michael@0: /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
michael@0:  * This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "ImageDataSerializer.h"
michael@0: #include "gfx2DGlue.h"                  // for SurfaceFormatToImageFormat
michael@0: #include "gfxImageSurface.h"            // for gfxImageSurface
michael@0: #include "gfxPoint.h"                   // for gfxIntSize
michael@0: #include "mozilla/Assertions.h"         // for MOZ_ASSERT, etc
michael@0: #include "mozilla/gfx/2D.h"             // for DataSourceSurface, Factory
michael@0: #include "mozilla/gfx/Tools.h"          // for GetAlignedStride, etc
michael@0: #include "mozilla/mozalloc.h"           // for operator delete, etc
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace layers {
michael@0: 
michael@0: using namespace gfx;
michael@0: 
michael@0: // The Data is layed out as follows:
michael@0: //
michael@0: //  +-------------------+   -++ --+   <-- ImageDataSerializerBase::mData pointer
michael@0: //  | SurfaceBufferInfo |     |   |
michael@0: //  +-------------------+   --+   | offset
michael@0: //  |        ...        |         |
michael@0: //  +-------------------+   ------+
michael@0: //  |                   |
michael@0: //  |       data        |
michael@0: //  |                   |
michael@0: //  +-------------------+
michael@0: 
michael@0: // Structure written at the beginning of the data blob containing the image
michael@0: // (as shown in the figure above). It contains the necessary informations to
michael@0: // read the image in the blob.
michael@0: namespace {
michael@0: struct SurfaceBufferInfo
michael@0: {
michael@0:   uint32_t width;
michael@0:   uint32_t height;
michael@0:   SurfaceFormat format;
michael@0: 
michael@0:   static uint32_t GetOffset()
michael@0:   {
michael@0:     return GetAlignedStride<16>(sizeof(SurfaceBufferInfo));
michael@0:   }
michael@0: };
michael@0: } // anonymous namespace
michael@0: 
michael@0: static SurfaceBufferInfo*
michael@0: GetBufferInfo(uint8_t* aData, size_t aDataSize)
michael@0: {
michael@0:   return aDataSize >= sizeof(SurfaceBufferInfo)
michael@0:          ? reinterpret_cast<SurfaceBufferInfo*>(aData)
michael@0:          : nullptr;
michael@0: }
michael@0: 
michael@0: void
michael@0: ImageDataSerializer::InitializeBufferInfo(IntSize aSize,
michael@0:                                           SurfaceFormat aFormat)
michael@0: {
michael@0:   SurfaceBufferInfo* info = GetBufferInfo(mData, mDataSize);
michael@0:   MOZ_ASSERT(info); // OK to assert here, this method is client-side-only
michael@0:   info->width = aSize.width;
michael@0:   info->height = aSize.height;
michael@0:   info->format = aFormat;
michael@0:   Validate();
michael@0: }
michael@0: 
michael@0: static inline uint32_t
michael@0: ComputeStride(SurfaceFormat aFormat, uint32_t aWidth)
michael@0: {
michael@0:   return GetAlignedStride<4>(BytesPerPixel(aFormat) * aWidth);
michael@0: }
michael@0: 
michael@0: uint32_t
michael@0: ImageDataSerializerBase::ComputeMinBufferSize(IntSize aSize,
michael@0:                                           SurfaceFormat aFormat)
michael@0: {
michael@0:   uint32_t bufsize = aSize.height * ComputeStride(aFormat, aSize.width);
michael@0:   return SurfaceBufferInfo::GetOffset()
michael@0:        + GetAlignedStride<16>(bufsize);
michael@0: }
michael@0: 
michael@0: void
michael@0: ImageDataSerializerBase::Validate()
michael@0: {
michael@0:   mIsValid = false;
michael@0:   if (!mData) {
michael@0:     return;
michael@0:   }
michael@0:   SurfaceBufferInfo* info = GetBufferInfo(mData, mDataSize);
michael@0:   if (!info) {
michael@0:     return;
michael@0:   }
michael@0:   size_t requiredSize =
michael@0:            ComputeMinBufferSize(IntSize(info->width, info->height), info->format);
michael@0:   mIsValid = requiredSize <= mDataSize;
michael@0: }
michael@0: 
michael@0: uint8_t*
michael@0: ImageDataSerializerBase::GetData()
michael@0: {
michael@0:   MOZ_ASSERT(IsValid());
michael@0:   return mData + SurfaceBufferInfo::GetOffset();
michael@0: }
michael@0: 
michael@0: uint32_t
michael@0: ImageDataSerializerBase::GetStride() const
michael@0: {
michael@0:   MOZ_ASSERT(IsValid());
michael@0:   SurfaceBufferInfo* info = GetBufferInfo(mData, mDataSize);
michael@0:   return ComputeStride(GetFormat(), info->width);
michael@0: }
michael@0: 
michael@0: IntSize
michael@0: ImageDataSerializerBase::GetSize() const
michael@0: {
michael@0:   MOZ_ASSERT(IsValid());
michael@0:   SurfaceBufferInfo* info = GetBufferInfo(mData, mDataSize);
michael@0:   return IntSize(info->width, info->height);
michael@0: }
michael@0: 
michael@0: SurfaceFormat
michael@0: ImageDataSerializerBase::GetFormat() const
michael@0: {
michael@0:   MOZ_ASSERT(IsValid());
michael@0:   return GetBufferInfo(mData, mDataSize)->format;
michael@0: }
michael@0: 
michael@0: TemporaryRef<gfxImageSurface>
michael@0: ImageDataSerializerBase::GetAsThebesSurface()
michael@0: {
michael@0:   MOZ_ASSERT(IsValid());
michael@0:   IntSize size = GetSize();
michael@0:   return new gfxImageSurface(GetData(),
michael@0:                              gfxIntSize(size.width, size.height),
michael@0:                              GetStride(),
michael@0:                              SurfaceFormatToImageFormat(GetFormat()));
michael@0: }
michael@0: 
michael@0: TemporaryRef<DrawTarget>
michael@0: ImageDataSerializerBase::GetAsDrawTarget(gfx::BackendType aBackend)
michael@0: {
michael@0:   MOZ_ASSERT(IsValid());
michael@0:   return gfx::Factory::CreateDrawTargetForData(aBackend,
michael@0:                                                GetData(), GetSize(),
michael@0:                                                GetStride(), GetFormat());
michael@0: }
michael@0: 
michael@0: TemporaryRef<gfx::DataSourceSurface>
michael@0: ImageDataSerializerBase::GetAsSurface()
michael@0: {
michael@0:   MOZ_ASSERT(IsValid());
michael@0:   return Factory::CreateWrappingDataSourceSurface(GetData(),
michael@0:                                                   GetStride(),
michael@0:                                                   GetSize(),
michael@0:                                                   GetFormat());
michael@0: }
michael@0: 
michael@0: } // namespace layers
michael@0: } // namespace mozilla