From b6f80d855eb00bfe70bf00b7026945edd81897f5 Mon Sep 17 00:00:00 2001
From: David Ludwig <dludwig@pobox.com>
Date: Fri, 29 Nov 2013 00:19:46 -0500
Subject: [PATCH] WinRT: enable the OpenGL ES 2 SDL_Renderer backend, if and
 when OpenGL ES 2 support is compiled in

---
 VisualC-WinRT/SDL/SDL-WinRT_VS2012.vcxproj         |  4 ++++
 VisualC-WinRT/SDL/SDL-WinRT_VS2012.vcxproj.filters | 12 ++++++++++++
 include/SDL_config_winrt.h                         |  4 ++++
 src/render/opengles2/SDL_render_gles2.c            |  8 ++++++++
 4 files changed, 28 insertions(+)

diff --git a/VisualC-WinRT/SDL/SDL-WinRT_VS2012.vcxproj b/VisualC-WinRT/SDL/SDL-WinRT_VS2012.vcxproj
index 8e9765fc6d5da..43bbb1a593554 100644
--- a/VisualC-WinRT/SDL/SDL-WinRT_VS2012.vcxproj
+++ b/VisualC-WinRT/SDL/SDL-WinRT_VS2012.vcxproj
@@ -104,6 +104,8 @@
       <CompileAsWinRT Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</CompileAsWinRT>
       <CompileAsWinRT Condition="'$(Configuration)|$(Platform)'=='Release|x64'">true</CompileAsWinRT>
     </ClCompile>
+    <ClCompile Include="..\..\src\render\opengles2\SDL_render_gles2.c" />
+    <ClCompile Include="..\..\src\render\opengles2\SDL_shaders_gles2.c" />
     <ClCompile Include="..\..\src\render\SDL_render.c" />
     <ClCompile Include="..\..\src\render\SDL_yuv_mmx.c" />
     <ClCompile Include="..\..\src\render\SDL_yuv_sw.c" />
@@ -284,6 +286,8 @@
     <ClInclude Include="..\..\src\joystick\SDL_sysjoystick.h" />
     <ClInclude Include="..\..\src\render\direct3d11\SDL_render_d3d11_cpp.h" />
     <ClInclude Include="..\..\src\render\mmx.h" />
+    <ClInclude Include="..\..\src\render\opengles2\SDL_gles2funcs.h" />
+    <ClInclude Include="..\..\src\render\opengles2\SDL_shaders_gles2.h" />
     <ClInclude Include="..\..\src\render\SDL_sysrender.h" />
     <ClInclude Include="..\..\src\render\SDL_yuv_sw_c.h" />
     <ClInclude Include="..\..\src\render\software\SDL_blendfillrect.h" />
diff --git a/VisualC-WinRT/SDL/SDL-WinRT_VS2012.vcxproj.filters b/VisualC-WinRT/SDL/SDL-WinRT_VS2012.vcxproj.filters
index 20f2f541c5ecf..b3c0686b4ece9 100644
--- a/VisualC-WinRT/SDL/SDL-WinRT_VS2012.vcxproj.filters
+++ b/VisualC-WinRT/SDL/SDL-WinRT_VS2012.vcxproj.filters
@@ -285,6 +285,12 @@
     <ClCompile Include="..\..\src\video\winrt\SDL_winrtopengles.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\src\render\opengles2\SDL_render_gles2.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\src\render\opengles2\SDL_shaders_gles2.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\..\include\begin_code.h">
@@ -635,6 +641,12 @@
     <ClInclude Include="..\..\include\SDL_egl.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\src\render\opengles2\SDL_gles2funcs.h">
+      <Filter>Source Files</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\src\render\opengles2\SDL_shaders_gles2.h">
+      <Filter>Source Files</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <Filter Include="Header Files">
diff --git a/include/SDL_config_winrt.h b/include/SDL_config_winrt.h
index 210d1e6607831..de09fbce73d5f 100644
--- a/include/SDL_config_winrt.h
+++ b/include/SDL_config_winrt.h
@@ -179,6 +179,10 @@ typedef unsigned int uintptr_t;
 /* Enable appropriate renderer(s) */
 #define SDL_VIDEO_RENDER_D3D11  1
 
+#if SDL_VIDEO_OPENGL_ES2
+#define SDL_VIDEO_RENDER_OGL_ES2 1
+#endif
+
 /* Enable system power support */
 // TODO, WinRT: investigate system power support.  The Win32-based APIs don't work on WinRT.
 #define SDL_POWER_DISABLED  1
diff --git a/src/render/opengles2/SDL_render_gles2.c b/src/render/opengles2/SDL_render_gles2.c
index 31a1598c07dd8..2c0828a020263 100644
--- a/src/render/opengles2/SDL_render_gles2.c
+++ b/src/render/opengles2/SDL_render_gles2.c
@@ -1772,6 +1772,14 @@ GLES2_CreateRenderer(SDL_Window *window, Uint32 flags)
         return NULL;
     }
 
+#if __WINRT__
+    /* DLudwig, 2013-11-29: ANGLE for WinRT doesn't seem to work unless VSync
+     * is turned on.  Not doing so will freeze the screen's contents to that
+     * of the first drawn frame.
+     */
+    flags |= SDL_RENDERER_PRESENTVSYNC;
+#endif
+
     if (flags & SDL_RENDERER_PRESENTVSYNC) {
         SDL_GL_SetSwapInterval(1);
     } else {