rex_fill_rect
rex_fill_rect(dc, 0, 0, LIGHT_XRES - 1, LIGHT_YRES - 1, 0);
rex_fill_rect(c, from_x, from_y, to_x, to_y, attr);
rex_fill_rect(c, from_x, from_y, to_x, to_y, attr);
rex_fill_rect(c, 0, 0, LIGHT_XRES-1, LIGHT_YRES-1, 0);