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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 "include/core/SkCanvas.h"
9 #include "include/core/SkPath.h"
10 #include "include/core/SkRRect.h"
11 #include "include/core/SkTime.h"
12 #include "include/utils/SkInterpolator.h"
13 #include "samplecode/Sample.h"
14 
15 // This slide tests out the match up between BW clipping and rendering. It can
16 // draw a large rect through some clip geometry and draw the same geometry
17 // normally. Which one is drawn first can be toggled. The pair of objects is translated
18 // fractionally (via an animator) to expose snapping bugs. The key bindings are:
19 //      1-9: the different geometries
20 //      t:   toggle which is drawn first the clip or the normal geometry
21 //      f:   flip-flops which corner the bottom AA clip rect occupies in the complex clip cases
22 
23 // The possible geometric combinations to test
24 enum Geometry {
25     kRect_Geometry,
26     kRRect_Geometry,
27     kCircle_Geometry,
28     kConvexPath_Geometry,
29     kConcavePath_Geometry,
30     kRectAndRect_Geometry,
31     kRectAndRRect_Geometry,
32     kRectAndConvex_Geometry,
33     kRectAndConcave_Geometry
34 };
35 
36 // The basic rect used is [kMin,kMin]..[kMax,kMax]
37 static const float kMin = 100.5f;
38 static const float kMid = 200.0f;
39 static const float kMax = 299.5f;
40 
41 // The translation applied to the base AA rect in the combination cases
42 // (i.e., kRectAndRect through kRectAndConcave)
43 static const float kXlate = 100.0f;
44 
create_rect(const SkPoint & offset)45 SkRect create_rect(const SkPoint& offset) {
46     SkRect r = SkRect::MakeLTRB(kMin, kMin, kMax, kMax);
47     r.offset(offset);
48     return r;
49 }
50 
create_rrect(const SkPoint & offset)51 SkRRect create_rrect(const SkPoint& offset) {
52     SkRRect rrect;
53     rrect.setRectXY(create_rect(offset), 10, 10);
54     return rrect;
55 }
56 
create_circle(const SkPoint & offset)57 SkRRect create_circle(const SkPoint& offset) {
58     SkRRect circle;
59     circle.setOval(create_rect(offset));
60     return circle;
61 }
62 
create_convex_path(const SkPoint & offset)63 SkPath create_convex_path(const SkPoint& offset) {
64     SkPath convexPath;
65     convexPath.moveTo(kMin, kMin);
66     convexPath.lineTo(kMax, kMax);
67     convexPath.lineTo(kMin, kMax);
68     convexPath.close();
69     convexPath.offset(offset.fX, offset.fY);
70     return convexPath;
71 }
72 
create_concave_path(const SkPoint & offset)73 SkPath create_concave_path(const SkPoint& offset) {
74     SkPath concavePath;
75     concavePath.moveTo(kMin, kMin);
76     concavePath.lineTo(kMid, 105.0f);
77     concavePath.lineTo(kMax, kMin);
78     concavePath.lineTo(295.0f, kMid);
79     concavePath.lineTo(kMax, kMax);
80     concavePath.lineTo(kMid, 295.0f);
81     concavePath.lineTo(kMin, kMax);
82     concavePath.lineTo(105.0f, kMid);
83     concavePath.close();
84 
85     concavePath.offset(offset.fX, offset.fY);
86     return concavePath;
87 }
88 
draw_normal_geom(SkCanvas * canvas,const SkPoint & offset,int geom,bool useAA)89 static void draw_normal_geom(SkCanvas* canvas, const SkPoint& offset, int geom, bool useAA) {
90     SkPaint p;
91     p.setAntiAlias(useAA);
92     p.setColor(SK_ColorBLACK);
93 
94     switch (geom) {
95     case kRect_Geometry:                // fall thru
96     case kRectAndRect_Geometry:
97         canvas->drawRect(create_rect(offset), p);
98         break;
99     case kRRect_Geometry:               // fall thru
100     case kRectAndRRect_Geometry:
101         canvas->drawRRect(create_rrect(offset), p);
102         break;
103     case kCircle_Geometry:
104         canvas->drawRRect(create_circle(offset), p);
105         break;
106     case kConvexPath_Geometry:          // fall thru
107     case kRectAndConvex_Geometry:
108         canvas->drawPath(create_convex_path(offset), p);
109         break;
110     case kConcavePath_Geometry:         // fall thru
111     case kRectAndConcave_Geometry:
112         canvas->drawPath(create_concave_path(offset), p);
113         break;
114     }
115 }
116 
117 class ClipDrawMatchView : public Sample {
118     SkInterpolator  fTrans;
119     Geometry        fGeom;
120     bool            fClipFirst = true;
121     int             fSign = 1;
122     const double    fStart = SkTime::GetMSecs();
123 
124 public:
ClipDrawMatchView()125     ClipDrawMatchView() : fTrans(2, 5), fGeom(kRect_Geometry) {}
126 
127 private:
onOnceBeforeDraw()128     void onOnceBeforeDraw() override {
129         SkScalar values[2];
130 
131         fTrans.setRepeatCount(999);
132         values[0] = values[1] = 0;
133         fTrans.setKeyFrame(0, GetMSecs() + 1000, values);
134         values[1] = 1;
135         fTrans.setKeyFrame(1, GetMSecs() + 2000, values);
136         values[0] = values[1] = 1;
137         fTrans.setKeyFrame(2, GetMSecs() + 3000, values);
138         values[1] = 0;
139         fTrans.setKeyFrame(3, GetMSecs() + 4000, values);
140         values[0] = 0;
141         fTrans.setKeyFrame(4, GetMSecs() + 5000, values);
142     }
143 
name()144     SkString name() override { return SkString("ClipDrawMatch"); }
145 
onChar(SkUnichar uni)146     bool onChar(SkUnichar uni) override {
147             switch (uni) {
148                 case '1': fGeom = kRect_Geometry; return true;
149                 case '2': fGeom = kRRect_Geometry; return true;
150                 case '3': fGeom = kCircle_Geometry; return true;
151                 case '4': fGeom = kConvexPath_Geometry; return true;
152                 case '5': fGeom = kConcavePath_Geometry; return true;
153                 case '6': fGeom = kRectAndRect_Geometry; return true;
154                 case '7': fGeom = kRectAndRRect_Geometry; return true;
155                 case '8': fGeom = kRectAndConvex_Geometry; return true;
156                 case '9': fGeom = kRectAndConcave_Geometry; return true;
157                 case 'f': fSign = -fSign; return true;
158                 case 't': fClipFirst = !fClipFirst; return true;
159                 default: break;
160             }
161             return false;
162     }
163 
drawClippedGeom(SkCanvas * canvas,const SkPoint & offset,bool useAA)164     void drawClippedGeom(SkCanvas* canvas, const SkPoint& offset, bool useAA) {
165 
166         int count = canvas->save();
167 
168         switch (fGeom) {
169         case kRect_Geometry:
170             canvas->clipRect(create_rect(offset), useAA);
171             break;
172         case kRRect_Geometry:
173             canvas->clipRRect(create_rrect(offset), useAA);
174             break;
175         case kCircle_Geometry:
176             canvas->clipRRect(create_circle(offset), useAA);
177             break;
178         case kConvexPath_Geometry:
179             canvas->clipPath(create_convex_path(offset), useAA);
180             break;
181         case kConcavePath_Geometry:
182             canvas->clipPath(create_concave_path(offset), useAA);
183             break;
184         case kRectAndRect_Geometry: {
185             SkRect r = create_rect(offset);
186             r.offset(fSign * kXlate, fSign * kXlate);
187             canvas->clipRect(r, true); // AA here forces shader clips
188             canvas->clipRect(create_rect(offset), useAA);
189             } break;
190         case kRectAndRRect_Geometry: {
191             SkRect r = create_rect(offset);
192             r.offset(fSign * kXlate, fSign * kXlate);
193             canvas->clipRect(r, true); // AA here forces shader clips
194             canvas->clipRRect(create_rrect(offset), useAA);
195             } break;
196         case kRectAndConvex_Geometry: {
197             SkRect r = create_rect(offset);
198             r.offset(fSign * kXlate, fSign * kXlate);
199             canvas->clipRect(r, true); // AA here forces shader clips
200             canvas->clipPath(create_convex_path(offset), useAA);
201             } break;
202         case kRectAndConcave_Geometry: {
203             SkRect r = create_rect(offset);
204             r.offset(fSign * kXlate, fSign * kXlate);
205             canvas->clipRect(r, true); // AA here forces shader clips
206             canvas->clipPath(create_concave_path(offset), useAA);
207             } break;
208         }
209 
210         SkISize size = canvas->getBaseLayerSize();
211         SkRect bigR = SkRect::MakeWH(SkIntToScalar(size.width()), SkIntToScalar(size.height()));
212 
213         SkPaint p;
214         p.setColor(SK_ColorRED);
215 
216         canvas->drawRect(bigR, p);
217         canvas->restoreToCount(count);
218     }
219 
220     // Draw a big red rect through some clip geometry and also draw that same
221     // geometry in black. The order in which they are drawn can be swapped.
222     // This tests whether the clip and normally drawn geometry match up.
drawGeometry(SkCanvas * canvas,const SkPoint & offset,bool useAA)223     void drawGeometry(SkCanvas* canvas, const SkPoint& offset, bool useAA) {
224         if (fClipFirst) {
225             this->drawClippedGeom(canvas, offset, useAA);
226         }
227 
228         draw_normal_geom(canvas, offset, fGeom, useAA);
229 
230         if (!fClipFirst) {
231             this->drawClippedGeom(canvas, offset, useAA);
232         }
233     }
234 
onDrawContent(SkCanvas * canvas)235     void onDrawContent(SkCanvas* canvas) override {
236         SkScalar trans[2];
237         fTrans.timeToValues(GetMSecs(), trans);
238 
239         SkPoint offset;
240         offset.set(trans[0], trans[1]);
241 
242         int saveCount = canvas->save();
243         this->drawGeometry(canvas, offset, false);
244         canvas->restoreToCount(saveCount);
245     }
246 
GetMSecs() const247     SkMSec GetMSecs() const {
248         return static_cast<SkMSec>(SkTime::GetMSecs() - fStart);
249     }
250 };
251 
252 DEF_SAMPLE( return new ClipDrawMatchView(); )
253