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 "gm/gm.h"
9 #include "include/core/SkCanvas.h"
10 #include "include/core/SkColor.h"
11 #include "include/core/SkMatrix.h"
12 #include "include/core/SkPaint.h"
13 #include "include/core/SkPath.h"
14 #include "include/core/SkPoint.h"
15 #include "include/core/SkPoint3.h"
16 #include "include/core/SkRRect.h"
17 #include "include/core/SkRect.h"
18 #include "include/core/SkScalar.h"
19 #include "include/core/SkTypes.h"
20 #include "include/private/SkShadowFlags.h"
21 #include "include/private/SkTArray.h"
22 #include "include/private/SkTDArray.h"
23 #include "include/utils/SkShadowUtils.h"
24
25 #include <initializer_list>
26
draw_shadow(SkCanvas * canvas,const SkPath & path,SkScalar height,SkColor color,SkPoint3 lightPos,SkScalar lightR,bool isAmbient,uint32_t flags)27 void draw_shadow(SkCanvas* canvas, const SkPath& path, SkScalar height, SkColor color,
28 SkPoint3 lightPos, SkScalar lightR, bool isAmbient, uint32_t flags) {
29 SkScalar ambientAlpha = isAmbient ? .5f : 0.f;
30 SkScalar spotAlpha = isAmbient ? 0.f : .5f;
31 SkColor ambientColor = SkColorSetARGB(ambientAlpha*SkColorGetA(color), SkColorGetR(color),
32 SkColorGetG(color), SkColorGetB(color));
33 SkColor spotColor = SkColorSetARGB(spotAlpha*SkColorGetA(color), SkColorGetR(color),
34 SkColorGetG(color), SkColorGetB(color));
35 SkShadowUtils::DrawShadow(canvas, path, SkPoint3{ 0, 0, height}, lightPos, lightR,
36 ambientColor, spotColor, flags);
37 }
38
39 static constexpr int kW = 800;
40 static constexpr int kH = 960;
41
42 enum ShadowMode {
43 kDebugColorNoOccluders,
44 kDebugColorOccluders,
45 kGrayscale
46 };
47
draw_paths(SkCanvas * canvas,ShadowMode mode)48 void draw_paths(SkCanvas* canvas, ShadowMode mode) {
49 SkTArray<SkPath> paths;
50 paths.push_back().addRoundRect(SkRect::MakeWH(50, 50), 10, 10);
51 SkRRect oddRRect;
52 oddRRect.setNinePatch(SkRect::MakeWH(50, 50), 9, 13, 6, 16);
53 paths.push_back().addRRect(oddRRect);
54 paths.push_back().addRect(SkRect::MakeWH(50, 50));
55 paths.push_back().addCircle(25, 25, 25);
56 paths.push_back().cubicTo(100, 50, 20, 100, 0, 0);
57 paths.push_back().addOval(SkRect::MakeWH(20, 60));
58
59 // star
60 SkTArray<SkPath> concavePaths;
61 concavePaths.push_back().moveTo(0.0f, -33.3333f);
62 concavePaths.back().lineTo(9.62f, -16.6667f);
63 concavePaths.back().lineTo(28.867f, -16.6667f);
64 concavePaths.back().lineTo(19.24f, 0.0f);
65 concavePaths.back().lineTo(28.867f, 16.6667f);
66 concavePaths.back().lineTo(9.62f, 16.6667f);
67 concavePaths.back().lineTo(0.0f, 33.3333f);
68 concavePaths.back().lineTo(-9.62f, 16.6667f);
69 concavePaths.back().lineTo(-28.867f, 16.6667f);
70 concavePaths.back().lineTo(-19.24f, 0.0f);
71 concavePaths.back().lineTo(-28.867f, -16.6667f);
72 concavePaths.back().lineTo(-9.62f, -16.6667f);
73 concavePaths.back().close();
74
75 // dumbbell
76 concavePaths.push_back().moveTo(50, 0);
77 concavePaths.back().cubicTo(100, 25, 60, 50, 50, 0);
78 concavePaths.back().cubicTo(0, -25, 40, -50, 50, 0);
79
80 static constexpr SkScalar kPad = 15.f;
81 static constexpr SkScalar kLightR = 100.f;
82 static constexpr SkScalar kHeight = 50.f;
83
84 // transform light position relative to canvas to handle tiling
85 SkPoint lightXY = canvas->getTotalMatrix().mapXY(250, 400);
86 SkPoint3 lightPos = { lightXY.fX, lightXY.fY, 500 };
87
88 canvas->translate(3 * kPad, 3 * kPad);
89 canvas->save();
90 SkScalar x = 0;
91 SkScalar dy = 0;
92 SkTDArray<SkMatrix> matrices;
93 matrices.push()->reset();
94 SkMatrix* m = matrices.push();
95 m->setRotate(33.f, 25.f, 25.f);
96 m->postScale(1.2f, 0.8f, 25.f, 25.f);
97 for (auto& m : matrices) {
98 for (int flags : { kNone_ShadowFlag, kTransparentOccluder_ShadowFlag }) {
99 int pathCounter = 0;
100 for (const auto& path : paths) {
101 SkRect postMBounds = path.getBounds();
102 m.mapRect(&postMBounds);
103 SkScalar w = postMBounds.width() + kHeight;
104 SkScalar dx = w + kPad;
105 if (x + dx > kW - 3 * kPad) {
106 canvas->restore();
107 canvas->translate(0, dy);
108 canvas->save();
109 x = 0;
110 dy = 0;
111 }
112
113 canvas->save();
114 canvas->concat(m);
115
116 // flip a couple of paths to test 180° rotation
117 if (kTransparentOccluder_ShadowFlag == flags && 0 == pathCounter % 3) {
118 canvas->save();
119 canvas->rotate(180, 25, 25);
120 }
121 if (kDebugColorNoOccluders == mode || kDebugColorOccluders == mode) {
122 draw_shadow(canvas, path, kHeight, SK_ColorRED, lightPos, kLightR,
123 true, flags);
124 draw_shadow(canvas, path, kHeight, SK_ColorBLUE, lightPos, kLightR,
125 false, flags);
126 } else if (kGrayscale == mode) {
127 SkColor ambientColor = SkColorSetARGB(0.1f * 255, 0, 0, 0);
128 SkColor spotColor = SkColorSetARGB(0.25f * 255, 0, 0, 0);
129 SkShadowUtils::DrawShadow(canvas, path, SkPoint3{0, 0, kHeight}, lightPos,
130 kLightR, ambientColor, spotColor, flags);
131 }
132
133 SkPaint paint;
134 paint.setAntiAlias(true);
135 if (kDebugColorNoOccluders == mode) {
136 // Draw the path outline in green on top of the ambient and spot shadows.
137 if (SkToBool(flags & kTransparentOccluder_ShadowFlag)) {
138 paint.setColor(SK_ColorCYAN);
139 } else {
140 paint.setColor(SK_ColorGREEN);
141 }
142 paint.setStyle(SkPaint::kStroke_Style);
143 paint.setStrokeWidth(0);
144 } else {
145 paint.setColor(kDebugColorOccluders == mode ? SK_ColorLTGRAY : SK_ColorWHITE);
146 if (SkToBool(flags & kTransparentOccluder_ShadowFlag)) {
147 paint.setAlphaf(0.5f);
148 }
149 paint.setStyle(SkPaint::kFill_Style);
150 }
151 canvas->drawPath(path, paint);
152 if (kTransparentOccluder_ShadowFlag == flags && 0 == pathCounter % 3) {
153 canvas->restore();
154 }
155 canvas->restore();
156
157 canvas->translate(dx, 0);
158 x += dx;
159 dy = SkTMax(dy, postMBounds.height() + kPad + kHeight);
160 ++pathCounter;
161 }
162 }
163 }
164
165 // concave paths
166 canvas->restore();
167 canvas->translate(kPad, dy);
168 canvas->save();
169 x = kPad;
170 dy = 0;
171 for (auto& m : matrices) {
172 // for the concave paths we are not clipping, so transparent and opaque are the same
173 for (const auto& path : concavePaths) {
174 SkRect postMBounds = path.getBounds();
175 m.mapRect(&postMBounds);
176 SkScalar w = postMBounds.width() + kHeight;
177 SkScalar dx = w + kPad;
178
179 canvas->save();
180 canvas->concat(m);
181
182 if (kDebugColorNoOccluders == mode || kDebugColorOccluders == mode) {
183 draw_shadow(canvas, path, kHeight, SK_ColorRED, lightPos, kLightR,
184 true, kNone_ShadowFlag);
185 draw_shadow(canvas, path, kHeight, SK_ColorBLUE, lightPos, kLightR,
186 false, kNone_ShadowFlag);
187 } else if (kGrayscale == mode) {
188 SkColor ambientColor = SkColorSetARGB(0.1f * 255, 0, 0, 0);
189 SkColor spotColor = SkColorSetARGB(0.25f * 255, 0, 0, 0);
190 SkShadowUtils::DrawShadow(canvas, path, SkPoint3{ 0, 0, kHeight }, lightPos,
191 kLightR, ambientColor, spotColor, kNone_ShadowFlag);
192 }
193
194 SkPaint paint;
195 paint.setAntiAlias(true);
196 if (kDebugColorNoOccluders == mode) {
197 // Draw the path outline in green on top of the ambient and spot shadows.
198 paint.setColor(SK_ColorGREEN);
199 paint.setStyle(SkPaint::kStroke_Style);
200 paint.setStrokeWidth(0);
201 } else {
202 paint.setColor(kDebugColorOccluders == mode ? SK_ColorLTGRAY : SK_ColorWHITE);
203 paint.setStyle(SkPaint::kFill_Style);
204 }
205 canvas->drawPath(path, paint);
206 canvas->restore();
207
208 canvas->translate(dx, 0);
209 x += dx;
210 dy = SkTMax(dy, postMBounds.height() + kPad + kHeight);
211 }
212 }
213
214 // Show where the light is in x,y as a circle (specified in device space).
215 SkMatrix invCanvasM = canvas->getTotalMatrix();
216 if (invCanvasM.invert(&invCanvasM)) {
217 canvas->save();
218 canvas->concat(invCanvasM);
219 SkPaint paint;
220 paint.setColor(SK_ColorBLACK);
221 paint.setAntiAlias(true);
222 canvas->drawCircle(lightPos.fX, lightPos.fY, kLightR / 10.f, paint);
223 canvas->restore();
224 }
225 }
226
DEF_SIMPLE_GM(shadow_utils,canvas,kW,kH)227 DEF_SIMPLE_GM(shadow_utils, canvas, kW, kH) {
228 draw_paths(canvas, kDebugColorNoOccluders);
229 }
230
DEF_SIMPLE_GM(shadow_utils_occl,canvas,kW,kH)231 DEF_SIMPLE_GM(shadow_utils_occl, canvas, kW, kH) {
232 draw_paths(canvas, kDebugColorOccluders);
233 }
234
DEF_SIMPLE_GM(shadow_utils_gray,canvas,kW,kH)235 DEF_SIMPLE_GM(shadow_utils_gray, canvas, kW, kH) {
236 draw_paths(canvas, kGrayscale);
237 }
238