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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 "gm.h"
9 #include "sk_tool_utils.h"
10 #include "SkGradientShader.h"
11 #include "SkLinearGradient.h"
12 
13 namespace skiagm {
14 
15 struct GradData {
16     int              fCount;
17     const SkColor*   fColors;
18     const SkColor4f* fColors4f;
19     const SkScalar*  fPos;
20 };
21 
22 constexpr SkColor gColors[] = {
23     SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorWHITE, SK_ColorBLACK
24 };
25 constexpr SkColor4f gColors4f[] ={
26     { 1.0f, 0.0f, 0.0f, 1.0f }, // Red
27     { 0.0f, 1.0f, 0.0f, 1.0f }, // Green
28     { 0.0f, 0.0f, 1.0f, 1.0f }, // Blue
29     { 1.0f, 1.0f, 1.0f, 1.0f }, // White
30     { 0.0f, 0.0f, 0.0f, 1.0f }  // Black
31 };
32 constexpr SkScalar gPos0[] = { 0, SK_Scalar1 };
33 constexpr SkScalar gPos1[] = { SK_Scalar1/4, SK_Scalar1*3/4 };
34 constexpr SkScalar gPos2[] = {
35     0, SK_Scalar1/8, SK_Scalar1/2, SK_Scalar1*7/8, SK_Scalar1
36 };
37 
38 constexpr SkScalar gPosClamp[]   = {0.0f, 0.0f, 1.0f, 1.0f};
39 constexpr SkColor  gColorClamp[] = {
40     SK_ColorRED, SK_ColorGREEN, SK_ColorGREEN, SK_ColorBLUE
41 };
42 constexpr SkColor4f gColor4fClamp[] ={
43     { 1.0f, 0.0f, 0.0f, 1.0f }, // Red
44     { 0.0f, 1.0f, 0.0f, 1.0f }, // Green
45     { 0.0f, 1.0f, 0.0f, 1.0f }, // Green
46     { 0.0f, 0.0f, 1.0f, 1.0f }  // Blue
47 };
48 constexpr GradData gGradData[] = {
49     { 2, gColors, gColors4f, nullptr },
50     { 2, gColors, gColors4f, gPos0 },
51     { 2, gColors, gColors4f, gPos1 },
52     { 5, gColors, gColors4f, nullptr },
53     { 5, gColors, gColors4f, gPos2 },
54     { 4, gColorClamp, gColor4fClamp, gPosClamp }
55 };
56 
MakeLinear(const SkPoint pts[2],const GradData & data,SkShader::TileMode tm,const SkMatrix & localMatrix)57 static sk_sp<SkShader> MakeLinear(const SkPoint pts[2], const GradData& data,
58                                   SkShader::TileMode tm, const SkMatrix& localMatrix) {
59     return SkGradientShader::MakeLinear(pts, data.fColors, data.fPos, data.fCount, tm, 0,
60                                         &localMatrix);
61 }
62 
MakeLinear4f(const SkPoint pts[2],const GradData & data,SkShader::TileMode tm,const SkMatrix & localMatrix)63 static sk_sp<SkShader> MakeLinear4f(const SkPoint pts[2], const GradData& data,
64                                     SkShader::TileMode tm, const SkMatrix& localMatrix) {
65     auto srgb = SkColorSpace::MakeSRGBLinear();
66     return SkGradientShader::MakeLinear(pts, data.fColors4f, srgb, data.fPos, data.fCount, tm, 0,
67                                         &localMatrix);
68 }
69 
MakeRadial(const SkPoint pts[2],const GradData & data,SkShader::TileMode tm,const SkMatrix & localMatrix)70 static sk_sp<SkShader> MakeRadial(const SkPoint pts[2], const GradData& data,
71                                   SkShader::TileMode tm, const SkMatrix& localMatrix) {
72     SkPoint center;
73     center.set(SkScalarAve(pts[0].fX, pts[1].fX),
74                SkScalarAve(pts[0].fY, pts[1].fY));
75     return SkGradientShader::MakeRadial(center, center.fX, data.fColors, data.fPos, data.fCount,
76                                         tm, 0, &localMatrix);
77 }
78 
MakeRadial4f(const SkPoint pts[2],const GradData & data,SkShader::TileMode tm,const SkMatrix & localMatrix)79 static sk_sp<SkShader> MakeRadial4f(const SkPoint pts[2], const GradData& data,
80                                     SkShader::TileMode tm, const SkMatrix& localMatrix) {
81     SkPoint center;
82     center.set(SkScalarAve(pts[0].fX, pts[1].fX),
83                SkScalarAve(pts[0].fY, pts[1].fY));
84     auto srgb = SkColorSpace::MakeSRGBLinear();
85     return SkGradientShader::MakeRadial(center, center.fX, data.fColors4f, srgb, data.fPos,
86                                         data.fCount, tm, 0, &localMatrix);
87 }
88 
MakeSweep(const SkPoint pts[2],const GradData & data,SkShader::TileMode,const SkMatrix & localMatrix)89 static sk_sp<SkShader> MakeSweep(const SkPoint pts[2], const GradData& data,
90                                  SkShader::TileMode, const SkMatrix& localMatrix) {
91     SkPoint center;
92     center.set(SkScalarAve(pts[0].fX, pts[1].fX),
93                SkScalarAve(pts[0].fY, pts[1].fY));
94     return SkGradientShader::MakeSweep(center.fX, center.fY, data.fColors, data.fPos, data.fCount,
95                                        0, &localMatrix);
96 }
97 
MakeSweep4f(const SkPoint pts[2],const GradData & data,SkShader::TileMode,const SkMatrix & localMatrix)98 static sk_sp<SkShader> MakeSweep4f(const SkPoint pts[2], const GradData& data,
99                                    SkShader::TileMode, const SkMatrix& localMatrix) {
100     SkPoint center;
101     center.set(SkScalarAve(pts[0].fX, pts[1].fX),
102                SkScalarAve(pts[0].fY, pts[1].fY));
103     auto srgb = SkColorSpace::MakeSRGBLinear();
104     return SkGradientShader::MakeSweep(center.fX, center.fY, data.fColors4f, srgb, data.fPos,
105                                        data.fCount, 0, &localMatrix);
106 }
107 
Make2Radial(const SkPoint pts[2],const GradData & data,SkShader::TileMode tm,const SkMatrix & localMatrix)108 static sk_sp<SkShader> Make2Radial(const SkPoint pts[2], const GradData& data,
109                                    SkShader::TileMode tm, const SkMatrix& localMatrix) {
110     SkPoint center0, center1;
111     center0.set(SkScalarAve(pts[0].fX, pts[1].fX),
112                 SkScalarAve(pts[0].fY, pts[1].fY));
113     center1.set(SkScalarInterp(pts[0].fX, pts[1].fX, SkIntToScalar(3)/5),
114                 SkScalarInterp(pts[0].fY, pts[1].fY, SkIntToScalar(1)/4));
115     return SkGradientShader::MakeTwoPointConical(center1, (pts[1].fX - pts[0].fX) / 7,
116                                                  center0, (pts[1].fX - pts[0].fX) / 2,
117                                                  data.fColors, data.fPos, data.fCount, tm,
118                                                  0, &localMatrix);
119 }
120 
Make2Radial4f(const SkPoint pts[2],const GradData & data,SkShader::TileMode tm,const SkMatrix & localMatrix)121 static sk_sp<SkShader> Make2Radial4f(const SkPoint pts[2], const GradData& data,
122                                      SkShader::TileMode tm, const SkMatrix& localMatrix) {
123     SkPoint center0, center1;
124     center0.set(SkScalarAve(pts[0].fX, pts[1].fX),
125                 SkScalarAve(pts[0].fY, pts[1].fY));
126     center1.set(SkScalarInterp(pts[0].fX, pts[1].fX, SkIntToScalar(3) / 5),
127                 SkScalarInterp(pts[0].fY, pts[1].fY, SkIntToScalar(1) / 4));
128     auto srgb = SkColorSpace::MakeSRGBLinear();
129     return SkGradientShader::MakeTwoPointConical(center1, (pts[1].fX - pts[0].fX) / 7,
130                                                  center0, (pts[1].fX - pts[0].fX) / 2,
131                                                  data.fColors4f, srgb, data.fPos, data.fCount, tm,
132                                                  0, &localMatrix);
133 }
134 
Make2Conical(const SkPoint pts[2],const GradData & data,SkShader::TileMode tm,const SkMatrix & localMatrix)135 static sk_sp<SkShader> Make2Conical(const SkPoint pts[2], const GradData& data,
136                                     SkShader::TileMode tm, const SkMatrix& localMatrix) {
137     SkPoint center0, center1;
138     SkScalar radius0 = (pts[1].fX - pts[0].fX) / 10;
139     SkScalar radius1 = (pts[1].fX - pts[0].fX) / 3;
140     center0.set(pts[0].fX + radius0, pts[0].fY + radius0);
141     center1.set(pts[1].fX - radius1, pts[1].fY - radius1);
142     return SkGradientShader::MakeTwoPointConical(center1, radius1, center0, radius0,
143                                                  data.fColors, data.fPos,
144                                                  data.fCount, tm, 0, &localMatrix);
145 }
146 
Make2Conical4f(const SkPoint pts[2],const GradData & data,SkShader::TileMode tm,const SkMatrix & localMatrix)147 static sk_sp<SkShader> Make2Conical4f(const SkPoint pts[2], const GradData& data,
148                                       SkShader::TileMode tm, const SkMatrix& localMatrix) {
149     SkPoint center0, center1;
150     SkScalar radius0 = (pts[1].fX - pts[0].fX) / 10;
151     SkScalar radius1 = (pts[1].fX - pts[0].fX) / 3;
152     center0.set(pts[0].fX + radius0, pts[0].fY + radius0);
153     center1.set(pts[1].fX - radius1, pts[1].fY - radius1);
154     auto srgb = SkColorSpace::MakeSRGBLinear();
155     return SkGradientShader::MakeTwoPointConical(center1, radius1, center0, radius0,
156                                                  data.fColors4f, srgb, data.fPos,
157                                                  data.fCount, tm, 0, &localMatrix);
158 }
159 
160 typedef sk_sp<SkShader> (*GradMaker)(const SkPoint pts[2], const GradData& data,
161                                      SkShader::TileMode tm, const SkMatrix& localMatrix);
162 constexpr GradMaker gGradMakers[] = {
163     MakeLinear, MakeRadial, MakeSweep, Make2Radial, Make2Conical
164 };
165 constexpr GradMaker gGradMakers4f[] ={
166     MakeLinear4f, MakeRadial4f, MakeSweep4f, Make2Radial4f, Make2Conical4f
167 };
168 
169 ///////////////////////////////////////////////////////////////////////////////
170 
171 class GradientsGM : public GM {
172 public:
GradientsGM(bool dither)173     GradientsGM(bool dither) : fDither(dither) {
174         this->setBGColor(sk_tool_utils::color_to_565(0xFFDDDDDD));
175     }
176 
177 protected:
178 
onShortName()179     SkString onShortName() {
180         return SkString(fDither ? "gradients" : "gradients_nodither");
181     }
182 
onISize()183     virtual SkISize onISize() { return SkISize::Make(840, 815); }
184 
onDraw(SkCanvas * canvas)185     virtual void onDraw(SkCanvas* canvas) {
186 
187         SkPoint pts[2] = {
188             { 0, 0 },
189             { SkIntToScalar(100), SkIntToScalar(100) }
190         };
191         SkShader::TileMode tm = SkShader::kClamp_TileMode;
192         SkRect r = { 0, 0, SkIntToScalar(100), SkIntToScalar(100) };
193         SkPaint paint;
194         paint.setAntiAlias(true);
195         paint.setDither(fDither);
196 
197         canvas->translate(SkIntToScalar(20), SkIntToScalar(20));
198         for (size_t i = 0; i < SK_ARRAY_COUNT(gGradData); i++) {
199             canvas->save();
200             for (size_t j = 0; j < SK_ARRAY_COUNT(gGradMakers); j++) {
201                 SkMatrix scale = SkMatrix::I();
202 
203                 if (i == 5) { // if the clamp case
204                     scale.setScale(0.5f, 0.5f);
205                     scale.postTranslate(25.f, 25.f);
206                 }
207 
208                 paint.setShader(gGradMakers[j](pts, gGradData[i], tm, scale));
209                 canvas->drawRect(r, paint);
210                 canvas->translate(0, SkIntToScalar(120));
211             }
212             canvas->restore();
213             canvas->translate(SkIntToScalar(120), 0);
214         }
215     }
216 
217 protected:
218     bool fDither;
219 
220 private:
221     typedef GM INHERITED;
222 };
223 DEF_GM( return new GradientsGM(true); )
224 DEF_GM( return new GradientsGM(false); )
225 
226 // Like the original gradients GM, but using the SkColor4f shader factories. Should be identical.
227 class Gradients4fGM : public GM {
228 public:
Gradients4fGM(bool dither)229     Gradients4fGM(bool dither) : fDither(dither) {
230         this->setBGColor(sk_tool_utils::color_to_565(0xFFDDDDDD));
231     }
232 
233 protected:
234 
onShortName()235     SkString onShortName() {
236         return SkString(fDither ? "gradients4f" : "gradients4f_nodither");
237     }
238 
onISize()239     virtual SkISize onISize() { return SkISize::Make(840, 815); }
240 
onDraw(SkCanvas * canvas)241     virtual void onDraw(SkCanvas* canvas) {
242 
243         SkPoint pts[2] ={
244             { 0, 0 },
245             { SkIntToScalar(100), SkIntToScalar(100) }
246         };
247         SkShader::TileMode tm = SkShader::kClamp_TileMode;
248         SkRect r ={ 0, 0, SkIntToScalar(100), SkIntToScalar(100) };
249         SkPaint paint;
250         paint.setAntiAlias(true);
251         paint.setDither(fDither);
252 
253         canvas->translate(SkIntToScalar(20), SkIntToScalar(20));
254         for (size_t i = 0; i < SK_ARRAY_COUNT(gGradData); i++) {
255             canvas->save();
256             for (size_t j = 0; j < SK_ARRAY_COUNT(gGradMakers4f); j++) {
257                 SkMatrix scale = SkMatrix::I();
258 
259                 if (i == 5) { // if the clamp case
260                     scale.setScale(0.5f, 0.5f);
261                     scale.postTranslate(25.f, 25.f);
262                 }
263 
264                 paint.setShader(gGradMakers4f[j](pts, gGradData[i], tm, scale));
265                 canvas->drawRect(r, paint);
266                 canvas->translate(0, SkIntToScalar(120));
267             }
268             canvas->restore();
269             canvas->translate(SkIntToScalar(120), 0);
270         }
271     }
272 
273 protected:
274     bool fDither;
275 
276 private:
277     typedef GM INHERITED;
278 };
279 DEF_GM(return new Gradients4fGM(true); )
280 DEF_GM(return new Gradients4fGM(false); )
281 
282 // Based on the original gradient slide, but with perspective applied to the
283 // gradient shaders' local matrices
284 class GradientsLocalPerspectiveGM : public GM {
285 public:
GradientsLocalPerspectiveGM(bool dither)286     GradientsLocalPerspectiveGM(bool dither) : fDither(dither) {
287         this->setBGColor(sk_tool_utils::color_to_565(0xFFDDDDDD));
288     }
289 
290 protected:
291 
onShortName()292     SkString onShortName() {
293         return SkString(fDither ? "gradients_local_perspective" :
294                                   "gradients_local_perspective_nodither");
295     }
296 
onISize()297     virtual SkISize onISize() { return SkISize::Make(840, 815); }
298 
onDraw(SkCanvas * canvas)299     virtual void onDraw(SkCanvas* canvas) {
300 
301         SkPoint pts[2] = {
302             { 0, 0 },
303             { SkIntToScalar(100), SkIntToScalar(100) }
304         };
305         SkShader::TileMode tm = SkShader::kClamp_TileMode;
306         SkRect r = { 0, 0, SkIntToScalar(100), SkIntToScalar(100) };
307         SkPaint paint;
308         paint.setAntiAlias(true);
309         paint.setDither(fDither);
310 
311         canvas->translate(SkIntToScalar(20), SkIntToScalar(20));
312         for (size_t i = 0; i < SK_ARRAY_COUNT(gGradData); i++) {
313             canvas->save();
314             for (size_t j = 0; j < SK_ARRAY_COUNT(gGradMakers); j++) {
315                 // apply an increasing y perspective as we move to the right
316                 SkMatrix perspective;
317                 perspective.setIdentity();
318                 perspective.setPerspY(SkIntToScalar(i+1) / 500);
319                 perspective.setSkewX(SkIntToScalar(i+1) / 10);
320 
321                 paint.setShader(gGradMakers[j](pts, gGradData[i], tm, perspective));
322                 canvas->drawRect(r, paint);
323                 canvas->translate(0, SkIntToScalar(120));
324             }
325             canvas->restore();
326             canvas->translate(SkIntToScalar(120), 0);
327         }
328     }
329 
330 private:
331     bool fDither;
332 
333     typedef GM INHERITED;
334 };
335 DEF_GM( return new GradientsLocalPerspectiveGM(true); )
336 DEF_GM( return new GradientsLocalPerspectiveGM(false); )
337 
338 // Based on the original gradient slide, but with perspective applied to
339 // the view matrix
340 class GradientsViewPerspectiveGM : public GradientsGM {
341 public:
GradientsViewPerspectiveGM(bool dither)342     GradientsViewPerspectiveGM(bool dither) : INHERITED(dither) { }
343 
344 protected:
onShortName()345     SkString onShortName() {
346         return SkString(fDither ? "gradients_view_perspective" :
347                                   "gradients_view_perspective_nodither");
348     }
349 
onISize()350     virtual SkISize onISize() { return SkISize::Make(840, 500); }
351 
onDraw(SkCanvas * canvas)352     virtual void onDraw(SkCanvas* canvas) {
353         SkMatrix perspective;
354         perspective.setIdentity();
355         perspective.setPerspY(0.001f);
356         perspective.setSkewX(SkIntToScalar(8) / 25);
357         canvas->concat(perspective);
358         INHERITED::onDraw(canvas);
359     }
360 
361 private:
362     typedef GradientsGM INHERITED;
363 };
364 DEF_GM( return new GradientsViewPerspectiveGM(true); )
365 DEF_GM( return new GradientsViewPerspectiveGM(false); )
366 
367 /*
368  Inspired by this <canvas> javascript, where we need to detect that we are not
369  solving a quadratic equation, but must instead solve a linear (since our X^2
370  coefficient is 0)
371 
372  ctx.fillStyle = '#f00';
373  ctx.fillRect(0, 0, 100, 50);
374 
375  var g = ctx.createRadialGradient(-80, 25, 70, 0, 25, 150);
376  g.addColorStop(0, '#f00');
377  g.addColorStop(0.01, '#0f0');
378  g.addColorStop(0.99, '#0f0');
379  g.addColorStop(1, '#f00');
380  ctx.fillStyle = g;
381  ctx.fillRect(0, 0, 100, 50);
382  */
383 class GradientsDegenrate2PointGM : public GM {
384 public:
GradientsDegenrate2PointGM(bool dither)385     GradientsDegenrate2PointGM(bool dither) : fDither(dither) {}
386 
387 protected:
onShortName()388     SkString onShortName() {
389         return SkString(fDither ? "gradients_degenerate_2pt" : "gradients_degenerate_2pt_nodither");
390     }
391 
onISize()392     virtual SkISize onISize() { return SkISize::Make(320, 320); }
393 
drawBG(SkCanvas * canvas)394     void drawBG(SkCanvas* canvas) {
395         canvas->drawColor(SK_ColorBLUE);
396     }
397 
onDraw(SkCanvas * canvas)398     virtual void onDraw(SkCanvas* canvas) {
399         this->drawBG(canvas);
400 
401         SkColor colors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorGREEN, SK_ColorRED };
402         SkScalar pos[] = { 0, 0.01f, 0.99f, SK_Scalar1 };
403         SkPoint c0;
404         c0.iset(-80, 25);
405         SkScalar r0 = SkIntToScalar(70);
406         SkPoint c1;
407         c1.iset(0, 25);
408         SkScalar r1 = SkIntToScalar(150);
409         SkPaint paint;
410         paint.setShader(SkGradientShader::MakeTwoPointConical(c0, r0, c1, r1, colors,
411                                                               pos, SK_ARRAY_COUNT(pos),
412                                                               SkShader::kClamp_TileMode));
413         paint.setDither(fDither);
414         canvas->drawPaint(paint);
415     }
416 
417 private:
418     bool fDither;
419 
420     typedef GM INHERITED;
421 };
422 DEF_GM( return new GradientsDegenrate2PointGM(true); )
DEF_GM(return new GradientsDegenrate2PointGM (false);)423 DEF_GM( return new GradientsDegenrate2PointGM(false); )
424 
425 /* bug.skia.org/517
426 <canvas id="canvas"></canvas>
427 <script>
428 var c = document.getElementById("canvas");
429 var ctx = c.getContext("2d");
430 ctx.fillStyle = '#ff0';
431 ctx.fillRect(0, 0, 100, 50);
432 
433 var g = ctx.createRadialGradient(200, 25, 20, 200, 25, 10);
434 g.addColorStop(0, '#0f0');
435 g.addColorStop(0.003, '#f00');  // 0.004 makes this work
436 g.addColorStop(1, '#ff0');
437 ctx.fillStyle = g;
438 ctx.fillRect(0, 0, 100, 50);
439 </script>
440 */
441 
442 // should draw only green
443 DEF_SIMPLE_GM(small_color_stop, canvas, 100, 150) {
444     SkColor colors[] = { SK_ColorGREEN, SK_ColorRED, SK_ColorYELLOW };
445     SkScalar pos[] = { 0, 0.003f, SK_Scalar1 };  // 0.004f makes this work
446     SkPoint c0 = { 200, 25 };
447     SkScalar r0 = 20;
448     SkPoint c1 = { 200, 25 };
449     SkScalar r1 = 10;
450 
451     SkPaint paint;
452     paint.setColor(SK_ColorYELLOW);
453     canvas->drawRect(SkRect::MakeWH(100, 150), paint);
454     paint.setShader(SkGradientShader::MakeTwoPointConical(c0, r0, c1, r1, colors, pos,
455                                                           SK_ARRAY_COUNT(pos),
456                                                           SkShader::kClamp_TileMode));
457     canvas->drawRect(SkRect::MakeWH(100, 150), paint);
458 }
459 
460 
461 /// Tests correctness of *optimized* codepaths in gradients.
462 
463 class ClampedGradientsGM : public GM {
464 public:
ClampedGradientsGM(bool dither)465     ClampedGradientsGM(bool dither) : fDither(dither) {}
466 
467 protected:
onShortName()468     SkString onShortName() {
469         return SkString(fDither ? "clamped_gradients" : "clamped_gradients_nodither");
470     }
471 
onISize()472     virtual SkISize onISize() { return SkISize::Make(640, 510); }
473 
drawBG(SkCanvas * canvas)474     void drawBG(SkCanvas* canvas) {
475         canvas->drawColor(sk_tool_utils::color_to_565(0xFFDDDDDD));
476     }
477 
onDraw(SkCanvas * canvas)478     virtual void onDraw(SkCanvas* canvas) {
479         this->drawBG(canvas);
480 
481         SkRect r = { 0, 0, SkIntToScalar(100), SkIntToScalar(300) };
482         SkPaint paint;
483         paint.setDither(fDither);
484         paint.setAntiAlias(true);
485 
486         SkPoint center;
487         center.iset(0, 300);
488         canvas->translate(SkIntToScalar(20), SkIntToScalar(20));
489         paint.setShader(SkGradientShader::MakeRadial(
490             SkPoint(center),
491             SkIntToScalar(200), gColors, nullptr, 5,
492             SkShader::kClamp_TileMode));
493         canvas->drawRect(r, paint);
494     }
495 
496 private:
497     bool fDither;
498 
499     typedef GM INHERITED;
500 };
501 DEF_GM( return new ClampedGradientsGM(true); )
502 DEF_GM( return new ClampedGradientsGM(false); )
503 
504 /// Checks quality of large radial gradients, which may display
505 /// some banding.
506 
507 class RadialGradientGM : public GM {
508 public:
RadialGradientGM()509     RadialGradientGM() {}
510 
511 protected:
512 
onShortName()513     SkString onShortName() override { return SkString("radial_gradient"); }
onISize()514     SkISize onISize() override { return SkISize::Make(1280, 1280); }
drawBG(SkCanvas * canvas)515     void drawBG(SkCanvas* canvas) {
516         canvas->drawColor(0xFF000000);
517     }
onDraw(SkCanvas * canvas)518     void onDraw(SkCanvas* canvas) override {
519         const SkISize dim = this->getISize();
520 
521         this->drawBG(canvas);
522 
523         SkPaint paint;
524         paint.setDither(true);
525         SkPoint center;
526         center.set(SkIntToScalar(dim.width())/2, SkIntToScalar(dim.height())/2);
527         SkScalar radius = SkIntToScalar(dim.width())/2;
528         const SkColor colors[] = { 0x7f7f7f7f, 0x7f7f7f7f, 0xb2000000 };
529         const SkScalar pos[] = { 0.0f,
530                              0.35f,
531                              1.0f };
532         paint.setShader(SkGradientShader::MakeRadial(center, radius, colors, pos,
533                                                      SK_ARRAY_COUNT(pos),
534                                                      SkShader::kClamp_TileMode));
535         SkRect r = {
536             0, 0, SkIntToScalar(dim.width()), SkIntToScalar(dim.height())
537         };
538         canvas->drawRect(r, paint);
539     }
540 private:
541     typedef GM INHERITED;
542 };
543 DEF_GM( return new RadialGradientGM; )
544 
545 class RadialGradient2GM : public GM {
546 public:
RadialGradient2GM(bool dither)547     RadialGradient2GM(bool dither) : fDither(dither) {}
548 
549 protected:
550 
onShortName()551     SkString onShortName() override {
552         return SkString(fDither ? "radial_gradient2" : "radial_gradient2_nodither");
553     }
554 
onISize()555     SkISize onISize() override { return SkISize::Make(800, 400); }
drawBG(SkCanvas * canvas)556     void drawBG(SkCanvas* canvas) {
557         canvas->drawColor(0xFF000000);
558     }
559 
560     // Reproduces the example given in bug 7671058.
onDraw(SkCanvas * canvas)561     void onDraw(SkCanvas* canvas) override {
562         SkPaint paint1, paint2, paint3;
563         paint1.setStyle(SkPaint::kFill_Style);
564         paint2.setStyle(SkPaint::kFill_Style);
565         paint3.setStyle(SkPaint::kFill_Style);
566 
567         const SkColor sweep_colors[] =
568             { 0xFFFF0000, 0xFFFFFF00, 0xFF00FF00, 0xFF00FFFF, 0xFF0000FF, 0xFFFF00FF, 0xFFFF0000 };
569         const SkColor colors1[] = { 0xFFFFFFFF, 0x00000000 };
570         const SkColor colors2[] = { 0xFF000000, 0x00000000 };
571 
572         const SkScalar cx = 200, cy = 200, radius = 150;
573         SkPoint center;
574         center.set(cx, cy);
575 
576         // We can either interpolate endpoints and premultiply each point (default, more precision),
577         // or premultiply the endpoints first, avoiding the need to premultiply each point (cheap).
578         const uint32_t flags[] = { 0, SkGradientShader::kInterpolateColorsInPremul_Flag };
579 
580         for (size_t i = 0; i < SK_ARRAY_COUNT(flags); i++) {
581             paint1.setShader(SkGradientShader::MakeSweep(cx, cy, sweep_colors,
582                                                          nullptr, SK_ARRAY_COUNT(sweep_colors),
583                                                          flags[i], nullptr));
584             paint2.setShader(SkGradientShader::MakeRadial(center, radius, colors1,
585                                                           nullptr, SK_ARRAY_COUNT(colors1),
586                                                           SkShader::kClamp_TileMode,
587                                                           flags[i], nullptr));
588             paint3.setShader(SkGradientShader::MakeRadial(center, radius, colors2,
589                                                           nullptr, SK_ARRAY_COUNT(colors2),
590                                                           SkShader::kClamp_TileMode,
591                                                           flags[i], nullptr));
592             paint1.setDither(fDither);
593             paint2.setDither(fDither);
594             paint3.setDither(fDither);
595 
596             canvas->drawCircle(cx, cy, radius, paint1);
597             canvas->drawCircle(cx, cy, radius, paint3);
598             canvas->drawCircle(cx, cy, radius, paint2);
599 
600             canvas->translate(400, 0);
601         }
602     }
603 
604 private:
605     bool fDither;
606 
607     typedef GM INHERITED;
608 };
609 DEF_GM( return new RadialGradient2GM(true); )
610 DEF_GM( return new RadialGradient2GM(false); )
611 
612 // Shallow radial (shows banding on raster)
613 class RadialGradient3GM : public GM {
614 public:
RadialGradient3GM(bool dither)615     RadialGradient3GM(bool dither) : fDither(dither) { }
616 
617 protected:
onShortName()618     SkString onShortName() override {
619         return SkString(fDither ? "radial_gradient3" : "radial_gradient3_nodither");
620     }
621 
onISize()622     SkISize onISize() override { return SkISize::Make(500, 500); }
623 
runAsBench() const624     bool runAsBench() const override { return true; }
625 
onOnceBeforeDraw()626     void onOnceBeforeDraw() override {
627         const SkPoint center = { 0, 0 };
628         const SkScalar kRadius = 3000;
629         const SkColor gColors[] = { 0xFFFFFFFF, 0xFF000000 };
630         fShader = SkGradientShader::MakeRadial(center, kRadius, gColors, nullptr, 2,
631                                                SkShader::kClamp_TileMode);
632     }
633 
onDraw(SkCanvas * canvas)634     void onDraw(SkCanvas* canvas) override {
635         SkPaint paint;
636         paint.setShader(fShader);
637         paint.setDither(fDither);
638         canvas->drawRect(SkRect::MakeWH(500, 500), paint);
639     }
640 
641 private:
642     sk_sp<SkShader> fShader;
643     bool fDither;
644 
645     typedef GM INHERITED;
646 };
647 DEF_GM( return new RadialGradient3GM(true); )
648 DEF_GM( return new RadialGradient3GM(false); )
649 
650 class RadialGradient4GM : public GM {
651 public:
RadialGradient4GM(bool dither)652     RadialGradient4GM(bool dither) : fDither(dither) { }
653 
654 protected:
onShortName()655     SkString onShortName() override {
656         return SkString(fDither ? "radial_gradient4" : "radial_gradient4_nodither");
657     }
658 
onISize()659     SkISize onISize() override { return SkISize::Make(500, 500); }
660 
onOnceBeforeDraw()661     void onOnceBeforeDraw() override {
662         const SkPoint center = { 250, 250 };
663         const SkScalar kRadius = 250;
664         const SkColor colors[] = { SK_ColorRED, SK_ColorRED, SK_ColorWHITE, SK_ColorWHITE,
665                 SK_ColorRED };
666         const SkScalar pos[] = { 0, .4f, .4f, .8f, .8f, 1 };
667         fShader = SkGradientShader::MakeRadial(center, kRadius, colors, pos,
668                                                SK_ARRAY_COUNT(gColors), SkShader::kClamp_TileMode);
669     }
670 
onDraw(SkCanvas * canvas)671     void onDraw(SkCanvas* canvas) override {
672         SkPaint paint;
673         paint.setAntiAlias(true);
674         paint.setDither(fDither);
675         paint.setShader(fShader);
676         canvas->drawRect(SkRect::MakeWH(500, 500), paint);
677     }
678 
679 private:
680     sk_sp<SkShader> fShader;
681     bool fDither;
682 
683     typedef GM INHERITED;
684 };
685 DEF_GM( return new RadialGradient4GM(true); )
686 DEF_GM( return new RadialGradient4GM(false); )
687 
688 class LinearGradientGM : public GM {
689 public:
LinearGradientGM(bool dither)690     LinearGradientGM(bool dither) : fDither(dither) { }
691 
692 protected:
onShortName()693     SkString onShortName() override {
694         return SkString(fDither ? "linear_gradient" : "linear_gradient_nodither");
695     }
696 
697     const SkScalar kWidthBump = 30.f;
698     const SkScalar kHeight = 5.f;
699     const SkScalar kMinWidth = 540.f;
700 
onISize()701     SkISize onISize() override { return SkISize::Make(500, 500); }
702 
onOnceBeforeDraw()703     void onOnceBeforeDraw() override {
704         SkPoint pts[2] = { {0, 0}, {0, 0} };
705         const SkColor colors[] = { SK_ColorWHITE, SK_ColorWHITE, 0xFF008200, 0xFF008200,
706                 SK_ColorWHITE, SK_ColorWHITE };
707         const SkScalar unitPos[] = { 0, 50, 70, 500, 540 };
708         SkScalar pos[6];
709         pos[5] = 1;
710         for (int index = 0; index < (int) SK_ARRAY_COUNT(fShader); ++index) {
711             pts[1].fX = 500.f + index * kWidthBump;
712             for (int inner = 0; inner < (int) SK_ARRAY_COUNT(unitPos); ++inner) {
713                 pos[inner] = unitPos[inner] / (kMinWidth + index * kWidthBump);
714             }
715             fShader[index] = SkGradientShader::MakeLinear(pts, colors, pos,
716                     SK_ARRAY_COUNT(gColors), SkShader::kClamp_TileMode);
717         }
718     }
719 
onDraw(SkCanvas * canvas)720     void onDraw(SkCanvas* canvas) override {
721         SkPaint paint;
722         paint.setAntiAlias(true);
723         paint.setDither(fDither);
724         for (int index = 0; index < (int) SK_ARRAY_COUNT(fShader); ++index) {
725             paint.setShader(fShader[index]);
726             canvas->drawRect(SkRect::MakeLTRB(0, index * kHeight, kMinWidth + index * kWidthBump,
727                     (index + 1) * kHeight), paint);
728         }
729     }
730 
731 private:
732     sk_sp<SkShader> fShader[100];
733     bool fDither;
734 
735     typedef GM INHERITED;
736 };
737 DEF_GM( return new LinearGradientGM(true); )
738 DEF_GM( return new LinearGradientGM(false); )
739 
740 class LinearGradientTinyGM : public GM {
741 public:
LinearGradientTinyGM(uint32_t flags,const char * suffix=nullptr)742     LinearGradientTinyGM(uint32_t flags, const char* suffix = nullptr)
743     : fName("linear_gradient_tiny")
744     , fFlags(flags) {
745         fName.append(suffix);
746     }
747 
748 protected:
onShortName()749     SkString onShortName() override {
750         return fName;
751     }
752 
onISize()753     SkISize onISize() override {
754         return SkISize::Make(600, 500);
755     }
756 
onDraw(SkCanvas * canvas)757     void onDraw(SkCanvas* canvas) override {
758         const SkScalar kRectSize = 100;
759         const unsigned kStopCount = 3;
760         const SkColor colors[kStopCount] = { SK_ColorGREEN, SK_ColorRED, SK_ColorGREEN };
761         const struct {
762             SkPoint pts[2];
763             SkScalar pos[kStopCount];
764         } configs[] = {
765             { { SkPoint::Make(0, 0),        SkPoint::Make(10, 0) },       { 0, 0.999999f,    1 }},
766             { { SkPoint::Make(0, 0),        SkPoint::Make(10, 0) },       { 0, 0.000001f,    1 }},
767             { { SkPoint::Make(0, 0),        SkPoint::Make(10, 0) },       { 0, 0.999999999f, 1 }},
768             { { SkPoint::Make(0, 0),        SkPoint::Make(10, 0) },       { 0, 0.000000001f, 1 }},
769 
770             { { SkPoint::Make(0, 0),        SkPoint::Make(0, 10) },       { 0, 0.999999f,    1 }},
771             { { SkPoint::Make(0, 0),        SkPoint::Make(0, 10) },       { 0, 0.000001f,    1 }},
772             { { SkPoint::Make(0, 0),        SkPoint::Make(0, 10) },       { 0, 0.999999999f, 1 }},
773             { { SkPoint::Make(0, 0),        SkPoint::Make(0, 10) },       { 0, 0.000000001f, 1 }},
774 
775             { { SkPoint::Make(0, 0),        SkPoint::Make(0.00001f, 0) }, { 0, 0.5f, 1 }},
776             { { SkPoint::Make(9.99999f, 0), SkPoint::Make(10, 0) },       { 0, 0.5f, 1 }},
777             { { SkPoint::Make(0, 0),        SkPoint::Make(0, 0.00001f) }, { 0, 0.5f, 1 }},
778             { { SkPoint::Make(0, 9.99999f), SkPoint::Make(0, 10) },       { 0, 0.5f, 1 }},
779         };
780 
781         SkPaint paint;
782         for (unsigned i = 0; i < SK_ARRAY_COUNT(configs); ++i) {
783             SkAutoCanvasRestore acr(canvas, true);
784             paint.setShader(SkGradientShader::MakeLinear(configs[i].pts, colors, configs[i].pos,
785                                                          kStopCount, SkShader::kClamp_TileMode,
786                                                          fFlags, nullptr));
787             canvas->translate(kRectSize * ((i % 4) * 1.5f + 0.25f),
788                               kRectSize * ((i / 4) * 1.5f + 0.25f));
789 
790             canvas->drawRect(SkRect::MakeWH(kRectSize, kRectSize), paint);
791         }
792     }
793 
794 private:
795     typedef GM INHERITED;
796 
797     SkString fName;
798     uint32_t fFlags;
799 };
800 DEF_GM( return new LinearGradientTinyGM(0); )
801 DEF_GM( return new LinearGradientTinyGM(SkLinearGradient::kForce4fContext_PrivateFlag, "_4f"); )
802 }
803 
804 ///////////////////////////////////////////////////////////////////////////////////////////////////
805 
806 struct GradRun {
807     SkColor  fColors[4];
808     SkScalar fPos[4];
809     int      fCount;
810 };
811 
812 #define SIZE 121
813 
make_linear(const GradRun & run,SkShader::TileMode mode)814 static sk_sp<SkShader> make_linear(const GradRun& run, SkShader::TileMode mode) {
815     const SkPoint pts[] { { 30, 30 }, { SIZE - 30, SIZE - 30 } };
816     return SkGradientShader::MakeLinear(pts, run.fColors, run.fPos, run.fCount, mode);
817 }
818 
make_radial(const GradRun & run,SkShader::TileMode mode)819 static sk_sp<SkShader> make_radial(const GradRun& run, SkShader::TileMode mode) {
820     const SkScalar half = SIZE * 0.5f;
821     return SkGradientShader::MakeRadial({half,half}, half - 10, run.fColors, run.fPos,
822                                         run.fCount, mode);
823 }
824 
make_conical(const GradRun & run,SkShader::TileMode mode)825 static sk_sp<SkShader> make_conical(const GradRun& run, SkShader::TileMode mode) {
826     const SkScalar half = SIZE * 0.5f;
827     const SkPoint center { half, half };
828     return SkGradientShader::MakeTwoPointConical(center, 20, center, half - 10,
829                                                  run.fColors, run.fPos, run.fCount, mode);
830 }
831 
make_sweep(const GradRun & run,SkShader::TileMode)832 static sk_sp<SkShader> make_sweep(const GradRun& run, SkShader::TileMode) {
833     const SkScalar half = SIZE * 0.5f;
834     return SkGradientShader::MakeSweep(half, half, run.fColors, run.fPos, run.fCount);
835 }
836 
837 /*
838  *  Exercise duplicate color-stops, at the ends, and in the middle
839  *
840  *  At the time of this writing, only Linear correctly deals with duplicates at the ends,
841  *  and then only correctly on CPU backend.
842  */
843 DEF_SIMPLE_GM(gradients_dup_color_stops, canvas, 704, 564) {
844     const SkColor preColor  = 0xFFFF0000;   // clamp color before start
845     const SkColor postColor = 0xFF0000FF;   // clamp color after end
846     const SkColor color0    = 0xFF000000;
847     const SkColor color1    = 0xFF00FF00;
848     const SkColor badColor  = 0xFF3388BB;   // should never be seen, fills out fixed-size array
849 
850     const GradRun runs[] = {
851         {   { color0, color1, badColor, badColor },
852             { 0, 1, -1, -1 },
853             2,
854         },
855         {   { preColor, color0, color1, badColor },
856             { 0, 0, 1, -1 },
857             3,
858         },
859         {   { color0, color1, postColor, badColor },
860             { 0, 1, 1, -1 },
861             3,
862         },
863         {   { preColor, color0, color1, postColor },
864             { 0, 0, 1, 1 },
865             4,
866         },
867         {   { color0, color0, color1, color1 },
868             { 0, 0.5f, 0.5f, 1 },
869             4,
870         },
871     };
872     sk_sp<SkShader> (*factories[])(const GradRun&, SkShader::TileMode) {
873         make_linear, make_radial, make_conical, make_sweep
874     };
875 
876     const SkRect rect = SkRect::MakeWH(SIZE, SIZE);
877     const SkScalar dx = SIZE + 20;
878     const SkScalar dy = SIZE + 20;
879     const SkShader::TileMode mode = SkShader::kClamp_TileMode;
880 
881     SkPaint paint;
882     canvas->translate(10, 10 - dy);
883     for (auto factory : factories) {
884         canvas->translate(0, dy);
885         SkAutoCanvasRestore acr(canvas, true);
886         for (const auto& run : runs) {
887             paint.setShader(factory(run, mode));
888             canvas->drawRect(rect, paint);
889             canvas->translate(dx, 0);
890         }
891     }
892 }
893 
draw_many_stops(SkCanvas * canvas,uint32_t flags)894 static void draw_many_stops(SkCanvas* canvas, uint32_t flags) {
895     const unsigned kStopCount = 200;
896     const SkPoint pts[] = { {50, 50}, {450, 465}};
897 
898     SkColor colors[kStopCount];
899     for (unsigned i = 0; i < kStopCount; i++) {
900         switch (i % 5) {
901         case 0: colors[i] = SK_ColorRED; break;
902         case 1: colors[i] = SK_ColorGREEN; break;
903         case 2: colors[i] = SK_ColorGREEN; break;
904         case 3: colors[i] = SK_ColorBLUE; break;
905         case 4: colors[i] = SK_ColorRED; break;
906         }
907     }
908 
909     SkPaint p;
910     p.setShader(SkGradientShader::MakeLinear(
911         pts, colors, nullptr, SK_ARRAY_COUNT(colors), SkShader::kClamp_TileMode, flags, nullptr));
912 
913     canvas->drawRect(SkRect::MakeXYWH(0, 0, 500, 500), p);
914 }
915 
916 DEF_SIMPLE_GM(gradient_many_stops, canvas, 500, 500) {
917     draw_many_stops(canvas, 0);
918 }
919 
920 DEF_SIMPLE_GM(gradient_many_stops_4f, canvas, 500, 500) {
921     draw_many_stops(canvas, SkLinearGradient::kForce4fContext_PrivateFlag);
922 }
923 
draw_subpixel_gradient(SkCanvas * canvas,uint32_t flags)924 static void draw_subpixel_gradient(SkCanvas* canvas, uint32_t flags) {
925     const SkPoint pts[] = { {50, 50}, {50.1f, 50.1f}};
926     SkColor colors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE };
927     SkPaint p;
928     p.setShader(SkGradientShader::MakeLinear(
929         pts, colors, nullptr, SK_ARRAY_COUNT(colors), SkShader::kRepeat_TileMode, flags, nullptr));
930     canvas->drawRect(SkRect::MakeXYWH(0, 0, 500, 500), p);
931 }
932 
933 DEF_SIMPLE_GM(gradient_subpixel, canvas, 500, 500) {
934     draw_subpixel_gradient(canvas, 0);
935 }
936 
937 DEF_SIMPLE_GM(gradient_subpixel_4f, canvas, 500, 500) {
938     draw_subpixel_gradient(canvas, SkLinearGradient::kForce4fContext_PrivateFlag);
939 }
940