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1 /*
2  * Copyright 2012 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 "include/core/SkBlendMode.h"
9 #include "include/core/SkCanvas.h"
10 #include "include/core/SkColor.h"
11 #include "include/core/SkFont.h"
12 #include "include/core/SkImageInfo.h"
13 #include "include/core/SkMatrix.h"
14 #include "include/core/SkPaint.h"
15 #include "include/core/SkPath.h"
16 #include "include/core/SkPathMeasure.h"
17 #include "include/core/SkPoint.h"
18 #include "include/core/SkRRect.h"
19 #include "include/core/SkRect.h"
20 #include "include/core/SkRefCnt.h"
21 #include "include/core/SkScalar.h"
22 #include "include/core/SkShader.h"
23 #include "include/core/SkString.h"
24 #include "include/core/SkSurface.h"
25 #include "include/core/SkTypes.h"
26 #include "include/private/SkTArray.h"
27 #include "include/private/SkTemplates.h"
28 #include "include/utils/SkTextUtils.h"
29 #include "samplecode/Sample.h"
30 #include "src/core/SkGeometry.h"
31 #include "src/core/SkPathPriv.h"
32 #include "src/core/SkPointPriv.h"
33 #include "src/core/SkStroke.h"
34 #include "tools/ToolUtils.h"
35 
36 #include <cfloat>
37 
38 class SkEvent;
39 
hittest(const SkPoint & target,SkScalar x,SkScalar y)40 static bool hittest(const SkPoint& target, SkScalar x, SkScalar y) {
41     const SkScalar TOL = 7;
42     return SkPoint::Distance(target, SkPoint::Make(x, y)) <= TOL;
43 }
44 
getOnCurvePoints(const SkPath & path,SkPoint storage[])45 static int getOnCurvePoints(const SkPath& path, SkPoint storage[]) {
46     int count = 0;
47     for (auto [verb, pts, w] : SkPathPriv::Iterate(path)) {
48         switch (verb) {
49             case SkPathVerb::kMove:
50             case SkPathVerb::kLine:
51             case SkPathVerb::kQuad:
52             case SkPathVerb::kConic:
53             case SkPathVerb::kCubic:
54                 storage[count++] = pts[0];
55                 break;
56             default:
57                 break;
58         }
59     }
60     return count;
61 }
62 
getContourCounts(const SkPath & path,SkTArray<int> * contourCounts)63 static void getContourCounts(const SkPath& path, SkTArray<int>* contourCounts) {
64     int count = 0;
65     for (auto [verb, pts, w] : SkPathPriv::Iterate(path)) {
66         switch (verb) {
67             case SkPathVerb::kMove:
68             case SkPathVerb::kLine:
69                 count += 1;
70                 break;
71             case SkPathVerb::kQuad:
72             case SkPathVerb::kConic:
73                 count += 2;
74                 break;
75             case SkPathVerb::kCubic:
76                 count += 3;
77                 break;
78             case SkPathVerb::kClose:
79                 contourCounts->push_back(count);
80                 count = 0;
81                 break;
82             default:
83                 break;
84         }
85     }
86     if (count > 0) {
87         contourCounts->push_back(count);
88     }
89 }
90 
erase(const sk_sp<SkSurface> & surface)91 static void erase(const sk_sp<SkSurface>& surface) {
92     SkCanvas* canvas = surface->getCanvas();
93     if (canvas) {
94         canvas->clear(SK_ColorTRANSPARENT);
95     }
96 }
97 
98 struct StrokeTypeButton {
99     SkRect fBounds;
100     char fLabel;
101     bool fEnabled;
102 };
103 
104 struct CircleTypeButton : public StrokeTypeButton {
105     bool fFill;
106 };
107 
108 class QuadStrokerView : public Sample {
109     enum {
110         SKELETON_COLOR = 0xFF0000FF,
111         WIREFRAME_COLOR = 0x80FF0000
112     };
113 
114     enum {
115         kCount = 18
116     };
117     SkPoint fPts[kCount];
118     SkRect fWeightControl;
119     SkRect fRadiusControl;
120     SkRect fErrorControl;
121     SkRect fWidthControl;
122     SkRect fBounds;
123     SkMatrix fMatrix, fInverse;
124     sk_sp<SkShader> fShader;
125     sk_sp<SkSurface> fMinSurface;
126     sk_sp<SkSurface> fMaxSurface;
127     StrokeTypeButton fCubicButton;
128     StrokeTypeButton fConicButton;
129     StrokeTypeButton fQuadButton;
130     StrokeTypeButton fArcButton;
131     StrokeTypeButton fRRectButton;
132     CircleTypeButton fCircleButton;
133     StrokeTypeButton fTextButton;
134     SkString fText;
135     SkScalar fTextSize;
136     SkScalar fWeight;
137     SkScalar fRadius;
138     SkScalar fWidth, fDWidth;
139     SkScalar fWidthScale;
140     int fW, fH, fZoom;
141     bool fAnimate;
142     bool fDrawRibs;
143     bool fDrawTangents;
144     bool fDrawTDivs;
145 #ifdef SK_DEBUG
146     #define kStrokerErrorMin 0.001f
147     #define kStrokerErrorMax 5
148 #endif
149     #define kWidthMin 1
150     #define kWidthMax 100
151 public:
QuadStrokerView()152     QuadStrokerView() {
153         this->setBGColor(SK_ColorLTGRAY);
154 
155         fPts[0].set(50, 200);  // cubic
156         fPts[1].set(50, 100);
157         fPts[2].set(150, 50);
158         fPts[3].set(300, 50);
159 
160         fPts[4].set(350, 200);  // conic
161         fPts[5].set(350, 100);
162         fPts[6].set(450, 50);
163 
164         fPts[7].set(150, 300);  // quad
165         fPts[8].set(150, 200);
166         fPts[9].set(250, 150);
167 
168         fPts[10].set(250, 200);  // arc
169         fPts[11].set(250, 300);
170         fPts[12].set(150, 350);
171 
172         fPts[13].set(200, 200); // rrect
173         fPts[14].set(400, 400);
174 
175         fPts[15].set(250, 250);  // oval
176         fPts[16].set(450, 450);
177 
178         fText = "a";
179         fTextSize = 12;
180         fWidth = 50;
181         fDWidth = 0.25f;
182         fWeight = 1;
183         fRadius = 150;
184 
185         fCubicButton.fLabel = 'C';
186         fCubicButton.fEnabled = false;
187         fConicButton.fLabel = 'K';
188         fConicButton.fEnabled = false;
189         fQuadButton.fLabel = 'Q';
190         fQuadButton.fEnabled = false;
191         fArcButton.fLabel = 'A';
192         fArcButton.fEnabled = true;
193         fRRectButton.fLabel = 'R';
194         fRRectButton.fEnabled = false;
195         fCircleButton.fLabel = 'O';
196         fCircleButton.fEnabled = true;
197         fCircleButton.fFill = true;
198         fTextButton.fLabel = 'T';
199         fTextButton.fEnabled = false;
200         fAnimate = false;
201         setAsNeeded();
202     }
203 
204 protected:
name()205     SkString name() override { return SkString("QuadStroker"); }
206 
onChar(SkUnichar uni)207     bool onChar(SkUnichar uni) override {
208         if (fTextButton.fEnabled) {
209             switch (uni) {
210                 case ' ':
211                     fText = "";
212                     break;
213                 case '-':
214                     fTextSize = std::max(1.0f, fTextSize - 1);
215                     break;
216                 case '+':
217                 case '=':
218                     fTextSize += 1;
219                     break;
220                 default:
221                     fText.appendUnichar(uni);
222             }
223             return true;
224         }
225         return false;
226     }
227 
onSizeChange()228     void onSizeChange() override {
229         fRadiusControl.setXYWH(this->width() - 200, 30, 30, 400);
230         fWeightControl.setXYWH(this->width() - 150, 30, 30, 400);
231         fErrorControl.setXYWH(this->width() - 100, 30, 30, 400);
232         fWidthControl.setXYWH(this->width() -  50, 30, 30, 400);
233         int buttonOffset = 450;
234         fCubicButton.fBounds.setXYWH(this->width() - 50, SkIntToScalar(buttonOffset), 30, 30);
235         buttonOffset += 50;
236         fConicButton.fBounds.setXYWH(this->width() - 50, SkIntToScalar(buttonOffset), 30, 30);
237         buttonOffset += 50;
238         fQuadButton.fBounds.setXYWH(this->width() - 50, SkIntToScalar(buttonOffset), 30, 30);
239         buttonOffset += 50;
240         fArcButton.fBounds.setXYWH(this->width() - 50, SkIntToScalar(buttonOffset), 30, 30);
241         buttonOffset += 50;
242         fRRectButton.fBounds.setXYWH(this->width() - 50, SkIntToScalar(buttonOffset), 30, 30);
243         buttonOffset += 50;
244         fCircleButton.fBounds.setXYWH(this->width() - 50, SkIntToScalar(buttonOffset), 30, 30);
245         buttonOffset += 50;
246         fTextButton.fBounds.setXYWH(this->width() - 50, SkIntToScalar(buttonOffset), 30, 30);
247         this->INHERITED::onSizeChange();
248     }
249 
copyMinToMax()250      void copyMinToMax() {
251         erase(fMaxSurface);
252         SkCanvas* canvas = fMaxSurface->getCanvas();
253         canvas->save();
254         canvas->concat(fMatrix);
255         fMinSurface->draw(canvas, 0, 0);
256         canvas->restore();
257 
258         SkPaint paint;
259         paint.setBlendMode(SkBlendMode::kClear);
260         for (int iy = 1; iy < fH; ++iy) {
261             SkScalar y = SkIntToScalar(iy * fZoom);
262             canvas->drawLine(0, y - SK_ScalarHalf, 999, y - SK_ScalarHalf, paint);
263         }
264         for (int ix = 1; ix < fW; ++ix) {
265             SkScalar x = SkIntToScalar(ix * fZoom);
266             canvas->drawLine(x - SK_ScalarHalf, 0, x - SK_ScalarHalf, 999, paint);
267         }
268     }
269 
setWHZ(int width,int height,int zoom)270    void setWHZ(int width, int height, int zoom) {
271         fZoom = zoom;
272         fBounds.setIWH(width * zoom, height * zoom);
273         fMatrix.setScale(SkIntToScalar(zoom), SkIntToScalar(zoom));
274         fInverse.setScale(SK_Scalar1 / zoom, SK_Scalar1 / zoom);
275         fShader = ToolUtils::create_checkerboard_shader(0xFFCCCCCC, 0xFFFFFFFF, zoom);
276 
277         SkImageInfo info = SkImageInfo::MakeN32Premul(width, height);
278         fMinSurface = SkSurface::MakeRaster(info);
279         info = info.makeWH(width * zoom, height * zoom);
280         fMaxSurface = SkSurface::MakeRaster(info);
281     }
282 
draw_points(SkCanvas * canvas,const SkPath & path,SkColor color,bool show_lines)283     void draw_points(SkCanvas* canvas, const SkPath& path, SkColor color,
284                      bool show_lines) {
285         SkPaint paint;
286         paint.setColor(color);
287         paint.setAlpha(0x80);
288         paint.setAntiAlias(true);
289         int n = path.countPoints();
290         SkAutoSTArray<32, SkPoint> pts(n);
291         if (show_lines && fDrawTangents) {
292             SkTArray<int> contourCounts;
293             getContourCounts(path, &contourCounts);
294             SkPoint* ptPtr = pts.get();
295             for (int i = 0; i < contourCounts.count(); ++i) {
296                 int count = contourCounts[i];
297                 path.getPoints(ptPtr, count);
298                 canvas->drawPoints(SkCanvas::kPolygon_PointMode, count, ptPtr, paint);
299                 ptPtr += count;
300             }
301         } else {
302             n = getOnCurvePoints(path, pts.get());
303         }
304         paint.setStrokeWidth(5);
305         canvas->drawPoints(SkCanvas::kPoints_PointMode, n, pts.get(), paint);
306     }
307 
draw_ribs(SkCanvas * canvas,const SkPath & path,SkScalar width,SkColor color)308     void draw_ribs(SkCanvas* canvas, const SkPath& path, SkScalar width,
309                    SkColor color) {
310         const SkScalar radius = width / 2;
311 
312         SkPathMeasure meas(path, false);
313         SkScalar total = meas.getLength();
314 
315         SkScalar delta = 8;
316         SkPaint paint, labelP;
317         paint.setColor(color);
318         labelP.setColor(color & 0xff5f9f5f);
319         SkFont font;
320         SkPoint pos, tan;
321         int index = 0;
322         for (SkScalar dist = 0; dist <= total; dist += delta) {
323             if (meas.getPosTan(dist, &pos, &tan)) {
324                 tan.scale(radius);
325                 SkPointPriv::RotateCCW(&tan);
326                 canvas->drawLine(pos.x() + tan.x(), pos.y() + tan.y(),
327                                  pos.x() - tan.x(), pos.y() - tan.y(), paint);
328                 if (0 == index % 10) {
329                     SkString label;
330                     label.appendS32(index);
331                     SkRect dot = SkRect::MakeXYWH(pos.x() - 2, pos.y() - 2, 4, 4);
332                     canvas->drawRect(dot, labelP);
333                     canvas->drawString(label,
334                         pos.x() - tan.x() * 1.25f, pos.y() - tan.y() * 1.25f, font, labelP);
335                 }
336             }
337             ++index;
338         }
339     }
340 
draw_t_divs(SkCanvas * canvas,const SkPath & path,SkScalar width,SkColor color)341     void draw_t_divs(SkCanvas* canvas, const SkPath& path, SkScalar width, SkColor color) {
342         const SkScalar radius = width / 2;
343         SkPaint paint;
344         paint.setColor(color);
345         SkPathMeasure meas(path, false);
346         SkScalar total = meas.getLength();
347         SkScalar delta = 8;
348         int ribs = 0;
349         for (SkScalar dist = 0; dist <= total; dist += delta) {
350             ++ribs;
351         }
352         const uint8_t* verbs = SkPathPriv::VerbData(path);
353         if (path.countVerbs() < 2 || SkPath::kMove_Verb != verbs[0]) {
354             SkASSERT(0);
355             return;
356         }
357         auto verb = static_cast<SkPath::Verb>(verbs[1]);
358         SkASSERT(SkPath::kLine_Verb <= verb && verb <= SkPath::kCubic_Verb);
359         const SkPoint* pts = SkPathPriv::PointData(path);
360         SkPoint pos, tan;
361         for (int index = 0; index < ribs; ++index) {
362             SkScalar t = (SkScalar) index / ribs;
363             switch (verb) {
364                 case SkPath::kLine_Verb:
365                     tan = pts[1] - pts[0];
366                     pos = pts[0];
367                     pos.fX += tan.fX * t;
368                     pos.fY += tan.fY * t;
369                     break;
370                 case SkPath::kQuad_Verb:
371                     pos = SkEvalQuadAt(pts, t);
372                     tan = SkEvalQuadTangentAt(pts, t);
373                     break;
374                 case SkPath::kConic_Verb: {
375                     SkConic conic(pts, SkPathPriv::ConicWeightData(path)[0]);
376                     pos = conic.evalAt(t);
377                     tan = conic.evalTangentAt(t);
378                     } break;
379                 case SkPath::kCubic_Verb:
380                     SkEvalCubicAt(pts, t, &pos, &tan, nullptr);
381                     break;
382                 default:
383                     SkASSERT(0);
384                     return;
385             }
386             tan.setLength(radius);
387             SkPointPriv::RotateCCW(&tan);
388             canvas->drawLine(pos.x() + tan.x(), pos.y() + tan.y(),
389                                 pos.x() - tan.x(), pos.y() - tan.y(), paint);
390             if (0 == index % 10) {
391                 SkString label;
392                 label.appendS32(index);
393                 canvas->drawString(label,
394                     pos.x() + tan.x() * 1.25f, pos.y() + tan.y() * 1.25f, SkFont(), paint);
395             }
396         }
397     }
398 
draw_stroke(SkCanvas * canvas,const SkPath & path,SkScalar width,SkScalar scale,bool drawText)399     void draw_stroke(SkCanvas* canvas, const SkPath& path, SkScalar width, SkScalar scale,
400             bool drawText) {
401         if (path.isEmpty()) {
402             return;
403         }
404         SkRect bounds = path.getBounds();
405         this->setWHZ(SkScalarCeilToInt(bounds.right()), drawText
406                 ? SkScalarRoundToInt(scale * 3 / 2) : SkScalarRoundToInt(scale),
407                 SkScalarRoundToInt(950.0f / scale));
408         erase(fMinSurface);
409         SkPaint paint;
410         paint.setColor(0x1f1f0f0f);
411         paint.setStyle(SkPaint::kStroke_Style);
412         paint.setStrokeWidth(width * scale * scale);
413         paint.setColor(0x3f0f1f3f);
414         if (drawText) {
415             fMinSurface->getCanvas()->drawPath(path, paint);
416             this->copyMinToMax();
417             fMaxSurface->draw(canvas, 0, 0);
418         }
419         paint.setAntiAlias(true);
420         paint.setStyle(SkPaint::kStroke_Style);
421         paint.setStrokeWidth(1);
422 
423         paint.setColor(SKELETON_COLOR);
424         SkPath scaled;
425         SkMatrix matrix;
426         matrix.reset();
427         matrix.setScale(950 / scale, 950 / scale);
428         if (drawText) {
429             path.transform(matrix, &scaled);
430         } else {
431             scaled = path;
432         }
433         canvas->drawPath(scaled, paint);
434         draw_points(canvas, scaled, SKELETON_COLOR, true);
435 
436         if (fDrawRibs) {
437             draw_ribs(canvas, scaled, width, 0xFF00FF00);
438         }
439 
440         if (fDrawTDivs) {
441             draw_t_divs(canvas, scaled, width, 0xFF3F3F00);
442         }
443 
444         SkPath fill;
445 
446         SkPaint p;
447         p.setStyle(SkPaint::kStroke_Style);
448         if (drawText) {
449             p.setStrokeWidth(width * scale * scale);
450         } else {
451             p.setStrokeWidth(width);
452         }
453         p.getFillPath(path, &fill);
454         SkPath scaledFill;
455         if (drawText) {
456             fill.transform(matrix, &scaledFill);
457         } else {
458             scaledFill = fill;
459         }
460         paint.setColor(WIREFRAME_COLOR);
461         canvas->drawPath(scaledFill, paint);
462         draw_points(canvas, scaledFill, WIREFRAME_COLOR, false);
463     }
464 
draw_fill(SkCanvas * canvas,const SkRect & rect,SkScalar width)465     void draw_fill(SkCanvas* canvas, const SkRect& rect, SkScalar width) {
466         if (rect.isEmpty()) {
467             return;
468         }
469         SkPaint paint;
470         paint.setColor(0x1f1f0f0f);
471         paint.setStyle(SkPaint::kStroke_Style);
472         paint.setStrokeWidth(width);
473         SkPath path;
474         SkScalar maxSide = std::max(rect.width(), rect.height()) / 2;
475         SkPoint center = { rect.fLeft + maxSide, rect.fTop + maxSide };
476         path.addCircle(center.fX, center.fY, maxSide);
477         canvas->drawPath(path, paint);
478         paint.setStyle(SkPaint::kFill_Style);
479         path.reset();
480         path.addCircle(center.fX, center.fY, maxSide - width / 2);
481         paint.setColor(0x3f0f1f3f);
482         canvas->drawPath(path, paint);
483         path.reset();
484         path.setFillType(SkPathFillType::kEvenOdd);
485         path.addCircle(center.fX, center.fY, maxSide + width / 2);
486         SkRect outside = SkRect::MakeXYWH(center.fX - maxSide - width, center.fY - maxSide - width,
487                 (maxSide + width) * 2, (maxSide + width) * 2);
488         path.addRect(outside);
489         canvas->drawPath(path, paint);
490     }
491 
draw_button(SkCanvas * canvas,const StrokeTypeButton & button)492     void draw_button(SkCanvas* canvas, const StrokeTypeButton& button) {
493         SkPaint paint;
494         paint.setAntiAlias(true);
495         paint.setStyle(SkPaint::kStroke_Style);
496         paint.setColor(button.fEnabled ? 0xFF3F0000 : 0x6F3F0000);
497         canvas->drawRect(button.fBounds, paint);
498         paint.setColor(button.fEnabled ? 0xFF3F0000 : 0x6F3F0000);
499         paint.setStyle(SkPaint::kFill_Style);
500         SkFont font;
501         font.setSize(25.0f);
502         SkTextUtils::Draw(canvas, &button.fLabel, 1, SkTextEncoding::kUTF8,
503                 button.fBounds.centerX(), button.fBounds.fBottom - 5,
504                 font, paint, SkTextUtils::kCenter_Align);
505     }
506 
draw_control(SkCanvas * canvas,const SkRect & bounds,SkScalar value,SkScalar min,SkScalar max,const char * name)507     void draw_control(SkCanvas* canvas, const SkRect& bounds, SkScalar value,
508             SkScalar min, SkScalar max, const char* name) {
509         SkPaint paint;
510         paint.setAntiAlias(true);
511         paint.setStyle(SkPaint::kStroke_Style);
512         canvas->drawRect(bounds, paint);
513         SkScalar scale = max - min;
514         SkScalar yPos = bounds.fTop + (value - min) * bounds.height() / scale;
515         paint.setColor(0xFFFF0000);
516         canvas->drawLine(bounds.fLeft - 5, yPos, bounds.fRight + 5, yPos, paint);
517         SkString label;
518         label.printf("%0.3g", value);
519         paint.setColor(0xFF000000);
520         paint.setStyle(SkPaint::kFill_Style);
521         SkFont font(nullptr, 11.0f);
522         canvas->drawString(label, bounds.fLeft + 5, yPos - 5, font, paint);
523         font.setSize(13.0f);
524         canvas->drawString(name, bounds.fLeft, bounds.bottom() + 11, font, paint);
525     }
526 
setForGeometry()527     void setForGeometry() {
528         fDrawRibs = true;
529         fDrawTangents = true;
530         fDrawTDivs = false;
531         fWidthScale = 1;
532     }
533 
setForText()534     void setForText() {
535         fDrawRibs = fDrawTangents = fDrawTDivs = false;
536         fWidthScale = 0.002f;
537     }
538 
setForSingles()539     void setForSingles() {
540         setForGeometry();
541         fDrawTDivs = true;
542     }
543 
setAsNeeded()544     void setAsNeeded() {
545         if (fConicButton.fEnabled || fCubicButton.fEnabled || fQuadButton.fEnabled) {
546             setForSingles();
547         } else if (fRRectButton.fEnabled || fCircleButton.fEnabled || fArcButton.fEnabled) {
548             setForGeometry();
549         } else {
550             setForText();
551         }
552     }
553 
arcCenter(SkPoint * center)554     bool arcCenter(SkPoint* center) {
555         SkPath path;
556         path.moveTo(fPts[10]);
557         path.arcTo(fPts[11], fPts[12], fRadius);
558         SkPath::Iter iter(path, false);
559         SkPoint pts[4];
560         iter.next(pts);
561         if (SkPath::kLine_Verb == iter.next(pts)) {
562             iter.next(pts);
563         }
564         SkVector before = pts[0] - pts[1];
565         SkVector after = pts[1] - pts[2];
566         before.setLength(fRadius);
567         after.setLength(fRadius);
568         SkVector beforeCCW, afterCCW;
569         SkPointPriv::RotateCCW(before, &beforeCCW);
570         SkPointPriv::RotateCCW(after, &afterCCW);
571         beforeCCW += pts[0];
572         afterCCW += pts[2];
573         *center = beforeCCW;
574         if (SkScalarNearlyEqual(beforeCCW.fX, afterCCW.fX)
575                 && SkScalarNearlyEqual(beforeCCW.fY, afterCCW.fY)) {
576             return true;
577         }
578         SkVector beforeCW, afterCW;
579         SkPointPriv::RotateCW(before, &beforeCW);
580         SkPointPriv::RotateCW(after, &afterCW);
581         beforeCW += pts[0];
582         afterCW += pts[2];
583         *center = beforeCW;
584         return SkScalarNearlyEqual(beforeCW.fX, afterCW.fX)
585                 && SkScalarNearlyEqual(beforeCCW.fY, afterCW.fY);
586     }
587 
onDrawContent(SkCanvas * canvas)588     void onDrawContent(SkCanvas* canvas) override {
589         SkPath path;
590         SkScalar width = fWidth;
591 
592         if (fCubicButton.fEnabled) {
593             path.moveTo(fPts[0]);
594             path.cubicTo(fPts[1], fPts[2], fPts[3]);
595             setForSingles();
596             draw_stroke(canvas, path, width, 950, false);
597         }
598 
599         if (fConicButton.fEnabled) {
600             path.reset();
601             path.moveTo(fPts[4]);
602             path.conicTo(fPts[5], fPts[6], fWeight);
603             setForSingles();
604             draw_stroke(canvas, path, width, 950, false);
605         }
606 
607         if (fQuadButton.fEnabled) {
608             path.reset();
609             path.moveTo(fPts[7]);
610             path.quadTo(fPts[8], fPts[9]);
611             setForSingles();
612             draw_stroke(canvas, path, width, 950, false);
613         }
614 
615         if (fArcButton.fEnabled) {
616             path.reset();
617             path.moveTo(fPts[10]);
618             path.arcTo(fPts[11], fPts[12], fRadius);
619             setForGeometry();
620             draw_stroke(canvas, path, width, 950, false);
621             SkPath pathPts;
622             pathPts.moveTo(fPts[10]);
623             pathPts.lineTo(fPts[11]);
624             pathPts.lineTo(fPts[12]);
625             draw_points(canvas, pathPts, SK_ColorDKGRAY, true);
626         }
627 
628         if (fRRectButton.fEnabled) {
629             SkScalar rad = 32;
630             SkRect r;
631             r.setBounds(&fPts[13], 2);
632             path.reset();
633             SkRRect rr;
634             rr.setRectXY(r, rad, rad);
635             path.addRRect(rr);
636             setForGeometry();
637             draw_stroke(canvas, path, width, 950, false);
638 
639             path.reset();
640             SkRRect rr2;
641             rr.inset(width/2, width/2, &rr2);
642             path.addRRect(rr2, SkPathDirection::kCCW);
643             rr.inset(-width/2, -width/2, &rr2);
644             path.addRRect(rr2, SkPathDirection::kCW);
645             SkPaint paint;
646             paint.setAntiAlias(true);
647             paint.setColor(0x40FF8844);
648             canvas->drawPath(path, paint);
649         }
650 
651         if (fCircleButton.fEnabled) {
652             path.reset();
653             SkRect r;
654             r.setBounds(&fPts[15], 2);
655             path.addOval(r);
656             setForGeometry();
657             if (fCircleButton.fFill) {
658                 if (fArcButton.fEnabled) {
659                     SkPoint center;
660                     if (arcCenter(&center)) {
661                         r.setLTRB(center.fX - fRadius, center.fY - fRadius,
662                                   center.fX + fRadius, center.fY + fRadius);
663                     }
664                 }
665                 draw_fill(canvas, r, width);
666             } else {
667                 draw_stroke(canvas, path, width, 950, false);
668             }
669         }
670 
671         if (fTextButton.fEnabled) {
672             path.reset();
673             SkFont font;
674             font.setSize(fTextSize);
675             SkTextUtils::GetPath(fText.c_str(), fText.size(), SkTextEncoding::kUTF8,
676                                  0, fTextSize, font, &path);
677             setForText();
678             draw_stroke(canvas, path, width * fWidthScale / fTextSize, fTextSize, true);
679         }
680 
681         if (fAnimate) {
682             fWidth += fDWidth;
683             if (fDWidth > 0 && fWidth > kWidthMax) {
684                 fDWidth = -fDWidth;
685             } else if (fDWidth < 0 && fWidth < kWidthMin) {
686                 fDWidth = -fDWidth;
687             }
688         }
689         setAsNeeded();
690         if (fConicButton.fEnabled) {
691             draw_control(canvas, fWeightControl, fWeight, 0, 5, "weight");
692         }
693         if (fArcButton.fEnabled) {
694             draw_control(canvas, fRadiusControl, fRadius, 0, 500, "radius");
695         }
696 #ifdef SK_DEBUG
697         draw_control(canvas, fErrorControl, gDebugStrokerError, kStrokerErrorMin, kStrokerErrorMax,
698                 "error");
699 #endif
700         draw_control(canvas, fWidthControl, fWidth * fWidthScale, kWidthMin * fWidthScale,
701                 kWidthMax * fWidthScale, "width");
702         draw_button(canvas, fQuadButton);
703         draw_button(canvas, fCubicButton);
704         draw_button(canvas, fConicButton);
705         draw_button(canvas, fArcButton);
706         draw_button(canvas, fRRectButton);
707         draw_button(canvas, fCircleButton);
708         draw_button(canvas, fTextButton);
709     }
710 
711     class MyClick : public Click {
712     public:
713         int fIndex;
MyClick(int index)714         MyClick(int index) : fIndex(index) {}
715     };
716 
onFindClickHandler(SkScalar x,SkScalar y,skui::ModifierKey modi)717     Sample::Click* onFindClickHandler(SkScalar x, SkScalar y, skui::ModifierKey modi) override {
718         for (size_t i = 0; i < SK_ARRAY_COUNT(fPts); ++i) {
719             if (hittest(fPts[i], x, y)) {
720                 return new MyClick((int)i);
721             }
722         }
723         const SkRect& rectPt = SkRect::MakeXYWH(x, y, 1, 1);
724         if (fWeightControl.contains(rectPt)) {
725             return new MyClick((int) SK_ARRAY_COUNT(fPts) + 1);
726         }
727         if (fRadiusControl.contains(rectPt)) {
728             return new MyClick((int) SK_ARRAY_COUNT(fPts) + 2);
729         }
730 #ifdef SK_DEBUG
731         if (fErrorControl.contains(rectPt)) {
732             return new MyClick((int) SK_ARRAY_COUNT(fPts) + 3);
733         }
734 #endif
735         if (fWidthControl.contains(rectPt)) {
736             return new MyClick((int) SK_ARRAY_COUNT(fPts) + 4);
737         }
738         if (fCubicButton.fBounds.contains(rectPt)) {
739             fCubicButton.fEnabled ^= true;
740             return new MyClick((int) SK_ARRAY_COUNT(fPts) + 5);
741         }
742         if (fConicButton.fBounds.contains(rectPt)) {
743             fConicButton.fEnabled ^= true;
744             return new MyClick((int) SK_ARRAY_COUNT(fPts) + 6);
745         }
746         if (fQuadButton.fBounds.contains(rectPt)) {
747             fQuadButton.fEnabled ^= true;
748             return new MyClick((int) SK_ARRAY_COUNT(fPts) + 7);
749         }
750         if (fArcButton.fBounds.contains(rectPt)) {
751             fArcButton.fEnabled ^= true;
752             return new MyClick((int) SK_ARRAY_COUNT(fPts) + 8);
753         }
754         if (fRRectButton.fBounds.contains(rectPt)) {
755             fRRectButton.fEnabled ^= true;
756             return new MyClick((int) SK_ARRAY_COUNT(fPts) + 9);
757         }
758         if (fCircleButton.fBounds.contains(rectPt)) {
759             bool wasEnabled = fCircleButton.fEnabled;
760             fCircleButton.fEnabled = !fCircleButton.fFill;
761             fCircleButton.fFill = wasEnabled && !fCircleButton.fFill;
762             return new MyClick((int) SK_ARRAY_COUNT(fPts) + 10);
763         }
764         if (fTextButton.fBounds.contains(rectPt)) {
765             fTextButton.fEnabled ^= true;
766             return new MyClick((int) SK_ARRAY_COUNT(fPts) + 11);
767         }
768         return nullptr;
769     }
770 
MapScreenYtoValue(SkScalar y,const SkRect & control,SkScalar min,SkScalar max)771     static SkScalar MapScreenYtoValue(SkScalar y, const SkRect& control, SkScalar min,
772             SkScalar max) {
773         return (y - control.fTop) / control.height() * (max - min) + min;
774     }
775 
onClick(Click * click)776     bool onClick(Click* click) override {
777         int index = ((MyClick*)click)->fIndex;
778         if (index < (int) SK_ARRAY_COUNT(fPts)) {
779             fPts[index].offset(click->fCurr.fX - click->fPrev.fX,
780                                click->fCurr.fY - click->fPrev.fY);
781         } else if (index == (int) SK_ARRAY_COUNT(fPts) + 1) {
782             fWeight = MapScreenYtoValue(click->fCurr.fY, fWeightControl, 0, 5);
783         } else if (index == (int) SK_ARRAY_COUNT(fPts) + 2) {
784             fRadius = MapScreenYtoValue(click->fCurr.fY, fRadiusControl, 0, 500);
785         }
786 #ifdef SK_DEBUG
787         else if (index == (int) SK_ARRAY_COUNT(fPts) + 3) {
788             gDebugStrokerError = std::max(FLT_EPSILON, MapScreenYtoValue(click->fCurr.fY,
789                     fErrorControl, kStrokerErrorMin, kStrokerErrorMax));
790             gDebugStrokerErrorSet = true;
791         }
792 #endif
793         else if (index == (int) SK_ARRAY_COUNT(fPts) + 4) {
794             fWidth = std::max(FLT_EPSILON, MapScreenYtoValue(click->fCurr.fY, fWidthControl,
795                     kWidthMin, kWidthMax));
796             fAnimate = fWidth <= kWidthMin;
797         }
798         return true;
799     }
800 
801 private:
802     using INHERITED = Sample;
803 };
804 
805 ///////////////////////////////////////////////////////////////////////////////
806 
807 DEF_SAMPLE( return new QuadStrokerView(); )
808