Bug 1014614 - Fix readback of SurfaceTextureImage r=jgilbert

--HG--
extra : rebase_source : 3580c219b47615d55bfa3d1c672d017dd67ef0a1
extra : histedit_source : 24c932ac4ebabad7d706fa5599d5f32762ce5a02

gfx/layers/GLImages.cpp

@@ -0,0 +1,60 @@
+#ifdef MOZ_WIDGET_ANDROID
+
+#include "GLImages.h"
+#include "GLContext.h"
+#include "GLContextProvider.h"
+#include "ScopedGLHelpers.h"
+#include "GLImages.h"
+#include "GLBlitHelper.h"
+#include "GLReadTexImageHelper.h"
+#include "AndroidSurfaceTexture.h"
+
+using namespace mozilla;
+using namespace mozilla::gl;
+
+static Mutex sSnapshotMutex("SurfaceTextureImage::sSnapshotMutex");
+static nsRefPtr<GLContext> sSnapshotContext;
+
+TemporaryRef<gfx::SourceSurface>
+SurfaceTextureImage::GetAsSourceSurface()
+{
+  MutexAutoLock lock(sSnapshotMutex);
+
+  MOZ_ASSERT(NS_IsMainThread(), "Should be on the main thread");
+
+  if (!sSnapshotContext) {
+    SurfaceCaps caps = SurfaceCaps::ForRGBA();
+    sSnapshotContext = GLContextProvider::CreateOffscreen(gfxIntSize(16, 16), caps);
+
+    if (!sSnapshotContext) {
+      return nullptr;
+    }
+  }
+
+  sSnapshotContext->MakeCurrent();
+  ScopedTexture scopedTex(sSnapshotContext);
+  ScopedBindTexture boundTex(sSnapshotContext, scopedTex.Texture());
+  sSnapshotContext->fTexImage2D(LOCAL_GL_TEXTURE_2D, 0, LOCAL_GL_RGBA,
+                                mData.mSize.width, mData.mSize.height, 0,
+                                LOCAL_GL_RGBA,
+                                LOCAL_GL_UNSIGNED_BYTE,
+                                nullptr);
+
+  ScopedFramebufferForTexture fb(sSnapshotContext, scopedTex.Texture());
+
+  GLBlitHelper helper(sSnapshotContext);
+
+  helper.BlitImageToFramebuffer(this, mData.mSize, fb.FB(), false);
+  ScopedBindFramebuffer bind(sSnapshotContext, fb.FB());
+
+  RefPtr<DataSourceSurface> source =
+        Factory::CreateDataSourceSurface(mData.mSize, gfx::SurfaceFormat::B8G8R8A8);
+  if (NS_WARN_IF(!source)) {
+    return nullptr;
+  }
+
+  ReadPixelsIntoDataSurface(sSnapshotContext, source);
+  return source.forget();
+}
+
+#endif

gfx/layers/GLImages.h

@@ -57,10 +57,7 @@ public:
 
   gfx::IntSize GetSize() { return mData.mSize; }
 
-  virtual TemporaryRef<gfx::SourceSurface> GetAsSourceSurface() MOZ_OVERRIDE
-  {
-    return nullptr;
-  }
+  virtual TemporaryRef<gfx::SourceSurface> GetAsSourceSurface() MOZ_OVERRIDE;
 
   SurfaceTextureImage() : Image(nullptr, ImageFormat::SURFACE_TEXTURE) {}
 

gfx/layers/moz.build

@@ -288,6 +288,7 @@ UNIFIED_SOURCES += [
     'Compositor.cpp',
     'CopyableCanvasLayer.cpp',
     'Effects.cpp',
+    'GLImages.cpp',
     'ImageDataSerializer.cpp',
     'ImageLayers.cpp',
     'ipc/AsyncTransactionTracker.cpp',