Decode Bomb Jack tile ROMs into PNGs

bombjack_decode.c

#include <stdint.h>
#include "bombjack-roms.h"
#define STB_IMAGE_WRITE_IMPLEMENTATION
#include "stb_image_write.h"

#define BYTES_PER_PIXEL (3)

uint8_t buf[256 * 256 * BYTES_PER_PIXEL];
uint8_t buf_x4[1024 * 1024 * BYTES_PER_PIXEL];

void decode(int w, int h, uint8_t* rom0, uint8_t* rom1, uint8_t* rom2) {
    for (int y = 0; y < h; y++) {
        for (int x = 0; x < w; x++) {
            int tile_index = y * w + x;
            for (int yy = 0; yy < 8; yy++) {
                uint8_t bm0 = rom0[tile_index * 8 + yy];
                uint8_t bm1 = rom1[tile_index * 8 + yy];
                uint8_t bm2 = rom2[tile_index * 8 + yy];
                int py = y*8 + yy;
                int px = x*8;
                uint8_t* ptr = buf + (py*w*8 + px) * BYTES_PER_PIXEL;
                for (int xx=7; xx>=0; xx--) {
                    uint8_t pen = ((bm2>>xx)&1) | (((bm1>>xx)&1)<<1) | (((bm0>>xx)&1)<<2);
                    uint8_t c = pen << 5;
                    *ptr++ = c;
                    *ptr++ = c;
                    *ptr++ = c;
                }
            }
        }
    }
}

void resize() {
    for (uint32_t y = 0; y < 1024; y++) {
        for (uint32_t x = 0; x < 1024; x++) {
            uint32_t x0 = x>>2;
            uint32_t y0 = y>>2;
            uint8_t* src = buf + (y0*256 + x0) * BYTES_PER_PIXEL;
            uint8_t* dst = buf_x4 + (y*1024 + x)  * BYTES_PER_PIXEL;
            for (int i = 0; i < BYTES_PER_PIXEL; i++) {
                *dst++ = *src++;
            }
        }
    }
}

int main() {
    // foreground tiles
    decode(32, 16, dump_03_e08t, dump_04_h08t, dump_05_k08t);
    resize();
    stbi_write_png("bombjack_fg.png", 1024, 512, 3, buf_x4, 1024*3);
    // background tiles
    decode(32, 32, dump_06_l08t, dump_07_n08t, dump_08_r08t);
    resize();
    stbi_write_png("bombjack_bg.png", 1024, 1024, 3, buf_x4, 1024*3);
    // sprite tiles
    decode(32, 32, dump_16_m07b, dump_15_l07b, dump_14_j07b);
    resize();
    stbi_write_png("bombjack_sprites.png", 1024, 1024, 3, buf_x4, 1024*3);
    return 0;
}

Generated images:

Foreground Layer Tiles:

Background Layer Tiles:

Sprite Generator Tiles: