Try to adjust the mip levels to get box blur for free as needed.
[movit] / vignette_effect.frag
2012-10-02 Steinar H. GundersonRevert "Move calculation of normalized position for...
2012-10-02 Steinar H. GundersonMove calculation of normalized position for the vignett...
2012-10-02 Steinar H. GundersonRename .glsl to .vert/.frag.