From 6e692ea9cff3fa644bda40f7416f6678175c8513 Mon Sep 17 00:00:00 2001
From: Jeff Hutchinson <programmerjeff95@gmail.com>
Date: Fri, 25 Mar 2016 13:41:38 -0400
Subject: [PATCH] torque windows integration of epoxy

---
 Engine/source/gfx/gl/gfxGLDevice.cpp           |  4 ++--
 Engine/source/gfx/gl/tGL/tGL.cpp               | 12 +++++++++---
 Engine/source/gfx/gl/tGL/tWGL.h                |  4 ++--
 Engine/source/gfx/gl/win32/gfxGLDevice.win.cpp |  2 +-
 Engine/source/platformWin32/WinPlatformGL.cpp  |  8 ++++----
 5 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/Engine/source/gfx/gl/gfxGLDevice.cpp b/Engine/source/gfx/gl/gfxGLDevice.cpp
index 01bbd02ea..862cde345 100644
--- a/Engine/source/gfx/gl/gfxGLDevice.cpp
+++ b/Engine/source/gfx/gl/gfxGLDevice.cpp
@@ -81,8 +81,8 @@ void loadGLExtensions(void *context)
    GL::gglPerformExtensionBinds(context);
 }
 
-void STDCALL glDebugCallback(GLenum source, GLenum type, GLuint id,
-    GLenum severity, GLsizei length, const GLchar* message, void* userParam)
+void STDCALL glDebugCallback(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, 
+	const GLchar *message, const void *userParam)
 {
     if (severity == GL_DEBUG_SEVERITY_HIGH)
         Con::errorf("OPENGL: %s", message);
diff --git a/Engine/source/gfx/gl/tGL/tGL.cpp b/Engine/source/gfx/gl/tGL/tGL.cpp
index 8d62a7fd1..d56faa05e 100644
--- a/Engine/source/gfx/gl/tGL/tGL.cpp
+++ b/Engine/source/gfx/gl/tGL/tGL.cpp
@@ -25,13 +25,19 @@
 #include "core/strings/stringFunctions.h"
 #include "console/console.h"
 
+#ifdef TORQUE_OS_WIN
+   #include "tWGL.h"
+#endif
+
 namespace GL
 {
    void gglPerformBinds()
    {
-      glewExperimental = GL_TRUE;
-      GLenum err = glewInit();
-      AssertFatal(GLEW_OK == err, avar("Error: %s\n", glewGetErrorString(err)) );
+      // JTH: epoxy has one oddity with windows. You need to bind the context
+      // after creating the context to udpate the internals of epoxy.
+#ifdef TORQUE_OS_WIN
+      epoxy_handle_external_wglMakeCurrent();
+#endif
    }
 
    void gglPerformExtensionBinds(void *context)
diff --git a/Engine/source/gfx/gl/tGL/tWGL.h b/Engine/source/gfx/gl/tGL/tWGL.h
index af905dca0..18025e886 100644
--- a/Engine/source/gfx/gl/tGL/tWGL.h
+++ b/Engine/source/gfx/gl/tGL/tWGL.h
@@ -28,9 +28,9 @@
 #ifdef TORQUE_OPENGL
 
 #include "tGL.h"
-#include "GL/wglew.h"
+#include <epoxy/wgl.h>
 
-#define gglHasWExtension(EXTENSION) WGLEW_##EXTENSION
+#define gglHasWExtension(window, EXTENSION) epoxy_has_wgl_extension(window, "WGL_" # EXTENSION)
 
 #endif //TORQUE_OPENGL
 
diff --git a/Engine/source/gfx/gl/win32/gfxGLDevice.win.cpp b/Engine/source/gfx/gl/win32/gfxGLDevice.win.cpp
index 6d4d09d0b..045b2aa6f 100644
--- a/Engine/source/gfx/gl/win32/gfxGLDevice.win.cpp
+++ b/Engine/source/gfx/gl/win32/gfxGLDevice.win.cpp
@@ -272,7 +272,7 @@ void GFXGLDevice::init( const GFXVideoMode &mode, PlatformWindow *window )
    int debugFlag = 0;
 #endif
 
-   if( gglHasWExtension(ARB_create_context) )
+   if( gglHasWExtension(hdcGL, ARB_create_context) )
    {
       int const create_attribs[] = {
                WGL_CONTEXT_MAJOR_VERSION_ARB, OGL_MAJOR,
diff --git a/Engine/source/platformWin32/WinPlatformGL.cpp b/Engine/source/platformWin32/WinPlatformGL.cpp
index a85245ef1..a30212bad 100644
--- a/Engine/source/platformWin32/WinPlatformGL.cpp
+++ b/Engine/source/platformWin32/WinPlatformGL.cpp
@@ -5,10 +5,10 @@
 
 void PlatformGL::setVSync(const int i)
 {
-    if (WGLEW_EXT_swap_control)
-    {
-        wglSwapIntervalEXT(i);
-    }
+   if (gglHasWExtension(wglGetCurrentDC(), EXT_swap_control))
+   {
+      wglSwapIntervalEXT(i);
+   }
 }
 
 #endif