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/*
* gentexture.c
*
* Generate normal map stuff
*
* (c) 2008 Thomas White <taw27@cam.ac.uk>
*
* thrust3d - a silly game
*
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <png.h>
#include <stdlib.h>
#include <stdint.h>
int main(int argc, char *argv[]) {
FILE *fh;
png_bytep header;
png_structp png_ptr;
png_infop info_ptr;
png_infop end_info;
unsigned int width;
unsigned int height;
unsigned int bit_depth;
unsigned int channels;
png_bytep *row_pointers;
unsigned int x;
unsigned int y;
uint8_t *texels;
char *filename;
char *outfilename;
filename = argv[1];
outfilename = argv[2];
/* Open file */
fh = fopen(filename, "rb");
if ( !fh ) {
fprintf(stderr, "Couldn't open texture file '%s'\n", filename);
return 1;
}
/* Check it's actually a PNG file */
header = malloc(8);
fread(header, 1, 8, fh);
if ( png_sig_cmp(header, 0, 8)) {
fprintf(stderr, "Texture file '%s' is not a PNG file.\n", filename);
free(header);
fclose(fh);
return 1;
}
free(header);
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if ( !png_ptr ) {
fprintf(stderr, "Couldn't create PNG read structure.\n");
fclose(fh);
return 1;
}
info_ptr = png_create_info_struct(png_ptr);
if ( !info_ptr ) {
png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL);
fprintf(stderr, "Couldn't create PNG info structure.\n");
fclose(fh);
return 1;
}
end_info = png_create_info_struct(png_ptr);
if ( !end_info ) {
png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
printf("Couldn't create PNG end info structure.\n");
fclose(fh);
return 1;
}
if ( setjmp(png_jmpbuf(png_ptr)) ) {
png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
fclose(fh);
fprintf(stderr, "PNG read failed.\n");
return 1;
}
png_init_io(png_ptr, fh);
png_set_sig_bytes(png_ptr, 8);
/* Read! */
png_read_png(png_ptr, info_ptr, PNG_TRANSFORM_IDENTITY, NULL);
width = png_get_image_width(png_ptr, info_ptr);
height = png_get_image_height(png_ptr, info_ptr);
bit_depth = png_get_bit_depth(png_ptr, info_ptr);
channels = png_get_channels(png_ptr, info_ptr);
if ( bit_depth != 8 ) {
fprintf(stderr, "Texture image '%s' doesn't have 8 bits per channel per pixel.\n", filename);
png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
fclose(fh);
return 1;
}
if ( channels != 4 ) {
fprintf(stderr, "Texture image '%s' doesn't have 4 channels.\n", filename);
png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
fclose(fh);
return 1;
}
/* Get image data */
row_pointers = png_get_rows(png_ptr, info_ptr);
texels = malloc(4*width*height);
for ( y=0; y<height; y++ ) {
for ( x=0; x<width; x++ ) {
unsigned int r, g, b, a;
r = row_pointers[y][(channels*x)+0];
g = row_pointers[y][(channels*x)+1];
b = row_pointers[y][(channels*x)+2];
a = row_pointers[y][(channels*x)+3];
texels[4*(x + width*(height-1-y)) + 0] = r;
texels[4*(x + width*(height-1-y)) + 1] = g;
texels[4*(x + width*(height-1-y)) + 2] = b;
texels[4*(x + width*(height-1-y)) + 3] = a;
}
}
png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
fclose(fh);
fh = fopen(outfilename, "wb");
if (!fh) {
fprintf(stderr, "Couldn't open output file.\n");
return 1;
}
png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if ( !png_ptr ) {
fprintf(stderr, "Couldn't create PNG write structure.\n");
fclose(fh);
return 1;
}
info_ptr = png_create_info_struct(png_ptr);
if ( !info_ptr ) {
png_destroy_write_struct(&png_ptr, (png_infopp)NULL);
fprintf(stderr, "Couldn't create PNG info structure.\n");
fclose(fh);
return 1;
}
if ( setjmp(png_jmpbuf(png_ptr)) ) {
png_destroy_write_struct(&png_ptr, &info_ptr);
fclose(fh);
fprintf(stderr, "PNG write failed.\n");
return 1;
}
png_init_io(png_ptr, fh);
png_set_IHDR(png_ptr, info_ptr, width, height, 8, PNG_COLOR_TYPE_RGBA, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
/* Write the image data */
row_pointers = malloc(height*sizeof(png_bytep *));
for ( y=0; y<height; y++ ) {
row_pointers[y] = malloc(width*4);
for ( x=0; x<width; x++ ) {
row_pointers[y][4*x+0] = texels[4*(x + width*(height-1-y)) + 0];
row_pointers[y][4*x+1] = texels[4*(x + width*(height-1-y)) + 1];
row_pointers[y][4*x+2] = texels[4*(x + width*(height-1-y)) + 2];
row_pointers[y][4*x+3] = texels[4*(x + width*(height-1-y)) + 3];
}
}
png_set_rows(png_ptr, info_ptr, row_pointers);
png_write_png(png_ptr, info_ptr, PNG_TRANSFORM_IDENTITY, NULL);
png_destroy_write_struct(&png_ptr, &info_ptr);
for ( y=0; y<height; y++ ) {
free(row_pointers[y]);
}
free(row_pointers);
fclose(fh);
free(texels);
return 0;
}
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