1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/layers/ImageDataSerializer.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,161 @@
1.4 +/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
1.5 + * This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#include "ImageDataSerializer.h"
1.10 +#include "gfx2DGlue.h" // for SurfaceFormatToImageFormat
1.11 +#include "gfxImageSurface.h" // for gfxImageSurface
1.12 +#include "gfxPoint.h" // for gfxIntSize
1.13 +#include "mozilla/Assertions.h" // for MOZ_ASSERT, etc
1.14 +#include "mozilla/gfx/2D.h" // for DataSourceSurface, Factory
1.15 +#include "mozilla/gfx/Tools.h" // for GetAlignedStride, etc
1.16 +#include "mozilla/mozalloc.h" // for operator delete, etc
1.17 +
1.18 +namespace mozilla {
1.19 +namespace layers {
1.20 +
1.21 +using namespace gfx;
1.22 +
1.23 +// The Data is layed out as follows:
1.24 +//
1.25 +// +-------------------+ -++ --+ <-- ImageDataSerializerBase::mData pointer
1.26 +// | SurfaceBufferInfo | | |
1.27 +// +-------------------+ --+ | offset
1.28 +// | ... | |
1.29 +// +-------------------+ ------+
1.30 +// | |
1.31 +// | data |
1.32 +// | |
1.33 +// +-------------------+
1.34 +
1.35 +// Structure written at the beginning of the data blob containing the image
1.36 +// (as shown in the figure above). It contains the necessary informations to
1.37 +// read the image in the blob.
1.38 +namespace {
1.39 +struct SurfaceBufferInfo
1.40 +{
1.41 + uint32_t width;
1.42 + uint32_t height;
1.43 + SurfaceFormat format;
1.44 +
1.45 + static uint32_t GetOffset()
1.46 + {
1.47 + return GetAlignedStride<16>(sizeof(SurfaceBufferInfo));
1.48 + }
1.49 +};
1.50 +} // anonymous namespace
1.51 +
1.52 +static SurfaceBufferInfo*
1.53 +GetBufferInfo(uint8_t* aData, size_t aDataSize)
1.54 +{
1.55 + return aDataSize >= sizeof(SurfaceBufferInfo)
1.56 + ? reinterpret_cast<SurfaceBufferInfo*>(aData)
1.57 + : nullptr;
1.58 +}
1.59 +
1.60 +void
1.61 +ImageDataSerializer::InitializeBufferInfo(IntSize aSize,
1.62 + SurfaceFormat aFormat)
1.63 +{
1.64 + SurfaceBufferInfo* info = GetBufferInfo(mData, mDataSize);
1.65 + MOZ_ASSERT(info); // OK to assert here, this method is client-side-only
1.66 + info->width = aSize.width;
1.67 + info->height = aSize.height;
1.68 + info->format = aFormat;
1.69 + Validate();
1.70 +}
1.71 +
1.72 +static inline uint32_t
1.73 +ComputeStride(SurfaceFormat aFormat, uint32_t aWidth)
1.74 +{
1.75 + return GetAlignedStride<4>(BytesPerPixel(aFormat) * aWidth);
1.76 +}
1.77 +
1.78 +uint32_t
1.79 +ImageDataSerializerBase::ComputeMinBufferSize(IntSize aSize,
1.80 + SurfaceFormat aFormat)
1.81 +{
1.82 + uint32_t bufsize = aSize.height * ComputeStride(aFormat, aSize.width);
1.83 + return SurfaceBufferInfo::GetOffset()
1.84 + + GetAlignedStride<16>(bufsize);
1.85 +}
1.86 +
1.87 +void
1.88 +ImageDataSerializerBase::Validate()
1.89 +{
1.90 + mIsValid = false;
1.91 + if (!mData) {
1.92 + return;
1.93 + }
1.94 + SurfaceBufferInfo* info = GetBufferInfo(mData, mDataSize);
1.95 + if (!info) {
1.96 + return;
1.97 + }
1.98 + size_t requiredSize =
1.99 + ComputeMinBufferSize(IntSize(info->width, info->height), info->format);
1.100 + mIsValid = requiredSize <= mDataSize;
1.101 +}
1.102 +
1.103 +uint8_t*
1.104 +ImageDataSerializerBase::GetData()
1.105 +{
1.106 + MOZ_ASSERT(IsValid());
1.107 + return mData + SurfaceBufferInfo::GetOffset();
1.108 +}
1.109 +
1.110 +uint32_t
1.111 +ImageDataSerializerBase::GetStride() const
1.112 +{
1.113 + MOZ_ASSERT(IsValid());
1.114 + SurfaceBufferInfo* info = GetBufferInfo(mData, mDataSize);
1.115 + return ComputeStride(GetFormat(), info->width);
1.116 +}
1.117 +
1.118 +IntSize
1.119 +ImageDataSerializerBase::GetSize() const
1.120 +{
1.121 + MOZ_ASSERT(IsValid());
1.122 + SurfaceBufferInfo* info = GetBufferInfo(mData, mDataSize);
1.123 + return IntSize(info->width, info->height);
1.124 +}
1.125 +
1.126 +SurfaceFormat
1.127 +ImageDataSerializerBase::GetFormat() const
1.128 +{
1.129 + MOZ_ASSERT(IsValid());
1.130 + return GetBufferInfo(mData, mDataSize)->format;
1.131 +}
1.132 +
1.133 +TemporaryRef<gfxImageSurface>
1.134 +ImageDataSerializerBase::GetAsThebesSurface()
1.135 +{
1.136 + MOZ_ASSERT(IsValid());
1.137 + IntSize size = GetSize();
1.138 + return new gfxImageSurface(GetData(),
1.139 + gfxIntSize(size.width, size.height),
1.140 + GetStride(),
1.141 + SurfaceFormatToImageFormat(GetFormat()));
1.142 +}
1.143 +
1.144 +TemporaryRef<DrawTarget>
1.145 +ImageDataSerializerBase::GetAsDrawTarget(gfx::BackendType aBackend)
1.146 +{
1.147 + MOZ_ASSERT(IsValid());
1.148 + return gfx::Factory::CreateDrawTargetForData(aBackend,
1.149 + GetData(), GetSize(),
1.150 + GetStride(), GetFormat());
1.151 +}
1.152 +
1.153 +TemporaryRef<gfx::DataSourceSurface>
1.154 +ImageDataSerializerBase::GetAsSurface()
1.155 +{
1.156 + MOZ_ASSERT(IsValid());
1.157 + return Factory::CreateWrappingDataSourceSurface(GetData(),
1.158 + GetStride(),
1.159 + GetSize(),
1.160 + GetFormat());
1.161 +}
1.162 +
1.163 +} // namespace layers
1.164 +} // namespace mozilla
