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#include "core/platform/graphics/FloatPoint3D.h"
28#include "wtf/PassRefPtr.h"
29#include "wtf/RefCounted.h"
30
31namespace WebCore {
32
33enum LightType {
34    LS_DISTANT,
35    LS_POINT,
36    LS_SPOT
37};
38
39class TextStream;
40
41class LightSource : public RefCounted<LightSource> {
42public:
43
44    // Light vectors must be calculated for every pixel during
45    // painting. It is expensive to pass all these arguments to
46    // a frequently called function, especially because not all
47    // light sources require all of them. Instead, we just pass
48    // a reference to the following structure
49    struct PaintingData {
50        // SVGFELighting also use them
51        FloatPoint3D lightVector;
52        FloatPoint3D colorVector;
53        float lightVectorLength;
54        // Private members
55        FloatPoint3D directionVector;
56        FloatPoint3D privateColorVector;
57        float coneCutOffLimit;
58        float coneFullLight;
59        int specularExponent;
60    };
61
62    LightSource(LightType type)
63        : m_type(type)
64    { }
65
66    virtual ~LightSource() { }
67
68    LightType type() const { return m_type; }
69    virtual TextStream& externalRepresentation(TextStream&) const = 0;
70
71    virtual void initPaintingData(PaintingData&) = 0;
72    // z is a float number, since it is the alpha value scaled by a user
73    // specified "surfaceScale" constant, which type is <number> in the SVG standard
74    virtual void updatePaintingData(PaintingData&, int x, int y, float z) = 0;
75
76    virtual bool setAzimuth(float) { return false; }
77    virtual bool setElevation(float) { return false; }
78    virtual bool setX(float) { return false; }
79    virtual bool setY(float) { return false; }
80    virtual bool setZ(float) { return false; }
81    virtual bool setPointsAtX(float) { return false; }
82    virtual bool setPointsAtY(float) { return false; }
83    virtual bool setPointsAtZ(float) { return false; }
84    virtual bool setSpecularExponent(float) { return false; }
85    virtual bool setLimitingConeAngle(float) { return false; }
86
87private:
88    LightType m_type;
89};
90
91} // namespace WebCore
92
93#endif // LightSource_h
94