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 26SkRandom gRand; 27 28static 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 44class AnimatedTextView : public SampleView { 45public: 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 52protected: 53 // overrides from SkEventSink 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 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 } 134 135 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 148private: 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 164static SkView* MyFactory() { return new AnimatedTextView; } 165static SkViewRegister reg(MyFactory); 166