1 /*
2 * Copyright (C) 2008 Alex Mathews <possessedpenguinbob@gmail.com>
3 * Copyright (C) 2004, 2005, 2006, 2007 Nikolas Zimmermann <zimmermann@kde.org>
4 * Copyright (C) 2004, 2005 Rob Buis <buis@kde.org>
5 * Copyright (C) 2005 Eric Seidel <eric@webkit.org>
6 * Copyright (C) 2010 Zoltan Herczeg <zherczeg@webkit.org>
7 * Copyright (C) 2011 University of Szeged
8 * Copyright (C) 2011 Renata Hodovan <reni@webkit.org>
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY UNIVERSITY OF SZEGED ``AS IS'' AND ANY
20 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL UNIVERSITY OF SZEGED OR
23 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
26 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
27 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include "config.h"
33
34 #if ENABLE(FILTERS)
35 #include "SpotLightSource.h"
36
37 #include "TextStream.h"
38
39 namespace WebCore {
40
41 // spot-light edge darkening depends on an absolute treshold
42 // according to the SVG 1.1 SE light regression tests
43 static const float antiAliasTreshold = 0.016f;
44
initPaintingData(PaintingData & paintingData)45 void SpotLightSource::initPaintingData(PaintingData& paintingData)
46 {
47 paintingData.privateColorVector = paintingData.colorVector;
48 paintingData.directionVector.setX(m_direction.x() - m_position.x());
49 paintingData.directionVector.setY(m_direction.y() - m_position.y());
50 paintingData.directionVector.setZ(m_direction.z() - m_position.z());
51 paintingData.directionVector.normalize();
52
53 if (!m_limitingConeAngle) {
54 paintingData.coneCutOffLimit = 0.0f;
55 paintingData.coneFullLight = -antiAliasTreshold;
56 } else {
57 float limitingConeAngle = m_limitingConeAngle;
58 if (limitingConeAngle < 0.0f)
59 limitingConeAngle = -limitingConeAngle;
60 if (limitingConeAngle > 90.0f)
61 limitingConeAngle = 90.0f;
62 paintingData.coneCutOffLimit = cosf(deg2rad(180.0f - limitingConeAngle));
63 paintingData.coneFullLight = paintingData.coneCutOffLimit - antiAliasTreshold;
64 }
65
66 // Optimization for common specularExponent values
67 if (!m_specularExponent)
68 paintingData.specularExponent = 0;
69 else if (m_specularExponent == 1.0f)
70 paintingData.specularExponent = 1;
71 else // It is neither 0.0f nor 1.0f
72 paintingData.specularExponent = 2;
73 }
74
updatePaintingData(PaintingData & paintingData,int x,int y,float z)75 void SpotLightSource::updatePaintingData(PaintingData& paintingData, int x, int y, float z)
76 {
77 paintingData.lightVector.setX(m_position.x() - x);
78 paintingData.lightVector.setY(m_position.y() - y);
79 paintingData.lightVector.setZ(m_position.z() - z);
80 paintingData.lightVectorLength = paintingData.lightVector.length();
81
82 float cosineOfAngle = (paintingData.lightVector * paintingData.directionVector) / paintingData.lightVectorLength;
83 if (cosineOfAngle > paintingData.coneCutOffLimit) {
84 // No light is produced, scanlines are not updated
85 paintingData.colorVector.setX(0.0f);
86 paintingData.colorVector.setY(0.0f);
87 paintingData.colorVector.setZ(0.0f);
88 return;
89 }
90
91 // Set the color of the pixel
92 float lightStrength;
93 switch (paintingData.specularExponent) {
94 case 0:
95 lightStrength = 1.0f; // -cosineOfAngle ^ 0 == 1
96 break;
97 case 1:
98 lightStrength = -cosineOfAngle; // -cosineOfAngle ^ 1 == -cosineOfAngle
99 break;
100 default:
101 lightStrength = powf(-cosineOfAngle, m_specularExponent);
102 break;
103 }
104
105 if (cosineOfAngle > paintingData.coneFullLight)
106 lightStrength *= (paintingData.coneCutOffLimit - cosineOfAngle) / (paintingData.coneCutOffLimit - paintingData.coneFullLight);
107
108 if (lightStrength > 1.0f)
109 lightStrength = 1.0f;
110
111 paintingData.colorVector.setX(paintingData.privateColorVector.x() * lightStrength);
112 paintingData.colorVector.setY(paintingData.privateColorVector.y() * lightStrength);
113 paintingData.colorVector.setZ(paintingData.privateColorVector.z() * lightStrength);
114 }
115
setX(float x)116 bool SpotLightSource::setX(float x)
117 {
118 if (m_position.x() == x)
119 return false;
120 m_position.setX(x);
121 return true;
122 }
123
setY(float y)124 bool SpotLightSource::setY(float y)
125 {
126 if (m_position.y() == y)
127 return false;
128 m_position.setY(y);
129 return true;
130 }
131
setZ(float z)132 bool SpotLightSource::setZ(float z)
133 {
134 if (m_position.z() == z)
135 return false;
136 m_position.setZ(z);
137 return true;
138 }
139
setPointsAtX(float pointsAtX)140 bool SpotLightSource::setPointsAtX(float pointsAtX)
141 {
142 if (m_direction.x() == pointsAtX)
143 return false;
144 m_direction.setX(pointsAtX);
145 return true;
146 }
147
setPointsAtY(float pointsAtY)148 bool SpotLightSource::setPointsAtY(float pointsAtY)
149 {
150 if (m_direction.y() == pointsAtY)
151 return false;
152 m_direction.setY(pointsAtY);
153 return true;
154 }
155
setPointsAtZ(float pointsAtZ)156 bool SpotLightSource::setPointsAtZ(float pointsAtZ)
157 {
158 if (m_direction.z() == pointsAtZ)
159 return false;
160 m_direction.setZ(pointsAtZ);
161 return true;
162 }
163
setSpecularExponent(float specularExponent)164 bool SpotLightSource::setSpecularExponent(float specularExponent)
165 {
166 if (m_specularExponent == specularExponent)
167 return false;
168 m_specularExponent = specularExponent;
169 return true;
170 }
171
setLimitingConeAngle(float limitingConeAngle)172 bool SpotLightSource::setLimitingConeAngle(float limitingConeAngle)
173 {
174 if (m_limitingConeAngle == limitingConeAngle)
175 return false;
176 m_limitingConeAngle = limitingConeAngle;
177 return true;
178 }
179
operator <<(TextStream & ts,const FloatPoint3D & p)180 static TextStream& operator<<(TextStream& ts, const FloatPoint3D& p)
181 {
182 ts << "x=" << p.x() << " y=" << p.y() << " z=" << p.z();
183 return ts;
184 }
185
externalRepresentation(TextStream & ts) const186 TextStream& SpotLightSource::externalRepresentation(TextStream& ts) const
187 {
188 ts << "[type=SPOT-LIGHT] ";
189 ts << "[position=\"" << position() << "\"]";
190 ts << "[direction=\"" << direction() << "\"]";
191 ts << "[specularExponent=\"" << specularExponent() << "\"]";
192 ts << "[limitingConeAngle=\"" << limitingConeAngle() << "\"]";
193 return ts;
194 }
195
196 }; // namespace WebCore
197
198 #endif // ENABLE(FILTERS)
199