shiny/driver/gldriver: try multiple ANGLE platforms

On Windows mobile/gl uses ANGLE for EGL. ANGLE has multiple backends
and for some graphics cards one of these may work better than other.

Automatically try to choose the next platform when initialization fails:
1. Default
2. Direct3D 11
3. Direct3D 9
4. Direct3D 11 with WARP

Change-Id: Ief0911574afaf4ded3f578a1cd7b9639828f3486
Reviewed-on: https://go-review.googlesource.com/30754
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>

shiny/driver/gldriver/egl.go

@@ -30,13 +30,25 @@ const (
 	_EGL_CONFIG_CAVEAT   = 0x3027
 	_EGL_NONE            = 0x3038
 
+	_EGL_CONTEXT_CLIENT_VERSION = 0x3098
+)
+
+// ANGLE specific options found in eglext.h
+const (
 	_EGL_PLATFORM_ANGLE_ANGLE                   = 0x3202
 	_EGL_PLATFORM_ANGLE_TYPE_ANGLE              = 0x3203
 	_EGL_PLATFORM_ANGLE_MAX_VERSION_MAJOR_ANGLE = 0x3204
 	_EGL_PLATFORM_ANGLE_MAX_VERSION_MINOR_ANGLE = 0x3205
 	_EGL_PLATFORM_ANGLE_TYPE_DEFAULT_ANGLE      = 0x3206
 
-	_EGL_CONTEXT_CLIENT_VERSION = 0x3098
+	_EGL_PLATFORM_ANGLE_TYPE_D3D9_ANGLE            = 0x3207
+	_EGL_PLATFORM_ANGLE_TYPE_D3D11_ANGLE           = 0x3208
+	_EGL_PLATFORM_ANGLE_DEVICE_TYPE_ANGLE          = 0x3209
+	_EGL_PLATFORM_ANGLE_DEVICE_TYPE_HARDWARE_ANGLE = 0x320A
+	_EGL_PLATFORM_ANGLE_DEVICE_TYPE_WARP_ANGLE     = 0x320B
+
+	_EGL_PLATFORM_ANGLE_TYPE_OPENGL_ANGLE   = 0x320D
+	_EGL_PLATFORM_ANGLE_TYPE_OPENGLES_ANGLE = 0x320E
 )
 
 const (

shiny/driver/gldriver/win32.go

@@ -222,28 +222,72 @@ func eglErr() error {
 }
 
 func createEGLSurface(hwnd syscall.Handle, w *windowImpl) error {
-	displayAttrib := [...]eglInt{
-		_EGL_PLATFORM_ANGLE_TYPE_ANGLE,
-		_EGL_PLATFORM_ANGLE_TYPE_DEFAULT_ANGLE,
-		_EGL_PLATFORM_ANGLE_MAX_VERSION_MAJOR_ANGLE, _EGL_DONT_CARE,
-		_EGL_PLATFORM_ANGLE_MAX_VERSION_MINOR_ANGLE, _EGL_DONT_CARE,
-		_EGL_NONE,
+	var displayAttribPlatforms = [][]eglInt{
+		// Default
+		[]eglInt{
+			_EGL_PLATFORM_ANGLE_TYPE_ANGLE,
+			_EGL_PLATFORM_ANGLE_TYPE_DEFAULT_ANGLE,
+			_EGL_PLATFORM_ANGLE_MAX_VERSION_MAJOR_ANGLE, _EGL_DONT_CARE,
+			_EGL_PLATFORM_ANGLE_MAX_VERSION_MINOR_ANGLE, _EGL_DONT_CARE,
+			_EGL_NONE,
+		},
+		// Direct3D 11
+		[]eglInt{
+			_EGL_PLATFORM_ANGLE_TYPE_ANGLE,
+			_EGL_PLATFORM_ANGLE_TYPE_D3D11_ANGLE,
+			_EGL_PLATFORM_ANGLE_MAX_VERSION_MAJOR_ANGLE, _EGL_DONT_CARE,
+			_EGL_PLATFORM_ANGLE_MAX_VERSION_MINOR_ANGLE, _EGL_DONT_CARE,
+			_EGL_NONE,
+		},
+		// Direct3D 9
+		[]eglInt{
+			_EGL_PLATFORM_ANGLE_TYPE_ANGLE,
+			_EGL_PLATFORM_ANGLE_TYPE_D3D9_ANGLE,
+			_EGL_PLATFORM_ANGLE_MAX_VERSION_MAJOR_ANGLE, _EGL_DONT_CARE,
+			_EGL_PLATFORM_ANGLE_MAX_VERSION_MINOR_ANGLE, _EGL_DONT_CARE,
+			_EGL_NONE,
+		},
+		// Direct3D 11 with WARP
+		//   https://msdn.microsoft.com/en-us/library/windows/desktop/gg615082.aspx
+		[]eglInt{
+			_EGL_PLATFORM_ANGLE_TYPE_ANGLE,
+			_EGL_PLATFORM_ANGLE_TYPE_D3D11_ANGLE,
+			_EGL_PLATFORM_ANGLE_DEVICE_TYPE_ANGLE,
+			_EGL_PLATFORM_ANGLE_DEVICE_TYPE_WARP_ANGLE,
+			_EGL_PLATFORM_ANGLE_MAX_VERSION_MAJOR_ANGLE, _EGL_DONT_CARE,
+			_EGL_PLATFORM_ANGLE_MAX_VERSION_MINOR_ANGLE, _EGL_DONT_CARE,
+			_EGL_NONE,
+		},
 	}
 
 	dc, err := win32.GetDC(hwnd)
 	if err != nil {
 		return fmt.Errorf("win32.GetDC failed: %v", err)
 	}
-	display, _, _ := eglGetPlatformDisplayEXT.Call(
-		_EGL_PLATFORM_ANGLE_ANGLE,
-		uintptr(dc),
-		uintptr(unsafe.Pointer(&displayAttrib)),
-	)
-	if display == _EGL_NO_DISPLAY {
-		return fmt.Errorf("eglGetPlatformDisplayEXT failed: %v", eglErr())
-	}
-	if ret, _, _ := eglInitialize.Call(display, 0, 0); ret == 0 {
-		return fmt.Errorf("eglInitialize failed: %v", eglErr())
+
+	var display uintptr = _EGL_NO_DISPLAY
+	for i, displayAttrib := range displayAttribPlatforms {
+		lastTry := i == len(displayAttribPlatforms)-1
+
+		display, _, _ = eglGetPlatformDisplayEXT.Call(
+			_EGL_PLATFORM_ANGLE_ANGLE,
+			uintptr(dc),
+			uintptr(unsafe.Pointer(&displayAttrib[0])),
+		)
+
+		if display == _EGL_NO_DISPLAY {
+			if !lastTry {
+				continue
+			}
+			return fmt.Errorf("eglGetPlatformDisplayEXT failed: %v", eglErr())
+		}
+
+		if ret, _, _ := eglInitialize.Call(display, 0, 0); ret == 0 {
+			if !lastTry {
+				continue
+			}
+			return fmt.Errorf("eglInitialize failed: %v", eglErr())
+		}
 	}
 
 	eglBindAPI.Call(_EGL_OPENGL_ES_API)