Merge pull request #1567 from JeffProgrammer/epoxy

Added Epoxy in favor of GLEW

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);

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)

Engine/source/gfx/gl/tGL/tGL.h

@@ -22,15 +22,12 @@
 
 #ifndef T_GL_H
 #define T_GL_H
-#include "GL/glew.h"
 
-#if defined (TORQUE_OS_WIN)
-// This doesn't work on Mesa drivers.
-#define gglHasExtension(EXTENSION) GLEW_##EXTENSION
-#else
-// Slower but reliably detects extensions on Mesa.
-#define gglHasExtension(EXTENSION) glewGetExtension("GL_" # EXTENSION)
-#endif
+#include <epoxy/gl.h>
+
+// JTH: This is slow, we should probably check extensions once and cache them
+// directly inside of some compatability table.
+#define gglHasExtension(EXTENSION) epoxy_has_gl_extension("GL_" #EXTENSION)
 
 #endif
 

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
 

Engine/source/gfx/gl/tGL/tXGL.h

@@ -28,9 +28,9 @@
 #ifdef TORQUE_OS_LINUX
 
 #include "tGL.h"
-#include "GL/glxew.h"
+#include <epoxy/glx.h>
 
-#define gglHasXExtension(EXTENSION) GLXEW##EXTENSION
+#define gglHasXExtension(display, screen, EXTENSION) epoxy_has_glx_extension(display, screen, "GLX_" # EXTENSION)
 
 #endif //TORQUE_OS_LINUX
 

Engine/source/gfx/gl/win32/gfxGLDevice.win.cpp

@@ -272,7 +272,12 @@ void GFXGLDevice::init( const GFXVideoMode &mode, PlatformWindow *window )
    int debugFlag = 0;
 #endif
 
-   if( gglHasWExtension(ARB_create_context) )
+   // Create a temp rendering context, needed a current context to use wglCreateContextAttribsARB
+   HGLRC tempGLRC = wglCreateContext(hdcGL);
+   if (!wglMakeCurrent(hdcGL, tempGLRC))
+      AssertFatal(false, "Couldn't make temp GL context.");
+
+   if( gglHasWExtension(hdcGL, ARB_create_context) )
    {
       int const create_attribs[] = {
                WGL_CONTEXT_MAJOR_VERSION_ARB, OGL_MAJOR,
@@ -292,6 +297,10 @@ void GFXGLDevice::init( const GFXVideoMode &mode, PlatformWindow *window )
    else
       mContext = wglCreateContext( hdcGL );
 
+   // Delete temp rendering context
+   wglMakeCurrent(NULL, NULL);
+   wglDeleteContext(tempGLRC);
+
    if( !wglMakeCurrent( hdcGL, (HGLRC)mContext ) )
       AssertFatal( false , "GFXGLDevice::init - cannot make our context current. Or maybe we can't create it." );