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/*
* Based on libpng's example.c (so it needs libpng)
*/
#include <stdio.h>
#include <stdlib.h>
#include <png.h>
#include "png_image.h"
#include "../exception.h"
#include "../demolib_prefs.h"
#if DEMOLIB_IMAGE_PNG
/* ugly, but works (unless there is corrupted data :-D) */
char *curr_png_ptr = NULL;
void read_mem(png_structp png_ptr, png_bytep data, png_size_t length)
{
memcpy(data, curr_png_ptr, length);
curr_png_ptr += length;
}
PNGImage::PNGImage(File *file)
{
png_structp png_ptr;
png_infop info_ptr;
int bit_depth, color_type, interlace_type;
// png_color_16 my_background, *image_background;
png_info intent;
png_bytep *row_pointers;
float screen_gamma;
unsigned int row;
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (png_ptr == NULL) {
throw new FatalException("png_create_read_struct() failed");
}
/* Allocate/initialize the memory for image information. */
info_ptr = png_create_info_struct(png_ptr);
if (info_ptr == NULL) {
png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL);
throw new FatalException("png_create_info_struct() failed");
}
/* Set up error handling. */
if (setjmp(png_ptr->jmpbuf)) {
png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
throw new FatalException("PNG decompression failed");
}
/* Set up the memory reader. */
curr_png_ptr = file->get_data();
png_set_read_fn(png_ptr, NULL, read_mem);
png_uint_32 width, height;
png_read_info(png_ptr, info_ptr);
png_get_IHDR(png_ptr, info_ptr,
&width, &height,
&bit_depth, &color_type, &interlace_type, NULL, NULL);
this->width = width;
this->height = height;
if (color_type == PNG_COLOR_TYPE_GRAY) {
this->bpp = 8;
}
if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
this->bpp = 16;
}
if (color_type == PNG_COLOR_TYPE_PALETTE) {
this->bpp = 32;
}
if (color_type == PNG_COLOR_TYPE_RGB) {
this->bpp = 24;
}
if (color_type == PNG_COLOR_TYPE_RGBA) {
this->bpp = 32;
}
/* Allocate memory if needed */
this->image_buf = (unsigned char *)(malloc(this->width * this->height * this->bpp / 8));
if (this->image_buf == NULL) {
throw new FatalException("Couldn't allocate memory for JPEG image");
}
// png_set_strip_16(png_ptr);
png_set_packing(png_ptr);
if (color_type == PNG_COLOR_TYPE_PALETTE)
png_set_expand(png_ptr);
if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
png_set_expand(png_ptr);
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
png_set_expand(png_ptr);
/* if (png_get_bKGD(png_ptr, info_ptr, &image_background))
png_set_background(png_ptr, image_background,
PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
else
png_set_background(png_ptr, &my_background,
PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0); */
screen_gamma = 2.2;
if (png_get_sRGB(png_ptr, info_ptr, (int *)(&intent))) {
png_set_sRGB(png_ptr, &intent, 0);
} else {
double image_gamma;
if (png_get_gAMA(png_ptr, info_ptr, &image_gamma))
png_set_gamma(png_ptr, screen_gamma, image_gamma);
else
png_set_gamma(png_ptr, screen_gamma, 0.45455);
}
// png_set_bgr(png_ptr);
/* if (color_type != PNG_COLOR_TYPE_RGBA)
png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER); */
/* Allocate the row pointers (ick!) */
row_pointers = (png_bytep *)(malloc(sizeof(png_bytep) * this->height));
if (row_pointers == NULL) {
throw new FatalException("Out of memory");
}
for (row = 0; row < height; row++) {
row_pointers[row] = this->image_buf + (this->width * row * this->bpp / 8);
}
/* Read the image in one pass. */
png_read_image(png_ptr, row_pointers);
free(row_pointers);
png_read_end(png_ptr, info_ptr);
png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
}
PNGImage::~PNGImage()
{
free(this->image_buf);
}
unsigned char *PNGImage::get_pixel_data()
{
return this->image_buf;
}
#endif /* DEMOLIB_IMAGE_PNG */
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