From a9ccca3f72bcac0ba7e0851f2320194f8f3a7dff Mon Sep 17 00:00:00 2001
From: Andrzej Kapolka <drzej.k@gmail.com>
Date: Wed, 14 Aug 2013 16:13:30 -0700
Subject: [PATCH] Diffuse/add glow mode.

---
 interface/resources/shaders/diffuse.frag | 28 ++++++++++++++++++
 interface/src/renderer/GlowEffect.cpp    | 37 +++++++++++++++++++++++-
 interface/src/renderer/GlowEffect.h      |  4 ++-
 3 files changed, 67 insertions(+), 2 deletions(-)
 create mode 100644 interface/resources/shaders/diffuse.frag

diff --git a/interface/resources/shaders/diffuse.frag b/interface/resources/shaders/diffuse.frag
new file mode 100644
index 0000000000..f8be7075db
--- /dev/null
+++ b/interface/resources/shaders/diffuse.frag
@@ -0,0 +1,28 @@
+#version 120
+
+//
+//  diffuse.frag
+//  fragment shader
+//
+//  Created by Andrzej Kapolka on 8/14/13.
+//  Copyright (c) 2013 High Fidelity, Inc. All rights reserved.
+//
+
+// the texture containing the original color
+uniform sampler2D originalTexture;
+
+// the texture containing the diffused color
+uniform sampler2D diffusedTexture;
+
+void main(void) {
+    float ds = dFdx(gl_TexCoord[0].s);
+    float dt = dFdy(gl_TexCoord[0].t);
+    gl_FragColor = (texture2D(diffusedTexture, gl_TexCoord[0].st + vec2(-ds, -dt)) +
+        texture2D(diffusedTexture, gl_TexCoord[0].st + vec2(0.0, -dt)) +
+        texture2D(diffusedTexture, gl_TexCoord[0].st + vec2(ds, -dt)) +
+        texture2D(diffusedTexture, gl_TexCoord[0].st + vec2(ds, 0.0)) +
+        texture2D(diffusedTexture, gl_TexCoord[0].st + vec2(ds, dt)) +
+        texture2D(diffusedTexture, gl_TexCoord[0].st + vec2(0.0, dt)) +
+        texture2D(diffusedTexture, gl_TexCoord[0].st + vec2(-ds, dt)) +
+        texture2D(diffusedTexture, gl_TexCoord[0].st + vec2(-ds, 0.0))) / 8.5 + texture2D(originalTexture, gl_TexCoord[0].st) * 0.1;
+}
diff --git a/interface/src/renderer/GlowEffect.cpp b/interface/src/renderer/GlowEffect.cpp
index 8233fe1984..2be1bc0e8f 100644
--- a/interface/src/renderer/GlowEffect.cpp
+++ b/interface/src/renderer/GlowEffect.cpp
@@ -14,7 +14,7 @@
 #include "GlowEffect.h"
 #include "ProgramObject.h"
 
-GlowEffect::GlowEffect() : _renderMode(BLUR_ADD_MODE) {
+GlowEffect::GlowEffect() : _renderMode(DIFFUSE_ADD_MODE) {
 }
 
 static ProgramObject* createProgram(const QString& name) {
@@ -37,6 +37,7 @@ void GlowEffect::init() {
     _verticalBlurAddProgram = createProgram("vertical_blur_add");
     _verticalBlurProgram = createProgram("vertical_blur");
     _addSeparateProgram = createProgram("glow_add_separate");
+    _diffuseProgram = createProgram("diffuse");
     
     _verticalBlurAddProgram->bind();
     _verticalBlurAddProgram->setUniformValue("horizontallyBlurredTexture", 1);
@@ -45,6 +46,10 @@ void GlowEffect::init() {
     _addSeparateProgram->bind();
     _addSeparateProgram->setUniformValue("blurredTexture", 1);
     _addSeparateProgram->release();
+    
+    _diffuseProgram->bind();
+    _diffuseProgram->setUniformValue("diffusedTexture", 1);
+    _diffuseProgram->release();
 }
 
 void GlowEffect::prepare() {
@@ -108,6 +113,36 @@ void GlowEffect::render() {
         _addProgram->bind();
         renderFullscreenQuad();
         _addProgram->release();
+    
+    } else if (_renderMode == DIFFUSE_ADD_MODE) {
+        // diffuse into the secondary/tertiary (alternating between frames)
+        QOpenGLFramebufferObject* oldDiffusedFBO =
+            Application::getInstance()->getTextureCache()->getSecondaryFramebufferObject();
+        QOpenGLFramebufferObject* newDiffusedFBO =
+            Application::getInstance()->getTextureCache()->getTertiaryFramebufferObject();
+        if ((_isOddFrame = !_isOddFrame)) {
+            qSwap(oldDiffusedFBO, newDiffusedFBO);
+        }
+        newDiffusedFBO->bind();
+        
+        glActiveTexture(GL_TEXTURE1);
+        glBindTexture(GL_TEXTURE_2D, oldDiffusedFBO->texture());
+            
+        _diffuseProgram->bind();
+        renderFullscreenQuad();
+        _diffuseProgram->release();
+        
+        newDiffusedFBO->release();
+        
+        // add diffused texture to the primary
+        glBindTexture(GL_TEXTURE_2D, newDiffusedFBO->texture());
+        
+        _addSeparateProgram->bind();      
+        renderFullscreenQuad();
+        _addSeparateProgram->release();
+        
+        glBindTexture(GL_TEXTURE_2D, 0);
+        glActiveTexture(GL_TEXTURE0);
         
     } else { // _renderMode == BLUR_ADD_MODE || _renderMode == BLUR_PERSIST_ADD_MODE
         // render the primary to the secondary with the horizontal blur
diff --git a/interface/src/renderer/GlowEffect.h b/interface/src/renderer/GlowEffect.h
index d8ea3d18c2..cc01ce840f 100644
--- a/interface/src/renderer/GlowEffect.h
+++ b/interface/src/renderer/GlowEffect.h
@@ -35,7 +35,7 @@ public slots:
     
 private:
     
-    enum RenderMode { ADD_MODE, BLUR_ADD_MODE, BLUR_PERSIST_ADD_MODE, RENDER_MODE_COUNT };
+    enum RenderMode { ADD_MODE, BLUR_ADD_MODE, BLUR_PERSIST_ADD_MODE, DIFFUSE_ADD_MODE, RENDER_MODE_COUNT };
     
     RenderMode _renderMode;
     ProgramObject* _addProgram;
@@ -43,8 +43,10 @@ private:
     ProgramObject* _verticalBlurAddProgram;
     ProgramObject* _verticalBlurProgram;
     ProgramObject* _addSeparateProgram;
+    ProgramObject* _diffuseProgram;
     
     bool _isEmpty;
+    bool _isOddFrame;
 };
 
 #endif /* defined(__interface__GlowEffect__) */