From 4d4235dd4067055c2c15636e7b1c47e1700dd841 Mon Sep 17 00:00:00 2001
From: Ivan Safrin <ivansafrin@gmail.com>
Date: Mon, 23 Jan 2012 14:55:57 -0500
Subject: [PATCH] Tangent support in VBOs

---
 Core/Contents/Include/PolyGLVertexBuffer.h  |  6 +++--
 Core/Contents/Source/PolyGLRenderer.cpp     |  5 ++++
 Core/Contents/Source/PolyGLVertexBuffer.cpp | 26 +++++++++++++++++++++
 3 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/Core/Contents/Include/PolyGLVertexBuffer.h b/Core/Contents/Include/PolyGLVertexBuffer.h
index 312bc1cf4..9ddd7b4fb 100644
--- a/Core/Contents/Include/PolyGLVertexBuffer.h
+++ b/Core/Contents/Include/PolyGLVertexBuffer.h
@@ -49,13 +49,15 @@ namespace Polycode {
 		GLuint getTextCoordBufferID();	
 		GLuint getNormalBufferID();
 		GLuint getColorBufferID();
-		
+		GLuint getTangentBufferID();
+				
 	protected:
 		
 		GLuint vertexBufferID;
 		GLuint texCoordBufferID;
 		GLuint normalBufferID;
-		GLuint colorBufferID;		
+		GLuint colorBufferID;	
+		GLuint tangentBufferID;				
 	};
 	
 }
diff --git a/Core/Contents/Source/PolyGLRenderer.cpp b/Core/Contents/Source/PolyGLRenderer.cpp
index 1287455e5..fe8db5a40 100755
--- a/Core/Contents/Source/PolyGLRenderer.cpp
+++ b/Core/Contents/Source/PolyGLRenderer.cpp
@@ -356,6 +356,11 @@ void OpenGLRenderer::drawVertexBuffer(VertexBuffer *buffer) {
 	glNormalPointer(GL_FLOAT, 0, (char *) NULL );			
 	glBindBufferARB( GL_ARRAY_BUFFER_ARB, glVertexBuffer->getTextCoordBufferID());
 	glTexCoordPointer( 2, GL_FLOAT, 0, (char *) NULL );
+
+	glBindBufferARB( GL_ARRAY_BUFFER_ARB, glVertexBuffer->getTangentBufferID());	
+	glEnableVertexAttribArrayARB(6);	
+	glVertexAttribPointer(6, 3, GL_FLOAT, 0, 0,  (char *)NULL);
+	
 	
 	
 	GLenum mode = GL_TRIANGLES;
diff --git a/Core/Contents/Source/PolyGLVertexBuffer.cpp b/Core/Contents/Source/PolyGLVertexBuffer.cpp
index 84d31c931..177d05315 100644
--- a/Core/Contents/Source/PolyGLVertexBuffer.cpp
+++ b/Core/Contents/Source/PolyGLVertexBuffer.cpp
@@ -125,6 +125,28 @@ OpenGLVertexBuffer::OpenGLVertexBuffer(Mesh *mesh) : VertexBuffer() {
 	glBufferDataARB(GL_ARRAY_BUFFER_ARB, bufferSize*sizeof(GLfloat), buffer, GL_STATIC_DRAW_ARB);	
 	free(buffer);	
 		
+		
+
+	glGenBuffersARB(1, &tangentBufferID);
+	glBindBufferARB(GL_ARRAY_BUFFER_ARB, tangentBufferID);
+	
+	bufferSize = 0;
+	newBufferSize = 0;		
+	buffer = (GLfloat*)malloc(1);	
+	
+	for(int i=0; i < mesh->getPolygonCount(); i++) {
+		for(int j=0; j < mesh->getPolygon(i)->getVertexCount(); j++) {
+			newBufferSize = bufferSize + 3;			
+			buffer = (GLfloat*)realloc(buffer, newBufferSize * sizeof(GLfloat));		
+			buffer[bufferSize+0] = mesh->getPolygon(i)->getVertex(j)->tangent.x;
+			buffer[bufferSize+1] = mesh->getPolygon(i)->getVertex(j)->tangent.y;
+			buffer[bufferSize+2] = mesh->getPolygon(i)->getVertex(j)->tangent.z;
+			bufferSize = newBufferSize;					
+		}		   
+	}
+	
+	glBufferDataARB(GL_ARRAY_BUFFER_ARB, bufferSize*sizeof(GLfloat), buffer, GL_STATIC_DRAW_ARB);	
+	free(buffer);	
 	
 	glGenBuffersARB(1, &colorBufferID);
 	glBindBufferARB(GL_ARRAY_BUFFER_ARB, colorBufferID);
@@ -172,3 +194,7 @@ GLuint OpenGLVertexBuffer::getTextCoordBufferID() {
 GLuint OpenGLVertexBuffer::getVertexBufferID() {
 	return vertexBufferID;
 }
+
+GLuint OpenGLVertexBuffer::getTangentBufferID() {
+	return tangentBufferID;
+}