Add ShadowShaderAnimation benchmark

/*

 * Copyright (C) 2017 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 "TestSceneBase.h"

class ShadowShaderAnimation;

static TestScene::Registrar _ShadowShader(TestScene::Info{

    "shadowshader",

    "A set of overlapping shadowed areas with simple tessellation useful for"

    " benchmarking shadow shader performance.",

    TestScene::simpleCreateScene<ShadowShaderAnimation>

});

class ShadowShaderAnimation : public TestScene {

public:

    std::vector< sp<RenderNode> > cards;

    void createContent(int width, int height, Canvas& canvas) override {

        canvas.drawColor(0xFFFFFFFF, SkBlendMode::kSrcOver);

        canvas.insertReorderBarrier(true);

        int outset = 50;

        for (int i = 0; i < 10; i++) {

            sp<RenderNode> card = createCard(outset, outset,

                    width - (outset * 2), height - (outset * 2));

            canvas.drawRenderNode(card.get());

            cards.push_back(card);

        }

        canvas.insertReorderBarrier(false);

    }

    void doFrame(int frameNr) override {

        int curFrame = frameNr % 10;

        for (size_t ci = 0; ci < cards.size(); ci++) {

            cards[ci]->mutateStagingProperties().setTranslationX(curFrame);

            cards[ci]->mutateStagingProperties().setTranslationY(curFrame);

            cards[ci]->setPropertyFieldsDirty(RenderNode::X | RenderNode::Y);

        }

    }

private:

    sp<RenderNode> createCard(int x, int y, int width, int height) {

        return TestUtils::createNode(x, y, x + width, y + height,

                [width, height](RenderProperties& props, Canvas& canvas) {

            props.setElevation(1000);

            // Set 0 radius, no clipping, so shadow is easy to compute. Slightly transparent outline

            // to signal contents aren't opaque (not necessary though, as elevation is so high, no

            // inner content to cut out)

            props.mutableOutline().setRoundRect(0, 0, width, height, 0, 0.99f);

            props.mutableOutline().setShouldClip(false);

            // don't draw anything to card's canvas - we just want the shadow

        });

    }

};