summaryrefslogtreecommitdiff
path: root/indra/newview/app_settings/shaders/class1/deferred/skyV.glsl
blob: 62d134188c7d24e8b3d1dc53552342887a4a1845 (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
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
/**
 * @file WLSkyV.glsl
 *
 * $LicenseInfo:firstyear=2005&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2005, 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 mat4 modelview_projection_matrix;

ATTRIBUTE vec3 position;

// SKY ////////////////////////////////////////////////////////////////////////
// The vertex shader for creating the atmospheric sky
///////////////////////////////////////////////////////////////////////////////

// Output parameters
out vec3 vary_HazeColor;
out float vary_LightNormPosDot;

// Inputs
uniform vec3 camPosLocal;

uniform vec3  lightnorm;
uniform vec3  sunlight_color;
uniform vec3  moonlight_color;
uniform int   sun_up_factor;
uniform vec3  ambient_color;
uniform vec3  blue_horizon;
uniform vec3  blue_density;
uniform float haze_horizon;
uniform float haze_density;

uniform float cloud_shadow;
uniform float density_multiplier;
uniform float distance_multiplier;
uniform float max_y;

uniform vec3  glow;
uniform float sun_moon_glow_factor;

uniform int cube_snapshot;

// NOTE: Keep these in sync!
//       indra\newview\app_settings\shaders\class1\deferred\skyV.glsl
//       indra\newview\app_settings\shaders\class1\deferred\cloudsV.glsl
//       indra\newview\lllegacyatmospherics.cpp
void main()
{
    // World / view / projection
    vec4 pos = modelview_projection_matrix * vec4(position.xyz, 1.0);

    gl_Position = pos;

    // Get relative position
    vec3 rel_pos = position.xyz - camPosLocal.xyz + vec3(0, 50, 0);

    // Adj position vector to clamp altitude
    if (rel_pos.y > 0.)
    {
        rel_pos *= (max_y / rel_pos.y);
    }
    if (rel_pos.y < 0.)
    {
        rel_pos *= (-32000. / rel_pos.y);
    }

    // Normalized
    vec3  rel_pos_norm = normalize(rel_pos);
    float rel_pos_len  = length(rel_pos);

    // Grab this value and pass to frag shader for rainbows
    float rel_pos_lightnorm_dot = dot(rel_pos_norm, lightnorm.xyz);
    vary_LightNormPosDot = rel_pos_lightnorm_dot;

    // Initialize temp variables
    vec3 sunlight = (sun_up_factor == 1) ? sunlight_color : moonlight_color;
    
    // Sunlight attenuation effect (hue and brightness) due to atmosphere
    // this is used later for sunlight modulation at various altitudes
    vec3 light_atten = (blue_density + vec3(haze_density * 0.25)) * (density_multiplier * max_y);

    // Calculate relative weights
    vec3 combined_haze = abs(blue_density) + vec3(abs(haze_density));
    vec3 blue_weight   = blue_density / combined_haze;
    vec3 haze_weight   = haze_density / combined_haze;

    // Compute sunlight from rel_pos & lightnorm (for long rays like sky)
    float off_axis = 1.0 / max(1e-6, max(0., rel_pos_norm.y) + lightnorm.y);
    sunlight *= exp(-light_atten * off_axis);

    // Distance
    float density_dist = rel_pos_len * density_multiplier;

    // Transparency (-> combined_haze)
    // ATI Bugfix -- can't store combined_haze*density_dist in a variable because the ati
    // compiler gets confused.
    combined_haze = exp(-combined_haze * density_dist);

    // Compute haze glow
    float haze_glow = 1.0 - rel_pos_lightnorm_dot;
    // haze_glow is 0 at the sun and increases away from sun
    haze_glow = max(haze_glow, .001);
    // Set a minimum "angle" (smaller glow.y allows tighter, brighter hotspot)
    haze_glow *= glow.x;
    // Higher glow.x gives dimmer glow (because next step is 1 / "angle")
    haze_glow = pow(haze_glow, glow.z);
    // glow.z should be negative, so we're doing a sort of (1 / "angle") function

    // Add "minimum anti-solar illumination"
    // For sun, add to glow.  For moon, remove glow entirely. SL-13768
    haze_glow = (sun_moon_glow_factor < 1.0) ? 0.0 : (sun_moon_glow_factor * (haze_glow + 0.25));

    // Haze color above cloud
    vec3 color = (blue_horizon * blue_weight * (sunlight + ambient_color)
               + (haze_horizon * haze_weight) * (sunlight * haze_glow + ambient_color));

    // Final atmosphere additive
    color *= (1. - combined_haze);

    // Increase ambient when there are more clouds
    vec3 ambient = ambient_color + max(vec3(0), (1. - ambient_color)) * cloud_shadow * 0.5;

    // Dim sunlight by cloud shadow percentage
    sunlight *= max(0.0, (1. - cloud_shadow));

    // Haze color below cloud
    vec3 add_below_cloud = (blue_horizon * blue_weight * (sunlight + ambient) 
                         + (haze_horizon * haze_weight) * (sunlight * haze_glow + ambient));

    // Attenuate cloud color by atmosphere
    combined_haze = sqrt(combined_haze);  // less atmos opacity (more transparency) below clouds

    // At horizon, blend high altitude sky color towards the darker color below the clouds
    color += (add_below_cloud - color) * (1. - sqrt(combined_haze));

    // Haze color above cloud
    vary_HazeColor = color;
}