layout (std140) uniform BackgroundLayerUBO {
    highp vec2 u_pattern_tl_a;
    highp vec2 u_pattern_br_a;
    highp vec2 u_pattern_tl_b;
    highp vec2 u_pattern_br_b;
    highp vec2 u_texsize;
    highp vec2 u_pattern_size_a;
    highp vec2 u_pattern_size_b;
    highp vec2 u_pixel_coord_upper;
    highp vec2 u_pixel_coord_lower;
    highp float u_tile_units_to_pixels;
    highp float u_scale_a;
    highp float u_scale_b;
    highp float u_mix;
    highp float u_opacity;
    highp float pad;
};

uniform sampler2D u_image;

in mediump vec2 v_pos_a;
in mediump vec2 v_pos_b;

void main() {
    vec2 imagecoord = mod(v_pos_a, 1.0);
    vec2 pos = mix(u_pattern_tl_a / u_texsize, u_pattern_br_a / u_texsize, imagecoord);
    vec4 color1 = texture(u_image, pos);

    vec2 imagecoord_b = mod(v_pos_b, 1.0);
    vec2 pos2 = mix(u_pattern_tl_b / u_texsize, u_pattern_br_b / u_texsize, imagecoord_b);
    vec4 color2 = texture(u_image, pos2);

    fragColor = mix(color1, color2, u_mix) * u_opacity;

#ifdef OVERDRAW_INSPECTOR
    fragColor = vec4(1.0);
#endif
}