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 *
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
12 *
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * Library General Public License for more details.
17 *
18 * You should have received a copy of the GNU Library General Public License
19 * along with this library; see the file COPYING.LIB.  If not, write to
20 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
21 * Boston, MA 02110-1301, USA.
22 */
23
24#ifndef LightSource_h
25#define LightSource_h
26
27#if ENABLE(FILTERS)
28#include "FloatPoint3D.h"
29#include <wtf/PassRefPtr.h>
30#include <wtf/RefCounted.h>
31
32namespace WebCore {
33
34enum LightType {
35    LS_DISTANT,
36    LS_POINT,
37    LS_SPOT
38};
39
40class TextStream;
41
42class LightSource : public RefCounted<LightSource> {
43public:
44
45    // Light vectors must be calculated for every pixel during
46    // painting. It is expensive to pass all these arguments to
47    // a frequently called function, especially because not all
48    // light sources require all of them. Instead, we just pass
49    // a reference to the following structure
50    struct PaintingData {
51        // SVGFELighting also use them
52        FloatPoint3D lightVector;
53        FloatPoint3D colorVector;
54        float lightVectorLength;
55        // Private members
56        FloatPoint3D directionVector;
57        FloatPoint3D privateColorVector;
58        float coneCutOffLimit;
59        float coneFullLight;
60        int specularExponent;
61    };
62
63    LightSource(LightType type)
64        : m_type(type)
65    { }
66
67    virtual ~LightSource() { }
68
69    LightType type() const { return m_type; }
70    virtual TextStream& externalRepresentation(TextStream&) const = 0;
71
72    virtual void initPaintingData(PaintingData&) = 0;
73    // z is a float number, since it is the alpha value scaled by a user
74    // specified "surfaceScale" constant, which type is <number> in the SVG standard
75    virtual void updatePaintingData(PaintingData&, int x, int y, float z) = 0;
76
77    bool setAzimuth(float);
78    bool setElevation(float);
79    bool setX(float);
80    bool setY(float);
81    bool setZ(float);
82    bool setPointsAtX(float);
83    bool setPointsAtY(float);
84    bool setPointsAtZ(float);
85    bool setSpecularExponent(float);
86    bool setLimitingConeAngle(float);
87
88private:
89    LightType m_type;
90};
91
92} // namespace WebCore
93
94#endif // ENABLE(FILTERS)
95
96#endif // LightSource_h
97