1 /* 2 * Copyright 2020 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 "gm/gm.h" 9 #include "include/core/SkCanvas.h" 10 #include "include/core/SkColor.h" 11 #include "include/core/SkFont.h" 12 #include "include/core/SkFontTypes.h" 13 #include "include/core/SkPaint.h" 14 #include "include/core/SkPoint.h" 15 #include "include/core/SkRect.h" 16 #include "include/core/SkScalar.h" 17 #include "include/core/SkShader.h" 18 #include "include/core/SkSize.h" 19 #include "include/core/SkString.h" 20 #include "include/core/SkTypeface.h" 21 #include "tools/ToolUtils.h" 22 23 #include "modules/skparagraph/include/Paragraph.h" 24 #include "modules/skparagraph/src/ParagraphBuilderImpl.h" 25 26 static const char* gSpeach = "Five score years ago, a great American, in whose symbolic shadow we stand today, signed the Emancipation Proclamation. This momentous decree came as a great beacon light of hope to millions of Negro slaves who had been seared in the flames of withering injustice. It came as a joyous daybreak to end the long night of their captivity."; 27 28 namespace { 29 enum ParaFlags { 30 kTimeLayout = 1 << 0, 31 kUseUnderline = 1 << 1, 32 kShowVisitor = 1 << 2, 33 }; 34 } // namespace 35 36 class ParagraphGM : public skiagm::GM { 37 std::unique_ptr<skia::textlayout::Paragraph> fPara; 38 const unsigned fFlags; 39 40 public: ParagraphGM(unsigned flags)41 ParagraphGM(unsigned flags) : fFlags(flags) {} 42 buildParagraph()43 void buildParagraph() { 44 skia::textlayout::TextStyle style; 45 style.setForegroundColor(SkPaint()); 46 style.setFontFamilies({SkString("sans-serif")}); 47 style.setFontSize(30); 48 49 if (fFlags & kUseUnderline) { 50 style.setDecoration(skia::textlayout::TextDecoration::kUnderline); 51 style.setDecorationMode(skia::textlayout::TextDecorationMode::kThrough); 52 style.setDecorationColor(SK_ColorBLACK); 53 style.setDecorationThicknessMultiplier(2); 54 } 55 56 skia::textlayout::ParagraphStyle paraStyle; 57 paraStyle.setTextStyle(style); 58 59 auto collection = sk_make_sp<skia::textlayout::FontCollection>(); 60 collection->setDefaultFontManager(SkFontMgr::RefDefault()); 61 auto builder = skia::textlayout::ParagraphBuilderImpl::make( 62 paraStyle, collection, SkUnicode::Make()); 63 if (nullptr == builder) { 64 fPara = nullptr; 65 return; 66 } 67 68 builder->addText(gSpeach, strlen(gSpeach)); 69 70 fPara = builder->Build(); 71 fPara->layout(400); 72 } 73 74 protected: onOnceBeforeDraw()75 void onOnceBeforeDraw() override { 76 this->buildParagraph(); 77 } 78 onShortName()79 SkString onShortName() override { 80 SkString name; 81 name.printf("paragraph%s_%s", 82 fFlags & kTimeLayout ? "_layout" : "", 83 fFlags & kUseUnderline ? "_underline" : ""); 84 if (fFlags & kShowVisitor) { 85 name.append("_visitor"); 86 } 87 return name; 88 } 89 onISize()90 SkISize onISize() override { 91 if (fFlags & kShowVisitor) { 92 return SkISize::Make(810, 420); 93 } 94 return SkISize::Make(412, 420); 95 } 96 drawFromVisitor(SkCanvas * canvas,skia::textlayout::Paragraph * para) const97 void drawFromVisitor(SkCanvas* canvas, skia::textlayout::Paragraph* para) const { 98 SkPaint p, p2; 99 p.setColor(0xFF0000FF); 100 p2.setColor(0xFFFF0000); 101 p2.setStrokeWidth(4); 102 p2.setStrokeCap(SkPaint::kSquare_Cap); 103 SkPaint underp; 104 underp.setStroke(true); 105 underp.setStrokeWidth(2); 106 underp.setAntiAlias(true); 107 underp.setColor(p.getColor()); 108 const SkScalar GAP = 2; 109 110 para->visit([&](int, const skia::textlayout::Paragraph::VisitorInfo* info) { 111 if (!info) { 112 return; 113 } 114 canvas->drawGlyphs(info->count, info->glyphs, info->positions, info->origin, 115 info->font, p); 116 117 if (fFlags & kUseUnderline) { 118 // Need to modify positions to roll-in the orign 119 std::vector<SkPoint> pos; 120 for (int i = 0; i < info->count; ++i) { 121 pos.push_back({info->origin.fX + info->positions[i].fX, 122 info->origin.fY + info->positions[i].fY}); 123 } 124 125 const SkScalar X0 = pos[0].fX; 126 const SkScalar X1 = X0 + info->advanceX; 127 const SkScalar Y = pos[0].fY; 128 auto sects = info->font.getIntercepts(info->glyphs, info->count, pos.data(), 129 Y+1, Y+3); 130 131 SkScalar x0 = X0; 132 for (size_t i = 0; i < sects.size(); i += 2) { 133 SkScalar x1 = sects[i] - GAP; 134 if (x0 < x1) { 135 canvas->drawLine(x0, Y+2, x1, Y+2, underp); 136 } 137 x0 = sects[i+1] + GAP; 138 } 139 canvas->drawLine(x0, Y+2, X1, Y+2, underp); 140 } 141 142 if ((false)) { 143 if (info->utf8Starts) { 144 SkString str; 145 for (int i = 0; i < info->count; ++i) { 146 str.appendUnichar(gSpeach[info->utf8Starts[i]]); 147 } 148 SkDebugf("'%s'\n", str.c_str()); 149 } 150 151 // show position points 152 for (int i = 0; i < info->count; ++i) { 153 auto pos = info->positions[i]; 154 canvas->drawPoint(pos.fX + info->origin.fX, pos.fY + info->origin.fY, p2); 155 } 156 } 157 }); 158 } 159 onDraw(SkCanvas * canvas,SkString * errorMsg)160 DrawResult onDraw(SkCanvas* canvas, SkString* errorMsg) override { 161 if (nullptr == fPara) { 162 return DrawResult::kSkip; 163 } 164 165 if (fFlags & kShowVisitor) { 166 canvas->clear(SK_ColorWHITE); 167 fPara->layout(400); 168 fPara->paint(canvas, 10, 10); 169 canvas->translate(400+10, 10); 170 this->drawFromVisitor(canvas, fPara.get()); 171 return DrawResult::kOk; 172 } 173 174 const int loop = (this->getMode() == kGM_Mode) ? 1 : 50; 175 176 int parity = 0; 177 for (int i = 0; i < loop; ++i) { 178 SkAutoCanvasRestore acr(canvas, true); 179 180 if (fFlags & kTimeLayout) { 181 fPara->layout(400 + parity); 182 parity = (parity + 1) & 1; 183 } 184 fPara->paint(canvas, 10, 10); 185 } 186 // clean up if we've been looping 187 if (loop > 1) { 188 canvas->clear(SK_ColorWHITE); 189 fPara->layout(400); 190 fPara->paint(canvas, 10, 10); 191 } 192 193 if ((this->getMode() == kGM_Mode) && (fFlags & kTimeLayout)) { 194 return DrawResult::kSkip; 195 } 196 return DrawResult::kOk; 197 } 198 runAsBench() const199 bool runAsBench() const override { return true; } 200 onAnimate(double)201 bool onAnimate(double /*nanos*/) override { 202 return false; 203 } 204 205 private: 206 using INHERITED = skiagm::GM; 207 }; 208 DEF_GM(return new ParagraphGM(0);) 209 DEF_GM(return new ParagraphGM(kTimeLayout);) 210 DEF_GM(return new ParagraphGM(kUseUnderline);) 211 DEF_GM(return new ParagraphGM(kShowVisitor);) 212 DEF_GM(return new ParagraphGM(kShowVisitor | kUseUnderline);) 213