summaryrefslogtreecommitdiff
path: root/indra/newview/app_settings/shaders/class1/environment/waterFogF.glsl
blob: 011b3c86438a7dddb6a139ac9b03146d1a4a5bc7 (plain)
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
/**
 * @file class1\environment\waterFogF.glsl
 *
 * $LicenseInfo:firstyear=2007&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2007, Linden Research, Inc.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 * 
 * This library 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 * 
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */
 


uniform vec4 waterPlane;
uniform vec4 waterFogColor;
uniform float waterFogDensity;
uniform float waterFogKS;

vec3 getPositionEye();

vec3 srgb_to_linear(vec3 col);

vec4 applyWaterFogView(vec3 pos, vec4 color)
{
    vec3 view = normalize(pos);
    //normalize view vector
    float es = -(dot(view, waterPlane.xyz));

    //find intersection point with water plane and eye vector
    
    //get eye depth
    float e0 = max(-waterPlane.w, 0.0);
    
    vec3 int_v = waterPlane.w > 0.0 ? view * waterPlane.w/es : vec3(0.0, 0.0, 0.0);
    
    //get object depth
    float depth = length(pos - int_v);
        
    //get "thickness" of water
    float l = max(depth, 0.1);

    float kd = waterFogDensity;
    float ks = waterFogKS;
    vec4 kc = waterFogColor;
    
    float F = 0.98;
    
    float t1 = -kd * pow(F, ks * e0);
    float t2 = kd + ks * es;
    float t3 = pow(F, t2*l) - 1.0;
    
    float L = min(t1/t2*t3, 1.0);
    
    float D = pow(0.98, l*kd);
    
    color.rgb = color.rgb * D + kc.rgb * L;
    color.a = kc.a + color.a;

    return color;
}

vec4 applyWaterFogViewLinear(vec3 pos, vec4 color)
{
    if (dot(pos, waterPlane.xyz) + waterPlane.w > 0.0)
    {
        return color;
    }

    vec3 view = normalize(pos);
    //normalize view vector
    float es = -(dot(view, waterPlane.xyz));

    
    //find intersection point with water plane and eye vector

    //get eye depth
    float e0 = max(-waterPlane.w, 0.0);

    vec3 int_v = waterPlane.w > 0.0 ? view * waterPlane.w / es : vec3(0.0, 0.0, 0.0);

    //get object depth
    float depth = length(pos - int_v);

    //get "thickness" of water
    float l = max(depth, 0.1);

    float kd = waterFogDensity;
    float ks = waterFogKS;
    vec4 kc = waterFogColor;
    kc.rgb = srgb_to_linear(kc.rgb); // TODO -- pass in waterFogColor linear

    float F = 0.98;

    float t1 = -kd * pow(F, ks * e0);
    float t2 = kd + ks * es;
    float t3 = pow(F, t2 * l) - 1.0;

    float L = min(t1 / t2 * t3, 1.0);

    float D = pow(0.98, l * kd);

    color.rgb = color.rgb * D + kc.rgb * L;
    color.a = kc.a + color.a;

    return color;
}

vec4 applyWaterFog(vec4 color)
{
    //normalize view vector
    return applyWaterFogView(getPositionEye(), color);
}