                                               DistortionRenderDesc const &distortion,                                              const Vector0f &framebufferNDC ) {     // Scale to TanHalfFov space, but still distorted.     Vector0f tanEyeAngleDistorted;     tanEyeAngleDistorted.x = ( framebufferNDC.x - distortion.LensCenter.x ) * distortion.TanEyeAngleScale.x;     tanEyeAngleDistorted.y = ( framebufferNDC.y - distortion.LensCenter.y ) * distortion.TanEyeAngleScale.y;     // Distort.     float radiusSquared = ( tanEyeAngleDistorted.x * tanEyeAngleDistorted.x )                         + ( tanEyeAngleDistorted.y * tanEyeAngleDistorted.y );     