gecko/gfx/layers/ImageLayers.cpp
Robert O'Callahan 3c9a572fb4 Bug 663776. Part 3: Refactor layer transform snapping to distinguish translation-snapping from rect-snapping, and don't snap translation+scale transforms when we don't know all four edges of the rect that needs to be snapped. r=mattwoodrow
This separates SnapTransform into SnapTransformTranslation, which just snaps translations
and nothing else, and SnapTransform, which snaps translation+scale of rectangles.
2012-12-07 12:58:13 +13:00

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/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* 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/. */
#include "ImageLayers.h"
#include "ImageContainer.h"
namespace mozilla {
namespace layers {
ImageLayer::ImageLayer(LayerManager* aManager, void* aImplData)
: Layer(aManager, aImplData), mFilter(gfxPattern::FILTER_GOOD)
, mScaleMode(SCALE_NONE), mForceSingleTile(false)
{}
ImageLayer::~ImageLayer()
{}
void ImageLayer::SetContainer(ImageContainer* aContainer)
{
mContainer = aContainer;
}
void ImageLayer::ComputeEffectiveTransforms(const gfx3DMatrix& aTransformToSurface)
{
gfx3DMatrix local = GetLocalTransform();
// Snap image edges to pixel boundaries
gfxRect sourceRect(0, 0, 0, 0);
if (mContainer) {
sourceRect.SizeTo(mContainer->GetCurrentSize());
if (mScaleMode != SCALE_NONE &&
sourceRect.width != 0.0 && sourceRect.height != 0.0) {
NS_ASSERTION(mScaleMode == SCALE_STRETCH,
"No other scalemodes than stretch and none supported yet.");
local.Scale(mScaleToSize.width / sourceRect.width,
mScaleToSize.height / sourceRect.height, 1.0);
}
}
// Snap our local transform first, and snap the inherited transform as well.
// This makes our snapping equivalent to what would happen if our content
// was drawn into a ThebesLayer (gfxContext would snap using the local
// transform, then we'd snap again when compositing the ThebesLayer).
mEffectiveTransform =
SnapTransform(local, sourceRect, nullptr) *
SnapTransformTranslation(aTransformToSurface, nullptr);
ComputeEffectiveTransformForMaskLayer(aTransformToSurface);
}
}
}