1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
|
/* Copyright (C) 2012 Wildfire Games.
* This file is part of 0 A.D.
*
* 0 A.D. is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* 0 A.D. is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with 0 A.D. If not, see <http://www.gnu.org/licenses/>.
*/
/*
* Shadow mapping related texture and matrix management
*/
#ifndef INCLUDED_SHADOWMAP
#define INCLUDED_SHADOWMAP
#include "lib/ogl.h"
class CBoundingBoxAligned;
class CMatrix3D;
struct ShadowMapInternals;
/**
* Class ShadowMap: Maintain the shadow map texture and perform necessary OpenGL setup,
* including matrix calculations.
*
* The class will automatically generate a texture the first time the shadow map is rendered into.
* The texture will not be resized afterwards.
*/
class ShadowMap
{
public:
ShadowMap();
~ShadowMap();
/**
* RecreateTexture: Destroy the current shadow texture and force creation of
* a new one. Useful when the renderer's size has changed and the texture
* should be resized too.
*/
void RecreateTexture();
/**
* GetDepthTextureBits: Return the number of bits to use for depth textures when
* enabled.
*
* @return depth texture bit depth
*/
int GetDepthTextureBits() const;
/**
* SetDepthTextureBits: Sets the number of bits to use for depth textures when enabled.
* Possible values are 16, 24, 32 and 0 (= use default)
*
* @param bits number of bits
*/
void SetDepthTextureBits(int bits);
/**
* GetWidth: Return the width of the depth texture.
*
* @return depth texture width
*/
int GetWidth() const;
/**
* GetHeight: Return the height of the depth texture
*
* @return depth texture height
*/
int GetHeight() const;
/**
* SetupFrame: Configure light space for the given camera and light direction,
* create the shadow texture if necessary, etc.
*
* @param camera the camera that will be used for world rendering
* @param lightdir the direction of the (directional) sunlight
*/
void SetupFrame(const CCamera& camera, const CVector3D& lightdir);
/**
* Add the bounding box of an object that will cast a shadow.
* This is used to calculate the bounds for the shadow map.
*
* @param bounds world space bounding box
*/
void AddShadowCasterBound(const CBoundingBoxAligned& bounds);
/**
* Add the bounding box of an object that will receive a shadow.
* This is used to calculate the bounds for the shadow map.
*
* @param bounds world space bounding box
*/
void AddShadowReceiverBound(const CBoundingBoxAligned& bounds);
/**
* Compute the frustum originating at the light source, that encompasses
* all the objects passed into AddShadowReceiverBound so far.
*
* This frustum can be used to determine which objects might cast a visible
* shadow. Those objects should be passed to AddShadowCasterBound and
* then should be rendered into the shadow map.
*/
CFrustum GetShadowCasterCullFrustum();
/**
* BeginRender: Set OpenGL state for rendering into the shadow map texture.
*
* @todo this depends in non-obvious ways on the behaviour of the call-site
*/
void BeginRender();
/**
* EndRender: Finish rendering into the shadow map.
*
* @todo this depends in non-obvious ways on the behaviour of the call-site
*/
void EndRender();
/**
* GetTexture: Retrieve the OpenGL texture object name that contains the shadow map.
*
* @return the texture name of the shadow map texture
*/
GLuint GetTexture() const;
/**
* GetTextureMatrix: Retrieve the world-space to shadow map texture coordinates
* transformation matrix.
*
* @return the matrix that transforms world-space coordinates into homogenous
* shadow map texture coordinates
*/
const CMatrix3D& GetTextureMatrix() const;
/**
* Visualize shadow mapping calculations to help in
* debugging and optimal shadow map usage.
*/
void RenderDebugBounds();
/**
* Visualize shadow map texture to help in debugging.
*/
void RenderDebugTexture();
private:
ShadowMapInternals* m;
};
#endif // INCLUDED_SHADOWMAP
|
