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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 "bench/Benchmark.h"
9 #include "include/core/SkCanvas.h"
10 #include "include/core/SkPaint.h"
11 #include "include/core/SkPath.h"
12 #include "include/private/SkTDArray.h"
13 #include "include/utils/SkRandom.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.
gen_data(SkScalar yAvg,SkScalar ySpread,int count,SkRandom * random,SkTDArray<SkScalar> * dataPts)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.
gen_paths(const SkTDArray<SkScalar> & topData,const SkTDArray<SkScalar> * bottomData,SkScalar yBase,SkScalar xLeft,SkScalar xDelta,int leftShift,SkPath * plot,SkPath * fill)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:
ChartBench(bool aa)91     ChartBench(bool aa) {
92         fShift = 0;
93         fAA = aa;
94         fSize.fWidth = -1;
95         fSize.fHeight = -1;
96     }
97 
98 protected:
onGetName()99     const char* onGetName() override {
100         if (fAA) {
101             return "chart_aa";
102         } else {
103             return "chart_bw";
104         }
105     }
106 
onDraw(int loops,SkCanvas * canvas)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 = std::max(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