michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* vim: set sw=2 ts=8 et ft=cpp : */
michael@0: /* Copyright 2012 Mozilla Foundation and Mozilla contributors
michael@0:  *
michael@0:  * Licensed under the Apache License, Version 2.0 (the "License");
michael@0:  * you may not use this file except in compliance with the License.
michael@0:  * You may obtain a copy of the License at
michael@0:  *
michael@0:  *     http://www.apache.org/licenses/LICENSE-2.0
michael@0:  *
michael@0:  * Unless required by applicable law or agreed to in writing, software
michael@0:  * distributed under the License is distributed on an "AS IS" BASIS,
michael@0:  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
michael@0:  * See the License for the specific language governing permissions and
michael@0:  * limitations under the License.
michael@0:  */
michael@0: 
michael@0: class gfxASurface;
michael@0: class nsIntRegion;
michael@0: class nsIntSize;
michael@0: 
michael@0: namespace mozilla {
michael@0: 
michael@0: namespace Framebuffer {
michael@0: 
michael@0: //
michael@0: // The general usage of Framebuffer is
michael@0: //
michael@0: // -- in initialization code --
michael@0: //  Open();
michael@0: //
michael@0: // -- ready to paint next frame --
michael@0: //  nsRefPtr<gfxASurface> backBuffer = BackBuffer();
michael@0: //  // ...
michael@0: //  Paint(backBuffer);
michael@0: //  // ...
michael@0: //  Present();
michael@0: //
michael@0: 
michael@0: // Return true if the fbdev was successfully opened.  If this fails, 
michael@0: // the result of all further calls is undefined.  Open() is idempotent.
michael@0: bool Open();
michael@0: 
michael@0: // After Close(), the result of all further calls is undefined.
michael@0: // Close() is idempotent, and Open() can be called again after
michael@0: // Close().
michael@0: void Close();
michael@0: 
michael@0: // Return true if the fbdev was successfully opened or the size was
michael@0: // already cached.
michael@0: bool GetSize(nsIntSize *aScreenSize);
michael@0: 
michael@0: // Return the buffer to be drawn into, that will be the next frame.
michael@0: gfxASurface* BackBuffer();
michael@0: 
michael@0: // Swap the front buffer for the back buffer.  |aUpdated| is the
michael@0: // region of the back buffer that was repainted.
michael@0: void Present(const nsIntRegion& aUpdated);
michael@0: 
michael@0: } // namespace Framebuffer
michael@0: 
michael@0: } // namespace mozilla