/* * Copyright 2019 Google LLC * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #include "samplecode/Sample.h" #include "include/core/SkCanvas.h" #include "include/core/SkColor.h" #include "include/core/SkColorFilter.h" #include "include/core/SkFont.h" #include "include/core/SkImage.h" #include "include/core/SkImageFilter.h" #include "include/core/SkImageInfo.h" #include "include/core/SkPaint.h" #include "include/core/SkPoint.h" #include "include/core/SkRect.h" #include "include/core/SkSurface.h" #include "include/effects/SkDashPathEffect.h" #include "include/effects/SkGradientShader.h" #include "include/effects/SkImageFilters.h" #include "src/core/SkImageFilter_Base.h" #include "src/core/SkSpecialImage.h" #include "tools/ToolUtils.h" namespace { struct FilterNode { // Pointer to the actual filter in the DAG, so it still contains its input filters and // may be used as an input in an earlier node. Null when this represents the "source" input sk_sp fFilter; // FilterNodes wrapping each of fFilter's inputs. Leaf node when fInputNodes is empty. SkTArray fInputNodes; // Distance from root filter int fDepth; // The source content rect (this is the same for all nodes, but is stored here for convenience) skif::ParameterSpace fContent; // The mapping for the filter dag (same for all nodes, but stored here for convenience) skif::Mapping fMapping; // Cached reverse bounds using device-space clip bounds (e.g. no local bounds hint passed to // saveLayer). This represents the layer calculated in SkCanvas for the filtering. skif::LayerSpace fUnhintedLayerBounds; // Cached input bounds using the local draw bounds (e.g. saveLayer with a bounds rect, or // an auto-layer for a draw with image filter). This represents the layer bounds up to this // point of the DAG. skif::LayerSpace fHintedLayerBounds; // Cached output bounds based on local draw bounds. This represents the output up to this // point of the DAG. skif::LayerSpace fOutputBounds; FilterNode(const SkImageFilter* filter, const skif::Mapping& mapping, const skif::ParameterSpace& content, int depth) : fFilter(sk_ref_sp(filter)) , fDepth(depth) , fContent(content) , fMapping(mapping) { this->computeInputBounds(); this->computeOutputBounds(); if (fFilter) { fInputNodes.reserve_back(fFilter->countInputs()); for (int i = 0; i < fFilter->countInputs(); ++i) { fInputNodes.emplace_back(fFilter->getInput(i), mapping, content, depth + 1); } } } private: void computeOutputBounds() { if (fFilter) { // For visualization purposes, we want the output bounds in layer space, before it's // been transformed to device space. To achieve that, we mock a new mapping with the // identity matrix transform. skif::Mapping layerOnly{fMapping.layerMatrix()}; skif::DeviceSpace pseudoDeviceBounds = as_IFB(fFilter)->getOutputBounds(layerOnly, fContent); // Since layerOnly's device matrix is I, this is effectively a cast to layer space fOutputBounds = layerOnly.deviceToLayer(pseudoDeviceBounds); } else { fOutputBounds = fMapping.paramToLayer(fContent).roundOut(); } // Fill in children for (int i = 0; i < fInputNodes.count(); ++i) { fInputNodes[i].computeOutputBounds(); } } void computeInputBounds() { // As a proxy for what the base device had, use the content rect mapped to device space // (e.g. clipRect() was called with the same coords prior to the draw). skif::DeviceSpace targetOutput(fMapping.totalMatrix() .mapRect(SkRect(fContent)) .roundOut()); if (fFilter) { fHintedLayerBounds = as_IFB(fFilter)->getInputBounds(fMapping, targetOutput, &fContent); fUnhintedLayerBounds = as_IFB(fFilter)->getInputBounds(fMapping, targetOutput, nullptr); } else { fHintedLayerBounds = fMapping.paramToLayer(fContent).roundOut(); fUnhintedLayerBounds = fMapping.deviceToLayer(targetOutput); } } }; } // anonymous namespace static FilterNode build_dag(const SkMatrix& ctm, const SkRect& rect, const SkImageFilter* rootFilter) { // Emulate SkCanvas::internalSaveLayer's decomposition of the CTM. skif::ParameterSpace content(rect); skif::ParameterSpace center({rect.centerX(), rect.centerY()}); skif::Mapping mapping; SkAssertResult(mapping.decomposeCTM(ctm, rootFilter, center)); return FilterNode(rootFilter, mapping, content, 0); } static void draw_node(SkCanvas* canvas, const FilterNode& node) { canvas->clear(SK_ColorTRANSPARENT); SkPaint filterPaint; filterPaint.setImageFilter(node.fFilter); SkRect content = SkRect(node.fContent); SkPaint paint; static const SkColor kColors[2] = {SK_ColorGREEN, SK_ColorWHITE}; SkPoint points[2] = { {content.fLeft + 15.f, content.fTop + 15.f}, {content.fRight - 15.f, content.fBottom - 15.f} }; paint.setShader(SkGradientShader::MakeLinear(points, kColors, nullptr, SK_ARRAY_COUNT(kColors), SkTileMode::kRepeat)); SkPaint line; line.setStrokeWidth(0.f); line.setStyle(SkPaint::kStroke_Style); canvas->save(); canvas->concat(node.fMapping.deviceMatrix()); canvas->save(); canvas->concat(node.fMapping.layerMatrix()); canvas->saveLayer(&content, &filterPaint); canvas->drawRect(content, paint); canvas->restore(); // Completes the image filter // Draw content-rect bounds line.setColor(SK_ColorBLACK); canvas->drawRect(content, line); // Bounding boxes have all been mapped by the layer matrix from local to layer space, so undo // the layer matrix, leaving just the device matrix. canvas->restore(); // The hinted bounds of the layer saved for the filtering line.setColor(SK_ColorRED); canvas->drawRect(SkRect::Make(SkIRect(node.fHintedLayerBounds)).makeOutset(3.f, 3.f), line); // The bounds of the layer if there was no local content hint line.setColor(SK_ColorGREEN); canvas->drawRect(SkRect::Make(SkIRect(node.fUnhintedLayerBounds)).makeOutset(2.f, 2.f), line); // The output bounds in layer space line.setColor(SK_ColorBLUE); canvas->drawRect(SkRect::Make(SkIRect(node.fOutputBounds)).makeOutset(1.f, 1.f), line); // Device-space bounding box of the output bounds (e.g. what legacy DAG manipulation via // MatrixTransform would produce). static const SkScalar kDashParams[] = {6.f, 12.f}; line.setPathEffect(SkDashPathEffect::Make(kDashParams, 2, 0.f)); SkRect devOutputBounds = SkRect::Make(SkIRect(node.fMapping.layerToDevice(node.fOutputBounds))); canvas->restore(); // undoes device matrix canvas->drawRect(devOutputBounds, line); } static constexpr float kLineHeight = 16.f; static constexpr float kLineInset = 8.f; static float print_matrix(SkCanvas* canvas, const char* prefix, const SkMatrix& matrix, float x, float y, const SkFont& font, const SkPaint& paint) { canvas->drawString(prefix, x, y, font, paint); y += kLineHeight; for (int i = 0; i < 3; ++i) { SkString row; row.appendf("[%.2f %.2f %.2f]", matrix.get(i * 3), matrix.get(i * 3 + 1), matrix.get(i * 3 + 2)); canvas->drawString(row, x, y, font, paint); y += kLineHeight; } return y; } static float print_size(SkCanvas* canvas, const char* prefix, const SkIRect& rect, float x, float y, const SkFont& font, const SkPaint& paint) { canvas->drawString(prefix, x, y, font, paint); y += kLineHeight; SkString sz; sz.appendf("%d x %d", rect.width(), rect.height()); canvas->drawString(sz, x, y, font, paint); return y + kLineHeight; } static float print_info(SkCanvas* canvas, const FilterNode& node) { SkFont font(nullptr, 12); SkPaint text; text.setAntiAlias(true); float y = kLineHeight; if (node.fFilter) { canvas->drawString(node.fFilter->getTypeName(), kLineInset, y, font, text); y += kLineHeight; if (node.fDepth == 0) { // The mapping is the same for all nodes, so only print at the root y = print_matrix(canvas, "Param->Layer", node.fMapping.layerMatrix(), kLineInset, y, font, text); y = print_matrix(canvas, "Layer->Device", node.fMapping.deviceMatrix(), kLineInset, y, font, text); } y = print_size(canvas, "Layer Size", SkIRect(node.fUnhintedLayerBounds), kLineInset, y, font, text); y = print_size(canvas, "Layer Size (hinted)", SkIRect(node.fHintedLayerBounds), kLineInset, y, font, text); } else { canvas->drawString("Source Input", kLineInset, y, font, text); y += kLineHeight; } return y; } // Returns bottom edge in pixels that the subtree reached in canvas static float draw_dag(SkCanvas* canvas, SkSurface* nodeSurface, const FilterNode& node) { // First capture the results of the node, into nodeSurface draw_node(nodeSurface->getCanvas(), node); sk_sp nodeResults = nodeSurface->makeImageSnapshot(); // Fill in background of the filter node with a checkerboard canvas->save(); canvas->clipRect(SkRect::MakeWH(nodeResults->width(), nodeResults->height())); ToolUtils::draw_checkerboard(canvas, SK_ColorGRAY, SK_ColorLTGRAY, 10); canvas->restore(); // Display filtered results in current canvas' location (assumed CTM is set for this node) canvas->drawImage(nodeResults, 0, 0); SkPaint line; line.setAntiAlias(true); line.setStyle(SkPaint::kStroke_Style); line.setStrokeWidth(3.f); // Text info canvas->save(); canvas->translate(0, nodeResults->height()); float textHeight = print_info(canvas, node); canvas->restore(); // Border around filtered results + text info canvas->drawRect(SkRect::MakeWH(nodeResults->width(), nodeResults->height() + textHeight), line); static const float kPad = 20.f; float x = nodeResults->width() + kPad; float y = 0; for (int i = 0; i < node.fInputNodes.count(); ++i) { // Line connecting this node to its child canvas->drawLine(nodeResults->width(), 0.5f * nodeResults->height(), // right of node x, y + 0.5f * nodeResults->height(), line); // left of child canvas->save(); canvas->translate(x, y); y = draw_dag(canvas, nodeSurface, node.fInputNodes[i]); canvas->restore(); } return std::max(y, nodeResults->height() + textHeight + kPad); } static void draw_dag(SkCanvas* canvas, sk_sp filter, const SkRect& rect, const SkISize& surfaceSize) { // Get the current CTM, which includes all the viewer's UI modifications, which we want to // pass into our mock canvases for each DAG node. SkMatrix ctm = canvas->getTotalMatrix(); canvas->save(); // Reset the matrix so that the DAG layout and instructional text is fixed to the window. canvas->resetMatrix(); // Process the image filter DAG to display intermediate results later on, which will apply the // provided CTM during draw_node calls. FilterNode dag = build_dag(ctm, rect, filter.get()); sk_sp nodeSurface = canvas->makeSurface(canvas->imageInfo().makeDimensions(surfaceSize)); draw_dag(canvas, nodeSurface.get(), dag); canvas->restore(); } class ImageFilterDAGSample : public Sample { public: ImageFilterDAGSample() {} void onDrawContent(SkCanvas* canvas) override { static const SkRect kFilterRect = SkRect::MakeXYWH(20.f, 20.f, 60.f, 60.f); static const SkISize kFilterSurfaceSize = SkISize::Make( 2 * (kFilterRect.fRight + kFilterRect.fLeft), 2 * (kFilterRect.fBottom + kFilterRect.fTop)); // Somewhat clunky, but we want to use the viewer calculated CTM in the mini surfaces used // per DAG node. The rotation matrix viewer calculates is based on the sample size so trick // it into calculating the right matrix for us w/ 1 frame latency. this->setSize(kFilterSurfaceSize.width(), kFilterSurfaceSize.height()); // Make a large DAG // /--- Color Filter <---- Blur <--- Offset // Merge < // \--- Blur <--- Drop Shadow sk_sp drop2 = SkImageFilters::DropShadow( 10.f, 5.f, 3.f, 3.f, SK_ColorBLACK, nullptr); sk_sp blur1 = SkImageFilters::Blur(2.f, 2.f, std::move(drop2)); sk_sp offset3 = SkImageFilters::Offset(-5.f, -5.f, nullptr); sk_sp blur2 = SkImageFilters::Blur(4.f, 4.f, std::move(offset3)); sk_sp cf1 = SkImageFilters::ColorFilter( SkColorFilters::Blend(SK_ColorGRAY, SkBlendMode::kModulate), std::move(blur2)); sk_sp merge0 = SkImageFilters::Merge(std::move(blur1), std::move(cf1)); draw_dag(canvas, std::move(merge0), kFilterRect, kFilterSurfaceSize); } SkString name() override { return SkString("ImageFilterDAG"); } private: using INHERITED = Sample; }; DEF_SAMPLE(return new ImageFilterDAGSample();)