From 3132690c0b05e0ef25551c5c67928cbabbf2f13e Mon Sep 17 00:00:00 2001
From: Paulo Henrique Silva <ph.silva@gmail.com>
Date: Sat, 13 Sep 2014 19:31:40 +0200
Subject: [PATCH] Fix slow opengl canvas on Mac OS 10.9.

---
 common/gal/opengl/gpu_manager.cpp | 8 +++++++-
 include/gal/opengl/gpu_manager.h  | 3 +++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/common/gal/opengl/gpu_manager.cpp b/common/gal/opengl/gpu_manager.cpp
index 25cd5fa418..36d66a0f60 100644
--- a/common/gal/opengl/gpu_manager.cpp
+++ b/common/gal/opengl/gpu_manager.cpp
@@ -94,6 +94,7 @@ GPU_CACHED_MANAGER::~GPU_CACHED_MANAGER()
     {
         glBindBuffer( GL_ARRAY_BUFFER, 0 );
         glDeleteBuffers( 1, &m_verticesBuffer );
+        glDeleteBuffers( 1, &m_indicesBuffer );
     }
 }
 
@@ -105,6 +106,7 @@ void GPU_CACHED_MANAGER::Initialize()
     if( !m_buffersInitialized )
     {
         glGenBuffers( 1, &m_verticesBuffer );
+        glGenBuffers( 1, &m_indicesBuffer );
         m_buffersInitialized = true;
     }
 }
@@ -167,9 +169,13 @@ void GPU_CACHED_MANAGER::EndDrawing()
                                VertexSize, (GLvoid*) ShaderOffset );
     }
 
-    glDrawElements( GL_TRIANGLES, m_indicesSize, GL_UNSIGNED_INT, (GLvoid*) m_indices.get() );
+    glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, m_indicesBuffer );
+    glBufferData( GL_ELEMENT_ARRAY_BUFFER, m_indicesSize * sizeof(int), (GLvoid*) m_indices.get(), GL_DYNAMIC_DRAW );
+
+    glDrawElements( GL_TRIANGLES, m_indicesSize, GL_UNSIGNED_INT, 0 );
 
     glBindBuffer( GL_ARRAY_BUFFER, 0 );
+    glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, 0 );
 
     // Deactivate vertex array
     glDisableClientState( GL_COLOR_ARRAY );
diff --git a/include/gal/opengl/gpu_manager.h b/include/gal/opengl/gpu_manager.h
index 7415ac5cfc..870834f253 100644
--- a/include/gal/opengl/gpu_manager.h
+++ b/include/gal/opengl/gpu_manager.h
@@ -144,6 +144,9 @@ protected:
     ///> Handle to vertices buffer
     GLuint  m_verticesBuffer;
 
+    ///> Handle to indices buffer
+    GLuint  m_indicesBuffer;
+
     ///> Number of indices stored in the indices buffer
     unsigned int m_indicesSize;
 };