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#include <stdio.h>
#include <stdlib.h>
#include <SDL.h>
#include "../sdl/util.h"
#define STB_IMAGE_IMPLEMENTATION
#define STB_ASSERT(x)
#define STB_ONLY_PNG
#include "../sdl/stb_image.h"
typedef struct {
const Uint32 r,
g,
b,
a;
} mask_t;
#if SDL_BYTEORDER == SDL_BIG_ENDIAN
static const mask_t
MASK = { 0xff000000, 0x00ff0000, 0x0000ff00, 0x000000ff };
#else
static const mask_t
MASK = { 0x000000ff, 0x0000ff00, 0x00ff0000, 0xff000000 };
#endif /* SDL_BYTEORDER */
static SDL_Surface *
load_image(
const char * const png_path
) {
// load image
int x, y, n;
unsigned char * const data = stbi_load(png_path, &x, &y, &n, 4);
if (!data) {
die("stbi_load()");
}
// create surface
SDL_Surface *src = SDL_CreateRGBSurfaceFrom(data, x, y, 32, 4 * x, MASK.r, MASK.g, MASK.b, MASK.a);
if (!src) {
die("SDLCreateRGBSurfaceFrom(): %s", SDL_GetError());
}
// free image data
free(data);
// return surface
return src;
}
int main(int argc, char *argv[]) {
// check cli
if (argc < 3) {
printf("Usage: %s out.bmp <src_images...>", argv[0]);
exit(EXIT_FAILURE);
}
// create output surface
SDL_Surface *dst = SDL_CreateRGBSurfaceWithFormat(0, 256, 256, 32, SDL_PIXELFORMAT_RGBA32);
if (!dst) {
die("SDl_CreateRGBSurfaceWithFormat(): %s", SDL_GetError());
}
// walk input images
for (size_t i = 2; i < argc; i++) {
// load image
SDL_Surface * const src = load_image(argv[i]);
// copy/scale image
SDL_Rect dst_rect = { (i - 2) * 32, 0, 32, 32 };
if (SDL_BlitScaled(src, NULL, dst, &dst_rect)) {
die("SDL_BlitScaled(): %s", SDL_GetError());
}
// free surface
SDL_FreeSurface(src);
}
// save to output path
if (SDL_SaveBMP(dst, argv[1])) {
die("SDL_SaveBMP(): %s", SDL_GetError());
}
// free dst surface
SDL_FreeSurface(dst);
// return success
return EXIT_SUCCESS;
}
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