Add support for targetting GLES with DisplayWGL.

src/libANGLE/Display.cpp

@@ -176,12 +176,22 @@ rx::DisplayImpl *CreateDisplayFromAttribs(const AttributeMap &attribMap)
 #endif
         break;
 
+#if defined(ANGLE_ENABLE_OPENGL)
+      case EGL_PLATFORM_ANGLE_TYPE_OPENGLES_ANGLE:
+#if defined(ANGLE_PLATFORM_WINDOWS)
+          impl = new rx::DisplayWGL();
+#else
+          // No GLES support on this platform, fail display creation.
+          impl = nullptr;
+#endif
+          break;
+#endif
+
       default:
         UNREACHABLE();
         break;
     }
 
-    ASSERT(impl != nullptr);
     return impl;
 }
 
@@ -219,6 +229,12 @@ Display *Display::GetDisplayFromAttribs(void *native_display, const AttributeMap
     if (!display->isInitialized())
     {
         rx::DisplayImpl *impl = CreateDisplayFromAttribs(attribMap);
+        if (impl == nullptr)
+        {
+            // No valid display implementation for these attributes
+            return nullptr;
+        }
+
         display->setAttributes(impl, attribMap);
     }
 

src/libANGLE/renderer/gl/wgl/DisplayWGL.cpp

@@ -175,6 +175,18 @@ egl::Error DisplayWGL::initialize(egl::Display *display)
     ReleaseDC(dummyWindow, dummyDeviceContext);
     DestroyWindow(dummyWindow);
 
+    const egl::AttributeMap &displayAttributes = display->getAttributeMap();
+    EGLint requestedDisplayType =
+        displayAttributes.get(EGL_PLATFORM_ANGLE_TYPE_ANGLE, EGL_PLATFORM_ANGLE_TYPE_DEFAULT_ANGLE);
+    if (requestedDisplayType == EGL_PLATFORM_ANGLE_TYPE_OPENGLES_ANGLE &&
+        !mFunctionsWGL->hasExtension("WGL_EXT_create_context_es2_profile") &&
+        !mFunctionsWGL->hasExtension("WGL_EXT_create_context_es_profile"))
+    {
+        return egl::Error(EGL_NOT_INITIALIZED,
+                          "Cannot create an OpenGL ES platform on Windows without "
+                          "the WGL_EXT_create_context_es(2)_profile extension.");
+    }
+
     // Create the real intermediate context and windows
     mWindow = CreateWindowExA(0,
                               reinterpret_cast<const char *>(mWindowClass),
@@ -230,14 +242,21 @@ egl::Error DisplayWGL::initialize(egl::Display *display)
         // TODO: handle robustness
 
         int mask = 0;
-        // Request core profile
-        mask |= WGL_CONTEXT_CORE_PROFILE_BIT_ARB;
+
+        if (requestedDisplayType == EGL_PLATFORM_ANGLE_TYPE_OPENGLES_ANGLE)
+        {
+            mask |= WGL_CONTEXT_ES_PROFILE_BIT_EXT;
+        }
+        else
+        {
+            // Request core profile
+            mask |= WGL_CONTEXT_CORE_PROFILE_BIT_ARB;
+        }
 
         std::vector<int> contextCreationAttributes;
 
         // Don't request a specific version unless the user wants one.  WGL will return the highest version
         // that the driver supports if no version is requested.
-        const egl::AttributeMap &displayAttributes = display->getAttributeMap();
         EGLint requestedMajorVersion = displayAttributes.get(EGL_PLATFORM_ANGLE_MAX_VERSION_MAJOR_ANGLE, EGL_DONT_CARE);
         EGLint requestedMinorVersion = displayAttributes.get(EGL_PLATFORM_ANGLE_MAX_VERSION_MINOR_ANGLE, EGL_DONT_CARE);
         if (requestedMajorVersion != EGL_DONT_CARE && requestedMinorVersion != EGL_DONT_CARE)
@@ -248,6 +267,20 @@ egl::Error DisplayWGL::initialize(egl::Display *display)
             contextCreationAttributes.push_back(WGL_CONTEXT_MINOR_VERSION_ARB);
             contextCreationAttributes.push_back(requestedMinorVersion);
         }
+        else
+        {
+            // the ES profile will give us ES version 1.1 unless a higher version is requested.
+            // Requesting version 2.0 will give us the highest compatible version available (2.0,
+            // 3.0, 3.1, etc).
+            if (requestedDisplayType == EGL_PLATFORM_ANGLE_TYPE_OPENGLES_ANGLE)
+            {
+                contextCreationAttributes.push_back(WGL_CONTEXT_MAJOR_VERSION_ARB);
+                contextCreationAttributes.push_back(2);
+
+                contextCreationAttributes.push_back(WGL_CONTEXT_MINOR_VERSION_ARB);
+                contextCreationAttributes.push_back(0);
+            }
+        }
 
         // Set the flag attributes
         if (flags != 0)