aboutsummaryrefslogtreecommitdiffhomepage
path: root/gm/dashing.cpp
blob: e23c24ed3b0d0cb3f8da46d3f0433f262ac463fd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
/*
 * Copyright 2012 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "gm.h"
#include "SkCanvas.h"
#include "SkPaint.h"
#include "SkDashPathEffect.h"

static void drawline(SkCanvas* canvas, int on, int off, const SkPaint& paint,
                     SkScalar finalX = SkIntToScalar(600), SkScalar finalY = SkIntToScalar(0),
                     SkScalar phase = SkIntToScalar(0),
                     SkScalar startX = SkIntToScalar(0), SkScalar startY = SkIntToScalar(0)) {
    SkPaint p(paint);

    const SkScalar intervals[] = {
        SkIntToScalar(on),
        SkIntToScalar(off),
    };

    p.setPathEffect(SkDashPathEffect::Make(intervals, 2, phase));
    canvas->drawLine(startX, startY, finalX, finalY, p);
}

// earlier bug stopped us from drawing very long single-segment dashes, because
// SkPathMeasure was skipping very small delta-T values (nearlyzero). This is
// now fixes, so this giant dash should appear.
static void show_giant_dash(SkCanvas* canvas) {
    SkPaint paint;

    drawline(canvas, 1, 1, paint, SkIntToScalar(20 * 1000));
}

static void show_zero_len_dash(SkCanvas* canvas) {
    SkPaint paint;

    drawline(canvas, 2, 2, paint, SkIntToScalar(0));
    paint.setStyle(SkPaint::kStroke_Style);
    paint.setStrokeWidth(SkIntToScalar(2));
    canvas->translate(0, SkIntToScalar(20));
    drawline(canvas, 4, 4, paint, SkIntToScalar(0));
}

class DashingGM : public skiagm::GM {
public:
    DashingGM() {}

protected:

    SkString onShortName() {
        return SkString("dashing");
    }

    SkISize onISize() { return SkISize::Make(640, 340); }

    virtual void onDraw(SkCanvas* canvas) {
        constexpr struct {
            int fOnInterval;
            int fOffInterval;
        } gData[] = {
            { 1, 1 },
            { 4, 1 },
        };

        SkPaint paint;
        paint.setStyle(SkPaint::kStroke_Style);

        canvas->translate(SkIntToScalar(20), SkIntToScalar(20));
        canvas->translate(0, SK_ScalarHalf);
        for (int width = 0; width <= 2; ++width) {
            for (size_t data = 0; data < SK_ARRAY_COUNT(gData); ++data) {
                for (int aa = 0; aa <= 1; ++aa) {
                    int w = width * width * width;
                    paint.setAntiAlias(SkToBool(aa));
                    paint.setStrokeWidth(SkIntToScalar(w));

                    int scale = w ? w : 1;

                    drawline(canvas, gData[data].fOnInterval * scale,
                             gData[data].fOffInterval * scale,
                             paint);
                    canvas->translate(0, SkIntToScalar(20));
                }
            }
        }

        show_giant_dash(canvas);
        canvas->translate(0, SkIntToScalar(20));
        show_zero_len_dash(canvas);
        canvas->translate(0, SkIntToScalar(20));
        // Draw 0 on, 0 off dashed line
        paint.setStrokeWidth(SkIntToScalar(8));
        drawline(canvas, 0, 0, paint);
    }
};

///////////////////////////////////////////////////////////////////////////////

static void make_unit_star(SkPath* path, int n) {
    SkScalar rad = -SK_ScalarPI / 2;
    const SkScalar drad = (n >> 1) * SK_ScalarPI * 2 / n;

    path->moveTo(0, -SK_Scalar1);
    for (int i = 1; i < n; i++) {
        rad += drad;
        SkScalar cosV, sinV = SkScalarSinCos(rad, &cosV);
        path->lineTo(cosV, sinV);
    }
    path->close();
}

static void make_path_line(SkPath* path, const SkRect& bounds) {
    path->moveTo(bounds.left(), bounds.top());
    path->lineTo(bounds.right(), bounds.bottom());
}

static void make_path_rect(SkPath* path, const SkRect& bounds) {
    path->addRect(bounds);
}

static void make_path_oval(SkPath* path, const SkRect& bounds) {
    path->addOval(bounds);
}

static void make_path_star(SkPath* path, const SkRect& bounds) {
    make_unit_star(path, 5);
    SkMatrix matrix;
    matrix.setRectToRect(path->getBounds(), bounds, SkMatrix::kCenter_ScaleToFit);
    path->transform(matrix);
}

class Dashing2GM : public skiagm::GM {
public:
    Dashing2GM() {}

protected:

    SkString onShortName() {
        return SkString("dashing2");
    }

    SkISize onISize() { return SkISize::Make(640, 480); }

    virtual void onDraw(SkCanvas* canvas) {
        constexpr int gIntervals[] = {
            3,  // 3 dashes: each count [0] followed by intervals [1..count]
            2,  10, 10,
            4,  20, 5, 5, 5,
            2,  2, 2
        };

        void (*gProc[])(SkPath*, const SkRect&) = {
            make_path_line, make_path_rect, make_path_oval, make_path_star,
        };

        SkPaint paint;
        paint.setAntiAlias(true);
        paint.setStyle(SkPaint::kStroke_Style);
        paint.setStrokeWidth(SkIntToScalar(6));

        SkRect bounds = SkRect::MakeWH(SkIntToScalar(120), SkIntToScalar(120));
        bounds.offset(SkIntToScalar(20), SkIntToScalar(20));
        SkScalar dx = bounds.width() * 4 / 3;
        SkScalar dy = bounds.height() * 4 / 3;

        const int* intervals = &gIntervals[1];
        for (int y = 0; y < gIntervals[0]; ++y) {
            SkScalar vals[SK_ARRAY_COUNT(gIntervals)];  // more than enough
            int count = *intervals++;
            for (int i = 0; i < count; ++i) {
                vals[i] = SkIntToScalar(*intervals++);
            }
            SkScalar phase = vals[0] / 2;
            paint.setPathEffect(SkDashPathEffect::Make(vals, count, phase));

            for (size_t x = 0; x < SK_ARRAY_COUNT(gProc); ++x) {
                SkPath path;
                SkRect r = bounds;
                r.offset(x * dx, y * dy);
                gProc[x](&path, r);

                canvas->drawPath(path, paint);
            }
        }
    }
};

//////////////////////////////////////////////////////////////////////////////

// Test out the on/off line dashing Chrome if fond of
class Dashing3GM : public skiagm::GM {
public:
    Dashing3GM() {}

protected:

    SkString onShortName() {
        return SkString("dashing3");
    }

    SkISize onISize() { return SkISize::Make(640, 480); }

    // Draw a 100x100 block of dashed lines. The horizontal ones are BW
    // while the vertical ones are AA.
    void drawDashedLines(SkCanvas* canvas,
                         SkScalar lineLength,
                         SkScalar phase,
                         SkScalar dashLength,
                         int strokeWidth,
                         bool circles) {
        SkPaint p;
        p.setColor(SK_ColorBLACK);
        p.setStyle(SkPaint::kStroke_Style);
        p.setStrokeWidth(SkIntToScalar(strokeWidth));

        if (circles) {
            p.setStrokeCap(SkPaint::kRound_Cap);
        }

        SkScalar intervals[2] = { dashLength, dashLength };

        p.setPathEffect(SkDashPathEffect::Make(intervals, 2, phase));

        SkPoint pts[2];

        for (int y = 0; y < 100; y += 10*strokeWidth) {
            pts[0].set(0, SkIntToScalar(y));
            pts[1].set(lineLength, SkIntToScalar(y));

            canvas->drawPoints(SkCanvas::kLines_PointMode, 2, pts, p);
        }

        p.setAntiAlias(true);

        for (int x = 0; x < 100; x += 14*strokeWidth) {
            pts[0].set(SkIntToScalar(x), 0);
            pts[1].set(SkIntToScalar(x), lineLength);

            canvas->drawPoints(SkCanvas::kLines_PointMode, 2, pts, p);
        }
    }

    virtual void onDraw(SkCanvas* canvas) {
        // 1on/1off 1x1 squares with phase of 0 - points fastpath
        canvas->save();
            canvas->translate(2, 0);
            this->drawDashedLines(canvas, 100, 0, SK_Scalar1, 1, false);
        canvas->restore();

        // 1on/1off 1x1 squares with phase of .5 - rects fastpath (due to partial squares)
        canvas->save();
            canvas->translate(112, 0);
            this->drawDashedLines(canvas, 100, SK_ScalarHalf, SK_Scalar1, 1, false);
        canvas->restore();

        // 1on/1off 1x1 squares with phase of 1 - points fastpath
        canvas->save();
            canvas->translate(222, 0);
            this->drawDashedLines(canvas, 100, SK_Scalar1, SK_Scalar1, 1, false);
        canvas->restore();

        // 1on/1off 1x1 squares with phase of 1 and non-integer length - rects fastpath
        canvas->save();
            canvas->translate(332, 0);
            this->drawDashedLines(canvas, 99.5f, SK_ScalarHalf, SK_Scalar1, 1, false);
        canvas->restore();

        // 255on/255off 1x1 squares with phase of 0 - rects fast path
        canvas->save();
            canvas->translate(446, 0);
            this->drawDashedLines(canvas, 100, 0, SkIntToScalar(255), 1, false);
        canvas->restore();

        // 1on/1off 3x3 squares with phase of 0 - points fast path
        canvas->save();
            canvas->translate(2, 110);
            this->drawDashedLines(canvas, 100, 0, SkIntToScalar(3), 3, false);
        canvas->restore();

        // 1on/1off 3x3 squares with phase of 1.5 - rects fast path
        canvas->save();
            canvas->translate(112, 110);
            this->drawDashedLines(canvas, 100, 1.5f, SkIntToScalar(3), 3, false);
        canvas->restore();

        // 1on/1off 1x1 circles with phase of 1 - no fast path yet
        canvas->save();
            canvas->translate(2, 220);
            this->drawDashedLines(canvas, 100, SK_Scalar1, SK_Scalar1, 1, true);
        canvas->restore();

        // 1on/1off 3x3 circles with phase of 1 - no fast path yet
        canvas->save();
            canvas->translate(112, 220);
            this->drawDashedLines(canvas, 100, 0, SkIntToScalar(3), 3, true);
        canvas->restore();

        // 1on/1off 1x1 squares with rotation - should break fast path
        canvas->save();
            canvas->translate(332+SK_ScalarRoot2Over2*100, 110+SK_ScalarRoot2Over2*100);
            canvas->rotate(45);
            canvas->translate(-50, -50);

            this->drawDashedLines(canvas, 100, SK_Scalar1, SK_Scalar1, 1, false);
        canvas->restore();

        // 3on/3off 3x1 rects - should use rect fast path regardless of phase
        for (int phase = 0; phase <= 3; ++phase) {
            canvas->save();
                canvas->translate(SkIntToScalar(phase*110+2),
                                  SkIntToScalar(330));
                this->drawDashedLines(canvas, 100, SkIntToScalar(phase), SkIntToScalar(3), 1, false);
            canvas->restore();
        }
    }

};

//////////////////////////////////////////////////////////////////////////////

class Dashing4GM : public skiagm::GM {
public:
    Dashing4GM() {}

protected:

    SkString onShortName() {
        return SkString("dashing4");
    }

    SkISize onISize() { return SkISize::Make(640, 950); }

    virtual void onDraw(SkCanvas* canvas) {
        constexpr struct {
            int fOnInterval;
            int fOffInterval;
        } gData[] = {
            { 1, 1 },
            { 4, 2 },
            { 0, 4 }, // test for zero length on interval
        };

        SkPaint paint;
        paint.setStyle(SkPaint::kStroke_Style);

        canvas->translate(SkIntToScalar(20), SkIntToScalar(20));
        canvas->translate(0, SK_ScalarHalf);

        for (int width = 0; width <= 2; ++width) {
            for (size_t data = 0; data < SK_ARRAY_COUNT(gData); ++data) {
                for (int aa = 0; aa <= 1; ++aa) {
                    for (int cap = 0; cap <= 1; ++cap) {
                        int w = width * width * width;
                        paint.setAntiAlias(SkToBool(aa));
                        paint.setStrokeWidth(SkIntToScalar(w));

                        SkToBool(cap) ? paint.setStrokeCap(SkPaint::kSquare_Cap)
                            : paint.setStrokeCap(SkPaint::kRound_Cap);

                        int scale = w ? w : 1;

                        drawline(canvas, gData[data].fOnInterval * scale,
                                 gData[data].fOffInterval * scale,
                                 paint);
                        canvas->translate(0, SkIntToScalar(20));
                    }
                }
            }
        }

        for (int aa = 0; aa <= 1; ++aa) {
            paint.setAntiAlias(SkToBool(aa));
            paint.setStrokeWidth(8.f);
            paint.setStrokeCap(SkPaint::kSquare_Cap);
            // Single dash element that is cut off at start and end
            drawline(canvas, 32, 16, paint, 20.f, 0, 5.f);
            canvas->translate(0, SkIntToScalar(20));

            // Two dash elements where each one is cut off at beginning and end respectively
            drawline(canvas, 32, 16, paint, 56.f, 0, 5.f);
            canvas->translate(0, SkIntToScalar(20));

            // Many dash elements where first and last are cut off at beginning and end respectively
            drawline(canvas, 32, 16, paint, 584.f, 0, 5.f);
            canvas->translate(0, SkIntToScalar(20));

            // Diagonal dash line where src pnts are not axis aligned (as apposed to being diagonal from
            // a canvas rotation)
            drawline(canvas, 32, 16, paint, 600.f, 30.f);
            canvas->translate(0, SkIntToScalar(20));

            // Case where only the off interval exists on the line. Thus nothing should be drawn
            drawline(canvas, 32, 16, paint, 8.f, 0.f, 40.f);
            canvas->translate(0, SkIntToScalar(20));
        }
    }
};

//////////////////////////////////////////////////////////////////////////////

class Dashing5GM : public skiagm::GM {
public:
    Dashing5GM(bool doAA) : fDoAA(doAA) {}

protected:

    bool runAsBench() const override { return true; }

    SkString onShortName() override {
        if (fDoAA) {
            return SkString("dashing5_aa");
        } else {
            return SkString("dashing5_bw");
        }
    }

    SkISize onISize() override { return SkISize::Make(400, 200); }

    void onDraw(SkCanvas* canvas) override {
        constexpr int kOn = 4;
        constexpr int kOff = 4;
        constexpr int kIntervalLength = kOn + kOff;

        constexpr SkColor gColors[kIntervalLength] = {
            SK_ColorRED,
            SK_ColorGREEN,
            SK_ColorBLUE,
            SK_ColorCYAN,
            SK_ColorMAGENTA,
            SK_ColorYELLOW,
            SK_ColorGRAY,
            SK_ColorDKGRAY
        };

        SkPaint paint;
        paint.setStyle(SkPaint::kStroke_Style);

        paint.setAntiAlias(fDoAA);

        SkMatrix rot;
        rot.setRotate(90);
        SkASSERT(rot.rectStaysRect());

        canvas->concat(rot);

        int sign;       // used to toggle the direction of the lines
        int phase = 0;

        for (int x = 0; x < 200; x += 10) {
            paint.setStrokeWidth(SkIntToScalar(phase+1));
            paint.setColor(gColors[phase]);
            sign = (x % 20) ? 1 : -1;
            drawline(canvas, kOn, kOff, paint,
                     SkIntToScalar(x), -sign * SkIntToScalar(10003),
                     SkIntToScalar(phase),
                     SkIntToScalar(x),  sign * SkIntToScalar(10003));
            phase = (phase + 1) % kIntervalLength;
        }

        for (int y = -400; y < 0; y += 10) {
            paint.setStrokeWidth(SkIntToScalar(phase+1));
            paint.setColor(gColors[phase]);
            sign = (y % 20) ? 1 : -1;
            drawline(canvas, kOn, kOff, paint,
                     -sign * SkIntToScalar(10003), SkIntToScalar(y),
                     SkIntToScalar(phase),
                      sign * SkIntToScalar(10003), SkIntToScalar(y));
            phase = (phase + 1) % kIntervalLength;
        }
    }

private:
    bool fDoAA;
};

DEF_SIMPLE_GM(longpathdash, canvas, 612, 612) {
    SkPath lines;
    for (int x = 32; x < 256; x += 16) {
        for (SkScalar a = 0; a < 3.141592f * 2; a += 0.03141592f) {
            SkPoint pts[2] = {
                { 256 + (float) sin(a) * x,
                  256 + (float) cos(a) * x },
                { 256 + (float) sin(a + 3.141592 / 3) * (x + 64),
                  256 + (float) cos(a + 3.141592 / 3) * (x + 64) }
            };
            lines.moveTo(pts[0]);
            for (SkScalar i = 0; i < 1; i += 0.05f) {
                lines.lineTo(pts[0].fX * (1 - i) + pts[1].fX * i,
                             pts[0].fY * (1 - i) + pts[1].fY * i);
            }
        }
    }
    SkPaint p;
    p.setAntiAlias(true);
    p.setStyle(SkPaint::kStroke_Style);
    p.setStrokeWidth(1);
    const SkScalar intervals[] = { 1, 1 };
    p.setPathEffect(SkDashPathEffect::Make(intervals, SK_ARRAY_COUNT(intervals), 0));
    
    canvas->translate(50, 50);
    canvas->drawPath(lines, p);
}

DEF_SIMPLE_GM(longlinedash, canvas, 512, 512) {
    SkPaint p;
    p.setAntiAlias(true);
    p.setStyle(SkPaint::kStroke_Style);
    p.setStrokeWidth(80);

    const SkScalar intervals[] = { 2, 2 };
    p.setPathEffect(SkDashPathEffect::Make(intervals, SK_ARRAY_COUNT(intervals), 0));
    canvas->drawRect(SkRect::MakeXYWH(-10000, 100, 20000, 20), p);
}

DEF_SIMPLE_GM(longwavyline, canvas, 512, 512) {
    SkPaint p;
    p.setAntiAlias(true);
    p.setStyle(SkPaint::kStroke_Style);
    p.setStrokeWidth(2);

    SkPath wavy;
    wavy.moveTo(-10000, 100);
    for (SkScalar i = -10000; i < 10000; i += 20) {
        wavy.quadTo(i + 5, 95, i + 10, 100);
        wavy.quadTo(i + 15, 105, i + 20, 100);
    }
    canvas->drawPath(wavy, p);
}

DEF_SIMPLE_GM(dashtextcaps, canvas, 512, 512) {
    SkPaint p;
    p.setAntiAlias(true);
    p.setStyle(SkPaint::kStroke_Style);
    p.setStrokeWidth(10);
    p.setStrokeCap(SkPaint::kRound_Cap);
    p.setStrokeJoin(SkPaint::kRound_Join);
    p.setTextSize(100);
    p.setARGB(0xff, 0xbb, 0x00, 0x00);
    sk_tool_utils::set_portable_typeface(&p);
    const SkScalar intervals[] = { 12, 12 };
    p.setPathEffect(SkDashPathEffect::Make(intervals, SK_ARRAY_COUNT(intervals), 0));
    canvas->drawText("Sausages", 8, 10, 90, p);
    canvas->drawLine(8, 120, 456, 120, p);
}

//////////////////////////////////////////////////////////////////////////////

DEF_GM(return new DashingGM;)
DEF_GM(return new Dashing2GM;)
DEF_GM(return new Dashing3GM;)
DEF_GM(return new Dashing4GM;)
DEF_GM(return new Dashing5GM(true);)
DEF_GM(return new Dashing5GM(false);)