xref: /aosp_15_r20/external/skia/gm/arcto.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1 /*
2  * Copyright 2016 Google Inc.
3  *
4  * Use of this source code is governed by a BD-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/SkPaint.h"
12 #include "include/core/SkPathBuilder.h"
13 #include "include/core/SkPathEffect.h"
14 #include "include/core/SkPathMeasure.h"
15 #include "include/core/SkRect.h"
16 #include "include/core/SkScalar.h"
17 #include "include/core/SkString.h"
18 #include "include/core/SkTypes.h"
19 #include "include/effects/SkDashPathEffect.h"
20 #include "include/utils/SkParsePath.h"
21 #include "src/base/SkRandom.h"
22 #include "src/core/SkOSFile.h"
23 
24 #include <stdio.h>
25 
26 /* The test below generates a reference image using SVG. To compare the result for correctness,
27    enable the define below and then view the generated SVG in a browser.
28  */
29 static constexpr bool GENERATE_SVG_REFERENCE = false;
30 
31 /*
32 The arcto test below should draw the same as this SVG:
33 (Note that Skia's arcTo Direction parameter value is opposite SVG's sweep value, e.g. 0 / 1)
34 
35 <svg width="500" height="600">
36 <path d="M 50,100 A50,50,   0,0,1, 150,200" style="stroke:#660000; fill:none; stroke-width:2" />
37 <path d="M100,100 A50,100,  0,0,1, 200,200" style="stroke:#660000; fill:none; stroke-width:2" />
38 <path d="M150,100 A50,50,  45,0,1, 250,200" style="stroke:#660000; fill:none; stroke-width:2" />
39 <path d="M200,100 A50,100, 45,0,1, 300,200" style="stroke:#660000; fill:none; stroke-width:2" />
40 
41 <path d="M150,200 A50,50,   0,1,0, 150,300" style="stroke:#660000; fill:none; stroke-width:2" />
42 <path d="M200,200 A50,100,  0,1,0, 200,300" style="stroke:#660000; fill:none; stroke-width:2" />
43 <path d="M250,200 A50,50,  45,1,0, 250,300" style="stroke:#660000; fill:none; stroke-width:2" />
44 <path d="M300,200 A50,100, 45,1,0, 300,300" style="stroke:#660000; fill:none; stroke-width:2" />
45 
46 <path d="M250,400  A120,80 0 0,0 250,500"
47     fill="none" stroke="red" stroke-width="5" />
48 
49 <path d="M250,400  A120,80 0 1,1 250,500"
50     fill="none" stroke="green" stroke-width="5"/>
51 
52 <path d="M250,400  A120,80 0 1,0 250,500"
53     fill="none" stroke="purple" stroke-width="5"/>
54 
55 <path d="M250,400  A120,80 0 0,1 250,500"
56     fill="none" stroke="blue" stroke-width="5"/>
57 
58 <path d="M100,100  A  0, 0 0 0,1 200,200"
59     fill="none" stroke="blue" stroke-width="5" stroke-linecap="round"/>
60 
61 <path d="M200,100  A 80,80 0 0,1 200,100"
62     fill="none" stroke="blue" stroke-width="5" stroke-linecap="round"/>
63 </svg>
64  */
65 
66 DEF_SIMPLE_GM(arcto, canvas, 500, 600) {
67     SkPaint paint;
68     paint.setAntiAlias(true);
69     paint.setStyle(SkPaint::kStroke_Style);
70     paint.setStrokeWidth(2);
71     paint.setColor(0xFF660000);
72 //    canvas->scale(2, 2);  // for testing on retina
73     SkRect oval = SkRect::MakeXYWH(100, 100, 100, 100);
74 
75     for (SkScalar angle = 0; angle <= 45; angle += 45) {
76         for (int oHeight = 2; oHeight >= 1; --oHeight) {
77             SkPathBuilder svgArc;
78             SkScalar ovalHeight = oval.height() / oHeight;
79             svgArc.moveTo(oval.fLeft, oval.fTop);
80             svgArc.arcTo({oval.width() / 2, ovalHeight}, angle, SkPathBuilder::kSmall_ArcSize,
81                          SkPathDirection::kCW, {oval.right(), oval.bottom()});
82             canvas->drawPath(svgArc.detach(), paint);
83 
84             svgArc.moveTo(oval.fLeft + 100, oval.fTop + 100);
85             svgArc.arcTo({oval.width() / 2, ovalHeight}, angle, SkPathBuilder::kLarge_ArcSize,
86                          SkPathDirection::kCCW, {oval.right(), oval.bottom() + 100});
87             canvas->drawPath(svgArc.detach(), paint);
88             oval.offset(50, 0);
89 
90         }
91     }
92 
93     paint.setStrokeWidth(5);
94     const SkColor purple = 0xFF800080;
95     const SkColor darkgreen = 0xFF008000;
96     const SkColor colors[] = { SK_ColorRED, darkgreen, purple, SK_ColorBLUE };
97     const char* arcstrs[] = {
98         "M250,400  A120,80 0 0,0 250,500",
99         "M250,400  A120,80 0 1,1 250,500",
100         "M250,400  A120,80 0 1,0 250,500",
101         "M250,400  A120,80 0 0,1 250,500"
102     };
103     int cIndex = 0;
104     for (const char* arcstr : arcstrs) {
105         SkPath path;
106         SkParsePath::FromSVGString(arcstr, &path);
107         paint.setColor(colors[cIndex++]);
108         canvas->drawPath(path, paint);
109     }
110 
111     // test that zero length arcs still draw round cap
112     paint.setStrokeCap(SkPaint::kRound_Cap);
113     SkPathBuilder path;
114     path.moveTo(100, 100)
115         .arcTo({0, 0}, 0, SkPathBuilder::kLarge_ArcSize, SkPathDirection::kCW, {200, 200});
116     canvas->drawPath(path.detach(), paint);
117 
118     path.moveTo(200, 100)
119         .arcTo({80, 80}, 0, SkPathBuilder::kLarge_ArcSize, SkPathDirection::kCW, {200, 100});
120     canvas->drawPath(path.detach(), paint);
121 }
122 
123 enum {
124     kParsePathTestDimension = 500
125 };
126 
127 const struct Legal {
128     char fSymbol;
129     int fScalars;
130 } gLegal[] = {
131     { 'M', 2 },
132     { 'H', 1 },
133     { 'V', 1 },
134     { 'L', 2 },
135     { 'Q', 4 },
136     { 'T', 2 },
137     { 'C', 6 },
138     { 'S', 4 },
139     { 'A', 4 },
140     { 'Z', 0 },
141 };
142 
143 bool gEasy = false;  // set to true while debugging to suppress unusual whitespace
144 
145 // mostly do nothing, then bias towards spaces
146 const char gWhiteSpace[] = { 0, 0, 0, 0, 0, 0, 0, 0, ' ', ' ', ' ', ' ', 0x09, 0x0D, 0x0A };
147 
add_white(SkRandom * rand,SkString * atom)148 static void add_white(SkRandom* rand, SkString* atom) {
149     if (gEasy) {
150         atom->append(" ");
151         return;
152     }
153     int reps = rand->nextRangeU(0, 2);
154     for (int rep = 0; rep < reps; ++rep) {
155         int index = rand->nextRangeU(0, (int) std::size(gWhiteSpace) - 1);
156         if (gWhiteSpace[index]) {
157             atom->append(&gWhiteSpace[index], 1);
158         }
159     }
160 }
161 
add_comma(SkRandom * rand,SkString * atom)162 static void add_comma(SkRandom* rand, SkString* atom) {
163     if (gEasy) {
164         atom->append(",");
165         return;
166     }
167     size_t count = atom->size();
168     add_white(rand, atom);
169     if (rand->nextBool()) {
170         atom->append(",");
171     }
172     do {
173         add_white(rand, atom);
174     } while (count == atom->size());
175 }
176 
add_some_white(SkRandom * rand,SkString * atom)177 static void add_some_white(SkRandom* rand, SkString* atom) {
178     size_t count = atom->size();
179     do {
180         add_white(rand, atom);
181     } while (count == atom->size());
182 }
183 
make_random_svg_path(SkRandom * rand)184 static SkString make_random_svg_path(SkRandom* rand) {
185     SkString atom;
186     int legalIndex = rand->nextRangeU(0, (int) std::size(gLegal) - 1);
187     const Legal& legal = gLegal[legalIndex];
188     gEasy ? atom.append("\n") : add_white(rand, &atom);
189     char symbol = legal.fSymbol | (rand->nextBool() ? 0x20 : 0);
190     atom.append(&symbol, 1);
191     int reps = rand->nextRangeU(1, 3);
192     for (int rep = 0; rep < reps; ++rep) {
193         for (int index = 0; index < legal.fScalars; ++index) {
194             SkScalar coord = rand->nextRangeF(0, 100);
195             add_white(rand, &atom);
196             atom.appendScalar(coord);
197             if (rep < reps - 1 && index < legal.fScalars - 1) {
198                 add_comma(rand, &atom);
199             } else {
200                 add_some_white(rand, &atom);
201             }
202             if ('A' == legal.fSymbol && 1 == index) {
203                 atom.appendScalar(rand->nextRangeF(-720, 720));
204                 add_comma(rand, &atom);
205                 atom.appendU32(rand->nextRangeU(0, 1));
206                 add_comma(rand, &atom);
207                 atom.appendU32(rand->nextRangeU(0, 1));
208                 add_comma(rand, &atom);
209             }
210         }
211     }
212     return atom;
213 }
214 
DEF_SIMPLE_GM(parsedpaths,canvas,kParsePathTestDimension,kParsePathTestDimension)215 DEF_SIMPLE_GM(parsedpaths, canvas, kParsePathTestDimension, kParsePathTestDimension) {
216     SkString str;
217     FILE* file;
218     if (GENERATE_SVG_REFERENCE) {
219         file = sk_fopen("svgout.htm", kWrite_SkFILE_Flag);
220         str.printf("<svg width=\"%d\" height=\"%d\">\n", kParsePathTestDimension,
221                 kParsePathTestDimension);
222         sk_fwrite(str.c_str(), str.size(), file);
223     }
224     SkRandom rand;
225     SkPaint paint;
226     paint.setAntiAlias(true);
227     for (int xStart = 0; xStart < kParsePathTestDimension; xStart +=  100) {
228         canvas->save();
229         for (int yStart = 0; yStart < kParsePathTestDimension; yStart += 100) {
230             if (GENERATE_SVG_REFERENCE) {
231                 str.printf("<g transform='translate(%d,%d) scale(%d,%d)'>\n", xStart, yStart,
232                     1, 1);
233                 sk_fwrite(str.c_str(), str.size(), file);
234                 str.printf("<clipPath id='clip_%d_%d'>\n", xStart, yStart);
235                 sk_fwrite(str.c_str(), str.size(), file);
236                 str.printf("<rect width='100' height='100' x='0' y='0'></rect>\n");
237                 sk_fwrite(str.c_str(), str.size(), file);
238                 str.printf("</clipPath>\n");
239                 sk_fwrite(str.c_str(), str.size(), file);
240             }
241             int count = 3;
242             do {
243                 SkPath path;
244                 SkString spec;
245                 uint32_t y = rand.nextRangeU(30, 70);
246                 uint32_t x = rand.nextRangeU(30, 70);
247                 spec.printf("M %u,%u\n", x, y);
248                 for (uint32_t i = rand.nextRangeU(0, 10); i--; ) {
249                     spec.append(make_random_svg_path(&rand));
250                 }
251                 SkAssertResult(SkParsePath::FromSVGString(spec.c_str(), &path));
252                 paint.setColor(rand.nextU());
253                 canvas->save();
254                 canvas->clipRect(SkRect::MakeIWH(100, 100));
255                 canvas->drawPath(path, paint);
256                 canvas->restore();
257                 if (GENERATE_SVG_REFERENCE) {
258                     str.printf("<path d='\n");
259                     sk_fwrite(str.c_str(), str.size(), file);
260                     sk_fwrite(spec.c_str(), spec.size(), file);
261                     str.printf("\n' fill='#%06x' fill-opacity='%g'", paint.getColor() & 0xFFFFFF,
262                             paint.getAlpha() / 255.f);
263                     sk_fwrite(str.c_str(), str.size(), file);
264                     str.printf(" clip-path='url(#clip_%d_%d)'/>\n", xStart, yStart);
265                     sk_fwrite(str.c_str(), str.size(), file);
266                 }
267             } while (--count > 0);
268             if (GENERATE_SVG_REFERENCE) {
269                 str.printf("</g>\n");
270                 sk_fwrite(str.c_str(), str.size(), file);
271             }
272             canvas->translate(0, 100);
273         }
274         canvas->restore();
275         canvas->translate(100, 0);
276     }
277     if (GENERATE_SVG_REFERENCE) {
278         const char trailer[] = "</svg>\n";
279         sk_fwrite(trailer, sizeof(trailer) - 1, file);
280         sk_fclose(file);
281     }
282 }
283 
284 DEF_SIMPLE_GM(bug593049, canvas, 300, 300) {
285     canvas->translate(111, 0);
286 
287     SkPathBuilder p;
288     p.moveTo(-43.44464063610148f, 79.43535936389853f);
289     const SkScalar yOffset = 122.88f;
290     const SkScalar radius = 61.44f;
291     SkRect oval = SkRect::MakeXYWH(-radius, yOffset - radius, 2 * radius, 2 * radius);
292     p.arcTo(oval, 1.25f * 180, .5f * 180, false);
293 
294     SkPaint paint;
295     paint.setStyle(SkPaint::kStroke_Style);
296     paint.setStrokeCap(SkPaint::kRound_Cap);
297     paint.setStrokeWidth(15.36f);
298 
299     canvas->drawPath(p.detach(), paint);
300 }
301 
302 DEF_SIMPLE_GM(bug583299, canvas, 300, 300) {
303   const char* d="M60,60 A50,50 0 0 0 160,60 A50,50 0 0 0 60,60z";
304   SkPaint p;
305   p.setStyle(SkPaint::kStroke_Style);
306   p.setStrokeWidth(100);
307   p.setAntiAlias(true);
308   p.setColor(0xFF008200);
309   p.setStrokeCap(SkPaint::kSquare_Cap);
310   SkPath path;
311   SkParsePath::FromSVGString(d, &path);
312   SkPathMeasure meas(path, false);
313   SkScalar length = meas.getLength();
314   SkScalar intervals[] = {0, length };
315   int intervalCount = (int) std::size(intervals);
316   p.setPathEffect(SkDashPathEffect::Make(intervals, intervalCount, 0));
317   canvas->drawPath(path, p);
318 }
319