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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 "SkRandom.h"
     12 
     13 /**
     14  * This is a conversion of samplecode/SampleChart.cpp into a bench. It sure would be nice to be able
     15  * to write one subclass that can be a GM, bench, and/or Sample.
     16  */
     17 
     18 // Generates y values for the chart plots.
     19 static void gen_data(SkScalar yAvg, SkScalar ySpread, int count,
     20                      SkRandom* random, SkTDArray<SkScalar>* dataPts) {
     21     dataPts->setCount(count);
     22     for (int i = 0; i < count; ++i) {
     23         (*dataPts)[i] = random->nextRangeScalar(yAvg - SkScalarHalf(ySpread),
     24                                                 yAvg + SkScalarHalf(ySpread));
     25     }
     26 }
     27 
     28 // Generates a path to stroke along the top of each plot and a fill path for the area below each
     29 // plot. The fill path is bounded below by the bottomData plot points or a horizontal line at
     30 // yBase if bottomData == NULL.
     31 // The plots are animated by rotating the data points by leftShift.
     32 static void gen_paths(const SkTDArray<SkScalar>& topData,
     33                       const SkTDArray<SkScalar>* bottomData,
     34                       SkScalar yBase,
     35                       SkScalar xLeft, SkScalar xDelta,
     36                       int leftShift,
     37                       SkPath* plot, SkPath* fill) {
     38     plot->rewind();
     39     fill->rewind();
     40     plot->incReserve(topData.count());
     41     if (NULL == bottomData) {
     42         fill->incReserve(topData.count() + 2);
     43     } else {
     44         fill->incReserve(2 * topData.count());
     45     }
     46 
     47     leftShift %= topData.count();
     48     SkScalar x = xLeft;
     49 
     50     // Account for the leftShift using two loops
     51     int shiftToEndCount = topData.count() - leftShift;
     52     plot->moveTo(x, topData[leftShift]);
     53     fill->moveTo(x, topData[leftShift]);
     54 
     55     for (int i = 1; i < shiftToEndCount; ++i) {
     56         plot->lineTo(x, topData[i + leftShift]);
     57         fill->lineTo(x, topData[i + leftShift]);
     58         x += xDelta;
     59     }
     60 
     61     for (int i = 0; i < leftShift; ++i) {
     62         plot->lineTo(x, topData[i]);
     63         fill->lineTo(x, topData[i]);
     64         x += xDelta;
     65     }
     66 
     67     if (NULL != bottomData) {
     68         SkASSERT(bottomData->count() == topData.count());
     69         // iterate backwards over the previous graph's data to generate the bottom of the filled
     70         // area (and account for leftShift).
     71         for (int i = 0; i < leftShift; ++i) {
     72             x -= xDelta;
     73             fill->lineTo(x, (*bottomData)[leftShift - 1 - i]);
     74         }
     75         for (int i = 0; i < shiftToEndCount; ++i) {
     76             x -= xDelta;
     77             fill->lineTo(x, (*bottomData)[bottomData->count() - 1 - i]);
     78         }
     79     } else {
     80         fill->lineTo(x - xDelta, yBase);
     81         fill->lineTo(xLeft, yBase);
     82     }
     83 }
     84 
     85 // A set of scrolling line plots with the area between each plot filled. Stresses out GPU path
     86 // filling
     87 class ChartBench : public Benchmark {
     88 public:
     89     ChartBench(bool aa) {
     90         fShift = 0;
     91         fAA = aa;
     92         fSize.fWidth = -1;
     93         fSize.fHeight = -1;
     94     }
     95 
     96 protected:
     97     virtual const char* onGetName() SK_OVERRIDE {
     98         if (fAA) {
     99             return "chart_aa";
    100         } else {
    101             return "chart_bw";
    102         }
    103     }
    104 
    105     virtual void onDraw(const int loops, SkCanvas* canvas) SK_OVERRIDE {
    106         bool sizeChanged = false;
    107         if (canvas->getDeviceSize() != fSize) {
    108             fSize = canvas->getDeviceSize();
    109             sizeChanged = true;
    110         }
    111 
    112         SkScalar ySpread = SkIntToScalar(fSize.fHeight / 20);
    113 
    114         SkScalar height = SkIntToScalar(fSize.fHeight);
    115         if (sizeChanged) {
    116             int dataPointCount = SkMax32(fSize.fWidth / kPixelsPerTick + 1, 2);
    117 
    118             SkRandom random;
    119             for (int i = 0; i < kNumGraphs; ++i) {
    120                 SkScalar y = (kNumGraphs - i) * (height - ySpread) / (kNumGraphs + 1);
    121                 fData[i].reset();
    122                 gen_data(y, ySpread, dataPointCount, &random, fData + i);
    123             }
    124         }
    125 
    126         SkRandom colorRand;
    127         SkColor colors[kNumGraphs];
    128         for (int i = 0; i < kNumGraphs; ++i) {
    129             colors[i] = colorRand.nextU() | 0xff000000;
    130         }
    131 
    132         for (int frame = 0; frame < loops; ++frame) {
    133 
    134             canvas->clear(0xFFE0F0E0);
    135 
    136             SkPath plotPath;
    137             SkPath fillPath;
    138 
    139             static const SkScalar kStrokeWidth = SkIntToScalar(2);
    140             SkPaint plotPaint;
    141             SkPaint fillPaint;
    142             plotPaint.setAntiAlias(fAA);
    143             plotPaint.setStyle(SkPaint::kStroke_Style);
    144             plotPaint.setStrokeWidth(kStrokeWidth);
    145             plotPaint.setStrokeCap(SkPaint::kRound_Cap);
    146             plotPaint.setStrokeJoin(SkPaint::kRound_Join);
    147             fillPaint.setAntiAlias(fAA);
    148             fillPaint.setStyle(SkPaint::kFill_Style);
    149 
    150             SkTDArray<SkScalar>* prevData = NULL;
    151             for (int i = 0; i < kNumGraphs; ++i) {
    152                 gen_paths(fData[i],
    153                           prevData,
    154                           height,
    155                           0,
    156                           SkIntToScalar(kPixelsPerTick),
    157                           fShift,
    158                           &plotPath,
    159                           &fillPath);
    160 
    161                 // Make the fills partially transparent
    162                 fillPaint.setColor((colors[i] & 0x00ffffff) | 0x80000000);
    163                 canvas->drawPath(fillPath, fillPaint);
    164 
    165                 plotPaint.setColor(colors[i]);
    166                 canvas->drawPath(plotPath, plotPaint);
    167 
    168                 prevData = fData + i;
    169             }
    170 
    171             fShift += kShiftPerFrame;
    172         }
    173     }
    174 
    175 private:
    176     enum {
    177         kNumGraphs = 5,
    178         kPixelsPerTick = 3,
    179         kShiftPerFrame = 1,
    180     };
    181     int                 fShift;
    182     SkISize             fSize;
    183     SkTDArray<SkScalar> fData[kNumGraphs];
    184     bool                fAA;
    185 
    186     typedef Benchmark INHERITED;
    187 };
    188 
    189 //////////////////////////////////////////////////////////////////////////////
    190 
    191 DEF_BENCH( return new ChartBench(true); )
    192 DEF_BENCH( return new ChartBench(false); )
    193