| // Copyright 2011 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| |
| #include "config.h" |
| |
| #include "CCLayerTreeHostCommon.h" |
| |
| #include "CCLayerImpl.h" |
| #include "CCLayerIterator.h" |
| #include "CCLayerSorter.h" |
| #include "CCMathUtil.h" |
| #include "CCRenderSurface.h" |
| #include "FloatQuad.h" |
| #include "IntRect.h" |
| #include "LayerChromium.h" |
| #include "RenderSurfaceChromium.h" |
| #include <public/WebTransformationMatrix.h> |
| |
| using WebKit::WebTransformationMatrix; |
| |
| namespace cc { |
| |
| IntRect CCLayerTreeHostCommon::calculateVisibleRect(const IntRect& targetSurfaceRect, const IntRect& layerBoundRect, const WebTransformationMatrix& transform) |
| { |
| // Is this layer fully contained within the target surface? |
| IntRect layerInSurfaceSpace = CCMathUtil::mapClippedRect(transform, layerBoundRect); |
| if (targetSurfaceRect.contains(layerInSurfaceSpace)) |
| return layerBoundRect; |
| |
| // If the layer doesn't fill up the entire surface, then find the part of |
| // the surface rect where the layer could be visible. This avoids trying to |
| // project surface rect points that are behind the projection point. |
| IntRect minimalSurfaceRect = targetSurfaceRect; |
| minimalSurfaceRect.intersect(layerInSurfaceSpace); |
| |
| // Project the corners of the target surface rect into the layer space. |
| // This bounding rectangle may be larger than it needs to be (being |
| // axis-aligned), but is a reasonable filter on the space to consider. |
| // Non-invertible transforms will create an empty rect here. |
| const WebTransformationMatrix surfaceToLayer = transform.inverse(); |
| IntRect layerRect = enclosingIntRect(CCMathUtil::projectClippedRect(surfaceToLayer, FloatRect(minimalSurfaceRect))); |
| layerRect.intersect(layerBoundRect); |
| return layerRect; |
| } |
| |
| template<typename LayerType> |
| static inline bool layerIsInExisting3DRenderingContext(LayerType* layer) |
| { |
| // According to current W3C spec on CSS transforms, a layer is part of an established |
| // 3d rendering context if its parent has transform-style of preserves-3d. |
| return layer->parent() && layer->parent()->preserves3D(); |
| } |
| |
| template<typename LayerType> |
| static bool layerIsRootOfNewRenderingContext(LayerType* layer) |
| { |
| // According to current W3C spec on CSS transforms (Section 6.1), a layer is the |
| // beginning of 3d rendering context if its parent does not have transform-style: |
| // preserve-3d, but this layer itself does. |
| if (layer->parent()) |
| return !layer->parent()->preserves3D() && layer->preserves3D(); |
| |
| return layer->preserves3D(); |
| } |
| |
| template<typename LayerType> |
| static bool isLayerBackFaceVisible(LayerType* layer) |
| { |
| // The current W3C spec on CSS transforms says that backface visibility should be |
| // determined differently depending on whether the layer is in a "3d rendering |
| // context" or not. For Chromium code, we can determine whether we are in a 3d |
| // rendering context by checking if the parent preserves 3d. |
| |
| if (layerIsInExisting3DRenderingContext(layer)) |
| return layer->drawTransform().isBackFaceVisible(); |
| |
| // In this case, either the layer establishes a new 3d rendering context, or is not in |
| // a 3d rendering context at all. |
| return layer->transform().isBackFaceVisible(); |
| } |
| |
| template<typename LayerType> |
| static bool isSurfaceBackFaceVisible(LayerType* layer, const WebTransformationMatrix& drawTransform) |
| { |
| if (layerIsInExisting3DRenderingContext(layer)) |
| return drawTransform.isBackFaceVisible(); |
| |
| if (layerIsRootOfNewRenderingContext(layer)) |
| return layer->transform().isBackFaceVisible(); |
| |
| // If the renderSurface is not part of a new or existing rendering context, then the |
| // layers that contribute to this surface will decide back-face visibility for themselves. |
| return false; |
| } |
| |
| template<typename LayerType> |
| static inline bool layerClipsSubtree(LayerType* layer) |
| { |
| return layer->masksToBounds() || layer->maskLayer(); |
| } |
| |
| template<typename LayerType> |
| static IntRect calculateVisibleContentRect(LayerType* layer) |
| { |
| ASSERT(layer->renderTarget()); |
| |
| IntRect targetSurfaceRect = layer->renderTarget()->renderSurface()->contentRect(); |
| |
| targetSurfaceRect.intersect(layer->drawableContentRect()); |
| |
| if (targetSurfaceRect.isEmpty() || layer->contentBounds().isEmpty()) |
| return IntRect(); |
| |
| const IntRect contentRect = IntRect(IntPoint(), layer->contentBounds()); |
| IntRect visibleContentRect = CCLayerTreeHostCommon::calculateVisibleRect(targetSurfaceRect, contentRect, layer->drawTransform()); |
| return visibleContentRect; |
| } |
| |
| static bool isScaleOrTranslation(const WebTransformationMatrix& m) |
| { |
| return !m.m12() && !m.m13() && !m.m14() |
| && !m.m21() && !m.m23() && !m.m24() |
| && !m.m31() && !m.m32() && !m.m43() |
| && m.m44(); |
| } |
| |
| static inline bool transformToParentIsKnown(CCLayerImpl*) |
| { |
| return true; |
| } |
| |
| static inline bool transformToParentIsKnown(LayerChromium* layer) |
| { |
| return !layer->transformIsAnimating(); |
| } |
| |
| static inline bool transformToScreenIsKnown(CCLayerImpl*) |
| { |
| return true; |
| } |
| |
| static inline bool transformToScreenIsKnown(LayerChromium* layer) |
| { |
| return !layer->screenSpaceTransformIsAnimating(); |
| } |
| |
| template<typename LayerType> |
| static bool layerShouldBeSkipped(LayerType* layer) |
| { |
| // Layers can be skipped if any of these conditions are met. |
| // - does not draw content. |
| // - is transparent |
| // - has empty bounds |
| // - the layer is not double-sided, but its back face is visible. |
| // |
| // Some additional conditions need to be computed at a later point after the recursion is finished. |
| // - the intersection of render surface content and layer clipRect is empty |
| // - the visibleContentRect is empty |
| // |
| // Note, if the layer should not have been drawn due to being fully transparent, |
| // we would have skipped the entire subtree and never made it into this function, |
| // so it is safe to omit this check here. |
| |
| if (!layer->drawsContent() || layer->bounds().isEmpty()) |
| return true; |
| |
| LayerType* backfaceTestLayer = layer; |
| if (layer->useParentBackfaceVisibility()) { |
| ASSERT(layer->parent()); |
| ASSERT(!layer->parent()->useParentBackfaceVisibility()); |
| backfaceTestLayer = layer->parent(); |
| } |
| |
| // The layer should not be drawn if (1) it is not double-sided and (2) the back of the layer is known to be facing the screen. |
| if (!backfaceTestLayer->doubleSided() && transformToScreenIsKnown(backfaceTestLayer) && isLayerBackFaceVisible(backfaceTestLayer)) |
| return true; |
| |
| return false; |
| } |
| |
| static inline bool subtreeShouldBeSkipped(CCLayerImpl* layer) |
| { |
| // The opacity of a layer always applies to its children (either implicitly |
| // via a render surface or explicitly if the parent preserves 3D), so the |
| // entire subtree can be skipped if this layer is fully transparent. |
| return !layer->opacity(); |
| } |
| |
| static inline bool subtreeShouldBeSkipped(LayerChromium* layer) |
| { |
| // If the opacity is being animated then the opacity on the main thread is unreliable |
| // (since the impl thread may be using a different opacity), so it should not be trusted. |
| // In particular, it should not cause the subtree to be skipped. |
| return !layer->opacity() && !layer->opacityIsAnimating(); |
| } |
| |
| template<typename LayerType> |
| static bool subtreeShouldRenderToSeparateSurface(LayerType* layer, bool axisAlignedWithRespectToParent) |
| { |
| // The root layer has a special render surface that is set up externally, so |
| // it shouldn't be treated as a surface in this code. |
| if (!layer->parent()) |
| return false; |
| |
| // Cache this value, because otherwise it walks the entire subtree several times. |
| bool descendantDrawsContent = layer->descendantDrawsContent(); |
| |
| // |
| // A layer and its descendants should render onto a new RenderSurface if any of these rules hold: |
| // |
| |
| // If we force it. |
| if (layer->forceRenderSurface()) |
| return true; |
| |
| // If the layer uses a mask. |
| if (layer->maskLayer()) |
| return true; |
| |
| // If the layer has a reflection. |
| if (layer->replicaLayer()) |
| return true; |
| |
| // If the layer uses a CSS filter. |
| if (!layer->filters().isEmpty() || !layer->backgroundFilters().isEmpty()) |
| return true; |
| |
| // If the layer flattens its subtree (i.e. the layer doesn't preserve-3d), but it is |
| // treated as a 3D object by its parent (i.e. parent does preserve-3d). |
| if (layerIsInExisting3DRenderingContext(layer) && !layer->preserves3D() && descendantDrawsContent) |
| return true; |
| |
| // If the layer clips its descendants but it is not axis-aligned with respect to its parent. |
| if (layerClipsSubtree(layer) && !axisAlignedWithRespectToParent && descendantDrawsContent) |
| return true; |
| |
| // If the layer has opacity != 1 and does not have a preserves-3d transform style. |
| if (layer->opacity() != 1 && !layer->preserves3D() && descendantDrawsContent) |
| return true; |
| |
| return false; |
| } |
| |
| WebTransformationMatrix computeScrollCompensationForThisLayer(CCLayerImpl* scrollingLayer, const WebTransformationMatrix& parentMatrix) |
| { |
| // For every layer that has non-zero scrollDelta, we have to compute a transform that can undo the |
| // scrollDelta translation. In particular, we want this matrix to premultiply a fixed-position layer's |
| // parentMatrix, so we design this transform in three steps as follows. The steps described here apply |
| // from right-to-left, so Step 1 would be the right-most matrix: |
| // |
| // Step 1. transform from target surface space to the exact space where scrollDelta is actually applied. |
| // -- this is inverse of the matrix in step 3 |
| // Step 2. undo the scrollDelta |
| // -- this is just a translation by scrollDelta. |
| // Step 3. transform back to target surface space. |
| // -- this transform is the "partialLayerOriginTransform" = (parentMatrix * scale(layer->pageScaleDelta())); |
| // |
| // These steps create a matrix that both start and end in targetSurfaceSpace. So this matrix can |
| // pre-multiply any fixed-position layer's drawTransform to undo the scrollDeltas -- as long as |
| // that fixed position layer is fixed onto the same renderTarget as this scrollingLayer. |
| // |
| |
| WebTransformationMatrix partialLayerOriginTransform = parentMatrix; |
| partialLayerOriginTransform.scale(scrollingLayer->pageScaleDelta()); |
| |
| WebTransformationMatrix scrollCompensationForThisLayer = partialLayerOriginTransform; // Step 3 |
| scrollCompensationForThisLayer.translate(scrollingLayer->scrollDelta().width(), scrollingLayer->scrollDelta().height()); // Step 2 |
| scrollCompensationForThisLayer.multiply(partialLayerOriginTransform.inverse()); // Step 1 |
| return scrollCompensationForThisLayer; |
| } |
| |
| WebTransformationMatrix computeScrollCompensationMatrixForChildren(LayerChromium* currentLayer, const WebTransformationMatrix& currentParentMatrix, const WebTransformationMatrix& currentScrollCompensation) |
| { |
| // The main thread (i.e. LayerChromium) does not need to worry about scroll compensation. |
| // So we can just return an identity matrix here. |
| return WebTransformationMatrix(); |
| } |
| |
| WebTransformationMatrix computeScrollCompensationMatrixForChildren(CCLayerImpl* layer, const WebTransformationMatrix& parentMatrix, const WebTransformationMatrix& currentScrollCompensationMatrix) |
| { |
| // "Total scroll compensation" is the transform needed to cancel out all scrollDelta translations that |
| // occurred since the nearest container layer, even if there are renderSurfaces in-between. |
| // |
| // There are some edge cases to be aware of, that are not explicit in the code: |
| // - A layer that is both a fixed-position and container should not be its own container, instead, that means |
| // it is fixed to an ancestor, and is a container for any fixed-position descendants. |
| // - A layer that is a fixed-position container and has a renderSurface should behave the same as a container |
| // without a renderSurface, the renderSurface is irrelevant in that case. |
| // - A layer that does not have an explicit container is simply fixed to the viewport |
| // (i.e. the root renderSurface, and it would still compensate for root layer's scrollDelta). |
| // - If the fixed-position layer has its own renderSurface, then the renderSurface is |
| // the one who gets fixed. |
| // |
| // This function needs to be called AFTER layers create their own renderSurfaces. |
| // |
| |
| // Avoid the overheads (including stack allocation and matrix initialization/copy) if we know that the scroll compensation doesn't need to be reset or adjusted. |
| if (!layer->isContainerForFixedPositionLayers() && layer->scrollDelta().isZero() && !layer->renderSurface()) |
| return currentScrollCompensationMatrix; |
| |
| // Start as identity matrix. |
| WebTransformationMatrix nextScrollCompensationMatrix; |
| |
| // If this layer is not a container, then it inherits the existing scroll compensations. |
| if (!layer->isContainerForFixedPositionLayers()) |
| nextScrollCompensationMatrix = currentScrollCompensationMatrix; |
| |
| // If the current layer has a non-zero scrollDelta, then we should compute its local scrollCompensation |
| // and accumulate it to the nextScrollCompensationMatrix. |
| if (!layer->scrollDelta().isZero()) { |
| WebTransformationMatrix scrollCompensationForThisLayer = computeScrollCompensationForThisLayer(layer, parentMatrix); |
| nextScrollCompensationMatrix.multiply(scrollCompensationForThisLayer); |
| } |
| |
| // If the layer created its own renderSurface, we have to adjust nextScrollCompensationMatrix. |
| // The adjustment allows us to continue using the scrollCompensation on the next surface. |
| // Step 1 (right-most in the math): transform from the new surface to the original ancestor surface |
| // Step 2: apply the scroll compensation |
| // Step 3: transform back to the new surface. |
| if (layer->renderSurface() && !nextScrollCompensationMatrix.isIdentity()) |
| nextScrollCompensationMatrix = layer->renderSurface()->drawTransform().inverse() * nextScrollCompensationMatrix * layer->renderSurface()->drawTransform(); |
| |
| return nextScrollCompensationMatrix; |
| } |
| |
| // Should be called just before the recursive calculateDrawTransformsInternal(). |
| template<typename LayerType, typename LayerList> |
| void setupRootLayerAndSurfaceForRecursion(LayerType* rootLayer, LayerList& renderSurfaceLayerList, const IntSize& deviceViewportSize) |
| { |
| if (!rootLayer->renderSurface()) |
| rootLayer->createRenderSurface(); |
| |
| rootLayer->renderSurface()->setContentRect(IntRect(IntPoint::zero(), deviceViewportSize)); |
| rootLayer->renderSurface()->clearLayerList(); |
| |
| ASSERT(renderSurfaceLayerList.isEmpty()); |
| renderSurfaceLayerList.append(rootLayer); |
| } |
| |
| // Recursively walks the layer tree starting at the given node and computes all the |
| // necessary transformations, clipRects, render surfaces, etc. |
| template<typename LayerType, typename LayerList, typename RenderSurfaceType, typename LayerSorter> |
| static void calculateDrawTransformsInternal(LayerType* layer, LayerType* rootLayer, const WebTransformationMatrix& parentMatrix, |
| const WebTransformationMatrix& fullHierarchyMatrix, const WebTransformationMatrix& currentScrollCompensationMatrix, |
| const IntRect& clipRectFromAncestor, bool ancestorClipsSubtree, |
| RenderSurfaceType* nearestAncestorThatMovesPixels, LayerList& renderSurfaceLayerList, LayerList& layerList, |
| LayerSorter* layerSorter, int maxTextureSize, float deviceScaleFactor, IntRect& drawableContentRectOfSubtree) |
| { |
| // This function computes the new matrix transformations recursively for this |
| // layer and all its descendants. It also computes the appropriate render surfaces. |
| // Some important points to remember: |
| // |
| // 0. Here, transforms are notated in Matrix x Vector order, and in words we describe what |
| // the transform does from left to right. |
| // |
| // 1. In our terminology, the "layer origin" refers to the top-left corner of a layer, and the |
| // positive Y-axis points downwards. This interpretation is valid because the orthographic |
| // projection applied at draw time flips the Y axis appropriately. |
| // |
| // 2. The anchor point, when given as a FloatPoint object, is specified in "unit layer space", |
| // where the bounds of the layer map to [0, 1]. However, as a WebTransformationMatrix object, |
| // the transform to the anchor point is specified in "pixel layer space", where the bounds |
| // of the layer map to [bounds.width(), bounds.height()]. |
| // |
| // 3. Definition of various transforms used: |
| // M[parent] is the parent matrix, with respect to the nearest render surface, passed down recursively. |
| // M[root] is the full hierarchy, with respect to the root, passed down recursively. |
| // Tr[origin] is the translation matrix from the parent's origin to this layer's origin. |
| // Tr[origin2anchor] is the translation from the layer's origin to its anchor point |
| // Tr[origin2center] is the translation from the layer's origin to its center |
| // M[layer] is the layer's matrix (applied at the anchor point) |
| // M[sublayer] is the layer's sublayer transform (applied at the layer's center) |
| // Tr[anchor2center] is the translation offset from the anchor point and the center of the layer |
| // S[content2layer] is the ratio of a layer's contentBounds() to its bounds(). |
| // |
| // Some shortcuts and substitutions are used in the code to reduce matrix multiplications: |
| // Tr[anchor2center] = Tr[origin2anchor].inverse() * Tr[origin2center] |
| // |
| // Some composite transforms can help in understanding the sequence of transforms: |
| // compositeLayerTransform = Tr[origin2anchor] * M[layer] * Tr[origin2anchor].inverse() |
| // compositeSublayerTransform = Tr[origin2center] * M[sublayer] * Tr[origin2center].inverse() |
| // |
| // In words, the layer transform is applied about the anchor point, and the sublayer transform is |
| // applied about the center of the layer. |
| // |
| // 4. When a layer (or render surface) is drawn, it is drawn into a "target render surface". Therefore the draw |
| // transform does not necessarily transform from screen space to local layer space. Instead, the draw transform |
| // is the transform between the "target render surface space" and local layer space. Note that render surfaces, |
| // except for the root, also draw themselves into a different target render surface, and so their draw |
| // transform and origin transforms are also described with respect to the target. |
| // |
| // Using these definitions, then: |
| // |
| // The draw transform for the layer is: |
| // M[draw] = M[parent] * Tr[origin] * compositeLayerTransform * S[content2layer] |
| // = M[parent] * Tr[layer->position()] * M[layer] * Tr[anchor2origin] * S[content2layer] |
| // |
| // Interpreting the math left-to-right, this transforms from the layer's render surface to the origin of the layer in content space. |
| // |
| // The screen space transform is: |
| // M[screenspace] = M[root] * Tr[origin] * compositeLayerTransform * S[content2layer] |
| // = M[root] * Tr[layer->position()] * M[layer] * Tr[origin2anchor].inverse() * S[content2layer] |
| // |
| // Interpreting the math left-to-right, this transforms from the root render surface's content space to the local layer's origin in layer space. |
| // |
| // The transform hierarchy that is passed on to children (i.e. the child's parentMatrix) is: |
| // M[parent]_for_child = M[parent] * Tr[origin] * compositeLayerTransform * compositeSublayerTransform |
| // = M[parent] * Tr[layer->position()] * M[layer] * Tr[anchor2center] * M[sublayer] * Tr[origin2center].inverse() |
| // = M[draw] * M[sublayer] * Tr[origin2center].inverse() |
| // |
| // and a similar matrix for the full hierarchy with respect to the root. |
| // |
| // Finally, note that the final matrix used by the shader for the layer is P * M[draw] * S . This final product |
| // is computed in drawTexturedQuad(), where: |
| // P is the projection matrix |
| // S is the scale adjustment (to scale up to the layer size) |
| // |
| // When a render surface has a replica layer, that layer's transform is used to draw a second copy of the surface. |
| // Transforms named here are relative to the surface, unless they specify they are relative to the replica layer. |
| // |
| // We will denote a scale by device scale S[deviceScale] |
| // |
| // The render surface draw transform to its target surface origin is: |
| // M[surfaceDraw] = M[owningLayer->Draw] |
| // |
| // The render surface origin transform to its the root (screen space) origin is: |
| // M[surface2root] = M[owningLayer->screenspace] * S[deviceScale].inverse() |
| // |
| // The replica draw transform to its target surface origin is: |
| // M[replicaDraw] = S[deviceScale] * M[surfaceDraw] * Tr[replica->position() + replica->anchor()] * Tr[replica] * Tr[origin2anchor].inverse() * S[contentsScale].inverse() |
| // |
| // The replica draw transform to the root (screen space) origin is: |
| // M[replica2root] = M[surface2root] * Tr[replica->position()] * Tr[replica] * Tr[origin2anchor].inverse() |
| // |
| |
| // If we early-exit anywhere in this function, the drawableContentRect of this subtree should be considered empty. |
| drawableContentRectOfSubtree = IntRect(); |
| |
| if (subtreeShouldBeSkipped(layer)) |
| return; |
| |
| IntRect clipRectForSubtree; |
| bool subtreeShouldBeClipped = false; |
| |
| float drawOpacity = layer->opacity(); |
| bool drawOpacityIsAnimating = layer->opacityIsAnimating(); |
| if (layer->parent() && layer->parent()->preserves3D()) { |
| drawOpacity *= layer->parent()->drawOpacity(); |
| drawOpacityIsAnimating |= layer->parent()->drawOpacityIsAnimating(); |
| } |
| |
| IntSize bounds = layer->bounds(); |
| FloatPoint anchorPoint = layer->anchorPoint(); |
| FloatPoint position = layer->position() - layer->scrollDelta(); |
| |
| // Offset between anchor point and the center of the quad. |
| float centerOffsetX = (0.5 - anchorPoint.x()) * bounds.width(); |
| float centerOffsetY = (0.5 - anchorPoint.y()) * bounds.height(); |
| |
| WebTransformationMatrix layerLocalTransform; |
| // LT = S[pageScaleDelta] |
| layerLocalTransform.scale(layer->pageScaleDelta()); |
| // LT = S[pageScaleDelta] * Tr[origin] * Tr[origin2anchor] |
| layerLocalTransform.translate3d(position.x() + anchorPoint.x() * bounds.width(), position.y() + anchorPoint.y() * bounds.height(), layer->anchorPointZ()); |
| // LT = S[pageScaleDelta] * Tr[origin] * Tr[origin2anchor] * M[layer] |
| layerLocalTransform.multiply(layer->transform()); |
| // LT = S[pageScaleDelta] * Tr[origin] * Tr[origin2anchor] * M[layer] * Tr[anchor2center] |
| layerLocalTransform.translate3d(centerOffsetX, centerOffsetY, -layer->anchorPointZ()); |
| |
| WebTransformationMatrix combinedTransform = parentMatrix; |
| combinedTransform.multiply(layerLocalTransform); |
| |
| if (layer->fixedToContainerLayer()) { |
| // Special case: this layer is a composited fixed-position layer; we need to |
| // explicitly compensate for all ancestors' nonzero scrollDeltas to keep this layer |
| // fixed correctly. |
| combinedTransform = currentScrollCompensationMatrix * combinedTransform; |
| } |
| |
| // The drawTransform that gets computed below is effectively the layer's drawTransform, unless |
| // the layer itself creates a renderSurface. In that case, the renderSurface re-parents the transforms. |
| WebTransformationMatrix drawTransform = combinedTransform; |
| // M[draw] = M[parent] * LT * Tr[anchor2center] * Tr[center2origin] |
| drawTransform.translate(-layer->bounds().width() / 2.0, -layer->bounds().height() / 2.0); |
| if (!layer->contentBounds().isEmpty() && !layer->bounds().isEmpty()) { |
| // M[draw] = M[parent] * LT * Tr[anchor2origin] * S[layer2content] |
| drawTransform.scaleNonUniform(layer->bounds().width() / static_cast<double>(layer->contentBounds().width()), |
| layer->bounds().height() / static_cast<double>(layer->contentBounds().height())); |
| } |
| |
| // layerScreenSpaceTransform represents the transform between root layer's "screen space" and local content space. |
| WebTransformationMatrix layerScreenSpaceTransform = fullHierarchyMatrix; |
| if (!layer->preserves3D()) |
| CCMathUtil::flattenTransformTo2d(layerScreenSpaceTransform); |
| layerScreenSpaceTransform.multiply(drawTransform); |
| layer->setScreenSpaceTransform(layerScreenSpaceTransform); |
| |
| bool animatingTransformToTarget = layer->transformIsAnimating(); |
| bool animatingTransformToScreen = animatingTransformToTarget; |
| if (layer->parent()) { |
| animatingTransformToTarget |= layer->parent()->drawTransformIsAnimating(); |
| animatingTransformToScreen |= layer->parent()->screenSpaceTransformIsAnimating(); |
| } |
| |
| FloatRect contentRect(FloatPoint(), layer->contentBounds()); |
| |
| // fullHierarchyMatrix is the matrix that transforms objects between screen space (except projection matrix) and the most recent RenderSurface's space. |
| // nextHierarchyMatrix will only change if this layer uses a new RenderSurface, otherwise remains the same. |
| WebTransformationMatrix nextHierarchyMatrix = fullHierarchyMatrix; |
| WebTransformationMatrix sublayerMatrix; |
| |
| if (subtreeShouldRenderToSeparateSurface(layer, isScaleOrTranslation(combinedTransform))) { |
| // Check back-face visibility before continuing with this surface and its subtree |
| if (!layer->doubleSided() && transformToParentIsKnown(layer) && isSurfaceBackFaceVisible(layer, combinedTransform)) |
| return; |
| |
| if (!layer->renderSurface()) |
| layer->createRenderSurface(); |
| |
| RenderSurfaceType* renderSurface = layer->renderSurface(); |
| renderSurface->clearLayerList(); |
| |
| // The origin of the new surface is the upper left corner of the layer. |
| renderSurface->setDrawTransform(drawTransform); |
| WebTransformationMatrix layerDrawTransform; |
| layerDrawTransform.scale(deviceScaleFactor); |
| if (!layer->contentBounds().isEmpty() && !layer->bounds().isEmpty()) { |
| layerDrawTransform.scaleNonUniform(layer->bounds().width() / static_cast<double>(layer->contentBounds().width()), |
| layer->bounds().height() / static_cast<double>(layer->contentBounds().height())); |
| } |
| layer->setDrawTransform(layerDrawTransform); |
| |
| // The sublayer matrix transforms centered layer rects into target |
| // surface content space. |
| sublayerMatrix.makeIdentity(); |
| sublayerMatrix.scale(deviceScaleFactor); |
| sublayerMatrix.translate(0.5 * bounds.width(), 0.5 * bounds.height()); |
| |
| // The opacity value is moved from the layer to its surface, so that the entire subtree properly inherits opacity. |
| renderSurface->setDrawOpacity(drawOpacity); |
| renderSurface->setDrawOpacityIsAnimating(drawOpacityIsAnimating); |
| layer->setDrawOpacity(1); |
| layer->setDrawOpacityIsAnimating(false); |
| |
| renderSurface->setTargetSurfaceTransformsAreAnimating(animatingTransformToTarget); |
| renderSurface->setScreenSpaceTransformsAreAnimating(animatingTransformToScreen); |
| animatingTransformToTarget = false; |
| layer->setDrawTransformIsAnimating(animatingTransformToTarget); |
| layer->setScreenSpaceTransformIsAnimating(animatingTransformToScreen); |
| |
| // Update the aggregate hierarchy matrix to include the transform of the |
| // newly created RenderSurface. |
| nextHierarchyMatrix.multiply(renderSurface->drawTransform()); |
| |
| // The new renderSurface here will correctly clip the entire subtree. So, we do |
| // not need to continue propagating the clipping state further down the tree. This |
| // way, we can avoid transforming clipRects from ancestor target surface space to |
| // current target surface space that could cause more w < 0 headaches. |
| subtreeShouldBeClipped = false; |
| |
| if (layer->maskLayer()) |
| layer->maskLayer()->setRenderTarget(layer); |
| |
| if (layer->replicaLayer() && layer->replicaLayer()->maskLayer()) |
| layer->replicaLayer()->maskLayer()->setRenderTarget(layer); |
| |
| if (layer->filters().hasFilterThatMovesPixels()) |
| nearestAncestorThatMovesPixels = renderSurface; |
| |
| renderSurface->setNearestAncestorThatMovesPixels(nearestAncestorThatMovesPixels); |
| |
| renderSurfaceLayerList.append(layer); |
| } else { |
| layer->setDrawTransform(drawTransform); |
| layer->setDrawTransformIsAnimating(animatingTransformToTarget); |
| layer->setScreenSpaceTransformIsAnimating(animatingTransformToScreen); |
| sublayerMatrix = combinedTransform; |
| |
| layer->setDrawOpacity(drawOpacity); |
| layer->setDrawOpacityIsAnimating(drawOpacityIsAnimating); |
| |
| if (layer != rootLayer) { |
| ASSERT(layer->parent()); |
| layer->clearRenderSurface(); |
| |
| // Layers without renderSurfaces directly inherit the ancestor's clip status. |
| subtreeShouldBeClipped = ancestorClipsSubtree; |
| if (ancestorClipsSubtree) |
| clipRectForSubtree = clipRectFromAncestor; |
| |
| // Layers that are not their own renderTarget will render into the target of their nearest ancestor. |
| layer->setRenderTarget(layer->parent()->renderTarget()); |
| } else { |
| // FIXME: This root layer special case code should eventually go away. https://bugs.webkit.org/show_bug.cgi?id=92290 |
| ASSERT(!layer->parent()); |
| ASSERT(layer->renderSurface()); |
| ASSERT(ancestorClipsSubtree); |
| layer->renderSurface()->setClipRect(clipRectFromAncestor); |
| subtreeShouldBeClipped = false; |
| } |
| } |
| |
| IntRect rectInTargetSpace = enclosingIntRect(CCMathUtil::mapClippedRect(layer->drawTransform(), contentRect)); |
| |
| if (layerClipsSubtree(layer)) { |
| subtreeShouldBeClipped = true; |
| if (ancestorClipsSubtree && !layer->renderSurface()) { |
| clipRectForSubtree = clipRectFromAncestor; |
| clipRectForSubtree.intersect(rectInTargetSpace); |
| } else |
| clipRectForSubtree = rectInTargetSpace; |
| } |
| |
| // Flatten to 2D if the layer doesn't preserve 3D. |
| if (!layer->preserves3D()) |
| CCMathUtil::flattenTransformTo2d(sublayerMatrix); |
| |
| // Apply the sublayer transform at the center of the layer. |
| sublayerMatrix.multiply(layer->sublayerTransform()); |
| |
| // The coordinate system given to children is located at the layer's origin, not the center. |
| sublayerMatrix.translate3d(-bounds.width() * 0.5, -bounds.height() * 0.5, 0); |
| |
| LayerList& descendants = (layer->renderSurface() ? layer->renderSurface()->layerList() : layerList); |
| |
| // Any layers that are appended after this point are in the layer's subtree and should be included in the sorting process. |
| unsigned sortingStartIndex = descendants.size(); |
| |
| if (!layerShouldBeSkipped(layer)) |
| descendants.append(layer); |
| |
| WebTransformationMatrix nextScrollCompensationMatrix = computeScrollCompensationMatrixForChildren(layer, parentMatrix, currentScrollCompensationMatrix);; |
| |
| IntRect accumulatedDrawableContentRectOfChildren; |
| for (size_t i = 0; i < layer->children().size(); ++i) { |
| LayerType* child = layer->children()[i].get(); |
| IntRect drawableContentRectOfChildSubtree; |
| calculateDrawTransformsInternal<LayerType, LayerList, RenderSurfaceType, LayerSorter>(child, rootLayer, sublayerMatrix, nextHierarchyMatrix, nextScrollCompensationMatrix, |
| clipRectForSubtree, subtreeShouldBeClipped, nearestAncestorThatMovesPixels, |
| renderSurfaceLayerList, descendants, layerSorter, maxTextureSize, deviceScaleFactor, drawableContentRectOfChildSubtree); |
| if (!drawableContentRectOfChildSubtree.isEmpty()) { |
| accumulatedDrawableContentRectOfChildren.unite(drawableContentRectOfChildSubtree); |
| if (child->renderSurface()) |
| descendants.append(child); |
| } |
| } |
| |
| // Compute the total drawableContentRect for this subtree (the rect is in targetSurface space) |
| IntRect localDrawableContentRectOfSubtree = accumulatedDrawableContentRectOfChildren; |
| if (layer->drawsContent()) |
| localDrawableContentRectOfSubtree.unite(rectInTargetSpace); |
| if (subtreeShouldBeClipped) |
| localDrawableContentRectOfSubtree.intersect(clipRectForSubtree); |
| |
| // Compute the layer's drawable content rect (the rect is in targetSurface space) |
| IntRect drawableContentRectOfLayer = rectInTargetSpace; |
| if (subtreeShouldBeClipped) |
| drawableContentRectOfLayer.intersect(clipRectForSubtree); |
| layer->setDrawableContentRect(drawableContentRectOfLayer); |
| |
| // Compute the remaining properties for the render surface, if the layer has one. |
| if (layer->renderSurface() && layer != rootLayer) { |
| RenderSurfaceType* renderSurface = layer->renderSurface(); |
| IntRect clippedContentRect = localDrawableContentRectOfSubtree; |
| |
| // The render surface clipRect is expressed in the space where this surface draws, i.e. the same space as clipRectFromAncestor. |
| if (ancestorClipsSubtree) |
| renderSurface->setClipRect(clipRectFromAncestor); |
| else |
| renderSurface->setClipRect(IntRect()); |
| |
| // Don't clip if the layer is reflected as the reflection shouldn't be |
| // clipped. If the layer is animating, then the surface's transform to |
| // its target is not known on the main thread, and we should not use it |
| // to clip. |
| if (!layer->replicaLayer() && transformToParentIsKnown(layer)) { |
| // Note, it is correct to use ancestorClipsSubtree here, because we are looking at this layer's renderSurface, not the layer itself. |
| if (ancestorClipsSubtree && !clippedContentRect.isEmpty()) { |
| IntRect surfaceClipRect = CCLayerTreeHostCommon::calculateVisibleRect(renderSurface->clipRect(), clippedContentRect, renderSurface->drawTransform()); |
| clippedContentRect.intersect(surfaceClipRect); |
| } |
| } |
| |
| // The RenderSurface backing texture cannot exceed the maximum supported |
| // texture size. |
| clippedContentRect.setWidth(std::min(clippedContentRect.width(), maxTextureSize)); |
| clippedContentRect.setHeight(std::min(clippedContentRect.height(), maxTextureSize)); |
| |
| if (clippedContentRect.isEmpty()) |
| renderSurface->clearLayerList(); |
| |
| renderSurface->setContentRect(clippedContentRect); |
| renderSurface->setScreenSpaceTransform(layer->screenSpaceTransform()); |
| |
| if (layer->replicaLayer()) { |
| WebTransformationMatrix surfaceOriginToReplicaOriginTransform; |
| surfaceOriginToReplicaOriginTransform.scale(deviceScaleFactor); |
| surfaceOriginToReplicaOriginTransform.translate(layer->replicaLayer()->position().x() + layer->replicaLayer()->anchorPoint().x() * bounds.width(), |
| layer->replicaLayer()->position().y() + layer->replicaLayer()->anchorPoint().y() * bounds.height()); |
| surfaceOriginToReplicaOriginTransform.multiply(layer->replicaLayer()->transform()); |
| surfaceOriginToReplicaOriginTransform.translate(-layer->replicaLayer()->anchorPoint().x() * bounds.width(), -layer->replicaLayer()->anchorPoint().y() * bounds.height()); |
| surfaceOriginToReplicaOriginTransform.scale(1 / deviceScaleFactor); |
| |
| // Compute the replica's "originTransform" that maps from the replica's origin space to the target surface origin space. |
| WebTransformationMatrix replicaOriginTransform = layer->renderSurface()->drawTransform() * surfaceOriginToReplicaOriginTransform; |
| renderSurface->setReplicaDrawTransform(replicaOriginTransform); |
| |
| // Compute the replica's "screenSpaceTransform" that maps from the replica's origin space to the screen's origin space. |
| WebTransformationMatrix replicaScreenSpaceTransform = layer->renderSurface()->screenSpaceTransform() * surfaceOriginToReplicaOriginTransform; |
| renderSurface->setReplicaScreenSpaceTransform(replicaScreenSpaceTransform); |
| } |
| |
| // If a render surface has no layer list, then it and none of its children needed to get drawn. |
| if (!layer->renderSurface()->layerList().size()) { |
| // FIXME: Originally we asserted that this layer was already at the end of the |
| // list, and only needed to remove that layer. For now, we remove the |
| // entire subtree of surfaces to fix a crash bug. The root cause is |
| // https://bugs.webkit.org/show_bug.cgi?id=74147 and we should be able |
| // to put the original assert after fixing that. |
| while (renderSurfaceLayerList.last() != layer) { |
| renderSurfaceLayerList.last()->clearRenderSurface(); |
| renderSurfaceLayerList.removeLast(); |
| } |
| ASSERT(renderSurfaceLayerList.last() == layer); |
| renderSurfaceLayerList.removeLast(); |
| layer->clearRenderSurface(); |
| return; |
| } |
| } |
| |
| // If neither this layer nor any of its children were added, early out. |
| if (sortingStartIndex == descendants.size()) |
| return; |
| |
| // If preserves-3d then sort all the descendants in 3D so that they can be |
| // drawn from back to front. If the preserves-3d property is also set on the parent then |
| // skip the sorting as the parent will sort all the descendants anyway. |
| if (descendants.size() && layer->preserves3D() && (!layer->parent() || !layer->parent()->preserves3D())) |
| sortLayers(&descendants.at(sortingStartIndex), descendants.end(), layerSorter); |
| |
| if (layer->renderSurface()) |
| drawableContentRectOfSubtree = enclosingIntRect(layer->renderSurface()->drawableContentRect()); |
| else |
| drawableContentRectOfSubtree = localDrawableContentRectOfSubtree; |
| |
| return; |
| } |
| |
| // FIXME: Instead of using the following function to set visibility rects on a second |
| // tree pass, revise calculateVisibleContentRect() so that this can be done in a single |
| // pass inside calculateDrawTransformsInternal<>(). |
| template<typename LayerType, typename LayerList, typename RenderSurfaceType> |
| static void calculateVisibleRectsInternal(const LayerList& renderSurfaceLayerList) |
| { |
| // Use BackToFront since it's cheap and this isn't order-dependent. |
| typedef CCLayerIterator<LayerType, LayerList, RenderSurfaceType, CCLayerIteratorActions::BackToFront> CCLayerIteratorType; |
| |
| CCLayerIteratorType end = CCLayerIteratorType::end(&renderSurfaceLayerList); |
| for (CCLayerIteratorType it = CCLayerIteratorType::begin(&renderSurfaceLayerList); it != end; ++it) { |
| if (it.representsTargetRenderSurface()) { |
| LayerType* maskLayer = it->maskLayer(); |
| if (maskLayer) |
| maskLayer->setVisibleContentRect(IntRect(IntPoint(), it->contentBounds())); |
| LayerType* replicaMaskLayer = it->replicaLayer() ? it->replicaLayer()->maskLayer() : 0; |
| if (replicaMaskLayer) |
| replicaMaskLayer->setVisibleContentRect(IntRect(IntPoint(), it->contentBounds())); |
| } else if (it.representsItself()) { |
| IntRect visibleContentRect = calculateVisibleContentRect(*it); |
| it->setVisibleContentRect(visibleContentRect); |
| } |
| } |
| } |
| |
| void CCLayerTreeHostCommon::calculateDrawTransforms(LayerChromium* rootLayer, const IntSize& deviceViewportSize, float deviceScaleFactor, int maxTextureSize, Vector<RefPtr<LayerChromium> >& renderSurfaceLayerList) |
| { |
| IntRect totalDrawableContentRect; |
| WebTransformationMatrix identityMatrix; |
| WebTransformationMatrix deviceScaleTransform; |
| deviceScaleTransform.scale(deviceScaleFactor); |
| |
| setupRootLayerAndSurfaceForRecursion<LayerChromium, Vector<RefPtr<LayerChromium> > >(rootLayer, renderSurfaceLayerList, deviceViewportSize); |
| |
| cc::calculateDrawTransformsInternal<LayerChromium, Vector<RefPtr<LayerChromium> >, RenderSurfaceChromium, void>(rootLayer, rootLayer, deviceScaleTransform, identityMatrix, identityMatrix, |
| rootLayer->renderSurface()->contentRect(), true, 0, renderSurfaceLayerList, |
| rootLayer->renderSurface()->layerList(), 0, maxTextureSize, deviceScaleFactor, totalDrawableContentRect); |
| } |
| |
| void CCLayerTreeHostCommon::calculateDrawTransforms(CCLayerImpl* rootLayer, const IntSize& deviceViewportSize, float deviceScaleFactor, CCLayerSorter* layerSorter, int maxTextureSize, Vector<CCLayerImpl*>& renderSurfaceLayerList) |
| { |
| IntRect totalDrawableContentRect; |
| WebTransformationMatrix identityMatrix; |
| WebTransformationMatrix deviceScaleTransform; |
| deviceScaleTransform.scale(deviceScaleFactor); |
| |
| setupRootLayerAndSurfaceForRecursion<CCLayerImpl, Vector<CCLayerImpl*> >(rootLayer, renderSurfaceLayerList, deviceViewportSize); |
| |
| cc::calculateDrawTransformsInternal<CCLayerImpl, Vector<CCLayerImpl*>, CCRenderSurface, CCLayerSorter>(rootLayer, rootLayer, deviceScaleTransform, identityMatrix, identityMatrix, |
| rootLayer->renderSurface()->contentRect(), true, 0, renderSurfaceLayerList, |
| rootLayer->renderSurface()->layerList(), layerSorter, maxTextureSize, deviceScaleFactor, totalDrawableContentRect); |
| } |
| |
| void CCLayerTreeHostCommon::calculateVisibleRects(Vector<RefPtr<LayerChromium> >& renderSurfaceLayerList) |
| { |
| calculateVisibleRectsInternal<LayerChromium, Vector<RefPtr<LayerChromium> >, RenderSurfaceChromium>(renderSurfaceLayerList); |
| } |
| |
| void CCLayerTreeHostCommon::calculateVisibleRects(Vector<CCLayerImpl*>& renderSurfaceLayerList) |
| { |
| calculateVisibleRectsInternal<CCLayerImpl, Vector<CCLayerImpl*>, CCRenderSurface>(renderSurfaceLayerList); |
| } |
| |
| static bool pointHitsRect(const IntPoint& viewportPoint, const WebTransformationMatrix& localSpaceToScreenSpaceTransform, FloatRect localSpaceRect) |
| { |
| // If the transform is not invertible, then assume that this point doesn't hit this rect. |
| if (!localSpaceToScreenSpaceTransform.isInvertible()) |
| return false; |
| |
| // Transform the hit test point from screen space to the local space of the given rect. |
| bool clipped = false; |
| FloatPoint hitTestPointInLocalSpace = CCMathUtil::projectPoint(localSpaceToScreenSpaceTransform.inverse(), FloatPoint(viewportPoint), clipped); |
| |
| // If projectPoint could not project to a valid value, then we assume that this point doesn't hit this rect. |
| if (clipped) |
| return false; |
| |
| return localSpaceRect.contains(hitTestPointInLocalSpace); |
| } |
| |
| static bool pointIsClippedBySurfaceOrClipRect(const IntPoint& viewportPoint, CCLayerImpl* layer) |
| { |
| CCLayerImpl* currentLayer = layer; |
| |
| // Walk up the layer tree and hit-test any renderSurfaces and any layer clipRects that are active. |
| while (currentLayer) { |
| if (currentLayer->renderSurface() && !pointHitsRect(viewportPoint, currentLayer->renderSurface()->screenSpaceTransform(), currentLayer->renderSurface()->contentRect())) |
| return true; |
| |
| // Note that drawableContentRects are actually in targetSurface space, so the transform we |
| // have to provide is the target surface's screenSpaceTransform. |
| CCLayerImpl* renderTarget = currentLayer->renderTarget(); |
| if (layerClipsSubtree(currentLayer) && !pointHitsRect(viewportPoint, renderTarget->renderSurface()->screenSpaceTransform(), currentLayer->drawableContentRect())) |
| return true; |
| |
| currentLayer = currentLayer->parent(); |
| } |
| |
| // If we have finished walking all ancestors without having already exited, then the point is not clipped by any ancestors. |
| return false; |
| } |
| |
| CCLayerImpl* CCLayerTreeHostCommon::findLayerThatIsHitByPoint(const IntPoint& viewportPoint, Vector<CCLayerImpl*>& renderSurfaceLayerList) |
| { |
| CCLayerImpl* foundLayer = 0; |
| |
| typedef CCLayerIterator<CCLayerImpl, Vector<CCLayerImpl*>, CCRenderSurface, CCLayerIteratorActions::FrontToBack> CCLayerIteratorType; |
| CCLayerIteratorType end = CCLayerIteratorType::end(&renderSurfaceLayerList); |
| |
| for (CCLayerIteratorType it = CCLayerIteratorType::begin(&renderSurfaceLayerList); it != end; ++it) { |
| // We don't want to consider renderSurfaces for hit testing. |
| if (!it.representsItself()) |
| continue; |
| |
| CCLayerImpl* currentLayer = (*it); |
| |
| FloatRect contentRect(FloatPoint::zero(), currentLayer->contentBounds()); |
| if (!pointHitsRect(viewportPoint, currentLayer->screenSpaceTransform(), contentRect)) |
| continue; |
| |
| // At this point, we think the point does hit the layer, but we need to walk up |
| // the parents to ensure that the layer was not clipped in such a way that the |
| // hit point actually should not hit the layer. |
| if (pointIsClippedBySurfaceOrClipRect(viewportPoint, currentLayer)) |
| continue; |
| |
| foundLayer = currentLayer; |
| break; |
| } |
| |
| // This can potentially return 0, which means the viewportPoint did not successfully hit test any layers, not even the root layer. |
| return foundLayer; |
| } |
| |
| } // namespace cc |
