/**
 * DOC_TBA
 *
 * @name czm_multiplyWithColorBalance
 * @glslFunction
 */
vec3 czm_multiplyWithColorBalance(vec3 left, vec3 right)
{
    // Algorithm from Chapter 10 of Graphics Shaders.
    const vec3 W = vec3(0.2125, 0.7154, 0.0721);
    
    vec3 target = left * right;
    float leftLuminance = dot(left, W);
    float rightLuminance = dot(right, W);
    float targetLuminance = dot(target, W);
    
    return ((leftLuminance + rightLuminance) / (2.0 * targetLuminance)) * target;
}