Avoid calculating whitepoint for each sample for HDR (#722)

* Avoid calculating whitepoint for each sample for HDR

jme3-effects/src/main/resources/Common/MatDefs/Post/ToneMap.frag

@@ -1,10 +1,5 @@
+#extension GL_ARB_texture_multisample : enable
 #import "Common/ShaderLib/GLSLCompat.glsllib"
-#import "Common/ShaderLib/MultiSample.glsllib"
-
-uniform COLORTEXTURE m_Texture;
-uniform vec3 m_WhitePoint;
-
-varying vec2 texCoord;
 
 vec3 FilmicCurve(in vec3 x) {
     const float A = 0.22;
@@ -23,23 +18,36 @@ vec3 ToneMap_Filmic(vec3 color, vec3 whitePoint){
     return FilmicCurve(color) / FilmicCurve(whitePoint);
 }
 
-vec4 tonemap(int i) {
-
-    vec4 texVal = fetchTextureSample(m_Texture, texCoord, i);
-    vec3 toneMapped = ToneMap_Filmic(texVal.rgb, m_WhitePoint);
+uniform vec3 m_WhitePoint;
+varying vec2 texCoord;
  
-    return vec4(toneMapped, texVal.a);
-}
+#ifdef NUM_SAMPLES
 
+uniform sampler2DMS m_Texture;
 
-void main() {
-    #ifdef RESOLVE_MS
+vec4 ToneMap_TextureFilmic() {
+    ivec2 iTexC = ivec2(texCoord * vec2(textureSize(m_Texture)));
     vec4 color = vec4(0.0);
-        for (int i = 0; i < m_NumSamples; i++){
-            color += tonemap(i);
+    for (int i = 0; i < NUM_SAMPLES; i++) {
+        vec4 hdrColor = texelFetch(m_Texture, iTexC, i);
+        vec3 ldrColor = FilmicCurve(hdrColor.rgb);
+        color += vec4(ldrColor, hdrColor.a);
     }
-        gl_FragColor = color / m_NumSamples;
+    color.rgb /= FilmicCurve(m_WhitePoint);
+    return color / float(NUM_SAMPLES);
+}
+
 #else
-        gl_FragColor = tonemap(0);
+ 
+uniform sampler2D m_Texture;
+ 
+vec4 ToneMap_TextureFilmic() {
+    vec4 texVal = texture2D(m_Texture, texCoord);
+    return vec4(ToneMap_Filmic(texVal.rgb, m_WhitePoint), texVal.a);
+}
+ 
 #endif
+
+void main() {
+    gl_FragColor = ToneMap_TextureFilmic();
 }

jme3-effects/src/main/resources/Common/MatDefs/Post/ToneMap.j3md

@@ -15,9 +15,7 @@ MaterialDef Default GUI {
         }
 
         Defines {
-            RESOLVE_MS : NumSamples
+            NUM_SAMPLES : NumSamples
         }
-
     }
-
 }