#define PROGRAM_NAME "png_dimensions" #define USAGE_OPTS "front.png front.dimensions" #include "common.h" uint8_t read_png_dimensions(const char *filename) { uint32_t width_px = read_png_width(filename); if (width_px != 40 && width_px != 48 && width_px != 56) { error_exit("Not a valid width for \"%s\": %" PRIu32 " px\n", filename, width_px); } uint8_t width_tiles = (uint8_t)(width_px / 8); return (width_tiles << 4) | width_tiles; } int main(int argc, char *argv[]) { if (argc < 3) { usage_exit(1); } uint8_t output_byte = read_png_dimensions(argv[1]); write_u8(argv[2], &output_byte, 1); return 0; }