Changeset 3010 for GTP/trunk/App/Demos/Vis/FriendlyCulling/src/shaders/tonemap.cg

Timestamp:

10/07/08 03:02:30 (16 years ago)

Author:

mattausch

Message:

 

File:

• GTP/trunk/App/Demos/Vis/FriendlyCulling/src/shaders/tonemap.cg (modified) (3 diffs)

GTP/trunk/App/Demos/Vis/FriendlyCulling/src/shaders/tonemap.cg

@@ -20 +20 @@
 
 
-float4 DownSample(frag IN,
+/*float4 DownSample(frag IN,
                                   uniform sampler2D colors,
-                                  uniform float2 downSampleOffs[4]): COLOR
+                                  uniform float2 downSampleOffs[9]): COLOR
 {    
     float4 average = .0f;
 
-    for(int i = 0; i < 4; ++ i)
+        const float4 avgColor = tex2Dlod(colors, float4(IN.texCoord, 0, 0));
+
+        float j = 0;
+        float4 color;
+
+    for (int i = 0; i < 9; ++ i)
     {
-        average += tex2Dlod(colors, float4(IN.texCoord + downSampleOffs[i],0,0));
+                color = tex2Dlod(colors, float4(IN.texCoord + downSampleOffs[i], 0, 0));
+                if (abs(color.w - avgColor.w) < 1e-3f)
+                {
+                        average += color;
+                        ++ j;
+                }
     }
         
-    average *= 1.0f / 4.0f;
+    //average *= 1.0f / 9.0f;
+    average *= 1.0f / j;
+
+    return average;
+}*/
+  
+float4 DownSample(frag IN,
+                                  uniform sampler2D colors,
+                                  uniform float2 downSampleOffs[NUM_DOWNSAMPLES]): COLOR
+{    
+    float4 average = .0f;
+
+    for (int i = 0; i < NUM_DOWNSAMPLES; ++ i)
+    {
+                average += tex2Dlod(colors, float4(IN.texCoord + downSampleOffs[i], 0, 0));
+    }
+       
+        average *= 1.0f / (float)NUM_DOWNSAMPLES;
 
     return average;
 }
-    
+
+
+/** Does the first downsampling step and on the same time calculates the 
+        intensity.
+*/
 
 float4 GreyScaleDownSample(frag IN,
-                                                   uniform sampler2D colors
+                                                   uniform sampler2D colors,
+                                                   uniform float2 downSampleOffs[4]
                                                    ): COLOR
 {
@@ -50 +82 @@
         //float3 w = float3(0.2125f, 0.7154f, 0.0721f);
 
-        float4 cols[4];
-
-        cols[0] = tex2D(colors, IN.lt);
-        cols[1] = tex2D(colors, IN.lb);
-        cols[2] = tex2D(colors, IN.rt);
-        cols[3] = tex2D(colors, IN.rb);
+        float4 color;
 
         for (int i = 0; i < 4; ++ i)
         {
+                color = tex2D(colors, downSampleOffs[i]);
+
                 const float intensity = dot(cols[i].rgb, w);
 
@@ -65 +94 @@
         }
 
-        average = exp(average * 0.25f);
+        average *= 0.25f;
 
-        float4 c = cols[0] + cols[1] + cols[2] + cols[3];
-
-        return c * 0.25f;
         // Output the luminance to the render target
-        //return float4(average, maximum, 0.0f, 1.0f);
+        return float4(average, maximum, 0.0f, 1.0f);
 }
     
+
+/** Used for downsampling the tone map parameters (average loglum, maximum)
+        to the next lower level. This has to be applied until there is only
+        a 1x1 texture which holds the required numbers.
+*/
+float4 DownSampleForToneMapping(frag IN,
+                                                                uniform sampler2D colors,
+                                                                uniform float2 downSampleOffs[4]): COLOR
+{    
+        float average = .0f;
+        float maximum = .0f;
+        
+        float4 color;
+
+        for (int i = 0; i < 4; ++ i)
+        {
+                color = tex2D(colors, downSampleOffs[i]);
+
+                maximum = max(maximum, color.y);
+                average += color.x;
+        }
+
+        average *= 1.0f / (float)NUM_DOWNSAMPLES;
+
+        return float4(average, maximum, 0.0f, 1.0f);
+}
+
+
 
 pixel ToneMap(frag IN,