Use EGL_ANGLE_surface_orientation in Chrome to avoid a blit.

ui/gl/gl_surface_egl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/gl/gl_surface_egl.h"
 
 #if defined(OS_ANDROID)
 #include <android/native_window_jni.h>
 #endif
 
@@ skipping 62 matching lines @@
 #define EGL_ANGLE_platform_angle_opengl 1
 #define EGL_PLATFORM_ANGLE_TYPE_OPENGL_ANGLE 0x320D
 #define EGL_PLATFORM_ANGLE_TYPE_OPENGLES_ANGLE 0x320E
 #endif /* EGL_ANGLE_platform_angle_opengl */
 
 #ifndef EGL_ANGLE_x11_visual
 #define EGL_ANGLE_x11_visual 1
 #define EGL_X11_VISUAL_ID_ANGLE 0x33A3
 #endif /* EGL_ANGLE_x11_visual */
 
+#ifndef EGL_ANGLE_surface_orientation
+#define EGL_ANGLE_surface_orientation
+#define EGL_OPTIMAL_SURFACE_ORIENTATION_ANGLE 0x33A7
+#define EGL_SURFACE_ORIENTATION_ANGLE 0x33A8
+#define EGL_SURFACE_ORIENTATION_INVERT_X_ANGLE 0x0001
+#define EGL_SURFACE_ORIENTATION_INVERT_Y_ANGLE 0x0002
+#endif /* EGL_ANGLE_surface_orientation */
+
 using ui::GetLastEGLErrorString;
 
 namespace gfx {
 
 #if defined(OS_WIN)
 unsigned int NativeViewGLSurfaceEGL::current_swap_generation_ = 0;
 unsigned int NativeViewGLSurfaceEGL::swaps_this_generation_ = 0;
 unsigned int NativeViewGLSurfaceEGL::last_multiswap_generation_ = 0;
 
 const unsigned int MULTISWAP_FRAME_VSYNC_THRESHOLD = 60;
 #endif
 
 namespace {
 
 EGLConfig g_config;
 EGLDisplay g_display;
 EGLNativeDisplayType g_native_display;
 
 const char* g_egl_extensions = NULL;
 bool g_egl_create_context_robustness_supported = false;
 bool g_egl_sync_control_supported = false;
 bool g_egl_window_fixed_size_supported = false;
 bool g_egl_surfaceless_context_supported = false;
+bool g_egl_surface_orientation_supported = false;
 
 class EGLSyncControlVSyncProvider
     : public gfx::SyncControlVSyncProvider {
  public:
   explicit EGLSyncControlVSyncProvider(EGLSurface surface)
       : SyncControlVSyncProvider(),
         surface_(surface) {
   }
 
   ~EGLSyncControlVSyncProvider() override {}
@@ skipping 237 matching lines @@
     return false;
   }
 
   g_egl_extensions = eglQueryString(g_display, EGL_EXTENSIONS);
   g_egl_create_context_robustness_supported =
       HasEGLExtension("EGL_EXT_create_context_robustness");
   g_egl_sync_control_supported =
       HasEGLExtension("EGL_CHROMIUM_sync_control");
   g_egl_window_fixed_size_supported =
       HasEGLExtension("EGL_ANGLE_window_fixed_size");
+  g_egl_surface_orientation_supported =
+      HasEGLExtension("EGL_ANGLE_surface_orientation");
 
   // TODO(oetuaho@nvidia.com): Surfaceless is disabled on Android as a temporary
   // workaround, since code written for Android WebView takes different paths
   // based on whether GL surface objects have underlying EGL surface handles,
   // conflicting with the use of surfaceless. See https://crbug.com/382349
 #if defined(OS_ANDROID)
   DCHECK(!g_egl_surfaceless_context_supported);
 #else
   // Check if SurfacelessEGL is supported.
   g_egl_surfaceless_context_supported =
@@ skipping 108 matching lines @@
   return g_display;
 }
 
 NativeViewGLSurfaceEGL::NativeViewGLSurfaceEGL(EGLNativeWindowType window)
     : window_(window),
       config_(NULL),
       size_(1, 1),
       surface_(NULL),
       supports_post_sub_buffer_(false),
       alpha_(true),
+      flips_vertically_(false),
       swap_interval_(1) {
 #if defined(OS_ANDROID)
   if (window)
     ANativeWindow_acquire(window);
 #endif
 
 #if defined(OS_WIN)
   vsync_override_ = false;
   swap_generation_ = 0;
   RECT windowRect;
@@ skipping 31 matching lines @@
     egl_window_attributes.push_back(size_.width());
     egl_window_attributes.push_back(EGL_HEIGHT);
     egl_window_attributes.push_back(size_.height());
   }
 
   if (gfx::g_driver_egl.ext.b_EGL_NV_post_sub_buffer) {
     egl_window_attributes.push_back(EGL_POST_SUB_BUFFER_SUPPORTED_NV);
     egl_window_attributes.push_back(EGL_TRUE);
   }
 
+  if (g_egl_surface_orientation_supported) {
+    EGLint attrib;
+    eglGetConfigAttrib(GetDisplay(), GetConfig(),
+                       EGL_OPTIMAL_SURFACE_ORIENTATION_ANGLE, &attrib);
+    flips_vertically_ = (attrib == EGL_SURFACE_ORIENTATION_INVERT_Y_ANGLE);
+  }
+
+  if (flips_vertically_) {
+    egl_window_attributes.push_back(EGL_SURFACE_ORIENTATION_ANGLE);
+    egl_window_attributes.push_back(EGL_SURFACE_ORIENTATION_INVERT_Y_ANGLE);
+  }
+
   egl_window_attributes.push_back(EGL_NONE);
   // Create a surface for the native window.
   surface_ = eglCreateWindowSurface(
       GetDisplay(), GetConfig(), window_, &egl_window_attributes[0]);
 
   if (!surface_) {
     LOG(ERROR) << "eglCreateWindowSurface failed with error "
                << GetLastEGLErrorString();
     Destroy();
     return false;
@@ skipping 141 matching lines @@
 }
 
 EGLSurface NativeViewGLSurfaceEGL::GetHandle() {
   return surface_;
 }
 
 bool NativeViewGLSurfaceEGL::SupportsPostSubBuffer() {
   return supports_post_sub_buffer_;
 }
 
+bool NativeViewGLSurfaceEGL::FlipsVertically() const {
+  return flips_vertically_;
+}
+
 gfx::SwapResult NativeViewGLSurfaceEGL::PostSubBuffer(int x,
                                                       int y,
                                                       int width,
                                                       int height) {
   DCHECK(supports_post_sub_buffer_);
   if (!CommitAndClearPendingOverlays()) {
     DVLOG(1) << "Failed to commit pending overlay planes.";
     return gfx::SwapResult::SWAP_FAILED;
   }
+  if (flips_vertically_) {
+    // With EGL_SURFACE_ORIENTATION_INVERT_Y_ANGLE the contents are rendered
+    // inverted, but the PostSubBuffer rectangle is still measured from the
+    // bottom left.
+    y = GetSize().height() - y - height;
+  }
   if (!eglPostSubBufferNV(GetDisplay(), surface_, x, y, width, height)) {
     DVLOG(1) << "eglPostSubBufferNV failed with error "
              << GetLastEGLErrorString();
     return gfx::SwapResult::SWAP_FAILED;
   }
   return gfx::SwapResult::SWAP_ACK;
 }
 
 bool NativeViewGLSurfaceEGL::SupportsCommitOverlayPlanes() {
 #if defined(OS_ANDROID)
@@ skipping 225 matching lines @@
 }
 
 void* SurfacelessEGL::GetShareHandle() {
   return NULL;
 }
 
 SurfacelessEGL::~SurfacelessEGL() {
 }
 
 }  // namespace gfx