gecko-dev/image/SurfacePipeFactory.h

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C
Исходник Обычный вид История

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_image_SurfacePipeFactory_h
#define mozilla_image_SurfacePipeFactory_h
#include "SurfacePipe.h"
#include "SurfaceFilters.h"
namespace mozilla {
namespace image {
namespace detail {
/**
* FilterPipeline is a helper template for SurfacePipeFactory that determines
* the full type of the sequence of SurfaceFilters that a sequence of
* configuration structs corresponds to. To make this work, all configuration
* structs must include a typedef 'Filter' that identifies the SurfaceFilter
* they configure.
*/
template <typename... Configs>
struct FilterPipeline;
template <typename Config, typename... Configs>
struct FilterPipeline<Config, Configs...>
{
typedef typename Config::template Filter<typename FilterPipeline<Configs...>::Type> Type;
};
template <typename Config>
struct FilterPipeline<Config>
{
typedef typename Config::Filter Type;
};
} // namespace detail
/**
* Flags for SurfacePipeFactory, used in conjuction with the factory functions
* in SurfacePipeFactory to enable or disable various SurfacePipe
* functionality.
*/
enum class SurfacePipeFlags
{
DEINTERLACE = 1 << 0, // If set, deinterlace the image.
ADAM7_INTERPOLATE = 1 << 1, // If set, the caller is deinterlacing the
// image using ADAM7, and we may want to
// interpolate it for better intermediate results.
FLIP_VERTICALLY = 1 << 2, // If set, flip the image vertically.
PROGRESSIVE_DISPLAY = 1 << 3 // If set, we expect the image to be displayed
// progressively. This enables features that
// result in a better user experience for
// progressive display but which may be more
// computationally expensive.
};
MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(SurfacePipeFlags)
class SurfacePipeFactory
{
public:
/**
* Creates and initializes a normal (i.e., non-paletted) SurfacePipe.
*
* @param aDecoder The decoder whose current frame the SurfacePipe will write
* to.
* @param aFrameNum Which frame the SurfacePipe will write to. This will be 0
* for non-animated images.
* @param aInputSize The original size of the image.
* @param aOutputSize The size the SurfacePipe should output. Must be the same
* as @aInputSize or smaller. If smaller, the image will be
* downscaled during decoding.
* @param aFrameRect The portion of the image that actually contains data.
* @param aFormat The surface format of the image; generally B8G8R8A8 or
* B8G8R8X8.
* @param aFlags Flags enabling or disabling various functionality for the
* SurfacePipe; see the SurfacePipeFlags documentation for more
* information.
*
* @return A SurfacePipe if the parameters allowed one to be created
* successfully, or Nothing() if the SurfacePipe could not be
* initialized.
*/
static Maybe<SurfacePipe>
CreateSurfacePipe(Decoder* aDecoder,
uint32_t aFrameNum,
const nsIntSize& aInputSize,
const nsIntSize& aOutputSize,
const nsIntRect& aFrameRect,
gfx::SurfaceFormat aFormat,
SurfacePipeFlags aFlags)
{
const bool deinterlace = bool(aFlags & SurfacePipeFlags::DEINTERLACE);
const bool flipVertically = bool(aFlags & SurfacePipeFlags::FLIP_VERTICALLY);
const bool progressiveDisplay = bool(aFlags & SurfacePipeFlags::PROGRESSIVE_DISPLAY);
const bool downscale = aInputSize != aOutputSize;
const bool removeFrameRect =
!aFrameRect.IsEqualEdges(nsIntRect(0, 0, aInputSize.width, aInputSize.height));
// Don't interpolate if we're sure we won't show this surface to the user
// until it's completely decoded. The final pass of an ADAM7 image doesn't
// need interpolation, so we only need to interpolate if we'll be displaying
// the image while it's still being decoded.
const bool adam7Interpolate = bool(aFlags & SurfacePipeFlags::ADAM7_INTERPOLATE) &&
progressiveDisplay;
if (deinterlace && adam7Interpolate) {
MOZ_ASSERT_UNREACHABLE("ADAM7 deinterlacing is handled by libpng");
return Nothing();
}
// Construct configurations for the SurfaceFilters. Note that the order of
// these filters is significant. We want to deinterlace or interpolate raw
// input rows, before any other transformations, and we want to remove the
// frame rect (which may involve adding blank rows or columns to the image)
// before any downscaling, so that the new rows and columns are taken into
// account.
DeinterlacingConfig<uint32_t> deinterlacingConfig { progressiveDisplay };
ADAM7InterpolatingConfig interpolatingConfig;
RemoveFrameRectConfig removeFrameRectConfig { aFrameRect };
DownscalingConfig downscalingConfig { aInputSize, aFormat };
SurfaceConfig surfaceConfig { aDecoder, aFrameNum, aOutputSize,
aFormat, flipVertically };
Maybe<SurfacePipe> pipe;
if (downscale) {
if (removeFrameRect) {
if (deinterlace) {
pipe = MakePipe(deinterlacingConfig, removeFrameRectConfig,
downscalingConfig, surfaceConfig);
} else if (adam7Interpolate) {
pipe = MakePipe(interpolatingConfig, removeFrameRectConfig,
downscalingConfig, surfaceConfig);
} else { // (deinterlace and adam7Interpolate are false)
pipe = MakePipe(removeFrameRectConfig, downscalingConfig, surfaceConfig);
}
} else { // (removeFrameRect is false)
if (deinterlace) {
pipe = MakePipe(deinterlacingConfig, downscalingConfig, surfaceConfig);
} else if (adam7Interpolate) {
pipe = MakePipe(interpolatingConfig, downscalingConfig, surfaceConfig);
} else { // (deinterlace and adam7Interpolate are false)
pipe = MakePipe(downscalingConfig, surfaceConfig);
}
}
} else { // (downscale is false)
if (removeFrameRect) {
if (deinterlace) {
pipe = MakePipe(deinterlacingConfig, removeFrameRectConfig, surfaceConfig);
} else if (adam7Interpolate) {
pipe = MakePipe(interpolatingConfig, removeFrameRectConfig, surfaceConfig);
} else { // (deinterlace and adam7Interpolate are false)
pipe = MakePipe(removeFrameRectConfig, surfaceConfig);
}
} else { // (removeFrameRect is false)
if (deinterlace) {
pipe = MakePipe(deinterlacingConfig, surfaceConfig);
} else if (adam7Interpolate) {
pipe = MakePipe(interpolatingConfig, surfaceConfig);
} else { // (deinterlace and adam7Interpolate are false)
pipe = MakePipe(surfaceConfig);
}
}
}
return pipe;
}
/**
* Creates and initializes a paletted SurfacePipe.
*
* XXX(seth): We'll remove all support for paletted surfaces in bug 1247520,
* which means we can remove CreatePalettedSurfacePipe() entirely.
*
* @param aDecoder The decoder whose current frame the SurfacePipe will write
* to.
* @param aFrameNum Which frame the SurfacePipe will write to. This will be 0
* for non-animated images.
* @param aInputSize The original size of the image.
* @param aFrameRect The portion of the image that actually contains data.
* @param aFormat The surface format of the image; generally B8G8R8A8 or
* B8G8R8X8.
* @param aPaletteDepth The palette depth of the image.
* @param aFlags Flags enabling or disabling various functionality for the
* SurfacePipe; see the SurfacePipeFlags documentation for more
* information.
*
* @return A SurfacePipe if the parameters allowed one to be created
* successfully, or Nothing() if the SurfacePipe could not be
* initialized.
*/
static Maybe<SurfacePipe>
CreatePalettedSurfacePipe(Decoder* aDecoder,
uint32_t aFrameNum,
const nsIntSize& aInputSize,
const nsIntRect& aFrameRect,
gfx::SurfaceFormat aFormat,
uint8_t aPaletteDepth,
SurfacePipeFlags aFlags)
{
const bool deinterlace = bool(aFlags & SurfacePipeFlags::DEINTERLACE);
const bool flipVertically = bool(aFlags & SurfacePipeFlags::FLIP_VERTICALLY);
const bool progressiveDisplay = bool(aFlags & SurfacePipeFlags::PROGRESSIVE_DISPLAY);
// Construct configurations for the SurfaceFilters.
DeinterlacingConfig<uint8_t> deinterlacingConfig { progressiveDisplay };
PalettedSurfaceConfig palettedSurfaceConfig { aDecoder, aFrameNum, aInputSize,
aFrameRect, aFormat, aPaletteDepth,
flipVertically };
Maybe<SurfacePipe> pipe;
if (deinterlace) {
pipe = MakePipe(deinterlacingConfig, palettedSurfaceConfig);
} else {
pipe = MakePipe(palettedSurfaceConfig);
}
return pipe;
}
private:
template <typename... Configs>
static Maybe<SurfacePipe>
MakePipe(Configs... aConfigs)
{
auto pipe = MakeUnique<typename detail::FilterPipeline<Configs...>::Type>();
nsresult rv = pipe->Configure(aConfigs...);
if (NS_FAILED(rv)) {
return Nothing();
}
return Some(SurfacePipe { Move(pipe) } );
}
virtual ~SurfacePipeFactory() = 0;
};
} // namespace image
} // namespace mozilla
#endif // mozilla_image_SurfacePipeFactory_h