libs/hwui/pipeline/skia/ReorderBarrierDrawables.cpp - platform/frameworks/base - Git at Google

 /*
  * Copyright (C) 2016 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include "ReorderBarrierDrawables.h"
 #include "RenderNode.h"
 #include "SkiaDisplayList.h"
 #include "SkiaPipeline.h"

 #include <SkPathOps.h>
 #include <SkShadowUtils.h>

 namespace android {
 namespace uirenderer {
 namespace skiapipeline {

 StartReorderBarrierDrawable::StartReorderBarrierDrawable(SkiaDisplayList* data)
         : mEndChildIndex(0), mBeginChildIndex(data->mChildNodes.size()), mDisplayList(data) {}

 void StartReorderBarrierDrawable::onDraw(SkCanvas* canvas) {
     if (mChildren.empty()) {
         // mChildren is allocated and initialized only the first time onDraw is called and cached
         // for
         // subsequent calls
         mChildren.reserve(mEndChildIndex - mBeginChildIndex + 1);
         for (int i = mBeginChildIndex; i <= mEndChildIndex; i++) {
             mChildren.push_back(const_cast<RenderNodeDrawable*>(&mDisplayList->mChildNodes[i]));
         }
     }
     std::stable_sort(mChildren.begin(), mChildren.end(),
                      [](RenderNodeDrawable* a, RenderNodeDrawable* b) {
                          const float aZValue = a->getNodeProperties().getZ();
                          const float bZValue = b->getNodeProperties().getZ();
                          return aZValue < bZValue;
                      });

     size_t drawIndex = 0;
     const size_t endIndex = mChildren.size();
     while (drawIndex < endIndex) {
         RenderNodeDrawable* childNode = mChildren[drawIndex];
         SkASSERT(childNode);
         const float casterZ = childNode->getNodeProperties().getZ();
         if (casterZ >= -NON_ZERO_EPSILON) {  // draw only children with negative Z
             return;
         }
         SkAutoCanvasRestore acr(canvas, true);
         // Since we're drawing out of recording order, the child's matrix needs to be applied to the
         // canvas. In in-order drawing, the canvas already has the child's matrix applied.
         canvas->setMatrix(mDisplayList->mParentMatrix);
         canvas->concat(childNode->getRecordedMatrix());
         childNode->forceDraw(canvas);
         drawIndex++;
     }
 }

 EndReorderBarrierDrawable::EndReorderBarrierDrawable(StartReorderBarrierDrawable* startBarrier)
         : mStartBarrier(startBarrier) {
     mStartBarrier->mEndChildIndex = mStartBarrier->mDisplayList->mChildNodes.size() - 1;
 }

 #define SHADOW_DELTA 0.1f

 void EndReorderBarrierDrawable::onDraw(SkCanvas* canvas) {
     auto& zChildren = mStartBarrier->mChildren;

     /**
      * Draw shadows and (potential) casters mostly in order, but allow the shadows of casters
      * with very similar Z heights to draw together.
      *
      * This way, if Views A & B have the same Z height and are both casting shadows, the shadows are
      * underneath both, and neither's shadow is drawn on top of the other.
      */
     size_t drawIndex = 0;

     const size_t endIndex = zChildren.size();
     while (drawIndex < endIndex  // draw only children with positive Z
            && zChildren[drawIndex]->getNodeProperties().getZ() <= NON_ZERO_EPSILON)
         drawIndex++;
     size_t shadowIndex = drawIndex;

     float lastCasterZ = 0.0f;
     while (shadowIndex < endIndex || drawIndex < endIndex) {
         if (shadowIndex < endIndex) {
             const float casterZ = zChildren[shadowIndex]->getNodeProperties().getZ();

             // attempt to render the shadow if the caster about to be drawn is its caster,
             // OR if its caster's Z value is similar to the previous potential caster
             if (shadowIndex == drawIndex || casterZ - lastCasterZ < SHADOW_DELTA) {
                 this->drawShadow(canvas, zChildren[shadowIndex]);
                 lastCasterZ = casterZ;  // must do this even if current caster not casting a shadow
                 shadowIndex++;
                 continue;
             }
         }

         RenderNodeDrawable* childNode = zChildren[drawIndex];
         SkASSERT(childNode);
         SkAutoCanvasRestore acr(canvas, true);
         // Since we're drawing out of recording order, the child's matrix needs to be applied to the
         // canvas. In in-order drawing, the canvas already has the child's matrix applied.
         canvas->setMatrix(mStartBarrier->mDisplayList->mParentMatrix);
         canvas->concat(childNode->getRecordedMatrix());
         childNode->forceDraw(canvas);

         drawIndex++;
     }
 }

 static SkColor multiplyAlpha(SkColor color, float alpha) {
     return SkColorSetA(color, alpha * SkColorGetA(color));
 }

 // copied from FrameBuilder::deferShadow
 void EndReorderBarrierDrawable::drawShadow(SkCanvas* canvas, RenderNodeDrawable* caster) {
     const RenderProperties& casterProperties = caster->getNodeProperties();

     if (casterProperties.getAlpha() <= 0.0f || casterProperties.getOutline().getAlpha() <= 0.0f ||
         !casterProperties.getOutline().getPath() || casterProperties.getScaleX() == 0 ||
         casterProperties.getScaleY() == 0) {
         // no shadow to draw
         return;
     }

     const SkScalar casterAlpha =
             casterProperties.getAlpha() * casterProperties.getOutline().getAlpha();
     if (casterAlpha <= 0.0f) {
         return;
     }

     float ambientAlpha = (SkiaPipeline::getAmbientShadowAlpha() / 255.f) * casterAlpha;
     float spotAlpha = (SkiaPipeline::getSpotShadowAlpha() / 255.f) * casterAlpha;

     const RevealClip& revealClip = casterProperties.getRevealClip();
     const SkPath* revealClipPath = revealClip.getPath();
     if (revealClipPath && revealClipPath->isEmpty()) {
         // An empty reveal clip means nothing is drawn
         return;
     }

     bool clippedToBounds = casterProperties.getClippingFlags() & CLIP_TO_CLIP_BOUNDS;

     SkRect casterClipRect = SkRect::MakeEmpty();
     if (clippedToBounds) {
         Rect clipBounds;
         casterProperties.getClippingRectForFlags(CLIP_TO_CLIP_BOUNDS, &clipBounds);
         casterClipRect = clipBounds.toSkRect();
         if (casterClipRect.isEmpty()) {
             // An empty clip rect means nothing is drawn
             return;
         }
     }

     SkAutoCanvasRestore acr(canvas, true);
     // Since we're drawing out of recording order, the child's matrix needs to be applied to the
     // canvas. In in-order drawing, the canvas already has the child's matrix applied.
     canvas->setMatrix(mStartBarrier->mDisplayList->mParentMatrix);

     SkMatrix shadowMatrix;
     mat4 hwuiMatrix(caster->getRecordedMatrix());
     // TODO we don't pass the optional boolean to treat it as a 4x4 matrix
     // applyViewPropertyTransforms gets the same matrix, which render nodes apply with
     // RenderNodeDrawable::setViewProperties as a part if their draw.
     caster->getRenderNode()->applyViewPropertyTransforms(hwuiMatrix);
     hwuiMatrix.copyTo(shadowMatrix);
     canvas->concat(shadowMatrix);

     // default the shadow-casting path to the outline of the caster
     const SkPath* casterPath = casterProperties.getOutline().getPath();

     // intersect the shadow-casting path with the clipBounds, if present
     if (clippedToBounds && !casterClipRect.contains(casterPath->getBounds())) {
         casterPath = caster->getRenderNode()->getClippedOutline(casterClipRect);
     }

     // intersect the shadow-casting path with the reveal, if present
     SkPath tmpPath;  // holds temporary SkPath to store the result of intersections
     if (revealClipPath) {
         Op(*casterPath, *revealClipPath, kIntersect_SkPathOp, &tmpPath);
         tmpPath.setIsVolatile(true);
         casterPath = &tmpPath;
     }

     const Vector3 lightPos = SkiaPipeline::getLightCenter();
     SkPoint3 skiaLightPos = SkPoint3::Make(lightPos.x, lightPos.y, lightPos.z);
     SkPoint3 zParams;
     if (shadowMatrix.hasPerspective()) {
         // get the matrix with the full 3D transform
         mat4 zMatrix;
         caster->getRenderNode()->applyViewPropertyTransforms(zMatrix, true);
         zParams = SkPoint3::Make(zMatrix[2], zMatrix[6], zMatrix[mat4::kTranslateZ]);
     } else {
         zParams = SkPoint3::Make(0, 0, casterProperties.getZ());
     }
     SkColor ambientColor = multiplyAlpha(casterProperties.getAmbientShadowColor(), ambientAlpha);
     SkColor spotColor = multiplyAlpha(casterProperties.getSpotShadowColor(), spotAlpha);
     SkShadowUtils::DrawShadow(
             canvas, *casterPath, zParams, skiaLightPos, SkiaPipeline::getLightRadius(),
             ambientColor, spotColor,
             casterAlpha < 1.0f ? SkShadowFlags::kTransparentOccluder_ShadowFlag : 0);
 }

 }  // namespace skiapipeline
 }  // namespace uirenderer
 }  // namespace android
	/*
	* Copyright (C) 2016 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include "ReorderBarrierDrawables.h"
	#include "RenderNode.h"
	#include "SkiaDisplayList.h"
	#include "SkiaPipeline.h"

	#include <SkPathOps.h>
	#include <SkShadowUtils.h>

	namespace android {
	namespace uirenderer {
	namespace skiapipeline {

	StartReorderBarrierDrawable::StartReorderBarrierDrawable(SkiaDisplayList* data)
	: mEndChildIndex(0), mBeginChildIndex(data->mChildNodes.size()), mDisplayList(data) {}

	void StartReorderBarrierDrawable::onDraw(SkCanvas* canvas) {
	if (mChildren.empty()) {
	// mChildren is allocated and initialized only the first time onDraw is called and cached
	// for
	// subsequent calls
	mChildren.reserve(mEndChildIndex - mBeginChildIndex + 1);
	for (int i = mBeginChildIndex; i <= mEndChildIndex; i++) {
	mChildren.push_back(const_cast<RenderNodeDrawable*>(&mDisplayList->mChildNodes[i]));
	}
	}
	std::stable_sort(mChildren.begin(), mChildren.end(),
	[](RenderNodeDrawable* a, RenderNodeDrawable* b) {
	const float aZValue = a->getNodeProperties().getZ();
	const float bZValue = b->getNodeProperties().getZ();
	return aZValue < bZValue;
	});

	size_t drawIndex = 0;
	const size_t endIndex = mChildren.size();
	while (drawIndex < endIndex) {
	RenderNodeDrawable* childNode = mChildren[drawIndex];
	SkASSERT(childNode);
	const float casterZ = childNode->getNodeProperties().getZ();
	if (casterZ >= -NON_ZERO_EPSILON) { // draw only children with negative Z
	return;
	}
	SkAutoCanvasRestore acr(canvas, true);
	// Since we're drawing out of recording order, the child's matrix needs to be applied to the
	// canvas. In in-order drawing, the canvas already has the child's matrix applied.
	canvas->setMatrix(mDisplayList->mParentMatrix);
	canvas->concat(childNode->getRecordedMatrix());
	childNode->forceDraw(canvas);
	drawIndex++;
	}
	}

	EndReorderBarrierDrawable::EndReorderBarrierDrawable(StartReorderBarrierDrawable* startBarrier)
	: mStartBarrier(startBarrier) {
	mStartBarrier->mEndChildIndex = mStartBarrier->mDisplayList->mChildNodes.size() - 1;
	}

	#define SHADOW_DELTA 0.1f

	void EndReorderBarrierDrawable::onDraw(SkCanvas* canvas) {
	auto& zChildren = mStartBarrier->mChildren;

	/**
	* Draw shadows and (potential) casters mostly in order, but allow the shadows of casters
	* with very similar Z heights to draw together.
	*
	* This way, if Views A & B have the same Z height and are both casting shadows, the shadows are
	* underneath both, and neither's shadow is drawn on top of the other.
	*/
	size_t drawIndex = 0;

	const size_t endIndex = zChildren.size();
	while (drawIndex < endIndex // draw only children with positive Z
	&& zChildren[drawIndex]->getNodeProperties().getZ() <= NON_ZERO_EPSILON)
	drawIndex++;
	size_t shadowIndex = drawIndex;

	float lastCasterZ = 0.0f;
	while (shadowIndex < endIndex \|\| drawIndex < endIndex) {
	if (shadowIndex < endIndex) {
	const float casterZ = zChildren[shadowIndex]->getNodeProperties().getZ();

	// attempt to render the shadow if the caster about to be drawn is its caster,
	// OR if its caster's Z value is similar to the previous potential caster
	if (shadowIndex == drawIndex \|\| casterZ - lastCasterZ < SHADOW_DELTA) {
	this->drawShadow(canvas, zChildren[shadowIndex]);
	lastCasterZ = casterZ; // must do this even if current caster not casting a shadow
	shadowIndex++;
	continue;
	}
	}

	RenderNodeDrawable* childNode = zChildren[drawIndex];
	SkASSERT(childNode);
	SkAutoCanvasRestore acr(canvas, true);
	// Since we're drawing out of recording order, the child's matrix needs to be applied to the
	// canvas. In in-order drawing, the canvas already has the child's matrix applied.
	canvas->setMatrix(mStartBarrier->mDisplayList->mParentMatrix);
	canvas->concat(childNode->getRecordedMatrix());
	childNode->forceDraw(canvas);

	drawIndex++;
	}
	}

	static SkColor multiplyAlpha(SkColor color, float alpha) {
	return SkColorSetA(color, alpha * SkColorGetA(color));
	}

	// copied from FrameBuilder::deferShadow
	void EndReorderBarrierDrawable::drawShadow(SkCanvas* canvas, RenderNodeDrawable* caster) {
	const RenderProperties& casterProperties = caster->getNodeProperties();

	if (casterProperties.getAlpha() <= 0.0f \|\| casterProperties.getOutline().getAlpha() <= 0.0f \|\|
	!casterProperties.getOutline().getPath() \|\| casterProperties.getScaleX() == 0 \|\|
	casterProperties.getScaleY() == 0) {
	// no shadow to draw
	return;
	}

	const SkScalar casterAlpha =
	casterProperties.getAlpha() * casterProperties.getOutline().getAlpha();
	if (casterAlpha <= 0.0f) {
	return;
	}

	float ambientAlpha = (SkiaPipeline::getAmbientShadowAlpha() / 255.f) * casterAlpha;
	float spotAlpha = (SkiaPipeline::getSpotShadowAlpha() / 255.f) * casterAlpha;

	const RevealClip& revealClip = casterProperties.getRevealClip();
	const SkPath* revealClipPath = revealClip.getPath();
	if (revealClipPath && revealClipPath->isEmpty()) {
	// An empty reveal clip means nothing is drawn
	return;
	}

	bool clippedToBounds = casterProperties.getClippingFlags() & CLIP_TO_CLIP_BOUNDS;

	SkRect casterClipRect = SkRect::MakeEmpty();
	if (clippedToBounds) {
	Rect clipBounds;
	casterProperties.getClippingRectForFlags(CLIP_TO_CLIP_BOUNDS, &clipBounds);
	casterClipRect = clipBounds.toSkRect();
	if (casterClipRect.isEmpty()) {
	// An empty clip rect means nothing is drawn
	return;
	}
	}

	SkAutoCanvasRestore acr(canvas, true);
	// Since we're drawing out of recording order, the child's matrix needs to be applied to the
	// canvas. In in-order drawing, the canvas already has the child's matrix applied.
	canvas->setMatrix(mStartBarrier->mDisplayList->mParentMatrix);

	SkMatrix shadowMatrix;
	mat4 hwuiMatrix(caster->getRecordedMatrix());
	// TODO we don't pass the optional boolean to treat it as a 4x4 matrix
	// applyViewPropertyTransforms gets the same matrix, which render nodes apply with
	// RenderNodeDrawable::setViewProperties as a part if their draw.
	caster->getRenderNode()->applyViewPropertyTransforms(hwuiMatrix);
	hwuiMatrix.copyTo(shadowMatrix);
	canvas->concat(shadowMatrix);

	// default the shadow-casting path to the outline of the caster
	const SkPath* casterPath = casterProperties.getOutline().getPath();

	// intersect the shadow-casting path with the clipBounds, if present
	if (clippedToBounds && !casterClipRect.contains(casterPath->getBounds())) {
	casterPath = caster->getRenderNode()->getClippedOutline(casterClipRect);
	}

	// intersect the shadow-casting path with the reveal, if present
	SkPath tmpPath; // holds temporary SkPath to store the result of intersections
	if (revealClipPath) {
	Op(casterPath, revealClipPath, kIntersect_SkPathOp, &tmpPath);
	tmpPath.setIsVolatile(true);
	casterPath = &tmpPath;
	}

	const Vector3 lightPos = SkiaPipeline::getLightCenter();
	SkPoint3 skiaLightPos = SkPoint3::Make(lightPos.x, lightPos.y, lightPos.z);
	SkPoint3 zParams;
	if (shadowMatrix.hasPerspective()) {
	// get the matrix with the full 3D transform
	mat4 zMatrix;
	caster->getRenderNode()->applyViewPropertyTransforms(zMatrix, true);
	zParams = SkPoint3::Make(zMatrix[2], zMatrix[6], zMatrix[mat4::kTranslateZ]);
	} else {
	zParams = SkPoint3::Make(0, 0, casterProperties.getZ());
	}
	SkColor ambientColor = multiplyAlpha(casterProperties.getAmbientShadowColor(), ambientAlpha);
	SkColor spotColor = multiplyAlpha(casterProperties.getSpotShadowColor(), spotAlpha);
	SkShadowUtils::DrawShadow(
	canvas, *casterPath, zParams, skiaLightPos, SkiaPipeline::getLightRadius(),
	ambientColor, spotColor,
	casterAlpha < 1.0f ? SkShadowFlags::kTransparentOccluder_ShadowFlag : 0);
	}

	} // namespace skiapipeline
	} // namespace uirenderer
	} // namespace android