fixed midmap generation

improved distance metrics

src/main/java/bdv/jogl/VolumeRenderer/Scene/Texture.java

@@ -247,10 +247,7 @@ public class Texture {
 		}
 		updateTextureParameters(gl2);
 		GLErrorHandler.assertGL(gl2);
-		if(shouldGenerateMidmaps){
-			gl2.glGenerateMipmap(textureType);
-		}
-		GLErrorHandler.assertGL(gl2);
+
 		switch (dimensions.length) {
 		case 1:
 
@@ -288,6 +285,9 @@ public class Texture {
 		default:
 			break;
 		}
+		if(shouldGenerateMidmaps){
+			gl2.glGenerateMipmap(textureType);
+		}
 		GLErrorHandler.assertGL(gl2);
 	}
 	

src/main/java/bdv/jogl/VolumeRenderer/ShaderPrograms/MultiVolumeRenderer.java

@@ -617,9 +617,10 @@ public class MultiVolumeRenderer extends AbstractShaderSceneElement{
 		for(int i =0; i< sources.getMaxNumberOfVolumes(); i++){
 			location = getArrayEntryLocation(gl2, suvVolumeTexture, i);
 			Texture t = createVolumeTexture(gl2, location);
-			//	t.setTexParameteri(gl2, GL2.GL_TEXTURE_MIN_FILTER, GL2.GL_LINEAR_MIPMAP_LINEAR);
+				t.setTexParameteri(gl2, GL2.GL_TEXTURE_MIN_FILTER, GL2.GL_LINEAR_MIPMAP_LINEAR);
 			t.setShouldGenerateMidmaps(true);
 			volumeTextureMap.put(i, t);
+			GLErrorHandler.assertGL(gl2);
 		}
 		location = getLocation(suvColorTexture);
 		colorTexture = new Texture(GL2.GL_TEXTURE_1D,location,GL2.GL_RGBA,GL2.GL_RGBA,GL2.GL_FLOAT);

src/main/java/bdv/jogl/VolumeRenderer/ShaderPrograms/ShaderSources/functions/accumulator/MaxCurvatureDifference.java

@@ -2,7 +2,6 @@ package bdv.jogl.VolumeRenderer.ShaderPrograms.ShaderSources.functions.accumulat
 
 import static bdv.jogl.VolumeRenderer.ShaderPrograms.ShaderSources.MultiVolumeRendererShaderSource.scvMaxNumberOfVolumes;
 import static bdv.jogl.VolumeRenderer.ShaderPrograms.ShaderSources.MultiVolumeRendererShaderSource.sgvRayPositions;
-import static bdv.jogl.VolumeRenderer.ShaderPrograms.ShaderSources.MultiVolumeRendererShaderSource.suvVolumeTexture;
 import static bdv.jogl.VolumeRenderer.ShaderPrograms.ShaderSources.MultiVolumeRendererShaderSource.sgvVolumeNormalizeFactor;
 import static bdv.jogl.VolumeRenderer.utils.ShaderSourceUtil.addCodeArrayToList;
 import static bdv.jogl.VolumeRenderer.utils.ShaderSourceUtil.appendNewLines;
@@ -123,26 +122,26 @@ public class MaxCurvatureDifference extends AbstractVolumeAccumulator {
 				"uniform float "+suvCurvatureMax+";",
 				"uniform float "+suvCurvatureMin+";",
 				"float curveNormalizeFactor = 1.0/("+suvCurvatureMax+"-"+suvCurvatureMin+");",
+				"bool factorChanged = false;",
 				"",
 				"float "+getFunctionName()+"(float densities["+scvMaxNumberOfVolumes+"]) {",
-				"	float difference = 0.0;",		
+				"	float minValue = "+Float.MAX_VALUE+";",
+				"	float maxValue = "+Float.MIN_VALUE+";",			
+				"   if(!factorChanged){",
+				//TODO
+				"		"+sgvVolumeNormalizeFactor+" = curveNormalizeFactor;",
+				"		factorChanged = true;",
+				"	}",
 				"	for(int n = 0; n < "+scvMaxNumberOfVolumes+"; n++){",
-			    "		vec3 texCN = getCorrectedTexturePositions("+sgvRayPositions+", n);",
-				"		for(int m = 0; m < "+scvMaxNumberOfVolumes+";m++){",
-				"			if(densities[n]<0 || densities[m]<0){",
-				"				continue;",
-				"			}",	
-				"			vec3 texCM = getCorrectedTexturePositions("+sgvRayPositions+", m);",
-				"			float cn = texture("+suvCurvatureTexture+"[n],texCN).r;",
-				"			float cm = texture("+suvCurvatureTexture+"[m],texCM).r;",
-				"",
-				"			"+sgvVolumeNormalizeFactor+" = curveNormalizeFactor;",
-				"			//manhatten distance",
-				"			float currentDifference = cn-cm;",
-				"			difference = max(difference,currentDifference);",	
-				"		}",
+				"		if(densities[n] < 0.0 ){",
+				"			continue;",
+				"		}",	
+				"		vec3 texCN = getCorrectedTexturePositions("+sgvRayPositions+", n);",
+				"		float cn = texture("+suvCurvatureTexture+"[n],texCN).r;",
+				"		maxValue = max(maxValue,cn);",
+				"		minValue = min(minValue,cn);",	
 				"	}",
-				"	return difference;",	
+				"	return maxValue -minValue;",	
 				"}"
 		};
 		addCodeArrayToList(dec, code);

src/main/java/bdv/jogl/VolumeRenderer/ShaderPrograms/ShaderSources/functions/accumulator/MaxDifferenceAccumulator.java

@@ -19,17 +19,16 @@ public class MaxDifferenceAccumulator extends AbstractVolumeAccumulator {
 		String[] dec= new String[]{
 				"#line "+Thread.currentThread().getStackTrace()[1].getLineNumber()+ " 7",
 				"float "+getFunctionName()+"(float densities["+scvMaxNumberOfVolumes+"]) {",
-				"	float difference = 0;",		
+				"	float maxValue = 0.0;",
+				"	float minValue = "+Float.MAX_VALUE+";",
 				"	for(int n = 0; n < "+scvMaxNumberOfVolumes+"; n++){",
-				"		for(int m = 0; m < "+scvMaxNumberOfVolumes+";m++){",
-				"			if(densities[n]<0 || densities[m]<0){",
-				"				continue;",
-				"			}",	
-				"			float currentDifference = densities[n]-densities[m];",
-				"			difference = max(difference,currentDifference);",	
-				"		}",
+				"		if(densities[n]< 0.0 ){",
+				"			continue;",
+				"		}",	
+				"		maxValue = max(maxValue,densities[n]);",
+				"		minValue = min(minValue,densities[n]);",	
 				"	}",
-				"	return difference;",	
+				"	return maxValue - minValue;",	
 				"}"
 		};
 		addCodeArrayToList(dec, code);

src/main/java/bdv/jogl/VolumeRenderer/ShaderPrograms/ShaderSources/functions/accumulator/MidmapMaxDifference.java

@@ -27,32 +27,29 @@ public class MidmapMaxDifference extends AbstractVolumeAccumulator {
 				"	float ret["+scvMaxNumberOfVolumes+"];",
 				"	for(int i = 0; i < "+scvMaxNumberOfVolumes+";i++){",
 				"		vec3 textureCoord = getCorrectedTexturePositions(position,i);",
-				"		float midmapValue = textureLod("+suvVolumeTexture+"[i],textureCoord,1.0).r;",
+				"		float midmapValue = textureLod( "+suvVolumeTexture+"[i],textureCoord,1.0).r;",
 				"		ret[i] = midmapValue;",
 				"	}",
 				"	return ret;",
 				"}",
 				"",
 				"float "+getFunctionName()+"(float densities["+scvMaxNumberOfVolumes+"]){",
-				"	float density = 0;",
+				"	float maxValue = 0.0;",
+				"	float minValue = "+Float.MAX_VALUE+";",
 				"	float midMap["+scvMaxNumberOfVolumes+"] = getMidmapValues("+sgvRayPositions+");",	
-				"	int numberOfChanges=  0;",
+				"	int numberOfChanges = 0;",
 				"	for(int n = 0; n < "+scvMaxNumberOfVolumes+"; n++){",
 				"		if(densities[n] < 0.0){",
 				"			continue;",	
 				"		}",	
-				"		for(int m = n+1; m < "+scvMaxNumberOfVolumes+"; m++){",
-				"			if(densities[m] < 0.0){",
-				"				continue;",	
-				"			}",	
-				"			density = max(density, abs(midMap[n]-midMap[m]));",
-				"			numberOfChanges++;",
-				"		}",
+				"		maxValue = max(maxValue,midMap[n]);",
+				"		minValue = min(minValue,midMap[n]);",	
+				"		numberOfChanges++;",
 				"	}",
 				"	if(numberOfChanges ==0){",
 				"		return 0.0;",
 				"	}",
-				"	return density;",	
+				"	return maxValue - minValue;",	
 				"}"
 		};