aboutsummaryrefslogtreecommitdiffhomepage
path: root/gm/texteffects.cpp
blob: b98aea714e77e7e7a09683f0e3dc57455f72e11c (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
/*
 * Copyright 2011 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 "sk_tool_utils.h"
#include "SkBlurMask.h"
#include "SkBlurMaskFilter.h"
#include "SkReadBuffer.h"
#include "SkTextBlob.h"
#include "SkWriteBuffer.h"
#include "SkLayerRasterizer.h"

static void r0(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
    p.setMaskFilter(SkBlurMaskFilter::Make(kNormal_SkBlurStyle,
                                           SkBlurMask::ConvertRadiusToSigma(SkIntToScalar(3))));
    rastBuilder->addLayer(p, SkIntToScalar(3), SkIntToScalar(3));

    p.setMaskFilter(nullptr);
    p.setStyle(SkPaint::kStroke_Style);
    p.setStrokeWidth(SK_Scalar1);
    rastBuilder->addLayer(p);

    p.setAlpha(0x11);
    p.setStyle(SkPaint::kFill_Style);
    p.setBlendMode(SkBlendMode::kSrc);
    rastBuilder->addLayer(p);
}

static void r1(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
    rastBuilder->addLayer(p);

    p.setAlpha(0x40);
    p.setBlendMode(SkBlendMode::kSrc);
    p.setStyle(SkPaint::kStroke_Style);
    p.setStrokeWidth(SK_Scalar1*2);
    rastBuilder->addLayer(p);
}

static void r2(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
    p.setStyle(SkPaint::kStrokeAndFill_Style);
    p.setStrokeWidth(SK_Scalar1*4);
    rastBuilder->addLayer(p);

    p.setStyle(SkPaint::kStroke_Style);
    p.setStrokeWidth(SK_Scalar1*3/2);
    p.setBlendMode(SkBlendMode::kClear);
    rastBuilder->addLayer(p);
}

static void r3(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
    p.setStyle(SkPaint::kStroke_Style);
    p.setStrokeWidth(SK_Scalar1*3);
    rastBuilder->addLayer(p);

    p.setAlpha(0x20);
    p.setStyle(SkPaint::kFill_Style);
    p.setBlendMode(SkBlendMode::kSrc);
    rastBuilder->addLayer(p);
}

static void r4(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
    p.setAlpha(0x60);
    rastBuilder->addLayer(p, SkIntToScalar(3), SkIntToScalar(3));

    p.setAlpha(0xFF);
    p.setBlendMode(SkBlendMode::kClear);
    rastBuilder->addLayer(p, SK_Scalar1*3/2, SK_Scalar1*3/2);

    p.setBlendMode(SkBlendMode::kSrcOver);
    rastBuilder->addLayer(p);
}

#include "SkDiscretePathEffect.h"

static void r5(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
    rastBuilder->addLayer(p);

    p.setPathEffect(SkDiscretePathEffect::Make(SK_Scalar1*4, SK_Scalar1*3));
    p.setBlendMode(SkBlendMode::kSrcOut);
    rastBuilder->addLayer(p);
}

static void r6(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
    rastBuilder->addLayer(p);

    p.setAntiAlias(false);
    SkLayerRasterizer::Builder rastBuilder2;
    r5(&rastBuilder2, p);
    p.setRasterizer(rastBuilder2.detach());
    p.setBlendMode(SkBlendMode::kClear);
    rastBuilder->addLayer(p);
}

#include "Sk2DPathEffect.h"

static sk_sp<SkPathEffect> MakeDotEffect(SkScalar radius, const SkMatrix& matrix) {
    SkPath path;
    path.addCircle(0, 0, radius);
    return SkPath2DPathEffect::Make(matrix, path);
}

static void r7(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
    SkMatrix    lattice;
    lattice.setScale(SK_Scalar1*6, SK_Scalar1*6, 0, 0);
    lattice.postSkew(SK_Scalar1/3, 0, 0, 0);
    p.setPathEffect(MakeDotEffect(SK_Scalar1*4, lattice));
    rastBuilder->addLayer(p);
}

static void r8(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
    rastBuilder->addLayer(p);

    SkMatrix    lattice;
    lattice.setScale(SK_Scalar1*6, SK_Scalar1*6, 0, 0);
    lattice.postSkew(SK_Scalar1/3, 0, 0, 0);
    p.setPathEffect(MakeDotEffect(SK_Scalar1*2, lattice));
    p.setBlendMode(SkBlendMode::kClear);
    rastBuilder->addLayer(p);

    p.setPathEffect(nullptr);
    p.setBlendMode(SkBlendMode::kSrcOver);
    p.setStyle(SkPaint::kStroke_Style);
    p.setStrokeWidth(SK_Scalar1);
    rastBuilder->addLayer(p);
}

static void r9(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
    rastBuilder->addLayer(p);

    SkMatrix    lattice;
    lattice.setScale(SK_Scalar1, SK_Scalar1*6, 0, 0);
    lattice.postRotate(SkIntToScalar(30), 0, 0);
    p.setPathEffect(SkLine2DPathEffect::Make(SK_Scalar1*2, lattice));
    p.setBlendMode(SkBlendMode::kClear);
    rastBuilder->addLayer(p);

    p.setPathEffect(nullptr);
    p.setBlendMode(SkBlendMode::kSrcOver);
    p.setStyle(SkPaint::kStroke_Style);
    p.setStrokeWidth(SK_Scalar1);
    rastBuilder->addLayer(p);
}

typedef void (*raster_proc)(SkLayerRasterizer::Builder*, SkPaint&);

constexpr raster_proc gRastProcs[] = {
    r0, r1, r2, r3, r4, r5, r6, r7, r8, r9
};

static void apply_shader(SkPaint* paint, int index) {
    raster_proc proc = gRastProcs[index];
    if (proc) {
        SkPaint p;
        SkLayerRasterizer::Builder rastBuilder;

        p.setAntiAlias(true);
        proc(&rastBuilder, p);
        paint->setRasterizer(rastBuilder.detach());
    }

#if 0
    SkScalar dir[] = { SK_Scalar1, SK_Scalar1, SK_Scalar1 };
    paint->setMaskFilter(SkBlurMaskFilter::CreateEmboss(dir, SK_Scalar1/4, SkIntToScalar(4), SkIntToScalar(3)))->unref();
#endif
    paint->setColor(SK_ColorBLUE);
}

DEF_SIMPLE_GM(texteffects, canvas, 460, 680) {
        canvas->save();

        SkPaint     paint;
        paint.setAntiAlias(true);
        sk_tool_utils::set_portable_typeface(&paint);
        paint.setTextSize(SkIntToScalar(56));

        SkScalar    x = SkIntToScalar(20);
        SkScalar    y = paint.getTextSize();

        SkString str("Hamburgefons");

        for (int i = 0; i < static_cast<int>(SK_ARRAY_COUNT(gRastProcs)); i++) {
            apply_shader(&paint, i);

            //  paint.setMaskFilter(nullptr);
            //  paint.setColor(SK_ColorBLACK);

            canvas->drawString(str, x, y, paint);

            y += paint.getFontSpacing();
        }

        canvas->restore();
}

static SkPath create_underline(const SkTDArray<SkScalar>& intersections,
        SkScalar last, SkScalar finalPos,
        SkScalar uPos, SkScalar uWidth, SkScalar textSize) {
    SkPath underline;
    SkScalar end = last;
    for (int index = 0; index < intersections.count(); index += 2) {
        SkScalar start = intersections[index] - uWidth;;
        end = intersections[index + 1] + uWidth;
        if (start > last && last + textSize / 12 < start) {
            underline.moveTo(last, uPos);
            underline.lineTo(start, uPos);
        }
        last = end;
    }
    if (end < finalPos) {
        underline.moveTo(end, uPos);
        underline.lineTo(finalPos, uPos);
    }
    return underline;
}

static void find_intercepts(const char* test, size_t len, SkScalar x, SkScalar y,
        const SkPaint& paint, SkScalar uWidth, SkTDArray<SkScalar>* intersections) {
    SkScalar uPos = y + uWidth;
    SkScalar bounds[2] = { uPos - uWidth / 2, uPos + uWidth / 2 };
    int count = paint.getTextIntercepts(test, len, x, y, bounds, nullptr);
    SkASSERT(!(count % 2));
    if (count) {
        intersections->setCount(count);
        paint.getTextIntercepts(test, len, x, y, bounds, intersections->begin());
    }
}

DEF_SIMPLE_GM(fancyunderline, canvas, 900, 1350) {
    SkPaint paint;
    paint.setAntiAlias(true);
    const char* fam[] = { "sans-serif", "serif", "monospace" };
    const char test[] = "aAjJgGyY_|{-(~[,]qQ}pP}zZ";
    SkPoint textPt = { 10, 80 };
    for (size_t font = 0; font < SK_ARRAY_COUNT(fam); ++font) {
        sk_tool_utils::set_portable_typeface(&paint, fam[font]);
        for (SkScalar textSize = 100; textSize > 10; textSize -= 20) {
            paint.setTextSize(textSize);
            const SkScalar uWidth = textSize / 15;
            paint.setStrokeWidth(uWidth);
            paint.setStyle(SkPaint::kFill_Style);
            canvas->drawText(test, sizeof(test) - 1, textPt.fX, textPt.fY, paint);

            SkTDArray<SkScalar> intersections;
            find_intercepts(test, sizeof(test) - 1, textPt.fX, textPt.fY, paint, uWidth,
                &intersections);

            SkScalar start = textPt.fX;
            SkScalar end = paint.measureText(test, sizeof(test) - 1) + textPt.fX;
            SkScalar uPos = textPt.fY + uWidth;
            SkPath underline = create_underline(intersections, start, end, uPos, uWidth, textSize);
            paint.setStyle(SkPaint::kStroke_Style);
            canvas->drawPath(underline, paint);

            canvas->translate(0, textSize * 1.3f);
        }
        canvas->translate(0, 60);
    }
}

static void find_intercepts(const char* test, size_t len, const SkPoint* pos, const SkPaint& paint,
        SkScalar uWidth, SkTDArray<SkScalar>* intersections) {
    SkScalar uPos = pos[0].fY + uWidth;
    SkScalar bounds[2] = { uPos - uWidth / 2, uPos + uWidth / 2 };
    int count = paint.getPosTextIntercepts(test, len, pos, bounds, nullptr);
    SkASSERT(!(count % 2));
    if (count) {
        intersections->setCount(count);
        paint.getPosTextIntercepts(test, len, pos, bounds, intersections->begin());
    }
}

DEF_SIMPLE_GM(fancyposunderline, canvas, 900, 1350) {
    SkPaint paint;
    paint.setAntiAlias(true);
    const char* fam[] = { "sans-serif", "serif", "monospace" };
    const char test[] = "aAjJgGyY_|{-(~[,]qQ}pP}zZ";
    SkPoint textPt = { 10, 80 };
    for (size_t font = 0; font < SK_ARRAY_COUNT(fam); ++font) {
        sk_tool_utils::set_portable_typeface(&paint, fam[font]);
        for (SkScalar textSize = 100; textSize > 10; textSize -= 20) {
            paint.setTextSize(textSize);
            const SkScalar uWidth = textSize / 15;
            paint.setStrokeWidth(uWidth);
            paint.setStyle(SkPaint::kFill_Style);
            int widthCount = paint.getTextWidths(test, sizeof(test) - 1, nullptr);
            SkTDArray<SkScalar> widths;
            widths.setCount(widthCount);
            (void) paint.getTextWidths(test, sizeof(test) - 1, widths.begin());
            SkTDArray<SkPoint> pos;
            pos.setCount(widthCount);
            SkScalar posX = textPt.fX;
            for (int index = 0; index < widthCount; ++index) {
                pos[index].fX = posX;
                posX += widths[index];
                pos[index].fY = textPt.fY + (textSize / 25) * (index % 4);
            }
            canvas->drawPosText(test, sizeof(test) - 1, pos.begin(), paint);

            SkTDArray<SkScalar> intersections;
            find_intercepts(test, sizeof(test) - 1, pos.begin(), paint, uWidth, &intersections);

            SkScalar start = textPt.fX;
            SkScalar end = posX;
            SkScalar uPos = textPt.fY + uWidth;
            SkPath underline = create_underline(intersections, start, end, uPos, uWidth, textSize);
            paint.setStyle(SkPaint::kStroke_Style);
            canvas->drawPath(underline, paint);

            canvas->translate(0, textSize * 1.3f);
        }
        canvas->translate(0, 60);
    }
}

namespace {

sk_sp<SkTextBlob> MakeFancyBlob(const SkPaint& paint, const char* text) {
    SkPaint blobPaint(paint);

    const size_t textLen = strlen(text);
    const int glyphCount = blobPaint.textToGlyphs(text, textLen, nullptr);
    SkAutoTArray<SkGlyphID> glyphs(glyphCount);
    blobPaint.textToGlyphs(text, textLen, glyphs.get());

    blobPaint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
    const size_t glyphTextBytes = SkTo<uint32_t>(glyphCount) * sizeof(SkGlyphID);
    const int widthCount = blobPaint.getTextWidths(glyphs.get(), glyphTextBytes, nullptr);
    SkAssertResult(widthCount == glyphCount);

    SkAutoTArray<SkScalar> widths(glyphCount);
    blobPaint.getTextWidths(glyphs.get(), glyphTextBytes, widths.get());

    SkTextBlobBuilder blobBuilder;
    int glyphIndex = 0;
    SkScalar advance = 0;

    // Default-positioned run.
    {
        const int defaultRunLen = glyphCount / 3;
        const SkTextBlobBuilder::RunBuffer& buf = blobBuilder.allocRun(blobPaint,
                                                                       defaultRunLen,
                                                                       advance, 0);
        memcpy(buf.glyphs, glyphs.get(), SkTo<uint32_t>(defaultRunLen) * sizeof(SkGlyphID));

        for (int i = 0; i < defaultRunLen; ++i) {
            advance += widths[glyphIndex++];
        }
    }

    // Horizontal-positioned run.
    {
        const int horizontalRunLen = glyphCount / 3;
        const SkTextBlobBuilder::RunBuffer& buf = blobBuilder.allocRunPosH(blobPaint,
                                                                           horizontalRunLen,
                                                                           0);
        memcpy(buf.glyphs, glyphs.get() + glyphIndex,
               SkTo<uint32_t>(horizontalRunLen) * sizeof(SkGlyphID));
        for (int i = 0; i < horizontalRunLen; ++i) {
            buf.pos[i] = advance;
            advance += widths[glyphIndex++];
        }
    }

    // Full-positioned run.
    {
        const int fullRunLen = glyphCount - glyphIndex;
        const SkTextBlobBuilder::RunBuffer& buf = blobBuilder.allocRunPos(blobPaint, fullRunLen);
        memcpy(buf.glyphs, glyphs.get() + glyphIndex,
               SkTo<uint32_t>(fullRunLen) * sizeof(SkGlyphID));
        for (int i = 0; i < fullRunLen; ++i) {
            buf.pos[i * 2 + 0] = advance; // x offset
            buf.pos[i * 2 + 1] = 0;       // y offset
            advance += widths[glyphIndex++];
        }
    }

    return blobBuilder.make();
}

} // anonymous ns

DEF_SIMPLE_GM(fancyblobunderline, canvas, 1480, 1380) {
    SkPaint paint;
    paint.setAntiAlias(true);
    const char* fam[] = { "sans-serif", "serif", "monospace" };
    const char test[] = "aAjJgGyY_|{-(~[,]qQ}pP}zZ";
    const SkPoint blobOffset = { 10, 80 };

    for (size_t font = 0; font < SK_ARRAY_COUNT(fam); ++font) {
        sk_tool_utils::set_portable_typeface(&paint, fam[font]);
        for (SkScalar textSize = 100; textSize > 10; textSize -= 20) {
            paint.setTextSize(textSize);
            const SkScalar uWidth = textSize / 15;
            paint.setStrokeWidth(uWidth);
            paint.setStyle(SkPaint::kFill_Style);

            sk_sp<SkTextBlob> blob = MakeFancyBlob(paint, test);
            canvas->drawTextBlob(blob, blobOffset.x(), blobOffset.y(), paint);

            const SkScalar uPos = uWidth;
            const SkScalar bounds[2] = { uPos - uWidth / 2, uPos + uWidth / 2 };
            const int interceptCount = paint.getTextBlobIntercepts(blob.get(), bounds, nullptr);
            SkASSERT(!(interceptCount % 2));

            SkTDArray<SkScalar> intercepts;
            intercepts.setCount(interceptCount);
            paint.getTextBlobIntercepts(blob.get(), bounds, intercepts.begin());

            const SkScalar start = blob->bounds().left();
            const SkScalar end = blob->bounds().right();
            SkPath underline = create_underline(intercepts, start, end, uPos, uWidth, textSize);
            underline.offset(blobOffset.x(), blobOffset.y());
            paint.setStyle(SkPaint::kStroke_Style);
            canvas->drawPath(underline, paint);

            canvas->translate(0, textSize * 1.3f);
        }

        canvas->translate(0, 60);
    }
}

DEF_SIMPLE_GM(fancyunderlinebars, canvas, 1500, 460) {
    SkPaint paint;
    paint.setAntiAlias(true);
    const char test[] = " .}]_ .}]_ .}]_ .}]_ .}]_ .}]_ .}]_ .}]_ .}]_ .}]_ .}]_ .}]_ .}]_";
    SkPoint textPt = { 10, 80 };
    sk_tool_utils::set_portable_typeface(&paint, "serif");
    for (SkScalar textSize = 100; textSize > 10; textSize -= 20) {
        paint.setTextSize(textSize);
        SkScalar uWidth = textSize / 15;
        paint.setStrokeWidth(uWidth);
        paint.setStyle(SkPaint::kFill_Style);
        int widthCount = paint.getTextWidths(test, sizeof(test) - 1, nullptr);
        SkTDArray<SkScalar> widths;
        widths.setCount(widthCount);
        (void) paint.getTextWidths(test, sizeof(test) - 1, widths.begin());
        SkTDArray<SkPoint> pos;
        pos.setCount(widthCount);
        SkScalar posX = textPt.fX;
        pos[0] = textPt;
        posX += widths[0];
        for (int index = 1; index < widthCount; ++index) {
            pos[index].fX = posX;
            posX += widths[index];
            pos[index].fY = textPt.fY - (textSize / 50) * (index / 5) + textSize / 50 * 4;
        }
        canvas->drawPosText(test, sizeof(test) - 1, pos.begin(), paint);

        SkTDArray<SkScalar> intersections;
        find_intercepts(test, sizeof(test) - 1, pos.begin(), paint, uWidth, &intersections);

        SkScalar start = textPt.fX;
        SkScalar end = posX;
        SkScalar uPos = pos[0].fY + uWidth;
        SkPath underline = create_underline(intersections, start, end, uPos, uWidth, textSize);
        paint.setStyle(SkPaint::kStroke_Style);
        canvas->drawPath(underline, paint);
        canvas->translate(0, textSize * 1.3f);
    }
}