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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 "SkBenchmark.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, SkTDArray<SkScalar>* dataPts) {
     20     dataPts->setCount(count);
     21     static SkRandom gRandom;
     22     for (int i = 0; i < count; ++i) {
     23         (*dataPts)[i] = gRandom.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 SkBenchmark {
     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             for (int i = 0; i < kNumGraphs; ++i) {
    119                 SkScalar y = (kNumGraphs - i) * (height - ySpread) / (kNumGraphs + 1);
    120                 fData[i].reset();
    121                 gen_data(y, ySpread, dataPointCount, fData + i);
    122             }
    123         }
    124 
    125         for (int frame = 0; frame < loops; ++frame) {
    126 
    127             canvas->clear(0xFFE0F0E0);
    128 
    129             static SkRandom colorRand;
    130             static SkColor gColors[kNumGraphs] = { 0x0 };
    131             if (0 == gColors[0]) {
    132                 for (int i = 0; i < kNumGraphs; ++i) {
    133                     gColors[i] = colorRand.nextU() | 0xff000000;
    134                 }
    135             }
    136 
    137             SkPath plotPath;
    138             SkPath fillPath;
    139 
    140             static const SkScalar kStrokeWidth = SkIntToScalar(2);
    141             SkPaint plotPaint;
    142             SkPaint fillPaint;
    143             plotPaint.setAntiAlias(fAA);
    144             plotPaint.setStyle(SkPaint::kStroke_Style);
    145             plotPaint.setStrokeWidth(kStrokeWidth);
    146             plotPaint.setStrokeCap(SkPaint::kRound_Cap);
    147             plotPaint.setStrokeJoin(SkPaint::kRound_Join);
    148             fillPaint.setAntiAlias(fAA);
    149             fillPaint.setStyle(SkPaint::kFill_Style);
    150 
    151             SkTDArray<SkScalar>* prevData = NULL;
    152             for (int i = 0; i < kNumGraphs; ++i) {
    153                 gen_paths(fData[i],
    154                           prevData,
    155                           height,
    156                           0,
    157                           SkIntToScalar(kPixelsPerTick),
    158                           fShift,
    159                           &plotPath,
    160                           &fillPath);
    161 
    162                 // Make the fills partially transparent
    163                 fillPaint.setColor((gColors[i] & 0x00ffffff) | 0x80000000);
    164                 canvas->drawPath(fillPath, fillPaint);
    165 
    166                 plotPaint.setColor(gColors[i]);
    167                 canvas->drawPath(plotPath, plotPaint);
    168 
    169                 prevData = fData + i;
    170             }
    171 
    172             fShift += kShiftPerFrame;
    173         }
    174     }
    175 
    176 private:
    177     enum {
    178         kNumGraphs = 5,
    179         kPixelsPerTick = 3,
    180         kShiftPerFrame = 1,
    181     };
    182     int                 fShift;
    183     SkISize             fSize;
    184     SkTDArray<SkScalar> fData[kNumGraphs];
    185     bool                fAA;
    186 
    187     typedef SkBenchmark INHERITED;
    188 };
    189 
    190 //////////////////////////////////////////////////////////////////////////////
    191 
    192 DEF_BENCH( return new ChartBench(true); )
    193 DEF_BENCH( return new ChartBench(false); )
    194