| /* |
| * Copyright 2013 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "include/core/SkCanvas.h" |
| #include "include/core/SkPaint.h" |
| #include "include/core/SkPathBuilder.h" |
| #include "include/private/base/SkTDArray.h" |
| #include "src/base/SkRandom.h" |
| #include "tools/viewer/Slide.h" |
| |
| // Generates y values for the chart plots. |
| static void gen_data(SkScalar yAvg, SkScalar ySpread, int count, SkTDArray<SkScalar>* dataPts) { |
| dataPts->resize(count); |
| static SkRandom gRandom; |
| for (int i = 0; i < count; ++i) { |
| (*dataPts)[i] = gRandom.nextRangeScalar(yAvg - SkScalarHalf(ySpread), |
| yAvg + SkScalarHalf(ySpread)); |
| } |
| } |
| |
| // Generates a path to stroke along the top of each plot and a fill path for the area below each |
| // plot. The fill path is bounded below by the bottomData plot points or a horizontal line at |
| // yBase if bottomData == nullptr. |
| // The plots are animated by rotating the data points by leftShift. |
| static void gen_paths(const SkTDArray<SkScalar>& topData, |
| const SkTDArray<SkScalar>* bottomData, |
| SkScalar yBase, |
| SkScalar xLeft, SkScalar xDelta, |
| int leftShift, |
| SkPathBuilder* plot, SkPathBuilder* fill) { |
| plot->incReserve(topData.size()); |
| if (nullptr == bottomData) { |
| fill->incReserve(topData.size() + 2); |
| } else { |
| fill->incReserve(2 * topData.size()); |
| } |
| |
| leftShift %= topData.size(); |
| SkScalar x = xLeft; |
| |
| // Account for the leftShift using two loops |
| int shiftToEndCount = topData.size() - leftShift; |
| plot->moveTo(x, topData[leftShift]); |
| fill->moveTo(x, topData[leftShift]); |
| |
| for (int i = 1; i < shiftToEndCount; ++i) { |
| plot->lineTo(x, topData[i + leftShift]); |
| fill->lineTo(x, topData[i + leftShift]); |
| x += xDelta; |
| } |
| |
| for (int i = 0; i < leftShift; ++i) { |
| plot->lineTo(x, topData[i]); |
| fill->lineTo(x, topData[i]); |
| x += xDelta; |
| } |
| |
| if (bottomData) { |
| SkASSERT(bottomData->size() == topData.size()); |
| // iterate backwards over the previous graph's data to generate the bottom of the filled |
| // area (and account for leftShift). |
| for (int i = 0; i < leftShift; ++i) { |
| x -= xDelta; |
| fill->lineTo(x, (*bottomData)[leftShift - 1 - i]); |
| } |
| for (int i = 0; i < shiftToEndCount; ++i) { |
| x -= xDelta; |
| fill->lineTo(x, (*bottomData)[bottomData->size() - 1 - i]); |
| } |
| } else { |
| fill->lineTo(x - xDelta, yBase); |
| fill->lineTo(xLeft, yBase); |
| } |
| } |
| |
| // A set of scrolling line plots with the area between each plot filled. Stresses out GPU path |
| // filling |
| class ChartSlide : public Slide { |
| inline static constexpr int kNumGraphs = 5; |
| inline static constexpr int kPixelsPerTick = 3; |
| inline static constexpr int kShiftPerFrame = 1; |
| int fShift = 0; |
| SkISize fSize = {-1, -1}; |
| SkTDArray<SkScalar> fData[kNumGraphs]; |
| |
| public: |
| ChartSlide() { fName = "Chart"; } |
| |
| void draw(SkCanvas* canvas) override { |
| bool sizeChanged = false; |
| if (canvas->getBaseLayerSize() != fSize) { |
| fSize = canvas->getBaseLayerSize(); |
| sizeChanged = true; |
| } |
| |
| SkScalar ySpread = SkIntToScalar(fSize.fHeight / 20); |
| |
| SkScalar height = SkIntToScalar(fSize.fHeight); |
| |
| if (sizeChanged) { |
| int dataPointCount = std::max(fSize.fWidth / kPixelsPerTick + 1, 2); |
| |
| for (int i = 0; i < kNumGraphs; ++i) { |
| SkScalar y = (kNumGraphs - i) * (height - ySpread) / (kNumGraphs + 1); |
| fData[i].reset(); |
| gen_data(y, ySpread, dataPointCount, fData + i); |
| } |
| } |
| |
| canvas->clear(0xFFE0F0E0); |
| |
| static SkRandom colorRand; |
| static SkColor gColors[kNumGraphs] = { 0x0 }; |
| if (0 == gColors[0]) { |
| for (int i = 0; i < kNumGraphs; ++i) { |
| gColors[i] = colorRand.nextU() | 0xff000000; |
| } |
| } |
| |
| static const SkScalar kStrokeWidth = SkIntToScalar(2); |
| SkPaint plotPaint; |
| SkPaint fillPaint; |
| plotPaint.setAntiAlias(true); |
| plotPaint.setStyle(SkPaint::kStroke_Style); |
| plotPaint.setStrokeWidth(kStrokeWidth); |
| plotPaint.setStrokeCap(SkPaint::kRound_Cap); |
| plotPaint.setStrokeJoin(SkPaint::kRound_Join); |
| fillPaint.setAntiAlias(true); |
| fillPaint.setStyle(SkPaint::kFill_Style); |
| |
| SkPathBuilder plotPath, fillPath; |
| SkTDArray<SkScalar>* prevData = nullptr; |
| |
| for (int i = 0; i < kNumGraphs; ++i) { |
| gen_paths(fData[i], |
| prevData, |
| height, |
| 0, |
| SkIntToScalar(kPixelsPerTick), |
| fShift, |
| &plotPath, |
| &fillPath); |
| |
| // Make the fills partially transparent |
| fillPaint.setColor((gColors[i] & 0x00ffffff) | 0x80000000); |
| canvas->drawPath(fillPath.detach(), fillPaint); |
| |
| plotPaint.setColor(gColors[i]); |
| canvas->drawPath(plotPath.detach(), plotPaint); |
| |
| prevData = fData + i; |
| } |
| |
| fShift += kShiftPerFrame; |
| } |
| }; |
| |
| DEF_SLIDE( return new ChartSlide(); ) |