struct bmap32 {
    struct rect f;
    int32_t rows[32];
};
typedef struct bmap32 bmap32;

void draw_32(struct widget *w, bmap32 *m) {
    for (int x = 0; x < m->f.size.x && x + m->f.start.x < w->frame.size.x; ++x) {
        for (int y = 0; y < m->f.size.y && y + m->f.start.y < w->frame.size.y; ++y) {
            set_pixel(w, x + m->f.start.x, y + m->f.start.y, (m->rows[y] & (0x1 << (31 - x))) ? 0xff : 0x00);
        }
    }
}

// To use:
draw_32(w, &(bmap32){
    { .start = { 2, 6}, .size = { 5, 3 } },
    .rows = {
        0b0010000000000000 << 16,
        0b0111000000000000 << 16,
        0b1111100000000000 << 16,
    }
});