Implement Skia pipelines for OpenGL and Vulkan.

Implement Skia pipelines for OpenGL and Vulkan:
base SkiaPipeline, SkiaOpenGLPipeline and SkiaVulkanPipeline.
Write unit tests for SkiaPipeline.

Test: Built and run manually on angler-eng.
Change-Id: Ie02583426cb3547541ad9bf91700602a6163ff58
diff --git a/libs/hwui/pipeline/skia/SkiaPipeline.cpp b/libs/hwui/pipeline/skia/SkiaPipeline.cpp
new file mode 100644
index 0000000..03fa266
--- /dev/null
+++ b/libs/hwui/pipeline/skia/SkiaPipeline.cpp
@@ -0,0 +1,258 @@
+/*
+ * 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 "SkiaPipeline.h"
+
+#include "utils/TraceUtils.h"
+#include <SkOSFile.h>
+#include <SkPicture.h>
+#include <SkPictureRecorder.h>
+#include <SkPixelSerializer.h>
+#include <SkStream.h>
+
+using namespace android::uirenderer::renderthread;
+
+namespace android {
+namespace uirenderer {
+namespace skiapipeline {
+
+float   SkiaPipeline::mLightRadius = 0;
+uint8_t SkiaPipeline::mAmbientShadowAlpha = 0;
+uint8_t SkiaPipeline::mSpotShadowAlpha = 0;
+
+Vector3 SkiaPipeline::mLightCenter = {FLT_MIN, FLT_MIN, FLT_MIN};
+
+SkiaPipeline::SkiaPipeline(RenderThread& thread) :  mRenderThread(thread) { }
+
+TaskManager* SkiaPipeline::getTaskManager() {
+    return &mTaskManager;
+}
+
+void SkiaPipeline::onDestroyHardwareResources() {
+    // No need to flush the caches here. There is a timer
+    // which will flush temporary resources over time.
+}
+
+void SkiaPipeline::renderLayers(const FrameBuilder::LightGeometry& lightGeometry,
+        LayerUpdateQueue* layerUpdateQueue, bool opaque,
+        const BakedOpRenderer::LightInfo& lightInfo) {
+    updateLighting(lightGeometry, lightInfo);
+    ATRACE_NAME("draw layers");
+    renderLayersImpl(*layerUpdateQueue, opaque);
+    layerUpdateQueue->clear();
+}
+
+void SkiaPipeline::renderLayersImpl(const LayerUpdateQueue& layers, bool opaque) {
+    // Render all layers that need to be updated, in order.
+    for (size_t i = 0; i < layers.entries().size(); i++) {
+        RenderNode* layerNode = layers.entries()[i].renderNode;
+        // only schedule repaint if node still on layer - possible it may have been
+        // removed during a dropped frame, but layers may still remain scheduled so
+        // as not to lose info on what portion is damaged
+        if (CC_LIKELY(layerNode->getLayerSurface() != nullptr)) {
+            SkASSERT(layerNode->getLayerSurface());
+            SkASSERT(layerNode->getDisplayList()->isSkiaDL());
+            SkiaDisplayList* displayList = (SkiaDisplayList*)layerNode->getDisplayList();
+            if (!displayList || displayList->isEmpty()) {
+                SkDEBUGF(("%p drawLayers(%s) : missing drawable", this, layerNode->getName()));
+                return;
+            }
+
+            const Rect& layerDamage = layers.entries()[i].damage;
+
+            SkCanvas* layerCanvas = layerNode->getLayerSurface()->getCanvas();
+
+            int saveCount = layerCanvas->save();
+            SkASSERT(saveCount == 1);
+
+            layerCanvas->clipRect(layerDamage.toSkRect(), SkRegion::kReplace_Op);
+
+            auto savedLightCenter = mLightCenter;
+            // map current light center into RenderNode's coordinate space
+            layerNode->getSkiaLayer()->inverseTransformInWindow.mapPoint3d(mLightCenter);
+
+            const RenderProperties& properties = layerNode->properties();
+            const SkRect bounds = SkRect::MakeWH(properties.getWidth(), properties.getHeight());
+            if (properties.getClipToBounds() && layerCanvas->quickReject(bounds)) {
+                return;
+            }
+
+            layerCanvas->clear(SK_ColorTRANSPARENT);
+
+            RenderNodeDrawable root(layerNode, layerCanvas, false);
+            root.forceDraw(layerCanvas);
+            layerCanvas->restoreToCount(saveCount);
+            layerCanvas->flush();
+            mLightCenter = savedLightCenter;
+        }
+    }
+}
+
+bool SkiaPipeline::createOrUpdateLayer(RenderNode* node,
+        const DamageAccumulator& damageAccumulator) {
+    SkSurface* layer = node->getLayerSurface();
+    if (!layer || layer->width() != node->getWidth() || layer->height() != node->getHeight()) {
+        SkImageInfo info = SkImageInfo::MakeN32Premul(node->getWidth(), node->getHeight());
+        SkSurfaceProps props(0, kUnknown_SkPixelGeometry);
+        SkASSERT(mRenderThread.getGrContext() != nullptr);
+        node->setLayerSurface(
+                SkSurface::MakeRenderTarget(mRenderThread.getGrContext(), SkBudgeted::kYes,
+                        info, 0, &props));
+        if (node->getLayerSurface()) {
+            // update the transform in window of the layer to reset its origin wrt light source
+            // position
+            Matrix4 windowTransform;
+            damageAccumulator.computeCurrentTransform(&windowTransform);
+            node->getSkiaLayer()->inverseTransformInWindow = windowTransform;
+        }
+        return true;
+    }
+    return false;
+}
+
+void SkiaPipeline::destroyLayer(RenderNode* node) {
+    node->setLayerSurface(nullptr);
+}
+
+void SkiaPipeline::prepareToDraw(const RenderThread& thread, Bitmap* bitmap) {
+    GrContext* context = thread.getGrContext();
+    if (context) {
+        ATRACE_FORMAT("Bitmap#prepareToDraw %dx%d", bitmap->width(), bitmap->height());
+        SkBitmap skiaBitmap;
+        bitmap->getSkBitmap(&skiaBitmap);
+        sk_sp<SkImage> image = SkMakeImageFromRasterBitmap(skiaBitmap, kNever_SkCopyPixelsMode);
+        SkImage_pinAsTexture(image.get(), context);
+        SkImage_unpinAsTexture(image.get(), context);
+    }
+}
+
+// Encodes to PNG, unless there is already encoded data, in which case that gets
+// used.
+class PngPixelSerializer : public SkPixelSerializer {
+public:
+    bool onUseEncodedData(const void*, size_t) override { return true; }
+    SkData* onEncode(const SkPixmap& pixmap) override {
+        return SkImageEncoder::EncodeData(pixmap.info(), pixmap.addr(), pixmap.rowBytes(),
+                                          SkImageEncoder::kPNG_Type, 100);
+    }
+};
+
+void SkiaPipeline::renderFrame(const LayerUpdateQueue& layers, const SkRect& clip,
+        const std::vector<sp<RenderNode>>& nodes, bool opaque, const Rect &contentDrawBounds,
+        sk_sp<SkSurface> surface) {
+
+    // unpin all mutable images that were attached to nodes deleted while on the UI thread
+    SkiaDisplayList::cleanupImages(surface->getCanvas()->getGrContext());
+
+    // draw all layers up front
+    renderLayersImpl(layers, opaque);
+
+    // initialize the canvas for the current frame
+    SkCanvas* canvas = surface->getCanvas();
+
+    std::unique_ptr<SkPictureRecorder> recorder;
+    bool recordingPicture = false;
+    char prop[PROPERTY_VALUE_MAX];
+    if (skpCaptureEnabled()) {
+        property_get("debug.hwui.capture_frame_as_skp", prop, "0");
+        recordingPicture = prop[0] != '0' && !sk_exists(prop);
+        if (recordingPicture) {
+            recorder.reset(new SkPictureRecorder());
+            canvas = recorder->beginRecording(surface->width(), surface->height(),
+                    nullptr, SkPictureRecorder::kPlaybackDrawPicture_RecordFlag);
+        }
+    }
+
+    canvas->clipRect(clip, SkRegion::kReplace_Op);
+
+    if (!opaque) {
+        canvas->clear(SK_ColorTRANSPARENT);
+    }
+
+    // If there are multiple render nodes, they are laid out as follows:
+    // #0 - backdrop (content + caption)
+    // #1 - content (positioned at (0,0) and clipped to - its bounds mContentDrawBounds)
+    // #2 - additional overlay nodes
+    // Usually the backdrop cannot be seen since it will be entirely covered by the content. While
+    // resizing however it might become partially visible. The following render loop will crop the
+    // backdrop against the content and draw the remaining part of it. It will then draw the content
+    // cropped to the backdrop (since that indicates a shrinking of the window).
+    //
+    // Additional nodes will be drawn on top with no particular clipping semantics.
+
+    // The bounds of the backdrop against which the content should be clipped.
+    Rect backdropBounds = contentDrawBounds;
+    // Usually the contents bounds should be mContentDrawBounds - however - we will
+    // move it towards the fixed edge to give it a more stable appearance (for the moment).
+    // If there is no content bounds we ignore the layering as stated above and start with 2.
+    int layer = (contentDrawBounds.isEmpty() || nodes.size() == 1) ? 2 : 0;
+
+    for (const sp<RenderNode>& node : nodes) {
+        if (node->nothingToDraw()) continue;
+
+        SkASSERT(node->getDisplayList()->isSkiaDL());
+
+        int count = canvas->save();
+
+        if (layer == 0) {
+            const RenderProperties& properties = node->properties();
+            Rect targetBounds(properties.getLeft(), properties.getTop(),
+                              properties.getRight(), properties.getBottom());
+            // Move the content bounds towards the fixed corner of the backdrop.
+            const int x = targetBounds.left;
+            const int y = targetBounds.top;
+            // Remember the intersection of the target bounds and the intersection bounds against
+            // which we have to crop the content.
+            backdropBounds.set(x, y, x + backdropBounds.getWidth(), y + backdropBounds.getHeight());
+            backdropBounds.doIntersect(targetBounds);
+        } else if (layer == 1) {
+            // We shift and clip the content to match its final location in the window.
+            const SkRect clip = SkRect::MakeXYWH(contentDrawBounds.left, contentDrawBounds.top,
+                                                 backdropBounds.getWidth(), backdropBounds.getHeight());
+            const float dx = backdropBounds.left - contentDrawBounds.left;
+            const float dy = backdropBounds.top - contentDrawBounds.top;
+            canvas->translate(dx, dy);
+            // It gets cropped against the bounds of the backdrop to stay inside.
+            canvas->clipRect(clip, SkRegion::kIntersect_Op);
+        }
+
+        RenderNodeDrawable root(node.get(), canvas);
+        root.draw(canvas);
+        canvas->restoreToCount(count);
+        layer++;
+    }
+
+    if (skpCaptureEnabled() && recordingPicture) {
+        sk_sp<SkPicture> picture = recorder->finishRecordingAsPicture();
+        if (picture->approximateOpCount() > 0) {
+            SkFILEWStream stream(prop);
+            if (stream.isValid()) {
+                PngPixelSerializer serializer;
+                picture->serialize(&stream, &serializer);
+                stream.flush();
+                SkDebugf("Captured Drawing Output (%d bytes) for frame. %s", stream.bytesWritten(), prop);
+            }
+        }
+        surface->getCanvas()->drawPicture(picture);
+    }
+
+    ATRACE_NAME("flush commands");
+    canvas->flush();
+}
+
+} /* namespace skiapipeline */
+} /* namespace uirenderer */
+} /* namespace android */