Add a weight for vignette.

data/shaders/tonemap.frag

@@ -4,6 +4,7 @@ uniform sampler2D tex;
 uniform sampler2D logluminancetex;
 uniform float exposure = .09;
 uniform float Lwhite = 1.;
+uniform float vignette_weight = 0.;
 
 layout (std140) uniform MatrixesData
 {
@@ -43,12 +44,11 @@ void main()
     // Uncharted2 tonemap with Auria's custom coefficients
     vec4 perChannel = (col * (6.9 * col + .5)) / (col * (5.2 * col + 1.7) + 0.06);
     perChannel = pow(perChannel, vec4(2.2));
-    
+
     vec2 inside = uv - 0.5;
-    float vignette = 1 - dot(inside, inside);    
+    float vignette = 1. - dot(inside, inside) * vignette_weight;
     vignette = clamp(pow(vignette, 0.8), 0., 1.);
     //vignette = clamp(vignette + vignette - 0.5, 0., 1.15);
 
-    
     FragColor = vec4(perChannel.xyz * vignette, col.a);
 }