flat in int cellOffset;
in vec2 quadCoord;

out vec4 FragColor;

void main()
{
  float dist_sqr = dot(quadCoord, quadCoord);

  /* Discard outside the circle. */
  if (dist_sqr > 1.0) {
    discard;
  }

  vec3 view_nor = vec3(quadCoord, sqrt(max(0.0, 1.0 - dist_sqr)));
  vec3 world_nor = mat3(ViewMatrixInverse) * view_nor;
  IrradianceData ir_data = load_irradiance_cell(cellOffset, world_nor);
  FragColor = vec4(compute_irradiance(world_nor, ir_data), 1.0);
}