1 /*
2 * Copyright 2017 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/SkPaint.h"
10 #include "include/core/SkPath.h"
11 #include "include/utils/SkRandom.h"
12 #include "samplecode/Sample.h"
13 #include "src/core/SkPathPriv.h"
14 #include "src/core/SkScalerCache.h"
15 #include "src/core/SkStrikeCache.h"
16 #include "src/core/SkStrikeSpec.h"
17 #include "src/core/SkTaskGroup.h"
18 #include "tools/ToolUtils.h"
19
20 ////////////////////////////////////////////////////////////////////////////////////////////////////
21 // Static text from paths.
22 class PathText : public Sample {
23 public:
24 constexpr static int kNumPaths = 1500;
getName() const25 virtual const char* getName() const { return "PathText"; }
26
PathText()27 PathText() {}
28
reset()29 virtual void reset() {
30 for (Glyph& glyph : fGlyphs) {
31 glyph.reset(fRand, this->width(), this->height());
32 }
33 fGlyphAnimator->reset(&fRand, this->width(), this->height());
34 }
35
onOnceBeforeDraw()36 void onOnceBeforeDraw() final {
37 SkFont defaultFont;
38 SkStrikeSpec strikeSpec = SkStrikeSpec::MakeWithNoDevice(defaultFont);
39 auto strike = strikeSpec.findOrCreateStrike();
40 SkPath glyphPaths[52];
41 for (int i = 0; i < 52; ++i) {
42 // I and l are rects on OS X ...
43 char c = "aQCDEFGH7JKLMNOPBRZTUVWXYSAbcdefghijk1mnopqrstuvwxyz"[i];
44 SkPackedGlyphID id(defaultFont.unicharToGlyph(c));
45 sk_ignore_unused_variable(strike->getScalerContext()->getPath(id, &glyphPaths[i]));
46 }
47
48 for (int i = 0; i < kNumPaths; ++i) {
49 const SkPath& p = glyphPaths[i % 52];
50 fGlyphs[i].init(fRand, p);
51 }
52
53 this->Sample::onOnceBeforeDraw();
54 this->reset();
55 }
onSizeChange()56 void onSizeChange() final { this->Sample::onSizeChange(); this->reset(); }
57
name()58 SkString name() override { return SkString(this->getName()); }
59
60 bool onChar(SkUnichar) override;
61
onAnimate(double nanos)62 bool onAnimate(double nanos) final {
63 return fGlyphAnimator->animate(nanos, this->width(), this->height());
64 }
65
onDrawContent(SkCanvas * canvas)66 void onDrawContent(SkCanvas* canvas) override {
67 if (fDoClip) {
68 SkPath deviceSpaceClipPath = fClipPath;
69 deviceSpaceClipPath.transform(SkMatrix::Scale(this->width(), this->height()));
70 canvas->save();
71 canvas->clipPath(deviceSpaceClipPath, SkClipOp::kDifference, true);
72 canvas->clear(SK_ColorBLACK);
73 canvas->restore();
74 canvas->clipPath(deviceSpaceClipPath, SkClipOp::kIntersect, true);
75 }
76 fGlyphAnimator->draw(canvas);
77 }
78
79 protected:
80 struct Glyph {
81 void init(SkRandom& rand, const SkPath& path);
82 void reset(SkRandom& rand, int w, int h);
83
84 SkPath fPath;
85 SkPaint fPaint;
86 SkPoint fPosition;
87 SkScalar fZoom;
88 SkScalar fSpin;
89 SkPoint fMidpt;
90 };
91
92 class GlyphAnimator {
93 public:
GlyphAnimator(Glyph * glyphs)94 GlyphAnimator(Glyph* glyphs) : fGlyphs(glyphs) {}
reset(SkRandom *,int screenWidth,int screenHeight)95 virtual void reset(SkRandom*, int screenWidth, int screenHeight) {}
animate(double nanos,int screenWidth,int screenHeight)96 virtual bool animate(double nanos, int screenWidth, int screenHeight) { return false; }
draw(SkCanvas * canvas)97 virtual void draw(SkCanvas* canvas) {
98 for (int i = 0; i < kNumPaths; ++i) {
99 Glyph& glyph = fGlyphs[i];
100 SkAutoCanvasRestore acr(canvas, true);
101 canvas->translate(glyph.fPosition.x(), glyph.fPosition.y());
102 canvas->scale(glyph.fZoom, glyph.fZoom);
103 canvas->rotate(glyph.fSpin);
104 canvas->translate(-glyph.fMidpt.x(), -glyph.fMidpt.y());
105 canvas->drawPath(glyph.fPath, glyph.fPaint);
106 }
107 }
~GlyphAnimator()108 virtual ~GlyphAnimator() {}
109
110 protected:
111 Glyph* const fGlyphs;
112 };
113
114 class MovingGlyphAnimator;
115 class WavyGlyphAnimator;
116
117 Glyph fGlyphs[kNumPaths];
118 SkRandom fRand{25};
119 SkPath fClipPath = ToolUtils::make_star(SkRect{0, 0, 1, 1}, 11, 3);
120 bool fDoClip = false;
121 std::unique_ptr<GlyphAnimator> fGlyphAnimator = std::make_unique<GlyphAnimator>(fGlyphs);
122 };
123
init(SkRandom & rand,const SkPath & path)124 void PathText::Glyph::init(SkRandom& rand, const SkPath& path) {
125 fPath = path;
126 fPaint.setAntiAlias(true);
127 fPaint.setColor(rand.nextU() | 0x80808080);
128 }
129
reset(SkRandom & rand,int w,int h)130 void PathText::Glyph::reset(SkRandom& rand, int w, int h) {
131 int screensize = std::max(w, h);
132 const SkRect& bounds = fPath.getBounds();
133 SkScalar t;
134
135 fPosition = {rand.nextF() * w, rand.nextF() * h};
136 t = pow(rand.nextF(), 100);
137 fZoom = ((1 - t) * screensize / 50 + t * screensize / 3) /
138 std::max(bounds.width(), bounds.height());
139 fSpin = rand.nextF() * 360;
140 fMidpt = {bounds.centerX(), bounds.centerY()};
141 }
142
143 ////////////////////////////////////////////////////////////////////////////////////////////////////
144 // Text from paths with animated transformation matrices.
145 class PathText::MovingGlyphAnimator : public PathText::GlyphAnimator {
146 public:
MovingGlyphAnimator(Glyph * glyphs)147 MovingGlyphAnimator(Glyph* glyphs)
148 : GlyphAnimator(glyphs)
149 , fFrontMatrices(kNumPaths)
150 , fBackMatrices(kNumPaths) {
151 }
152
~MovingGlyphAnimator()153 ~MovingGlyphAnimator() override {
154 fBackgroundAnimationTask.wait();
155 }
156
reset(SkRandom * rand,int screenWidth,int screenHeight)157 void reset(SkRandom* rand, int screenWidth, int screenHeight) override {
158 const SkScalar screensize = static_cast<SkScalar>(std::max(screenWidth, screenHeight));
159
160 for (auto& v : fVelocities) {
161 for (SkScalar* d : {&v.fDx, &v.fDy}) {
162 SkScalar t = pow(rand->nextF(), 3);
163 *d = ((1 - t) / 60 + t / 10) * (rand->nextBool() ? screensize : -screensize);
164 }
165
166 SkScalar t = pow(rand->nextF(), 25);
167 v.fDSpin = ((1 - t) * 360 / 7.5 + t * 360 / 1.5) * (rand->nextBool() ? 1 : -1);
168 }
169
170 // Get valid front data.
171 fBackgroundAnimationTask.wait();
172 this->runAnimationTask(0, 0, screenWidth, screenHeight);
173 std::copy_n(fBackMatrices.get(), kNumPaths, fFrontMatrices.get());
174 fLastTick = 0;
175 }
176
animate(double nanos,int screenWidth,int screenHeight)177 bool animate(double nanos, int screenWidth, int screenHeight) final {
178 fBackgroundAnimationTask.wait();
179 this->swapAnimationBuffers();
180
181 const double tsec = 1e-9 * nanos;
182 const double dt = fLastTick ? (1e-9 * nanos - fLastTick) : 0;
183 fBackgroundAnimationTask.add(std::bind(&MovingGlyphAnimator::runAnimationTask, this, tsec,
184 dt, screenWidth, screenHeight));
185 fLastTick = 1e-9 * nanos;
186 return true;
187 }
188
189 /**
190 * Called on a background thread. Here we can only modify fBackMatrices.
191 */
runAnimationTask(double t,double dt,int w,int h)192 virtual void runAnimationTask(double t, double dt, int w, int h) {
193 for (int idx = 0; idx < kNumPaths; ++idx) {
194 Velocity* v = &fVelocities[idx];
195 Glyph* glyph = &fGlyphs[idx];
196 SkMatrix* backMatrix = &fBackMatrices[idx];
197
198 glyph->fPosition.fX += v->fDx * dt;
199 if (glyph->fPosition.x() < 0) {
200 glyph->fPosition.fX -= 2 * glyph->fPosition.x();
201 v->fDx = -v->fDx;
202 } else if (glyph->fPosition.x() > w) {
203 glyph->fPosition.fX -= 2 * (glyph->fPosition.x() - w);
204 v->fDx = -v->fDx;
205 }
206
207 glyph->fPosition.fY += v->fDy * dt;
208 if (glyph->fPosition.y() < 0) {
209 glyph->fPosition.fY -= 2 * glyph->fPosition.y();
210 v->fDy = -v->fDy;
211 } else if (glyph->fPosition.y() > h) {
212 glyph->fPosition.fY -= 2 * (glyph->fPosition.y() - h);
213 v->fDy = -v->fDy;
214 }
215
216 glyph->fSpin += v->fDSpin * dt;
217
218 backMatrix->setTranslate(glyph->fPosition.x(), glyph->fPosition.y());
219 backMatrix->preScale(glyph->fZoom, glyph->fZoom);
220 backMatrix->preRotate(glyph->fSpin);
221 backMatrix->preTranslate(-glyph->fMidpt.x(), -glyph->fMidpt.y());
222 }
223 }
224
swapAnimationBuffers()225 virtual void swapAnimationBuffers() {
226 std::swap(fFrontMatrices, fBackMatrices);
227 }
228
draw(SkCanvas * canvas)229 void draw(SkCanvas* canvas) override {
230 for (int i = 0; i < kNumPaths; ++i) {
231 SkAutoCanvasRestore acr(canvas, true);
232 canvas->concat(fFrontMatrices[i]);
233 canvas->drawPath(fGlyphs[i].fPath, fGlyphs[i].fPaint);
234 }
235 }
236
237 protected:
238 struct Velocity {
239 SkScalar fDx, fDy;
240 SkScalar fDSpin;
241 };
242
243 Velocity fVelocities[kNumPaths];
244 SkAutoTArray<SkMatrix> fFrontMatrices;
245 SkAutoTArray<SkMatrix> fBackMatrices;
246 SkTaskGroup fBackgroundAnimationTask;
247 double fLastTick;
248 };
249
250
251 ////////////////////////////////////////////////////////////////////////////////////////////////////
252 // Text from paths with animated control points.
253 class PathText::WavyGlyphAnimator : public PathText::MovingGlyphAnimator {
254 public:
WavyGlyphAnimator(Glyph * glyphs)255 WavyGlyphAnimator(Glyph* glyphs)
256 : MovingGlyphAnimator(glyphs)
257 , fFrontPaths(kNumPaths)
258 , fBackPaths(kNumPaths) {
259 }
260
~WavyGlyphAnimator()261 ~WavyGlyphAnimator() override {
262 fBackgroundAnimationTask.wait();
263 }
264
reset(SkRandom * rand,int screenWidth,int screenHeight)265 void reset(SkRandom* rand, int screenWidth, int screenHeight) override {
266 fWaves.reset(*rand, screenWidth, screenHeight);
267 this->MovingGlyphAnimator::reset(rand, screenWidth, screenHeight);
268 std::copy(fBackPaths.get(), fBackPaths.get() + kNumPaths, fFrontPaths.get());
269 }
270
271 /**
272 * Called on a background thread. Here we can only modify fBackPaths.
273 */
runAnimationTask(double t,double dt,int width,int height)274 void runAnimationTask(double t, double dt, int width, int height) override {
275 const float tsec = static_cast<float>(t);
276 this->MovingGlyphAnimator::runAnimationTask(t, 0.5 * dt, width, height);
277
278 for (int i = 0; i < kNumPaths; ++i) {
279 const Glyph& glyph = fGlyphs[i];
280 const SkMatrix& backMatrix = fBackMatrices[i];
281
282 const Sk2f matrix[3] = {
283 Sk2f(backMatrix.getScaleX(), backMatrix.getSkewY()),
284 Sk2f(backMatrix.getSkewX(), backMatrix.getScaleY()),
285 Sk2f(backMatrix.getTranslateX(), backMatrix.getTranslateY())
286 };
287
288 SkPath* backpath = &fBackPaths[i];
289 backpath->reset();
290 backpath->setFillType(SkPathFillType::kEvenOdd);
291
292 for (auto [verb, pts, w] : SkPathPriv::Iterate(glyph.fPath)) {
293 switch (verb) {
294 case SkPathVerb::kMove: {
295 SkPoint pt = fWaves.apply(tsec, matrix, pts[0]);
296 backpath->moveTo(pt.x(), pt.y());
297 break;
298 }
299 case SkPathVerb::kLine: {
300 SkPoint endpt = fWaves.apply(tsec, matrix, pts[1]);
301 backpath->lineTo(endpt.x(), endpt.y());
302 break;
303 }
304 case SkPathVerb::kQuad: {
305 SkPoint controlPt = fWaves.apply(tsec, matrix, pts[1]);
306 SkPoint endpt = fWaves.apply(tsec, matrix, pts[2]);
307 backpath->quadTo(controlPt.x(), controlPt.y(), endpt.x(), endpt.y());
308 break;
309 }
310 case SkPathVerb::kClose: {
311 backpath->close();
312 break;
313 }
314 case SkPathVerb::kCubic:
315 case SkPathVerb::kConic:
316 SK_ABORT("Unexpected path verb");
317 break;
318 }
319 }
320 }
321 }
322
swapAnimationBuffers()323 void swapAnimationBuffers() override {
324 this->MovingGlyphAnimator::swapAnimationBuffers();
325 std::swap(fFrontPaths, fBackPaths);
326 }
327
draw(SkCanvas * canvas)328 void draw(SkCanvas* canvas) override {
329 for (int i = 0; i < kNumPaths; ++i) {
330 canvas->drawPath(fFrontPaths[i], fGlyphs[i].fPaint);
331 }
332 }
333
334 private:
335 /**
336 * Describes 4 stacked sine waves that can offset a point as a function of wall time.
337 */
338 class Waves {
339 public:
340 void reset(SkRandom& rand, int w, int h);
341 SkPoint apply(float tsec, const Sk2f matrix[3], const SkPoint& pt) const;
342
343 private:
344 constexpr static double kAverageAngle = SK_ScalarPI / 8.0;
345 constexpr static double kMaxOffsetAngle = SK_ScalarPI / 3.0;
346
347 float fAmplitudes[4];
348 float fFrequencies[4];
349 float fDirsX[4];
350 float fDirsY[4];
351 float fSpeeds[4];
352 float fOffsets[4];
353 };
354
355 SkAutoTArray<SkPath> fFrontPaths;
356 SkAutoTArray<SkPath> fBackPaths;
357 Waves fWaves;
358 };
359
reset(SkRandom & rand,int w,int h)360 void PathText::WavyGlyphAnimator::Waves::reset(SkRandom& rand, int w, int h) {
361 const double pixelsPerMeter = 0.06 * std::max(w, h);
362 const double medianWavelength = 8 * pixelsPerMeter;
363 const double medianWaveAmplitude = 0.05 * 4 * pixelsPerMeter;
364 const double gravity = 9.8 * pixelsPerMeter;
365
366 for (int i = 0; i < 4; ++i) {
367 const double offsetAngle = (rand.nextF() * 2 - 1) * kMaxOffsetAngle;
368 const double intensity = pow(2, rand.nextF() * 2 - 1);
369 const double wavelength = intensity * medianWavelength;
370
371 fAmplitudes[i] = intensity * medianWaveAmplitude;
372 fFrequencies[i] = 2 * SK_ScalarPI / wavelength;
373 fDirsX[i] = cosf(kAverageAngle + offsetAngle);
374 fDirsY[i] = sinf(kAverageAngle + offsetAngle);
375 fSpeeds[i] = -sqrt(gravity * 2 * SK_ScalarPI / wavelength);
376 fOffsets[i] = rand.nextF() * 2 * SK_ScalarPI;
377 }
378 }
379
apply(float tsec,const Sk2f matrix[3],const SkPoint & pt) const380 SkPoint PathText::WavyGlyphAnimator::Waves::apply(float tsec, const Sk2f matrix[3],
381 const SkPoint& pt) const {
382 constexpr static int kTablePeriod = 1 << 12;
383 static float sin2table[kTablePeriod + 1];
384 static SkOnce initTable;
385 initTable([]() {
386 for (int i = 0; i <= kTablePeriod; ++i) {
387 const double sintheta = sin(i * (SK_ScalarPI / kTablePeriod));
388 sin2table[i] = static_cast<float>(sintheta * sintheta - 0.5);
389 }
390 });
391
392 const Sk4f amplitudes = Sk4f::Load(fAmplitudes);
393 const Sk4f frequencies = Sk4f::Load(fFrequencies);
394 const Sk4f dirsX = Sk4f::Load(fDirsX);
395 const Sk4f dirsY = Sk4f::Load(fDirsY);
396 const Sk4f speeds = Sk4f::Load(fSpeeds);
397 const Sk4f offsets = Sk4f::Load(fOffsets);
398
399 float devicePt[2];
400 (matrix[0] * pt.x() + matrix[1] * pt.y() + matrix[2]).store(devicePt);
401
402 const Sk4f t = (frequencies * (dirsX * devicePt[0] + dirsY * devicePt[1]) +
403 speeds * tsec +
404 offsets).abs() * (float(kTablePeriod) / float(SK_ScalarPI));
405
406 const Sk4i ipart = SkNx_cast<int>(t);
407 const Sk4f fpart = t - SkNx_cast<float>(ipart);
408
409 int32_t indices[4];
410 (ipart & (kTablePeriod-1)).store(indices);
411
412 const Sk4f left(sin2table[indices[0]], sin2table[indices[1]],
413 sin2table[indices[2]], sin2table[indices[3]]);
414 const Sk4f right(sin2table[indices[0] + 1], sin2table[indices[1] + 1],
415 sin2table[indices[2] + 1], sin2table[indices[3] + 1]);
416 const Sk4f height = amplitudes * (left * (1.f - fpart) + right * fpart);
417
418 Sk4f dy = height * dirsY;
419 Sk4f dx = height * dirsX;
420
421 float offsetY[4], offsetX[4];
422 (dy + SkNx_shuffle<2,3,0,1>(dy)).store(offsetY); // accumulate.
423 (dx + SkNx_shuffle<2,3,0,1>(dx)).store(offsetX);
424
425 return {devicePt[0] + offsetY[0] + offsetY[1], devicePt[1] - offsetX[0] - offsetX[1]};
426 }
427
onChar(SkUnichar unichar)428 bool PathText::onChar(SkUnichar unichar) {
429 switch (unichar) {
430 case 'X':
431 fDoClip = !fDoClip;
432 return true;
433 case 'S':
434 fGlyphAnimator = std::make_unique<GlyphAnimator>(fGlyphs);
435 fGlyphAnimator->reset(&fRand, this->width(), this->height());
436 return true;
437 case 'M':
438 fGlyphAnimator = std::make_unique<MovingGlyphAnimator>(fGlyphs);
439 fGlyphAnimator->reset(&fRand, this->width(), this->height());
440 return true;
441 case 'W':
442 fGlyphAnimator = std::make_unique<WavyGlyphAnimator>(fGlyphs);
443 fGlyphAnimator->reset(&fRand, this->width(), this->height());
444 return true;
445 }
446 return false;
447 }
448
449 ////////////////////////////////////////////////////////////////////////////////////////////////////
450
MakePathTextSample()451 Sample* MakePathTextSample() { return new PathText; }
452 static SampleRegistry gPathTextSample(MakePathTextSample);
453