200 lines
7.2 KiB
GLSL
200 lines
7.2 KiB
GLSL
/**
|
|
* @file class2/deferred/skyF.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;
|
|
|
|
// SKY ////////////////////////////////////////////////////////////////////////
|
|
// The vertex shader for creating the atmospheric sky
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
|
|
// Inputs
|
|
uniform vec3 camPosLocal;
|
|
|
|
uniform vec4 lightnorm;
|
|
uniform vec4 sunlight_color;
|
|
uniform vec4 moonlight_color;
|
|
uniform int sun_up_factor;
|
|
uniform vec4 ambient_color;
|
|
uniform vec4 blue_horizon;
|
|
uniform vec4 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 vec4 glow;
|
|
uniform float sun_moon_glow_factor;
|
|
|
|
uniform vec4 cloud_color;
|
|
|
|
#ifdef DEFINE_GL_FRAGCOLOR
|
|
out vec4 frag_data[3];
|
|
#else
|
|
#define frag_data gl_FragData
|
|
#endif
|
|
|
|
VARYING vec3 pos;
|
|
|
|
/////////////////////////////////////////////////////////////////////////
|
|
// The fragment shader for the sky
|
|
/////////////////////////////////////////////////////////////////////////
|
|
|
|
uniform sampler2D rainbow_map;
|
|
uniform sampler2D halo_map;
|
|
|
|
uniform float moisture_level;
|
|
uniform float droplet_radius;
|
|
uniform float ice_level;
|
|
|
|
vec3 rainbow(float d)
|
|
{
|
|
// d is the dot product of view and sun directions, so ranging -1.0..1.0
|
|
// 'interesting' values of d are the range -0.75..-0.825, when view is nearly opposite of sun vec
|
|
// Rainbox texture mode is GL_REPEAT, so tc of -.75 is equiv to 0.25, -0.825 equiv to 0.175.
|
|
|
|
// SL-13629 Rainbow texture has colors within the correct .175...250 range, but order is inverted.
|
|
// Rather than replace the texture, we mirror and translate the y tc to keep the colors within the
|
|
// interesting range, but in reversed order: i.e. d = (1 - d) - 1.575
|
|
d = clamp(-0.575 - d, 0.0, 1.0);
|
|
|
|
// With the colors in the lower 1/4 of the texture, inverting the coords leaves most of it inaccessible.
|
|
// So, we can stretch the texcoord above the colors (ie > 0.25) to fill the entire remaining coordinate
|
|
// space. This improves gradation, reduces banding within the rainbow interior. (1-0.25) / (0.425/0.25) = 4.2857
|
|
float interior_coord = max(0.0, d - 0.25) * 4.2857;
|
|
d = clamp(d, 0.0, 0.25) + interior_coord;
|
|
|
|
float rad = (droplet_radius - 5.0f) / 1024.0f;
|
|
return pow(texture2D(rainbow_map, vec2(rad, d)).rgb, vec3(1.8)) * moisture_level;
|
|
}
|
|
|
|
vec3 halo22(float d)
|
|
{
|
|
d = clamp(d, 0.1, 1.0);
|
|
float v = sqrt(clamp(1 - (d * d), 0, 1));
|
|
return texture2D(halo_map, vec2(0, v)).rgb * ice_level;
|
|
}
|
|
|
|
/// Soft clips the light with a gamma correction
|
|
vec3 scaleSoftClip(vec3 light);
|
|
|
|
void main()
|
|
{
|
|
// World / view / projection
|
|
// Get relative position (offset why?)
|
|
vec3 rel_pos = pos.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);
|
|
|
|
// Initialize temp variables
|
|
vec4 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
|
|
vec4 light_atten = (blue_density + vec4(haze_density * 0.25)) * (density_multiplier * max_y);
|
|
|
|
// Calculate relative weights
|
|
vec4 combined_haze = abs(blue_density) + vec4(abs(haze_density));
|
|
vec4 blue_weight = blue_density / combined_haze;
|
|
vec4 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 = dot(rel_pos_norm, lightnorm.xyz);
|
|
haze_glow = 1. - haze_glow;
|
|
// 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
|
|
vec4 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
|
|
// TODO 9/20: DJH what does this do? max(0,(1-ambient)) will change the color
|
|
vec4 ambient = ambient_color + max(vec4(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
|
|
vec4 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));
|
|
|
|
float optic_d = dot(rel_pos_norm, lightnorm.xyz);
|
|
vec3 halo_22 = halo22(optic_d);
|
|
color.rgb += rainbow(optic_d);
|
|
color.rgb += halo_22;
|
|
color.rgb *= 2.;
|
|
color.rgb = scaleSoftClip(color.rgb);
|
|
|
|
// Gamma correct for WL (soft clip effect).
|
|
frag_data[0] = vec4(color.rgb, 1.0);
|
|
frag_data[1] = vec4(0.0, 0.0, 0.0, 0.0);
|
|
frag_data[2] = vec4(0.0, 0.0, 0.0, 1.0); // 1.0 in norm.w masks off fog
|
|
}
|