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      1 /*
      2  * Copyright 2013 Google Inc.
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 
      8 #include "Benchmark.h"
      9 #include "SkCanvas.h"
     10 #include "SkPaint.h"
     11 #include "SkPath.h"
     12 #include "SkRandom.h"
     13 #include "SkTDArray.h"
     14 
     15 /**
     16  * This is a conversion of samplecode/SampleChart.cpp into a bench. It sure would be nice to be able
     17  * to write one subclass that can be a GM, bench, and/or Sample.
     18  */
     19 
     20 // Generates y values for the chart plots.
     21 static void gen_data(SkScalar yAvg, SkScalar ySpread, int count,
     22                      SkRandom* random, SkTDArray<SkScalar>* dataPts) {
     23     dataPts->setCount(count);
     24     for (int i = 0; i < count; ++i) {
     25         (*dataPts)[i] = random->nextRangeScalar(yAvg - SkScalarHalf(ySpread),
     26                                                 yAvg + SkScalarHalf(ySpread));
     27     }
     28 }
     29 
     30 // Generates a path to stroke along the top of each plot and a fill path for the area below each
     31 // plot. The fill path is bounded below by the bottomData plot points or a horizontal line at
     32 // yBase if bottomData == nullptr.
     33 // The plots are animated by rotating the data points by leftShift.
     34 static void gen_paths(const SkTDArray<SkScalar>& topData,
     35                       const SkTDArray<SkScalar>* bottomData,
     36                       SkScalar yBase,
     37                       SkScalar xLeft, SkScalar xDelta,
     38                       int leftShift,
     39                       SkPath* plot, SkPath* fill) {
     40     plot->rewind();
     41     fill->rewind();
     42     plot->incReserve(topData.count());
     43     if (nullptr == bottomData) {
     44         fill->incReserve(topData.count() + 2);
     45     } else {
     46         fill->incReserve(2 * topData.count());
     47     }
     48 
     49     leftShift %= topData.count();
     50     SkScalar x = xLeft;
     51 
     52     // Account for the leftShift using two loops
     53     int shiftToEndCount = topData.count() - leftShift;
     54     plot->moveTo(x, topData[leftShift]);
     55     fill->moveTo(x, topData[leftShift]);
     56 
     57     for (int i = 1; i < shiftToEndCount; ++i) {
     58         plot->lineTo(x, topData[i + leftShift]);
     59         fill->lineTo(x, topData[i + leftShift]);
     60         x += xDelta;
     61     }
     62 
     63     for (int i = 0; i < leftShift; ++i) {
     64         plot->lineTo(x, topData[i]);
     65         fill->lineTo(x, topData[i]);
     66         x += xDelta;
     67     }
     68 
     69     if (bottomData) {
     70         SkASSERT(bottomData->count() == topData.count());
     71         // iterate backwards over the previous graph's data to generate the bottom of the filled
     72         // area (and account for leftShift).
     73         for (int i = 0; i < leftShift; ++i) {
     74             x -= xDelta;
     75             fill->lineTo(x, (*bottomData)[leftShift - 1 - i]);
     76         }
     77         for (int i = 0; i < shiftToEndCount; ++i) {
     78             x -= xDelta;
     79             fill->lineTo(x, (*bottomData)[bottomData->count() - 1 - i]);
     80         }
     81     } else {
     82         fill->lineTo(x - xDelta, yBase);
     83         fill->lineTo(xLeft, yBase);
     84     }
     85 }
     86 
     87 // A set of scrolling line plots with the area between each plot filled. Stresses out GPU path
     88 // filling
     89 class ChartBench : public Benchmark {
     90 public:
     91     ChartBench(bool aa) {
     92         fShift = 0;
     93         fAA = aa;
     94         fSize.fWidth = -1;
     95         fSize.fHeight = -1;
     96     }
     97 
     98 protected:
     99     const char* onGetName() override {
    100         if (fAA) {
    101             return "chart_aa";
    102         } else {
    103             return "chart_bw";
    104         }
    105     }
    106 
    107     void onDraw(int loops, SkCanvas* canvas) override {
    108         bool sizeChanged = false;
    109         if (canvas->getBaseLayerSize() != fSize) {
    110             fSize = canvas->getBaseLayerSize();
    111             sizeChanged = true;
    112         }
    113 
    114         SkScalar ySpread = SkIntToScalar(fSize.fHeight / 20);
    115 
    116         SkScalar height = SkIntToScalar(fSize.fHeight);
    117         if (sizeChanged) {
    118             int dataPointCount = SkMax32(fSize.fWidth / kPixelsPerTick + 1, 2);
    119 
    120             SkRandom random;
    121             for (int i = 0; i < kNumGraphs; ++i) {
    122                 SkScalar y = (kNumGraphs - i) * (height - ySpread) / (kNumGraphs + 1);
    123                 fData[i].reset();
    124                 gen_data(y, ySpread, dataPointCount, &random, fData + i);
    125             }
    126         }
    127 
    128         SkRandom colorRand;
    129         SkColor colors[kNumGraphs];
    130         for (int i = 0; i < kNumGraphs; ++i) {
    131             colors[i] = colorRand.nextU() | 0xff000000;
    132         }
    133 
    134         for (int frame = 0; frame < loops; ++frame) {
    135             SkPath plotPath;
    136             SkPath fillPath;
    137 
    138             static const SkScalar kStrokeWidth = SkIntToScalar(2);
    139             SkPaint plotPaint;
    140             SkPaint fillPaint;
    141             plotPaint.setAntiAlias(fAA);
    142             plotPaint.setStyle(SkPaint::kStroke_Style);
    143             plotPaint.setStrokeWidth(kStrokeWidth);
    144             plotPaint.setStrokeCap(SkPaint::kRound_Cap);
    145             plotPaint.setStrokeJoin(SkPaint::kRound_Join);
    146             fillPaint.setAntiAlias(fAA);
    147             fillPaint.setStyle(SkPaint::kFill_Style);
    148 
    149             SkTDArray<SkScalar>* prevData = nullptr;
    150             for (int i = 0; i < kNumGraphs; ++i) {
    151                 gen_paths(fData[i],
    152                           prevData,
    153                           height,
    154                           0,
    155                           SkIntToScalar(kPixelsPerTick),
    156                           fShift,
    157                           &plotPath,
    158                           &fillPath);
    159 
    160                 // Make the fills partially transparent
    161                 fillPaint.setColor((colors[i] & 0x00ffffff) | 0x80000000);
    162                 canvas->drawPath(fillPath, fillPaint);
    163 
    164                 plotPaint.setColor(colors[i]);
    165                 canvas->drawPath(plotPath, plotPaint);
    166 
    167                 prevData = fData + i;
    168             }
    169 
    170             fShift += kShiftPerFrame;
    171         }
    172     }
    173 
    174 private:
    175     enum {
    176         kNumGraphs = 5,
    177         kPixelsPerTick = 3,
    178         kShiftPerFrame = 1,
    179     };
    180     int                 fShift;
    181     SkISize             fSize;
    182     SkTDArray<SkScalar> fData[kNumGraphs];
    183     bool                fAA;
    184 
    185     typedef Benchmark INHERITED;
    186 };
    187 
    188 //////////////////////////////////////////////////////////////////////////////
    189 
    190 DEF_BENCH( return new ChartBench(true); )
    191 DEF_BENCH( return new ChartBench(false); )
    192