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
163
164
165
166
167
168
169
|
/* Options:
*
* USE_COLOR: use glColor for diffuse colors
* USE_TEXTURE: use texture for diffuse colors
* USE_SCENE_LIGHTING: use lights (up to 8)
* USE_SOLID_LIGHTING: assume 3 directional lights for solid draw mode
* USE_TWO_SIDED: flip normal towards viewer
* NO_SPECULAR: use specular component
*/
#define NUM_SOLID_LIGHTS 3
#define NUM_SCENE_LIGHTS 8
#if defined(USE_SOLID_LIGHTING) || defined(USE_SCENE_LIGHTING)
varying vec3 varying_normal;
#ifndef USE_SOLID_LIGHTING
varying vec3 varying_position;
#endif
#endif
#ifdef USE_COLOR
varying vec4 varying_vertex_color;
#endif
#ifdef USE_TEXTURE
varying vec2 varying_texture_coord;
uniform sampler2D texture_map;
#endif
void main()
{
#if defined(USE_SOLID_LIGHTING) || defined(USE_SCENE_LIGHTING)
/* compute normal */
vec3 N = normalize(varying_normal);
#ifdef USE_TWO_SIDED
if (!gl_FrontFacing)
N = -N;
#endif
/* compute diffuse and specular lighting */
vec3 L_diffuse = vec3(0.0);
#ifndef NO_SPECULAR
vec3 L_specular = vec3(0.0);
#endif
#ifdef USE_SOLID_LIGHTING
/* assume 3 directional lights */
for (int i = 0; i < NUM_SOLID_LIGHTS; i++) {
vec3 light_direction = gl_LightSource[i].position.xyz;
/* diffuse light */
vec3 light_diffuse = gl_LightSource[i].diffuse.rgb;
float diffuse_bsdf = max(dot(N, light_direction), 0.0);
L_diffuse += light_diffuse*diffuse_bsdf;
#ifndef NO_SPECULAR
/* specular light */
vec3 light_specular = gl_LightSource[i].specular.rgb;
vec3 H = gl_LightSource[i].halfVector.xyz;
float specular_bsdf = pow(max(dot(N, H), 0.0), gl_FrontMaterial.shininess);
L_specular += light_specular*specular_bsdf;
#endif
}
#else
/* all 8 lights, makes no assumptions, potentially slow */
#ifndef NO_SPECULAR
/* view vector computation, depends on orthographics or perspective */
vec3 V = (gl_ProjectionMatrix[3][3] == 0.0) ? normalize(varying_position): vec3(0.0, 0.0, -1.0);
#endif
for (int i = 0; i < NUM_SCENE_LIGHTS; i++) {
/* todo: this is a slow check for disabled lights */
if (gl_LightSource[i].specular.a == 0.0)
continue;
float intensity = 1.0;
vec3 light_direction;
if (gl_LightSource[i].position.w == 0.0) {
/* directional light */
light_direction = gl_LightSource[i].position.xyz;
}
else {
/* point light */
vec3 d = gl_LightSource[i].position.xyz - varying_position;
light_direction = normalize(d);
/* spot light cone */
if (gl_LightSource[i].spotCutoff < 90.0) {
float cosine = max(dot(light_direction, -gl_LightSource[i].spotDirection), 0.0);
intensity = pow(cosine, gl_LightSource[i].spotExponent);
intensity *= step(gl_LightSource[i].spotCosCutoff, cosine);
}
/* falloff */
float distance = length(d);
intensity /= gl_LightSource[i].constantAttenuation +
gl_LightSource[i].linearAttenuation * distance +
gl_LightSource[i].quadraticAttenuation * distance * distance;
}
/* diffuse light */
vec3 light_diffuse = gl_LightSource[i].diffuse.rgb;
float diffuse_bsdf = max(dot(N, light_direction), 0.0);
L_diffuse += light_diffuse*diffuse_bsdf*intensity;
#ifndef NO_SPECULAR
/* specular light */
vec3 light_specular = gl_LightSource[i].specular.rgb;
vec3 H = normalize(light_direction - V);
float specular_bsdf = pow(max(dot(N, H), 0.0), gl_FrontMaterial.shininess);
L_specular += light_specular*specular_bsdf*intensity;
#endif
}
#endif
/* compute diffuse color, possibly from texture or vertex colors */
float alpha;
#if defined(USE_TEXTURE) && defined(USE_COLOR)
vec4 texture_color = texture2D(texture_map, varying_texture_coord);
L_diffuse *= texture_color.rgb * varying_vertex_color.rgb;
alpha = texture_color.a * varying_vertex_color.a;
#elif defined(USE_TEXTURE)
vec4 texture_color = texture2D(texture_map, varying_texture_coord);
L_diffuse *= texture_color.rgb;
alpha = texture_color.a;
#elif defined(USE_COLOR)
L_diffuse *= varying_vertex_color.rgb;
alpha = varying_vertex_color.a;
#else
L_diffuse *= gl_FrontMaterial.diffuse.rgb;
alpha = gl_FrontMaterial.diffuse.a;
#endif
/* sum lighting */
vec3 L = gl_FrontLightModelProduct.sceneColor.rgb + L_diffuse;
#ifndef NO_SPECULAR
L += L_specular*gl_FrontMaterial.specular.rgb;
#endif
/* write out fragment color */
gl_FragColor = vec4(L, alpha);
#else
/* no lighting */
#if defined(USE_TEXTURE) && defined(USE_COLOR)
gl_FragColor = texture2D(texture_map, varying_texture_coord) * varying_vertex_color;
#elif defined(USE_TEXTURE)
gl_FragColor = texture2D(texture_map, varying_texture_coord);
#elif defined(USE_COLOR)
gl_FragColor = varying_vertex_color;
#else
gl_FragColor = gl_FrontMaterial.diffuse;
#endif
#endif
}
|
