Support using OpenGL ES context on desktop

src/utils/win/SkWGL_win.cpp

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkWGL.h"
 
@@ skipping 227 matching lines @@
         GET_PROC(CreateContextAttribs, ARB);
 
         wglMakeCurrent(dummyDC, NULL);
         wglDeleteContext(dummyGLRC);
         destroy_dummy_window(dummyWND);
     }
 
     wglMakeCurrent(prevDC, prevGLRC);
 }
 
-HGLRC SkCreateWGLContext(HDC dc, int msaaSampleCount, bool preferCoreProfile) {
+HGLRC SkCreateWGLContext(HDC dc, int msaaSampleCount, SkWGLContextRequest contextType) {
     SkWGLExtensions extensions;
     if (!extensions.hasExtension(dc, "WGL_ARB_pixel_format")) {
         return NULL;
     }
 
     HDC prevDC = wglGetCurrentDC();
     HGLRC prevGLRC = wglGetCurrentContext();
     PIXELFORMATDESCRIPTOR pfd;
 
     int format = 0;
@@ skipping 41 matching lines @@
     if (0 == format) {
         // Either MSAA wasn't requested or creation failed
         unsigned int num;
         extensions.choosePixelFormat(dc, iAttrs, fAttrs, 1, &format, &num);
         DescribePixelFormat(dc, format, sizeof(pfd), &pfd);
         SkDEBUGCODE(BOOL set =) SetPixelFormat(dc, format, &pfd);
         SkASSERT(TRUE == set);
     }
 
     HGLRC glrc = NULL;
-    if (preferCoreProfile && extensions.hasExtension(dc, "WGL_ARB_create_context")) {
-        static const int kCoreGLVersions[] = {
-            4, 3,
-            4, 2,
-            4, 1,
-            4, 0,
-            3, 3,
-            3, 2,
-        };
-        int coreProfileAttribs[] = {
-            SK_WGL_CONTEXT_MAJOR_VERSION, -1,
-            SK_WGL_CONTEXT_MINOR_VERSION, -1,
-            SK_WGL_CONTEXT_PROFILE_MASK,  SK_WGL_CONTEXT_CORE_PROFILE_BIT,
+    if (kGLES_SkWGLContextRequest == contextType) {
+        if (!extensions.hasExtension(dc, "WGL_EXT_create_context_es2_profile")) {
+            return NULL;
+        }
+        static const int glesAttribs[] = {
+            SK_WGL_CONTEXT_MAJOR_VERSION, 3,
+            SK_WGL_CONTEXT_MINOR_VERSION, 0,
+            SK_WGL_CONTEXT_PROFILE_MASK,  SK_WGL_CONTEXT_ES2_PROFILE_BIT,
             0,
         };
-        for (int v = 0; v < SK_ARRAY_COUNT(kCoreGLVersions) / 2; ++v) {
-            coreProfileAttribs[1] = kCoreGLVersions[2 * v];
-            coreProfileAttribs[3] = kCoreGLVersions[2 * v + 1];
-            glrc = extensions.createContextAttribs(dc, NULL, coreProfileAttribs);
-            if (NULL != glrc) {
-                break;
+        glrc = extensions.createContextAttribs(dc, NULL, glesAttribs);
+        if (NULL == glrc) {
+            return NULL;
+        }
+    } else {
+        if (kGLPreferCoreProfile_SkWGLContextRequest == contextType &&
+            extensions.hasExtension(dc, "WGL_ARB_create_context")) {
+            static const int kCoreGLVersions[] = {
+                4, 3,
+                4, 2,
+                4, 1,
+                4, 0,
+                3, 3,
+                3, 2,
+            };
+            int coreProfileAttribs[] = {
+                SK_WGL_CONTEXT_MAJOR_VERSION, -1,
+                SK_WGL_CONTEXT_MINOR_VERSION, -1,
+                SK_WGL_CONTEXT_PROFILE_MASK,  SK_WGL_CONTEXT_CORE_PROFILE_BIT,
+                0,
+            };
+            for (int v = 0; v < SK_ARRAY_COUNT(kCoreGLVersions) / 2; ++v) {
+                coreProfileAttribs[1] = kCoreGLVersions[2 * v];
+                coreProfileAttribs[3] = kCoreGLVersions[2 * v + 1];
+                glrc = extensions.createContextAttribs(dc, NULL, coreProfileAttribs);
+                if (NULL != glrc) {
+                    break;
+                }
             }
         }
     }
 
     if (NULL == glrc) {
         glrc = wglCreateContext(dc);
     }
     SkASSERT(glrc);
 
     wglMakeCurrent(prevDC, prevGLRC);
     return glrc;
 }