Better names for the shaders.

interface/resources/shaders/perlin_modulate.frag

@@ -1,16 +1,22 @@
+#version 120
+
 //
-//  grainy_voxels.frag
+//  perlin_modulate.frag
 //  fragment shader
 //
 //  Created by Andrzej Kapolka on 5/15/13.
-//  Copyright (c) 2012 High Fidelity, Inc. All rights reserved.
+//  Copyright (c) 2013 High Fidelity, Inc. All rights reserved.
 //
 
-#version 120
-
 // the texture containing our permutations and normals
 uniform sampler2D permutationNormalTexture;
 
+// the noise frequency
+const float frequency = 1024.0;
+
+// the noise amplitude
+const float amplitude = 0.1;
+
 // the position in model space
 varying vec3 position;
 
@@ -53,5 +59,5 @@ float perlin(vec3 location) {
 }
 
 void main(void) {
-    gl_FragColor = vec4(gl_Color.rgb * (0.85 + perlin(position * 1024.0) * 0.15), 1.0);
+    gl_FragColor = vec4(gl_Color.rgb * (1.0 + amplitude*(perlin(position * frequency) - 1.0)), 1.0);
 }

interface/resources/shaders/perlin_modulate.vert

@@ -1,13 +1,13 @@
+#version 120
+
 //
-//  grainy_voxels.vert
+//  perlin_modulate.vert
 //  vertex shader
 //
 //  Created by Andrzej Kapolka on 5/15/13.
 //  Copyright (c) 2013 High Fidelity, Inc. All rights reserved.
 //
 
-#version 120
-
 // the position in model space
 varying vec3 position;
 

interface/src/VoxelSystem.cpp

@@ -503,12 +503,12 @@ void VoxelSystem::init() {
     
     // create our simple fragment shader
     switchToResourcesParentIfRequired();
-    _grainProgram = new ProgramObject();
-    _grainProgram->addShaderFromSourceFile(QGLShader::Vertex, "resources/shaders/grainy_voxels.vert");
-    _grainProgram->addShaderFromSourceFile(QGLShader::Fragment, "resources/shaders/grainy_voxels.frag");
-    _grainProgram->link();
+    _perlinModulateProgram = new ProgramObject();
+    _perlinModulateProgram->addShaderFromSourceFile(QGLShader::Vertex, "resources/shaders/perlin_modulate.vert");
+    _perlinModulateProgram->addShaderFromSourceFile(QGLShader::Fragment, "resources/shaders/perlin_modulate.frag");
+    _perlinModulateProgram->link();
     
-    _grainProgram->setUniformValue("permutationNormalTexture", 0);
+    _perlinModulateProgram->setUniformValue("permutationNormalTexture", 0);
     
     // create the permutation/normal texture
     glGenTextures(1, &_permutationNormalTextureID);
@@ -640,7 +640,7 @@ void VoxelSystem::render() {
     glBindBuffer(GL_ARRAY_BUFFER, _vboColorsID);
     glColorPointer(3, GL_UNSIGNED_BYTE, 0, 0);
 
-    _grainProgram->bind();
+    _perlinModulateProgram->bind();
     glBindTexture(GL_TEXTURE_2D, _permutationNormalTextureID);
 
     // draw the number of voxels we have
@@ -648,7 +648,7 @@ void VoxelSystem::render() {
     glScalef(TREE_SCALE, TREE_SCALE, TREE_SCALE);
     glDrawElements(GL_TRIANGLES, 36 * _voxelsInReadArrays, GL_UNSIGNED_INT, 0);
 
-    _grainProgram->release();
+    _perlinModulateProgram->release();
     glBindTexture(GL_TEXTURE_2D, 0);
 
     // deactivate vertex and color arrays after drawing

interface/src/VoxelSystem.h

@@ -135,7 +135,7 @@ private:
     pthread_mutex_t _bufferWriteLock;
     pthread_mutex_t _treeLock;
 
-    ProgramObject* _grainProgram;
+    ProgramObject* _perlinModulateProgram;
     GLuint _permutationNormalTextureID;
 
     ViewFrustum* _viewFrustum;