Enable GL_CHROMIUM_post_sub_buffer for osmesa

Small changes to WGC3DInProcessImpl to pass the extension up to WebKit.

BUG=none
TEST=with https://bugs.webkit.org/show_bug.cgi?id=67341 and --use-gl=osmesa


Review URL: http://codereview.chromium.org/8772021

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@112738 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 105 insertions, 0 deletions

diff --git a/ui/gfx/gl/gl_surface_linux.cc b/ui/gfx/gl/gl_surface_linux.cc
index cf067c2..b152b46 100644
--- a/ui/gfx/gl/gl_surface_linux.cc
+++ b/ui/gfx/gl/gl_surface_linux.cc
@@ -42,6 +42,8 @@ class NativeViewGLSurfaceOSMesa : public GLSurfaceOSMesa {
   virtual void Destroy();
   virtual bool IsOffscreen();
   virtual bool SwapBuffers();
+  virtual std::string GetExtensions();
+  virtual bool PostSubBuffer(int x, int y, int width, int height);
 
  private:
   bool UpdateSize();
@@ -194,6 +196,59 @@ bool NativeViewGLSurfaceOSMesa::SwapBuffers() {
   return true;
 }
 
+std::string NativeViewGLSurfaceOSMesa::GetExtensions() {
+  std::string extensions = gfx::GLSurfaceOSMesa::GetExtensions();
+  extensions += extensions.empty() ? "" : " ";
+  extensions += "GL_CHROMIUM_post_sub_buffer";
+  return extensions;
+}
+
+bool NativeViewGLSurfaceOSMesa::PostSubBuffer(
+    int x, int y, int width, int height) {
+  // Update the size before blitting so that the blit size is exactly the same
+  // as the window.
+  if (!UpdateSize()) {
+    LOG(ERROR) << "Failed to update size of GLContextOSMesa.";
+    return false;
+  }
+
+  gfx::Size size = GetSize();
+
+  // Move (0,0) from lower-left to upper-left
+  y = size.height() - y - height;
+
+  XWindowAttributes attributes;
+  if (!XGetWindowAttributes(g_osmesa_display, window_, &attributes)) {
+    LOG(ERROR) << "XGetWindowAttributes failed for window " << window_ << ".";
+    return false;
+  }
+
+  // Copy the frame into the pixmap.
+  ui::PutARGBImage(g_osmesa_display,
+                   attributes.visual,
+                   attributes.depth,
+                   pixmap_,
+                   pixmap_graphics_context_,
+                   static_cast<const uint8*>(GetHandle()),
+                   size.width(),
+                   size.height(),
+                   x, y,
+                   x, y,
+                   width,
+                   height);
+
+  // Copy the pixmap to the window.
+  XCopyArea(g_osmesa_display,
+            pixmap_,
+            window_,
+            window_graphics_context_,
+            x, y,
+            width, height,
+            x, y);
+
+  return true;
+}
+
 bool NativeViewGLSurfaceOSMesa::UpdateSize() {
   // Get the window size.
   XWindowAttributes attributes;
diff --git a/ui/gfx/gl/gl_surface_win.cc b/ui/gfx/gl/gl_surface_win.cc
index e6abf55..08b3396 100644
--- a/ui/gfx/gl/gl_surface_win.cc
+++ b/ui/gfx/gl/gl_surface_win.cc
@@ -30,6 +30,8 @@ class NativeViewGLSurfaceOSMesa : public GLSurfaceOSMesa {
   virtual void Destroy();
   virtual bool IsOffscreen();
   virtual bool SwapBuffers();
+  virtual std::string GetExtensions();
+  virtual bool PostSubBuffer(int x, int y, int width, int height);
 
  private:
   void UpdateSize();
@@ -134,6 +136,54 @@ bool NativeViewGLSurfaceOSMesa::SwapBuffers() {
   return true;
 }
 
+std::string NativeViewGLSurfaceOSMesa::GetExtensions() {
+  std::string extensions = gfx::GLSurfaceOSMesa::GetExtensions();
+  extensions += extensions.empty() ? "" : " ";
+  extensions += "GL_CHROMIUM_post_sub_buffer";
+  return extensions;
+}
+
+bool NativeViewGLSurfaceOSMesa::PostSubBuffer(
+    int x, int y, int width, int height) {
+  DCHECK(device_context_);
+
+  // Update the size before blitting so that the blit size is exactly the same
+  // as the window.
+  UpdateSize();
+
+  gfx::Size size = GetSize();
+
+  // Note: negating the height below causes GDI to treat the bitmap data as row
+  // 0 being at the top.
+  BITMAPV4HEADER info = { sizeof(BITMAPV4HEADER) };
+  info.bV4Width = size.width();
+  info.bV4Height = -size.height();
+  info.bV4Planes = 1;
+  info.bV4BitCount = 32;
+  info.bV4V4Compression = BI_BITFIELDS;
+  info.bV4RedMask = 0x000000FF;
+  info.bV4GreenMask = 0x0000FF00;
+  info.bV4BlueMask = 0x00FF0000;
+  info.bV4AlphaMask = 0xFF000000;
+
+  // Copy the back buffer to the window's device context. Do not check whether
+  // StretchDIBits succeeds or not. It will fail if the window has been
+  // destroyed but it is preferable to allow rendering to silently fail if the
+  // window is destroyed. This is because the primary application of this
+  // class of GLContext is for testing and we do not want every GL related ui /
+  // browser test to become flaky if there is a race condition between GL
+  // context destruction and window destruction.
+  StretchDIBits(device_context_,
+                x, size.height() - y - height, width, height,
+                x, y, width, height,
+                GetHandle(),
+                reinterpret_cast<BITMAPINFO*>(&info),
+                DIB_RGB_COLORS,
+                SRCCOPY);
+
+  return true;
+}
+
 void NativeViewGLSurfaceOSMesa::UpdateSize() {
   // Change back buffer size to that of window. If window handle is invalid, do
   // not change the back buffer size.