fix rgb order

[saturn.git] / vdp1_to_png.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <png.h>

#define WIDTH 512
#define HEIGHT 256

static unsigned short work_buf[WIDTH * HEIGHT];

static int writepng(const char *fname, const unsigned short *src)
{
	png_structp png_ptr = NULL;
	png_infop info_ptr = NULL;
	png_bytepp row_pointers;
	int i, j, ret = -1;
	FILE *f;

	f = fopen(fname, "wb");
	if (f == NULL) {
		printf(__FILE__ ": failed to open \"%s\"\n", fname);
		return -1;
	}

	row_pointers = calloc(HEIGHT, sizeof(row_pointers[0]));
	if (row_pointers == NULL)
		goto end1;

	for (i = 0; i < HEIGHT; i++) {
		unsigned char *dst = malloc(WIDTH * 3);
		if (dst == NULL)
			goto end2;
		row_pointers[i] = dst;
		for (j = 0; j < WIDTH; j++, src++, dst += 3) {
			unsigned short v = (*src >> 8) | (*src << 8);
			dst[0] = (v & 0x001f) << 3; // r
			dst[1] = (v & 0x03e0) >> 2; // g
			dst[2] = (v & 0x7c00) >> 7; // b
		}
	}

	/* initialize stuff */
	png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
	if (png_ptr == NULL) {
		fprintf(stderr, "png_create_write_struct() failed");
		goto end2;
	}

	info_ptr = png_create_info_struct(png_ptr);
	if (info_ptr == NULL) {
		fprintf(stderr, "png_create_info_struct() failed");
		goto end3;
	}

	if (setjmp(png_jmpbuf(png_ptr)) != 0) {
		fprintf(stderr, "error in png code\n");
		goto end4;
	}

	png_init_io(png_ptr, f);

	png_set_IHDR(png_ptr, info_ptr, WIDTH, HEIGHT,
		8, PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE,
		PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);

	png_write_info(png_ptr, info_ptr);
	png_write_image(png_ptr, row_pointers);
	png_write_end(png_ptr, NULL);

	ret = 0;

end4:
//	png_destroy_info_struct(png_ptr, &info_ptr); // freed below
end3:
	png_destroy_write_struct(&png_ptr, &info_ptr);
end2:
	for (i = 0; i < HEIGHT; i++)
		free(row_pointers[i]);
	free(row_pointers);
end1:
	fclose(f);
	return ret;
}

int main(int argc, char *argv[])
{
	FILE *f;

	if (argc != 3) {
		printf("usage:\n%s <fb_dump> <png>\n", argv[0]);
		return 1;
	}

	f = fopen(argv[1], "rb");
	if (!f) {
		perror("fopen fb_dump");
		return 1;
	}

	if (fread(work_buf, 1, sizeof(work_buf), f) != sizeof(work_buf))
		printf("read error?\n");

	writepng(argv[2], work_buf);
	return 0;
}