xref: /aosp_15_r20/external/skia/tools/viewer/ShadowColorSlide.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1 
2 /*
3  * Copyright 2017 Google Inc.
4  *
5  * Use of this source code is governed by a BSD-style license that can be
6  * found in the LICENSE file.
7  */
8 #include "include/core/SkCanvas.h"
9 #include "include/core/SkFont.h"
10 #include "include/core/SkImage.h"
11 #include "include/core/SkPath.h"
12 #include "include/core/SkPoint3.h"
13 #include "include/utils/SkShadowUtils.h"
14 #include "tools/Resources.h"
15 #include "tools/fonts/FontToolUtils.h"
16 #include "tools/viewer/Slide.h"
17 
18 ////////////////////////////////////////////////////////////////////////////
19 // Sample to demonstrate tonal color shadows
20 
21 class ShadowColorSlide : public Slide {
22     SkPath    fRectPath;
23     int       fZIndex;
24 
25     bool      fShowAmbient;
26     bool      fShowSpot;
27     bool      fUseAlt;
28     bool      fShowObject;
29     bool      fTwoPassColor;
30     bool      fDarkBackground;
31 
32 public:
ShadowColorSlide()33     ShadowColorSlide()
34         : fZIndex(8)
35         , fShowAmbient(true)
36         , fShowSpot(true)
37         , fUseAlt(false)
38         , fShowObject(true)
39         , fTwoPassColor(false)
40         , fDarkBackground(false) {
41         fName = "ShadowColor";
42     }
43 
load(SkScalar w,SkScalar h)44     void load(SkScalar w, SkScalar h) override {
45         fRectPath.addRect(SkRect::MakeXYWH(-50, -50, 100, 100));
46     }
47 
onChar(SkUnichar uni)48     bool onChar(SkUnichar uni) override {
49             bool handled = false;
50             switch (uni) {
51                 case 'W':
52                     fShowAmbient = !fShowAmbient;
53                     handled = true;
54                     break;
55                 case 'S':
56                     fShowSpot = !fShowSpot;
57                     handled = true;
58                     break;
59                 case 'T':
60                     fUseAlt = !fUseAlt;
61                     handled = true;
62                     break;
63                 case 'O':
64                     fShowObject = !fShowObject;
65                     handled = true;
66                     break;
67                 case 'X':
68                     fTwoPassColor = !fTwoPassColor;
69                     handled = true;
70                     break;
71                 case 'Z':
72                     fDarkBackground = !fDarkBackground;
73                     handled = true;
74                     break;
75                 case '>':
76                     fZIndex = std::min(9, fZIndex+1);
77                     handled = true;
78                     break;
79                 case '<':
80                     fZIndex = std::max(0, fZIndex-1);
81                     handled = true;
82                     break;
83                 default:
84                     break;
85             }
86             if (handled) {
87                 return true;
88             }
89             return false;
90     }
91 
draw(SkCanvas * canvas)92     void draw(SkCanvas* canvas) override {
93         const SkScalar kLightWidth = 600;
94         const SkScalar kAmbientAlpha = 0.03f;
95         const SkScalar kSpotAlpha = 0.25f;
96 
97         const SkScalar kZValues[10] = { 1, 2, 3, 4, 6, 8, 9, 12, 16, 24 };
98 
99         const SkColor kColors[30] = {
100             // purples
101             0xFF3A0072, 0xFF5D0099, 0xFF7F12B2, 0xFFA02AD1, 0xFFC245E5,
102             0xFFE95AF9, 0xFFFC79F0, 0xFFFDA6F0, 0xFFFFCCF8, 0xFFFFE1F9,
103             // oranges
104             0xFFEA3200, 0xFFFF4E00, 0xFFFF7300, 0xFFFF9100, 0xFFFFB000,
105             0xFFFFCE00, 0xFFFFE000, 0xFFFFF64D, 0xFFFFF98F, 0xFFFFFBCC,
106             // teals
107             0xFF004D51, 0xFF066266, 0xFF057F7F, 0xFF009999, 0xFF00B2B2,
108             0xFF15CCBE, 0xFF25E5CE, 0xFF2CFFE0, 0xFF80FFEA, 0xFFB3FFF0
109         };
110 
111         SkFont font = ToolUtils::DefaultFont();
112         SkPaint paint;
113         paint.setAntiAlias(true);
114         if (fDarkBackground) {
115             canvas->drawColor(0xFF111111);
116             paint.setColor(SK_ColorWHITE);
117         } else {
118             canvas->drawColor(0xFFEAEAEA);
119             paint.setColor(SK_ColorBLACK);
120         }
121         if (fTwoPassColor) {
122             canvas->drawString("Two pass", 10, 15, font, paint);
123         } else {
124             canvas->drawString("One pass", 10, 15, font, paint);
125         }
126 
127         SkPoint3 lightPos = { 75, -400, 600 };
128         SkPoint3 zPlaneParams = SkPoint3::Make(0, 0, kZValues[fZIndex]);
129         SkScalar yPos = 75;
130 
131         for (int row = 0; row < 3; ++row) {
132             lightPos.fX = 75;
133             SkScalar xPos = 75;
134             for (int col = 0; col < 10; ++col) {
135                 paint.setColor(kColors[10*row + col]);
136 
137                 canvas->save();
138                 canvas->translate(xPos, yPos);
139                 this->drawShadowedPath(canvas, fRectPath, zPlaneParams, paint, kAmbientAlpha,
140                                        lightPos, kLightWidth, kSpotAlpha);
141                 canvas->restore();
142 
143                 lightPos.fX += 120;
144                 xPos += 120;
145             }
146 
147             lightPos.fY += 200;
148             yPos += 200;
149         }
150     }
151 
152 private:
drawShadowedPath(SkCanvas * canvas,const SkPath & path,const SkPoint3 & zPlaneParams,const SkPaint & paint,SkScalar ambientAlpha,const SkPoint3 & lightPos,SkScalar lightWidth,SkScalar spotAlpha)153     void drawShadowedPath(SkCanvas* canvas, const SkPath& path,
154                           const SkPoint3& zPlaneParams,
155                           const SkPaint& paint, SkScalar ambientAlpha,
156                           const SkPoint3& lightPos, SkScalar lightWidth, SkScalar spotAlpha) {
157         if (!fShowAmbient) {
158             ambientAlpha = 0;
159         }
160         if (!fShowSpot) {
161             spotAlpha = 0;
162         }
163         uint32_t flags = 0;
164         if (fUseAlt) {
165             flags |= SkShadowFlags::kGeometricOnly_ShadowFlag;
166         }
167 
168         if (fTwoPassColor) {
169             SkColor ambientColor = SkColorSetARGB(ambientAlpha*255, 0, 0, 0);
170             SkShadowUtils::DrawShadow(canvas, path, zPlaneParams,
171                                       lightPos, lightWidth,
172                                       ambientColor, SK_ColorTRANSPARENT, flags);
173 
174             if (paint.getColor() != SK_ColorBLACK) {
175                 SkColor color = paint.getColor();
176 
177                 uint8_t max = std::max(std::max(SkColorGetR(color), SkColorGetG(color)),
178                                        SkColorGetB(color));
179                 uint8_t min = std::min(std::min(SkColorGetR(color), SkColorGetG(color)),
180                                        SkColorGetB(color));
181                 SkScalar luminance = 0.5f*(max + min) / 255.f;
182                 SkScalar alpha = (.6 - .4*luminance)*luminance*luminance + 0.3f;
183                 spotAlpha -= (alpha - 0.3f)*.5f;
184                 SkColor spotColor = SkColorSetARGB(alpha*SkColorGetA(color), SkColorGetR(color),
185                                                    SkColorGetG(color), SkColorGetB(color));
186 
187                 SkShadowUtils::DrawShadow(canvas, path, zPlaneParams,
188                                           lightPos, lightWidth,
189                                           SK_ColorTRANSPARENT, spotColor, flags);
190             }
191 
192             SkColor spotGreyscale = SkColorSetARGB(spotAlpha * 255, 0, 0, 0);
193             SkShadowUtils::DrawShadow(canvas, path, zPlaneParams,
194                                       lightPos, lightWidth,
195                                       SK_ColorTRANSPARENT, spotGreyscale, flags);
196         } else {
197             SkColor color = paint.getColor();
198             SkColor baseAmbient = SkColorSetARGB(ambientAlpha*SkColorGetA(color),
199                                                  SkColorGetR(color), SkColorGetG(color),
200                                                  SkColorGetB(color));
201             SkColor baseSpot = SkColorSetARGB(spotAlpha*SkColorGetA(color),
202                                               SkColorGetR(color), SkColorGetG(color),
203                                               SkColorGetB(color));
204             SkColor tonalAmbient, tonalSpot;
205             SkShadowUtils::ComputeTonalColors(baseAmbient, baseSpot, &tonalAmbient, &tonalSpot);
206             SkShadowUtils::DrawShadow(canvas, path, zPlaneParams,
207                                       lightPos, lightWidth,
208                                       tonalAmbient, tonalSpot, flags);
209         }
210         if (fShowObject) {
211             canvas->drawPath(path, paint);
212         } else {
213             SkPaint strokePaint;
214 
215             strokePaint.setColor(paint.getColor());
216             strokePaint.setStyle(SkPaint::kStroke_Style);
217 
218             canvas->drawPath(path, strokePaint);
219         }
220     }
221 };
222 
223 //////////////////////////////////////////////////////////////////////////////
224 
225 DEF_SLIDE( return new ShadowColorSlide(); )
226