varying vec2 vPosition;
#ifdef VERTEX
vec4 pos(mat4 transform_projection, vec4 vertex_position) {
vPosition = vertex_position.xy;
return transform_projection * vertex_position;
}
#endif
#ifdef FRAGMENT
vec4 effect(vec4 color, Image texture, vec2 texture_coords, vec2 screen_coords) {
vec2 pos = normalize(vPosition);
return vec4(pos.x, pos.y, 1. - pos.y, 1.) * color;
}
#endif