1 /*
2 * Copyright 2015 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 "SampleCode.h"
9 #include "SkView.h"
10 #include "SkCanvas.h"
11 #include "SkUtils.h"
12 #include "SkColorPriv.h"
13 #include "SkColorFilter.h"
14 #include "SkRandom.h"
15 #include "SkSystemEventTypes.h"
16 #include "SkTime.h"
17 #include "SkTypeface.h"
18 #include "SkXfermode.h"
19 #include "Timer.h"
20
21 #if SK_SUPPORT_GPU
22 #include "GrContext.h"
23 #include "SkGpuDevice.h"
24 #endif
25
26 SkRandom gRand;
27
DrawTheText(SkCanvas * canvas,const char text[],size_t length,SkScalar x,SkScalar y,const SkPaint & paint)28 static void DrawTheText(SkCanvas* canvas, const char text[], size_t length, SkScalar x, SkScalar y,
29 const SkPaint& paint) {
30 SkPaint p(paint);
31
32 p.setSubpixelText(true);
33 canvas->drawText(text, length, x, y, p);
34 }
35
36 // This sample demonstrates the cache behavior of bitmap vs. distance field text
37 // It renders variously sized text with an animated scale and rotation.
38 // Specifically one should:
39 // use 'D' to toggle between bitmap and distance field fonts
40 // use '2' to toggle between scaling the image by 2x
41 // -- this feature boosts the rendering out of the small point-size
42 // SDF-text special case (which falls back to bitmap fonts for small points)
43
44 class AnimatedTextView : public SampleView {
45 public:
AnimatedTextView()46 AnimatedTextView() : fScale(1.0f), fScaleInc(0.1f), fRotation(0.0f), fSizeScale(1) {
47 fCurrentTime = 0;
48 fTimer.start();
49 memset(fTimes, 0, sizeof(fTimes));
50 }
51
52 protected:
53 // overrides from SkEventSink
onQuery(SkEvent * evt)54 bool onQuery(SkEvent* evt) override {
55 if (SampleCode::TitleQ(*evt)) {
56 SampleCode::TitleR(evt, "AnimatedText");
57 return true;
58 }
59
60 SkUnichar uni;
61 if (SampleCode::CharQ(*evt, &uni)) {
62 if ('2' == uni) {
63 if (fSizeScale == 2) {
64 fSizeScale = 1;
65 } else {
66 fSizeScale = 2;
67 }
68 return true;
69 }
70 }
71 return this->INHERITED::onQuery(evt);
72 }
73
onDrawContent(SkCanvas * canvas)74 void onDrawContent(SkCanvas* canvas) override {
75 SkPaint paint;
76 SkSafeUnref(paint.setTypeface(SkTypeface::CreateFromFile("/skimages/samplefont.ttf")));
77 paint.setAntiAlias(true);
78 paint.setFilterQuality(kMedium_SkFilterQuality);
79
80 SkString outString("fps: ");
81 fTimer.end();
82
83 // TODO: generalize this timing code in utils
84 fTimes[fCurrentTime] = (float)(fTimer.fWall);
85 fCurrentTime = (fCurrentTime + 1) & 0x1f;
86
87 float meanTime = 0.0f;
88 for (int i = 0; i < 32; ++i) {
89 meanTime += fTimes[i];
90 }
91 meanTime /= 32.f;
92 SkScalar fps = 1000.f / meanTime;
93 outString.appendScalar(fps);
94 outString.append(" ms: ");
95 outString.appendScalar(meanTime);
96
97 SkString modeString("Text scale: ");
98 modeString.appendU32(fSizeScale);
99 modeString.append("x");
100
101 fTimer.start();
102
103 canvas->save();
104
105 #if SK_SUPPORT_GPU
106 SkBaseDevice* device = canvas->getDevice_just_for_deprecated_compatibility_testing();
107 GrContext* grContext = canvas->getGrContext();
108 if (grContext) {
109 GrTexture* tex = grContext->getFontAtlasTexture(GrMaskFormat::kA8_GrMaskFormat);
110 reinterpret_cast<SkGpuDevice*>(device)->drawTexture(tex,
111 SkRect::MakeXYWH(512, 10, 512, 512), paint);
112 }
113 #endif
114 canvas->translate(180, 180);
115 canvas->rotate(fRotation);
116 canvas->scale(fScale, fScale);
117 canvas->translate(-180, -180);
118
119 const char* text = "Hamburgefons";
120 size_t length = strlen(text);
121
122 SkScalar y = SkIntToScalar(0);
123 for (int i = 12; i <= 26; i++) {
124 paint.setTextSize(SkIntToScalar(i*fSizeScale));
125 y += paint.getFontSpacing();
126 DrawTheText(canvas, text, length, SkIntToScalar(110), y, paint);
127 }
128 canvas->restore();
129
130 paint.setTextSize(16);
131 // canvas->drawText(outString.c_str(), outString.size(), 512.f, 540.f, paint);
132 canvas->drawText(modeString.c_str(), modeString.size(), 768.f, 540.f, paint);
133 }
134
onAnimate(const SkAnimTimer & timer)135 bool onAnimate(const SkAnimTimer& timer) override {
136 // We add noise to the scale and rotation animations to
137 // keep the font atlas from falling into a steady state
138 fRotation += (1.0f + gRand.nextRangeF(-0.1f, 0.1f));
139 fScale += (fScaleInc + gRand.nextRangeF(-0.025f, 0.025f));
140 if (fScale >= 2.0f) {
141 fScaleInc = -0.1f;
142 } else if (fScale <= 1.0f) {
143 fScaleInc = 0.1f;
144 }
145 return true;
146 }
147
148 private:
149 float fScale;
150 float fScaleInc;
151 float fRotation;
152 int fSizeScale;
153
154 WallTimer fTimer;
155 float fTimes[32];
156 int fCurrentTime;
157
158
159 typedef SampleView INHERITED;
160 };
161
162 //////////////////////////////////////////////////////////////////////////////
163
MyFactory()164 static SkView* MyFactory() { return new AnimatedTextView; }
165 static SkViewRegister reg(MyFactory);
166