Revert "Revert "Use a less intrusive delta value""

This reverts commit 230076ffcbd05ecf8a05c165a95fec7823687c4a.

data/shaders/logluminance.frag

@@ -3,7 +3,7 @@ uniform sampler2D tex;
 in vec2 uv;
 out vec4 FragColor;
 
-float delta = .1;
+float delta = .0001;
 
 void main()
 {

data/shaders/tonemap.frag

@@ -9,15 +9,15 @@ out vec4 FragColor;
 vec3 getCIEYxy(vec3 rgbColor);
 vec3 getRGBFromCIEXxy(vec3 YxyColor);
 
-float exposure = .3;
+float exposure = .2;
 float whitePoint = 1.;
-float delta = .1;
+float delta = .0001;
 
 void main()
 {
     vec4 col = texture(tex, uv);
     float avgLuminance = textureLod(logluminancetex, uv, 10.).x;
-    avgLuminance = exp(avgLuminance) - delta;
+    avgLuminance = max(exp(avgLuminance) - delta, delta);
 
     vec3 Yxy = getCIEYxy(col.xyz);
     float Lp = Yxy.r * exposure / avgLuminance;