1 /*
2 * Copyright 2011 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/SkColorFilter.h"
10 #include "include/core/SkColorPriv.h"
11 #include "include/core/SkContourMeasure.h"
12 #include "include/core/SkGraphics.h"
13 #include "include/core/SkPath.h"
14 #include "include/core/SkRegion.h"
15 #include "include/core/SkShader.h"
16 #include "include/core/SkStream.h"
17 #include "include/core/SkTime.h"
18 #include "include/core/SkTypeface.h"
19 #include "include/core/SkVertices.h"
20 #include "include/effects/SkGradientShader.h"
21 #include "include/effects/SkOpPathEffect.h"
22 #include "include/private/SkTDArray.h"
23 #include "include/utils/SkRandom.h"
24 #include "samplecode/DecodeFile.h"
25 #include "samplecode/Sample.h"
26 #include "src/core/SkGeometry.h"
27 #include "src/core/SkOSFile.h"
28 #include "src/utils/SkUTF.h"
29 #include "tools/Resources.h"
30 #include "tools/timer/TimeUtils.h"
31
32 namespace {
make_shader0(SkIPoint * size)33 static sk_sp<SkShader> make_shader0(SkIPoint* size) {
34 SkBitmap bm;
35 decode_file(GetResourceAsData("images/dog.jpg"), &bm);
36 *size = SkIPoint{bm.width(), bm.height()};
37 return bm.makeShader();
38 }
39
make_shader1(const SkIPoint & size)40 static sk_sp<SkShader> make_shader1(const SkIPoint& size) {
41 SkPoint pts[] = { { 0, 0, },
42 { SkIntToScalar(size.fX), SkIntToScalar(size.fY) } };
43 SkColor colors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorRED };
44 return SkGradientShader::MakeLinear(pts, colors, nullptr,
45 SK_ARRAY_COUNT(colors), SkTileMode::kMirror);
46 }
47
48 class Patch {
49 public:
Patch()50 Patch() { sk_bzero(fPts, sizeof(fPts)); }
~Patch()51 ~Patch() {}
52
setPatch(const SkPoint pts[12])53 void setPatch(const SkPoint pts[12]) {
54 memcpy(fPts, pts, 12 * sizeof(SkPoint));
55 fPts[12] = pts[0]; // the last shall be first
56 }
setBounds(int w,int h)57 void setBounds(int w, int h) { fW = w; fH = h; }
58
59 void draw(SkCanvas*, const SkPaint&, int segsU, int segsV,
60 bool doTextures, bool doColors);
61
62 private:
63 SkPoint fPts[13];
64 int fW, fH;
65 };
66
eval_patch_edge(const SkPoint cubic[],SkPoint samples[],int segs)67 static void eval_patch_edge(const SkPoint cubic[], SkPoint samples[], int segs) {
68 SkScalar t = 0;
69 SkScalar dt = SK_Scalar1 / segs;
70
71 samples[0] = cubic[0];
72 for (int i = 1; i < segs; i++) {
73 t += dt;
74 SkEvalCubicAt(cubic, t, &samples[i], nullptr, nullptr);
75 }
76 }
77
eval_sheet(const SkPoint edge[],int nu,int nv,int iu,int iv,SkPoint * pt)78 static void eval_sheet(const SkPoint edge[], int nu, int nv, int iu, int iv,
79 SkPoint* pt) {
80 const int TL = 0;
81 const int TR = nu;
82 const int BR = TR + nv;
83 const int BL = BR + nu;
84
85 SkScalar u = SkIntToScalar(iu) / nu;
86 SkScalar v = SkIntToScalar(iv) / nv;
87
88 SkScalar uv = u * v;
89 SkScalar Uv = (1 - u) * v;
90 SkScalar uV = u * (1 - v);
91 SkScalar UV = (1 - u) * (1 - v);
92
93 SkScalar x0 = UV * edge[TL].fX + uV * edge[TR].fX + Uv * edge[BL].fX + uv * edge[BR].fX;
94 SkScalar y0 = UV * edge[TL].fY + uV * edge[TR].fY + Uv * edge[BL].fY + uv * edge[BR].fY;
95
96 SkScalar x = (1 - v) * edge[TL+iu].fX + u * edge[TR+iv].fX +
97 v * edge[BR+nu-iu].fX + (1 - u) * edge[BL+nv-iv].fX - x0;
98 SkScalar y = (1 - v) * edge[TL+iu].fY + u * edge[TR+iv].fY +
99 v * edge[BR+nu-iu].fY + (1 - u) * edge[BL+nv-iv].fY - y0;
100 pt->set(x, y);
101 }
102
make_color(SkScalar s,SkScalar t)103 static SkColor make_color(SkScalar s, SkScalar t) {
104 return SkColorSetARGB(0xFF, SkUnitScalarClampToByte(s), SkUnitScalarClampToByte(t), 0);
105 }
106
draw(SkCanvas * canvas,const SkPaint & paint,int nu,int nv,bool doTextures,bool doColors)107 void Patch::draw(SkCanvas* canvas, const SkPaint& paint, int nu, int nv,
108 bool doTextures, bool doColors) {
109 if (nu < 1 || nv < 1) {
110 return;
111 }
112
113 int i, npts = (nu + nv) * 2;
114 SkAutoSTMalloc<16, SkPoint> storage(npts + 1);
115 SkPoint* edge0 = storage.get();
116 SkPoint* edge1 = edge0 + nu;
117 SkPoint* edge2 = edge1 + nv;
118 SkPoint* edge3 = edge2 + nu;
119
120 // evaluate the edge points
121 eval_patch_edge(fPts + 0, edge0, nu);
122 eval_patch_edge(fPts + 3, edge1, nv);
123 eval_patch_edge(fPts + 6, edge2, nu);
124 eval_patch_edge(fPts + 9, edge3, nv);
125 edge3[nv] = edge0[0]; // the last shall be first
126
127 for (i = 0; i < npts; i++) {
128 // canvas->drawLine(edge0[i].fX, edge0[i].fY, edge0[i+1].fX, edge0[i+1].fY, paint);
129 }
130
131 int row, vertCount = (nu + 1) * (nv + 1);
132 SkAutoTMalloc<SkPoint> vertStorage(vertCount);
133 SkPoint* verts = vertStorage.get();
134
135 // first row
136 memcpy(verts, edge0, (nu + 1) * sizeof(SkPoint));
137 // rows
138 SkPoint* r = verts;
139 for (row = 1; row < nv; row++) {
140 r += nu + 1;
141 r[0] = edge3[nv - row];
142 for (int col = 1; col < nu; col++) {
143 eval_sheet(edge0, nu, nv, col, row, &r[col]);
144 }
145 r[nu] = edge1[row];
146 }
147 // last row
148 SkPoint* last = verts + nv * (nu + 1);
149 for (i = 0; i <= nu; i++) {
150 last[i] = edge2[nu - i];
151 }
152
153 // canvas->drawPoints(verts, vertCount, paint);
154
155 int stripCount = (nu + 1) * 2;
156 SkAutoTMalloc<SkPoint> stripStorage(stripCount * 2);
157 SkAutoTMalloc<SkColor> colorStorage(stripCount);
158 SkPoint* strip = stripStorage.get();
159 SkPoint* tex = strip + stripCount;
160 SkColor* colors = colorStorage.get();
161 SkScalar t = 0;
162 const SkScalar ds = SK_Scalar1 * fW / nu;
163 const SkScalar dt = SK_Scalar1 * fH / nv;
164 r = verts;
165 for (row = 0; row < nv; row++) {
166 SkPoint* upper = r;
167 SkPoint* lower = r + nu + 1;
168 r = lower;
169 SkScalar s = 0;
170 for (i = 0; i <= nu; i++) {
171 strip[i*2 + 0] = *upper++;
172 strip[i*2 + 1] = *lower++;
173 tex[i*2 + 0].set(s, t);
174 tex[i*2 + 1].set(s, t + dt);
175 colors[i*2 + 0] = make_color(s/fW, t/fH);
176 colors[i*2 + 1] = make_color(s/fW, (t + dt)/fH);
177 s += ds;
178 }
179 t += dt;
180 canvas->drawVertices(SkVertices::MakeCopy(SkVertices::kTriangleStrip_VertexMode, stripCount,
181 strip, doTextures ? tex : nullptr,
182 doColors ? colors : nullptr),
183 SkBlendMode::kModulate, paint);
184 }
185 }
186
drawpatches(SkCanvas * canvas,const SkPaint & paint,int nu,int nv,Patch * patch)187 static void drawpatches(SkCanvas* canvas, const SkPaint& paint, int nu, int nv,
188 Patch* patch) {
189 SkAutoCanvasRestore ar(canvas, true);
190
191 patch->draw(canvas, paint, nu, nv, false, false);
192 canvas->translate(SkIntToScalar(180), 0);
193 patch->draw(canvas, paint, nu, nv, true, false);
194 canvas->translate(SkIntToScalar(180), 0);
195 patch->draw(canvas, paint, nu, nv, false, true);
196 canvas->translate(SkIntToScalar(180), 0);
197 patch->draw(canvas, paint, nu, nv, true, true);
198 }
199
200 static constexpr SkScalar DX = 20;
201 static constexpr SkScalar DY = 0;
202 static constexpr SkScalar kS = 50;
203 static constexpr SkScalar kT = 40;
204
205 struct PatchView : public Sample {
206 sk_sp<SkShader> fShader0;
207 sk_sp<SkShader> fShader1;
208 SkScalar fAngle = 0;
209 SkIPoint fSize0 = {0, 0},
210 fSize1 = {0, 0};
211 SkPoint fPts[12] = {
212 {kS * 0, kT * 1},
213 {kS * 1, kT * 1},
214 {kS * 2, kT * 1},
215 {kS * 3, kT * 1},
216 {kS * 3, kT * 2},
217 {kS * 3, kT * 3},
218 {kS * 3, kT * 4},
219 {kS * 2, kT * 4},
220 {kS * 1, kT * 4},
221 {kS * 0, kT * 4},
222 {kS * 0, kT * 3},
223 {kS * 0, kT * 2},
224 };
225
onOnceBeforeDraw__anon9cb781bf0111::PatchView226 void onOnceBeforeDraw() override {
227 fShader0 = make_shader0(&fSize0);
228 fSize1 = fSize0;
229 if (fSize0.fX == 0 || fSize0.fY == 0) {
230 fSize1.set(2, 2);
231 }
232 fShader1 = make_shader1(fSize1);
233 this->setBGColor(SK_ColorGRAY);
234 }
235
name__anon9cb781bf0111::PatchView236 SkString name() override { return SkString("Patch"); }
237
onDrawContent__anon9cb781bf0111::PatchView238 void onDrawContent(SkCanvas* canvas) override {
239 const int nu = 10;
240 const int nv = 10;
241
242 SkPaint paint;
243 paint.setDither(true);
244 paint.setFilterQuality(kLow_SkFilterQuality);
245
246 canvas->translate(DX, DY);
247
248 Patch patch;
249
250 paint.setShader(fShader0);
251 if (fSize0.fX == 0) {
252 fSize0.fX = 1;
253 }
254 if (fSize0.fY == 0) {
255 fSize0.fY = 1;
256 }
257 patch.setBounds(fSize0.fX, fSize0.fY);
258
259 patch.setPatch(fPts);
260 drawpatches(canvas, paint, nu, nv, &patch);
261
262 paint.setShader(nullptr);
263 paint.setAntiAlias(true);
264 paint.setStrokeWidth(SkIntToScalar(5));
265 canvas->drawPoints(SkCanvas::kPoints_PointMode, SK_ARRAY_COUNT(fPts), fPts, paint);
266
267 canvas->translate(0, SkIntToScalar(300));
268
269 paint.setAntiAlias(false);
270 paint.setShader(fShader1);
271 {
272 SkMatrix m;
273 m.setSkew(1, 0);
274 paint.setShader(paint.getShader()->makeWithLocalMatrix(m));
275 }
276 {
277 SkMatrix m;
278 m.setRotate(fAngle);
279 paint.setShader(paint.getShader()->makeWithLocalMatrix(m));
280 }
281 patch.setBounds(fSize1.fX, fSize1.fY);
282 drawpatches(canvas, paint, nu, nv, &patch);
283 }
284
onAnimate__anon9cb781bf0111::PatchView285 bool onAnimate(double nanos) override {
286 fAngle = TimeUtils::Scaled(1e-9 * nanos, 60, 360);
287 return true;
288 }
289
290 class PtClick : public Click {
291 public:
292 int fIndex;
PtClick(int index)293 PtClick(int index) : fIndex(index) {}
294 };
295
hittest__anon9cb781bf0111::PatchView296 static bool hittest(const SkPoint& pt, SkScalar x, SkScalar y) {
297 return SkPoint::Length(pt.fX - x, pt.fY - y) < SkIntToScalar(5);
298 }
299
onFindClickHandler__anon9cb781bf0111::PatchView300 Sample::Click* onFindClickHandler(SkScalar x, SkScalar y, skui::ModifierKey modi) override {
301 x -= DX;
302 y -= DY;
303 for (size_t i = 0; i < SK_ARRAY_COUNT(fPts); i++) {
304 if (hittest(fPts[i], x, y)) {
305 return new PtClick((int)i);
306 }
307 }
308 return nullptr;
309 }
310
onClick__anon9cb781bf0111::PatchView311 bool onClick(Click* click) override {
312 fPts[((PtClick*)click)->fIndex].set(click->fCurr.fX - DX, click->fCurr.fY - DY);
313 return true;
314 }
315
316 private:
317 typedef Sample INHERITED;
318 };
319 } // namespace
320 DEF_SAMPLE( return new PatchView(); )
321
322 //////////////////////////////////////////////////////////////////////////////
323
324 namespace {
make_verts(const SkPath & path,SkScalar width)325 static sk_sp<SkVertices> make_verts(const SkPath& path, SkScalar width) {
326 auto meas = SkContourMeasureIter(path, false).next();
327 if (!meas) {
328 return nullptr;
329 }
330
331 const SkPoint src[2] = {
332 { 0, -width/2 }, { 0, width/2 },
333 };
334 SkTDArray<SkPoint> pts;
335
336 const SkScalar step = 2;
337 for (SkScalar distance = 0; distance < meas->length(); distance += step) {
338 SkMatrix mx;
339 if (!meas->getMatrix(distance, &mx)) {
340 continue;
341 }
342 SkPoint* dst = pts.append(2);
343 mx.mapPoints(dst, src, 2);
344 }
345
346 int vertCount = pts.count();
347 int indexCount = 0; // no texture
348 unsigned flags = SkVertices::kHasColors_BuilderFlag;
349 SkVertices::Builder builder(SkVertices::kTriangleStrip_VertexMode,
350 vertCount, indexCount, flags);
351 memcpy(builder.positions(), pts.begin(), vertCount * sizeof(SkPoint));
352 SkRandom rand;
353 for (int i = 0; i < vertCount; ++i) {
354 builder.colors()[i] = rand.nextU() | 0xFF000000;
355 }
356 SkDebugf("vert count = %d\n", vertCount);
357
358 return builder.detach();
359 }
360
361 class PseudoInkView : public Sample {
362 enum { N = 100 };
363 SkPath fPath;
364 sk_sp<SkVertices> fVertices[N];
365 SkPaint fSkeletonP, fStrokeP, fVertsP;
366 bool fDirty = true;
367
368 public:
PseudoInkView()369 PseudoInkView() {
370 fSkeletonP.setStyle(SkPaint::kStroke_Style);
371 fSkeletonP.setAntiAlias(true);
372
373 fStrokeP.setStyle(SkPaint::kStroke_Style);
374 fStrokeP.setStrokeWidth(30);
375 fStrokeP.setColor(0x44888888);
376 }
377
378 protected:
name()379 SkString name() override { return SkString("PseudoInk"); }
380
onAnimate(double nanos)381 bool onAnimate(double nanos) override { return true; }
382
onDrawContent(SkCanvas * canvas)383 void onDrawContent(SkCanvas* canvas) override {
384 if (fDirty) {
385 for (int i = 0; i < N; ++i) {
386 fVertices[i] = make_verts(fPath, 30);
387 }
388 fDirty = false;
389 }
390 for (int i = 0; i < N; ++i) {
391 canvas->drawVertices(fVertices[i], SkBlendMode::kSrc, fVertsP);
392 canvas->translate(1, 1);
393 }
394 // canvas->drawPath(fPath, fStrokeP);
395 // canvas->drawPath(fPath, fSkeletonP);
396 }
397
onFindClickHandler(SkScalar x,SkScalar y,skui::ModifierKey modi)398 Click* onFindClickHandler(SkScalar x, SkScalar y, skui::ModifierKey modi) override {
399 Click* click = new Click();
400 fPath.reset();
401 fPath.moveTo(x, y);
402 return click;
403 }
404
onClick(Click * click)405 bool onClick(Click* click) override {
406 switch (click->fState) {
407 case skui::InputState::kMove:
408 fPath.lineTo(click->fCurr);
409 fDirty = true;
410 break;
411 default:
412 break;
413 }
414 return true;
415 }
416
417 private:
418 typedef Sample INHERITED;
419 };
420 } // namespace
421 DEF_SAMPLE( return new PseudoInkView(); )
422
423 namespace {
424 // Show stroking options using patheffects (and pathops)
425 // and why strokeandfill is a hacks
426 class ManyStrokesView : public Sample {
427 SkPath fPath;
428 sk_sp<SkPathEffect> fPE[6];
429
430 public:
ManyStrokesView()431 ManyStrokesView() {
432 fPE[0] = SkStrokePathEffect::Make(20, SkPaint::kRound_Join, SkPaint::kRound_Cap);
433
434 auto p0 = SkStrokePathEffect::Make(25, SkPaint::kRound_Join, SkPaint::kRound_Cap);
435 auto p1 = SkStrokePathEffect::Make(20, SkPaint::kRound_Join, SkPaint::kRound_Cap);
436 fPE[1] = SkMergePathEffect::Make(p0, p1, SkPathOp::kDifference_SkPathOp);
437
438 fPE[2] = SkMergePathEffect::Make(nullptr, p1, SkPathOp::kDifference_SkPathOp);
439 fPE[3] = SkMergePathEffect::Make(nullptr, p1, SkPathOp::kUnion_SkPathOp);
440 fPE[4] = SkMergePathEffect::Make(p0, nullptr, SkPathOp::kDifference_SkPathOp);
441 fPE[5] = SkMergePathEffect::Make(p0, nullptr, SkPathOp::kIntersect_SkPathOp);
442 }
443
444 protected:
name()445 SkString name() override { return SkString("ManyStrokes"); }
446
onAnimate(double nanos)447 bool onAnimate(double nanos) override { return true; }
448
dodraw(SkCanvas * canvas,sk_sp<SkPathEffect> pe,SkScalar x,SkScalar y,const SkPaint * ptr=nullptr)449 void dodraw(SkCanvas* canvas, sk_sp<SkPathEffect> pe, SkScalar x, SkScalar y,
450 const SkPaint* ptr = nullptr) {
451 SkPaint paint;
452 paint.setAntiAlias(true);
453 paint.setPathEffect(pe);
454 canvas->save();
455 canvas->translate(x, y);
456 canvas->drawPath(fPath, ptr ? *ptr : paint);
457
458 paint.setPathEffect(nullptr);
459 paint.setStyle(SkPaint::kStroke_Style);
460 paint.setColor(SK_ColorGREEN);
461 canvas->drawPath(fPath, paint);
462
463 canvas->restore();
464 }
465
onDrawContent(SkCanvas * canvas)466 void onDrawContent(SkCanvas* canvas) override {
467 SkPaint p;
468 p.setColor(0);
469 this->dodraw(canvas, nullptr, 0, 0, &p);
470
471 this->dodraw(canvas, fPE[0], 300, 0);
472 this->dodraw(canvas, fPE[1], 0, 300);
473 this->dodraw(canvas, fPE[2], 300, 300);
474 this->dodraw(canvas, fPE[3], 600, 300);
475 this->dodraw(canvas, fPE[4], 900, 0);
476 this->dodraw(canvas, fPE[5], 900, 300);
477
478 p.setColor(SK_ColorBLACK);
479 p.setStyle(SkPaint::kStrokeAndFill_Style);
480 p.setStrokeJoin(SkPaint::kRound_Join);
481 p.setStrokeCap(SkPaint::kRound_Cap);
482 p.setStrokeWidth(20);
483 this->dodraw(canvas, nullptr, 600, 0, &p);
484 }
485
onFindClickHandler(SkScalar x,SkScalar y,skui::ModifierKey modi)486 Click* onFindClickHandler(SkScalar x, SkScalar y, skui::ModifierKey modi) override {
487 Click* click = new Click();
488 fPath.reset();
489 fPath.moveTo(x, y);
490 return click;
491 }
492
onClick(Click * click)493 bool onClick(Click* click) override {
494 switch (click->fState) {
495 case skui::InputState::kMove:
496 fPath.lineTo(click->fCurr);
497 break;
498 default:
499 break;
500 }
501 return true;
502 }
503
504 private:
505 typedef Sample INHERITED;
506 };
507 } // namespace
508 DEF_SAMPLE( return new ManyStrokesView(); )
509
