1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/layers/opengl/Composer2D.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,68 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
1.5 + * vim: sw=2 ts=8 et :
1.6 + */
1.7 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.8 + * License, v. 2.0. If a copy of the MPL was not distributed with this file,
1.9 + * You can obtain one at http://mozilla.org/MPL/2.0/. */
1.10 +
1.11 +#ifndef mozilla_layers_Composer2D_h
1.12 +#define mozilla_layers_Composer2D_h
1.13 +
1.14 +#include "gfxTypes.h"
1.15 +#include "nsISupportsImpl.h"
1.16 +
1.17 +/**
1.18 + * Many platforms have dedicated hardware for simple composition.
1.19 + * This hardware is usually faster or more power efficient than the
1.20 + * GPU. However, in exchange for this better performance, generality
1.21 + * has to be sacrificed: no 3d transforms, no intermediate surfaces,
1.22 + * no special shader effects, loss of other goodies depending on the
1.23 + * platform.
1.24 + *
1.25 + * Composer2D is a very simple interface to this class of hardware
1.26 + * that allows an implementation to "try rendering" with the fast
1.27 + * path. If the given layer tree requires more generality than the
1.28 + * hardware provides, the implementation should bail and have the
1.29 + * layer manager fall back on full GPU composition.
1.30 + */
1.31 +
1.32 +namespace mozilla {
1.33 +
1.34 +namespace gfx {
1.35 +struct Matrix;
1.36 +}
1.37 +
1.38 +namespace layers {
1.39 +
1.40 +class Layer;
1.41 +
1.42 +class Composer2D {
1.43 + NS_INLINE_DECL_REFCOUNTING(Composer2D)
1.44 +
1.45 +protected:
1.46 + // Protected destructor, to discourage deletion outside of Release():
1.47 + virtual ~Composer2D() {}
1.48 +
1.49 +public:
1.50 + /**
1.51 + * Return true if |aRoot| met the implementation's criteria for fast
1.52 + * composition and the render was successful. Return false to fall
1.53 + * back on the GPU.
1.54 + *
1.55 + * |aWorldTransform| must be applied to |aRoot|'s subtree when
1.56 + * rendering to the framebuffer. This is a global transform on the
1.57 + * entire scene, defined in GL space. If the Composer2D
1.58 + * implementation is unable to honor the transform, it should return
1.59 + * false.
1.60 + *
1.61 + * Currently, when TryRender() returns true, the entire framebuffer
1.62 + * must have been rendered.
1.63 + */
1.64 + virtual bool TryRender(Layer* aRoot, const gfx::Matrix& aWorldTransform,
1.65 + bool aGeometryChanged) = 0;
1.66 +};
1.67 +
1.68 +} // namespace layers
1.69 +} // namespace mozilla
1.70 +
1.71 +#endif // mozilla_layers_Composer2D_h
