1 files changed, 51 insertions, 0 deletions
diff --git a/pxpal.c b/pxpal.c
new file mode 100644
index 0000000..83f736c
--- /dev/null
+++ b/pxpal.c
@@ -0,0 +1,51 @@
+#include <stdint.h>
+#include <stdio.h>
+#define STB_IMAGE_IMPLEMENTATION
+#include "stb_image.h"
+
+int
+main(int argc, char **argv) {
+	if (argc != 2) {
+		fprintf(stderr, "usage: %s palette.png\n",
+		        argv[0]);
+		return 1;
+	}
+
+	int pal_w, pal_h, pal_col_chans;
+	uint8_t *const pal_data =
+	    stbi_load(argv[1], &pal_w, &pal_h, &pal_col_chans, 3);
+
+	if (pal_data == NULL) {
+		fprintf(stderr, "error: failed to load palette\n");
+		return 1;
+	}
+	if (pal_col_chans != 3) {
+		fprintf(stderr, "error: palette isn't RGB\n");
+		stbi_image_free(pal_data);
+		return 1;
+	}
+	if (pal_w * pal_h == 0) {
+		fprintf(stderr, "error: palette size is 0\n");
+		stbi_image_free(pal_data);
+		return 1;
+	}
+	if (pal_w * pal_h >= 256) {
+		fprintf(stderr, "error: palette size is greater than 255\n");
+		stbi_image_free(pal_data);
+		return 1;
+	}
+
+	printf("#include \"px.h\"\n\n"
+	       "__attribute__((constructor))\n"
+	       "static void set_pxpal(void)\n"
+	       "{\n");
+	for (int i = 0; i < pal_w * pal_h; i++) {
+		printf("\tpxpal[%d].r = %u; "
+		       "pxpal[%d].g = %u; "
+		       "pxpal[%d].b = %u;\n",
+		       i, (unsigned)pal_data[i * 3],
+		       i, (unsigned)pal_data[i * 3 + 1],
+		       i, (unsigned)pal_data[i * 3 + 2]);
+	}
+	printf("}\n");
+}