1 files changed, 87 insertions, 0 deletions
diff --git a/src/sprite-packer/main.c b/src/sprite-packer/main.c
new file mode 100644
index 0000000..945fa51
--- /dev/null
+++ b/src/sprite-packer/main.c
@@ -0,0 +1,87 @@
+#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;
+}