &info, NULL);
fz_warn("png reading failed");
return 0;
}
/*
* Read PNG header
*/
png_read_info(png, info);
switch (png_get_color_type(png, info))
{
case PNG_COLOR_TYPE_PALETTE:
case PNG_COLOR_TYPE_GRAY:
case PNG_COLOR_TYPE_RGB:
has_alpha = 0;
break;
case PNG_COLOR_TYPE_GRAY_ALPHA:
case PNG_COLOR_TYPE_RGB_ALPHA:
has_alpha = 1;
break;
default:
fz_warn("cannot handle this png color type");
has_alpha = 0;
break;
}
/*
* Clean up memory.
*/
png_destroy_read_struct(&png, &info, NULL);
return has_alpha;
}
int
xps_decode_png(xps_context *ctx, byte *rbuf, int rlen, xps_image *image)
{
png_structp png;
png_infop info;
struct xps_png_io_s io;
int npasses;
int pass;
int y;
/*
* Set up PNG structs and input source
*/
io.ptr = rbuf;
io.lim = rbuf + rlen;
png = png_create_read_struct_2(PNG_LIBPNG_VER_STRING,
NULL, NULL, NULL,
ctx, xps_png_malloc, xps_png_free);
if (!png)
return fz_throw("png_create_read_struct");
info = png_create_info_struct(png);
if (!info)
return fz_throw("png_create_info_struct");
png_set_read_fn(png, &io, xps_png_read);
png_set_crc_action(png, PNG_CRC_WARN_USE, PNG_CRC_WARN_USE);
/*
* Jump to here on errors.
*/
if (setjmp(png_jmpbuf(png)))
{
png_destroy_read_struct(&png, &info, NULL);
return fz_throw("png reading failed");
}
/*
* Read PNG header
*/
png_read_info(png, info);
if (png_get_interlace_type(png, info) == PNG_INTERLACE_ADAM7)
{
npasses = png_set_interlace_handling(png);
}
else
{
npasses = 1;
}
if (png_get_color_type(png, info) == PNG_COLOR_TYPE_PALETTE)
{
png_set_palette_to_rgb(png);
}
if (png_get_valid(png, info, PNG_INFO_tRNS))
{
/* this will also expand the depth to 8-bits */
png_set_tRNS_to_alpha(png);
}
png_read_update_info(png, info);
image->width = png_get_image_width(png, info);
image->height = png_get_image_height(png, info);
image->comps = png_get_channels(png, info);
image->bits = png_get_bit_depth(png, info);
/* See if we have an icc profile */
if (info->iccp_profile != NULL)
{
image->profilesize = info->iccp_proflen;
image->profile = fz_malloc(info->iccp_proflen);
if (image->profile)
{
/* If we can't create it, just ignore */
memcpy(image->profile, info->iccp_profile, info->iccp_proflen);
}
}
switch (png_get_color_type(png, info))
{
case PNG_COLOR_TYPE_GRAY:
image->colorspace = fz_devicegray;
image->hasalpha = 0;
break;
case PNG_COLOR_TYPE_RGB:
image->colorspace = fz_devicergb;
image->hasalpha = 0;
break;
case PNG_COLOR_TYPE_GRAY_ALPHA:
image->colorspace = fz_devicegray;
image->hasalpha = 1;
break;
case PNG_COLOR_TYPE_RGB_ALPHA:
image->colorspace = fz_devicergb;
image->hasalpha = 1;
break;
default:
return fz_throw("cannot handle this png color type");
}
/*
* Extract DPI, default to 96 dpi
*/
image->xres = 96;
image->yres = 96;
if (info->valid & PNG_INFO_pHYs)
{
png_uint_32 xres, yres;
int unit;
png_get_pHYs(png, info, &xres, &yres, &unit);
if (unit == PNG_RESOLUTION_METER)
{
image->xres = xres * 0.0254 + 0.5;
image->yres = yres * 0.0254 + 0.5;
}
}
/*
* Read rows, filling transformed output into image buffer.
*/
image->stride = (image->width * image->comps * image->bits + 7) / 8;
image->samples = fz_calloc(image->height, image->stride);
for (pass = 0; pass < npasses; pass++)
{
for (y = 0; y < image->height; y++)
{
png_read_row(png, image->samples + (y * image->stride), NULL);
}
}
/*
* Clean up memory.
*/
png_destroy_read_struct(&png, &info, NULL);
return fz_okay;
}
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