From ad67911f1a45370558f968cdc1540f707534c28f Mon Sep 17 00:00:00 2001
From: bruvzg <7645683+bruvzg@users.noreply.github.com>
Date: Tue, 6 Mar 2018 15:53:30 +0200
Subject: [PATCH] Explicitly set OpenGL profile to core (X11, Windows). Enable
 GLES2 on Windows.

---
 platform/windows/context_gl_win.cpp |  3 +++
 platform/windows/os_windows.cpp     | 16 ++++++++++++----
 platform/x11/context_gl_x11.cpp     |  1 +
 3 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/platform/windows/context_gl_win.cpp b/platform/windows/context_gl_win.cpp
index 8b57fdd9ceb..d312fbcb12b 100644
--- a/platform/windows/context_gl_win.cpp
+++ b/platform/windows/context_gl_win.cpp
@@ -38,6 +38,8 @@
 #define WGL_CONTEXT_MINOR_VERSION_ARB 0x2092
 #define WGL_CONTEXT_FLAGS_ARB 0x2094
 #define WGL_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB 0x00000002
+#define WGL_CONTEXT_PROFILE_MASK_ARB 0x9126
+#define WGL_CONTEXT_CORE_PROFILE_BIT_ARB 0x00000001
 
 typedef HGLRC(APIENTRY *PFNWGLCREATECONTEXTATTRIBSARBPROC)(HDC, HGLRC, const int *);
 
@@ -153,6 +155,7 @@ Error ContextGL_Win::initialize() {
 			WGL_CONTEXT_MAJOR_VERSION_ARB, 3, //we want a 3.3 context
 			WGL_CONTEXT_MINOR_VERSION_ARB, 3,
 			//and it shall be forward compatible so that we can only use up to date functionality
+			WGL_CONTEXT_PROFILE_MASK_ARB, WGL_CONTEXT_CORE_PROFILE_BIT_ARB,
 			WGL_CONTEXT_FLAGS_ARB, WGL_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB /*| _WGL_CONTEXT_DEBUG_BIT_ARB*/,
 			0
 		}; //zero indicates the end of the array
diff --git a/platform/windows/os_windows.cpp b/platform/windows/os_windows.cpp
index 910010187d9..13fe781ff34 100644
--- a/platform/windows/os_windows.cpp
+++ b/platform/windows/os_windows.cpp
@@ -30,6 +30,7 @@
 
 #include "os_windows.h"
 
+#include "drivers/gles2/rasterizer_gles2.h"
 #include "drivers/gles3/rasterizer_gles3.h"
 #include "drivers/windows/dir_access_windows.h"
 #include "drivers/windows/file_access_windows.h"
@@ -1069,12 +1070,19 @@ Error OS_Windows::initialize(const VideoMode &p_desired, int p_video_driver, int
 	}
 
 #if defined(OPENGL_ENABLED)
-	gl_context = memnew(ContextGL_Win(hWnd, true));
-	gl_context->initialize();
+	if (p_video_driver == VIDEO_DRIVER_GLES2) {
+		gl_context = memnew(ContextGL_Win(hWnd, false));
+		gl_context->initialize();
 
-	RasterizerGLES3::register_config();
+		RasterizerGLES2::register_config();
+		RasterizerGLES2::make_current();
+	} else {
+		gl_context = memnew(ContextGL_Win(hWnd, true));
+		gl_context->initialize();
 
-	RasterizerGLES3::make_current();
+		RasterizerGLES3::register_config();
+		RasterizerGLES3::make_current();
+	}
 
 	gl_context->set_use_vsync(video_mode.use_vsync);
 #endif
diff --git a/platform/x11/context_gl_x11.cpp b/platform/x11/context_gl_x11.cpp
index 7a659a27348..1a7cbc0d6d4 100644
--- a/platform/x11/context_gl_x11.cpp
+++ b/platform/x11/context_gl_x11.cpp
@@ -170,6 +170,7 @@ Error ContextGL_X11::initialize() {
 			static int context_attribs[] = {
 				GLX_CONTEXT_MAJOR_VERSION_ARB, 3,
 				GLX_CONTEXT_MINOR_VERSION_ARB, 3,
+				GLX_CONTEXT_PROFILE_MASK_ARB, GLX_CONTEXT_CORE_PROFILE_BIT_ARB,
 				GLX_CONTEXT_FLAGS_ARB, GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB /*|GLX_CONTEXT_DEBUG_BIT_ARB*/,
 				None
 			};