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fgdata/Shaders/road-ALS-ultra.frag

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C

// -*- mode: C; -*-
// Licence: GPL v2
// Authors: Frederic Bouvier and Gijs de Rooy
// with major additions and revisions by
// Emilian Huminiuc and Vivian Meazza 2011
// ported to Atmospheric Light Scattering
// by Thorsten Renk, 2013
// changes for road and traffic rendering
// by Thorsten Renk 2017
#version 120
varying vec3 VBinormal;
varying vec3 VNormal;
varying vec3 VTangent;
varying vec3 rawpos;
varying vec3 reflVec;
varying vec3 vViewVec;
varying vec3 vertVec;
varying float alpha;
uniform sampler2D BaseTex;
uniform sampler2D NormalTex;
uniform sampler2D ReflMapTex;
uniform sampler2D ReflGradientsTex;
uniform sampler3D ReflNoiseTex;
uniform samplerCube Environment;
uniform sampler2D GrainTex;
uniform int dirt_enabled;
uniform int dirt_multi;
uniform int nmap_dds;
uniform int nmap_enabled;
uniform int refl_enabled;
uniform int refl_type;
uniform int refl_map;
uniform int grain_texture_enabled;
uniform int road_traffic_direction;
uniform int rain_enabled;
uniform int road_traffic_enabled;
uniform int cloud_shadow_flag;
uniform int use_searchlight;
uniform int use_landing_light;
uniform int use_alt_landing_light;
uniform float amb_correction;
uniform float dirt_b_factor;
uniform float dirt_g_factor;
uniform float dirt_r_factor;
uniform float nmap_tile;
uniform float refl_correction;
uniform float refl_fresnel;
uniform float refl_fresnel_factor;
uniform float refl_noise;
uniform float refl_rainbow;
uniform float grain_magnification;
uniform float wetness;
uniform float rain_norm;
uniform float road_traffic_density;
uniform float streetlight_factor;
uniform float avisibility;
uniform float cloud_self_shading;
uniform float eye_alt;
uniform float ground_scattering;
uniform float hazeLayerAltitude;
uniform float moonlight;
uniform float overcast;
uniform float scattering;
uniform float terminator;
uniform float terrain_alt;
uniform float visibility;
uniform float air_pollution;
uniform float snowlevel;
uniform float snow_thickness_factor;
uniform float osg_SimulationTime;
uniform float landing_light1_offset;
uniform float landing_light2_offset;
uniform float landing_light3_offset;
uniform bool use_IR_vision;
// constants needed by the light and fog computations ###################################################
const float EarthRadius = 5800000.0;
const float terminator_width = 200000.0;
uniform vec3 dirt_r_color;
uniform vec3 dirt_g_color;
uniform vec3 dirt_b_color;
uniform vec3 streetlight_color;
float DotNoise2D(in vec2 coord, in float wavelength, in float fractionalMaxDotSize, in float dot_density);
float shadow_func (in float x, in float y, in float noise, in float dist);
float fog_func (in float targ, in float altitude);
float rayleigh_in_func(in float dist, in float air_pollution, in float avisibility, in float eye_alt, in float vertex_alt);
float alt_factor(in float eye_alt, in float vertex_alt);
float light_distance_fading(in float dist);
float fog_backscatter(in float avisibility);
float rand2D(in vec2 co);
float Noise2D(in vec2 coord, in float wavelength);
vec3 rayleigh_out_shift(in vec3 color, in float outscatter);
vec3 get_hazeColor(in float lightArg);
vec3 searchlight();
vec3 landing_light(in float offset, in float offsetv);
vec3 filter_combined (in vec3 color) ;
vec3 addLights(in vec3 color1, in vec3 color2);
float light_func (in float x, in float a, in float b, in float c, in float d, in float e)
{
if (x > 30.0) {return e;}
if (x < -15.0) {return 0.0;}
return e / pow((1.0 + a * exp(-b * (x-c)) ),(1.0/d));
}
void road_type_mapper (in vec2 coord, out float rtype_traffic_density, out float rtype_base_illumination, out float rtype_traffic_speed)
{
if (coord.s < 0.125)
{
rtype_traffic_density = 0;
rtype_base_illumination = 0;
rtype_traffic_speed = 0.0;
}
else if (coord.s < 0.250)
{
rtype_traffic_density = 0.3;
rtype_base_illumination = 0.65;
rtype_traffic_speed = 0.5;
}
else if (coord.s < 0.375)
{
rtype_traffic_density = 1.0;
rtype_base_illumination = 1.0;
rtype_traffic_speed = 1.0;
}
else if (coord.s < 0.5)
{
rtype_traffic_density = 0.0;
rtype_base_illumination = 0.0;
rtype_traffic_speed = 0.0;
}
else if (coord.s < 0.625)
{
rtype_traffic_density = 0.0;
rtype_base_illumination = 0.0;
rtype_traffic_speed = 0.0;
}
else if (coord.s < 0.750)
{
rtype_traffic_density = 1.0;
rtype_base_illumination = 0.65;
rtype_traffic_speed = 1.0;
}
else if (coord.s < 0.875)
{
rtype_traffic_density = 0.1;
rtype_base_illumination = 0.0;
rtype_traffic_speed = 0.3;
}
else
{
rtype_traffic_density = 0.0;
rtype_base_illumination = 0.0;
rtype_traffic_speed = 0.0;
}
}
void main (void)
{
vec4 texel = texture2D(BaseTex, gl_TexCoord[0].st);
vec4 nmap = texture2D(NormalTex, gl_TexCoord[0].st * nmap_tile);
vec4 reflmap = texture2D(ReflMapTex, gl_TexCoord[0].st);
vec4 noisevec = texture3D(ReflNoiseTex, rawpos.xyz);
vec4 grainTexel;
vec3 mixedcolor;
vec3 N = vec3(0.0,0.0,1.0);
// noise
float noise_1m = Noise2D(rawpos.xy, 1.0);
float noise_5m = Noise2D(rawpos.xy, 5.0);
// road type characteristics
float rtype_traffic_density = 0.0;
float rtype_base_illumination = 0.0;
float rtype_traffic_speed = 0.0;
road_type_mapper (gl_TexCoord[0].st, rtype_traffic_density, rtype_base_illumination, rtype_traffic_speed);
float pf = 0.0;
float pf1 = 0.0;
///some generic light scattering parameters
vec3 shadedFogColor = vec3(0.55, 0.67, 0.88);
vec3 moonLightColor = vec3 (0.095, 0.095, 0.15) * moonlight;
float alt = eye_alt;
float effective_scattering = min(scattering, cloud_self_shading);
/// BEGIN geometry for light
vec3 up = (gl_ModelViewMatrix * vec4(0.0,0.0,1.0,0.0)).xyz;
float dist = length(vertVec);
float vertex_alt = max(100.0,dot(up, vertVec) + alt);
float vertex_scattering = ground_scattering + (1.0 - ground_scattering) * smoothstep(hazeLayerAltitude -100.0, hazeLayerAltitude + 100.0, vertex_alt);
vec3 lightHorizon = gl_LightSource[0].position.xyz - up * dot(up,gl_LightSource[0].position.xyz);
float yprime = -dot(vertVec, lightHorizon);
float yprime_alt = yprime - sqrt(2.0 * EarthRadius * vertex_alt);
float lightArg = (terminator-yprime_alt)/100000.0;
float earthShade = 0.6 * (1.0 - smoothstep(-terminator_width+ terminator, terminator_width + terminator, yprime_alt)) + 0.4;
float mie_angle;
if (lightArg < 10.0)
{mie_angle = (0.5 * dot(normalize(vertVec), normalize(gl_LightSource[0].position.xyz)) ) + 0.5;}
else
{mie_angle = 1.0;}
float fog_vertex_alt = max(vertex_alt,hazeLayerAltitude);
float fog_yprime_alt = yprime_alt;
if (fog_vertex_alt > hazeLayerAltitude)
{
if (dist > 0.8 * avisibility)
{
fog_vertex_alt = mix(fog_vertex_alt, hazeLayerAltitude, smoothstep(0.8*avisibility, avisibility, dist));
fog_yprime_alt = yprime -sqrt(2.0 * EarthRadius * fog_vertex_alt);
}
}
else
{
fog_vertex_alt = hazeLayerAltitude;
fog_yprime_alt = yprime -sqrt(2.0 * EarthRadius * fog_vertex_alt);
}
float fog_lightArg = (terminator-fog_yprime_alt)/100000.0;
float fog_earthShade = 0.9 * smoothstep(terminator_width+ terminator, -terminator_width + terminator, fog_yprime_alt) + 0.1;
float ct = dot(normalize(up), normalize(vertVec));
vec3 relPos = (gl_ModelViewMatrixInverse * vec4 (vertVec,0.0)).xyz;
/// END geometry for light
/// BEGIN light
vec4 light_diffuse;
vec4 light_ambient;
float intensity;
light_diffuse.b = light_func(lightArg, 1.330e-05, 0.264, 3.827, 1.08e-05, 1.0);
light_diffuse.g = light_func(lightArg, 3.931e-06, 0.264, 3.827, 7.93e-06, 1.0);
light_diffuse.r = light_func(lightArg, 8.305e-06, 0.161, 3.827, 3.04e-05, 1.0);
light_diffuse.a = 1.0;
light_diffuse = light_diffuse * vertex_scattering;
light_ambient.r = light_func(lightArg, 0.236, 0.253, 1.073, 0.572, 0.33);
light_ambient.g = light_ambient.r * 0.4/0.33;
light_ambient.b = light_ambient.r * 0.5/0.33;
light_ambient.a = 1.0;
if (earthShade < 0.5)
{
intensity = length(light_ambient.rgb);
light_ambient.rgb = intensity * normalize(mix(light_ambient.rgb, shadedFogColor, 1.0 -smoothstep(0.1, 0.8,earthShade) ));
light_ambient.rgb = light_ambient.rgb + moonLightColor * (1.0 - smoothstep(0.4, 0.5, earthShade));
intensity = length(light_diffuse.rgb);
light_diffuse.rgb = intensity * normalize(mix(light_diffuse.rgb, shadedFogColor, 1.0 -smoothstep(0.1, 0.7,earthShade) ));
}
vec4 ep = gl_ModelViewMatrixInverse * vec4(0.0,0.0,0.0,1.0);
vec3 ecViewDir = (gl_ModelViewMatrix * (ep - vec4(rawpos, 1.0))).xyz;
vec3 HV = normalize(normalize(gl_LightSource[0].position.xyz) + normalize(ecViewDir));
/// END light
/// BEGIN grain overlay
if (grain_texture_enabled ==1)
{
grainTexel = texture2D(GrainTex, gl_TexCoord[0].st * grain_magnification);
texel.rgb = mix(texel.rgb, grainTexel.rgb, grainTexel.a );
}
else if (grain_texture_enabled == 2)
{
grainTexel = texture2D(GrainTex, rawpos.xy * grain_magnification);
texel.rgb = mix(texel.rgb, grainTexel.rgb, grainTexel.a );
}
/// END grain overlay
/// BEGIN procedural textures - cars and snow
vec2 roadCoords = gl_TexCoord[0].st;
roadCoords.s *=8.0;
roadCoords.s = fract(roadCoords.s);
vec4 snow_texel = vec4 (0.95, 0.95, 0.95, 1.0);
float noise_term = 0.5 * (noise_5m - 0.5);
noise_term += 0.5 * (noise_1m - 0.5);
snow_texel.a = snow_texel.a * 0.2+0.8* smoothstep(0.2,0.8, 0.3 +noise_term + 0.5*snow_thickness_factor +0.0001*(relPos.z +eye_alt -snowlevel) );
float noise_2000m = 0.0;
float noise_10m = 0.0;
float snowLaneShape = smoothstep(0.20, 0.28, roadCoords.s) * (1.0-smoothstep(0.42, 0.5, roadCoords.s));
snowLaneShape += smoothstep(0.6, 0.68, roadCoords.s) * (1.0-smoothstep(0.82, 0.9, roadCoords.s));
snow_texel.a *= (1.0 - 0.3* snowLaneShape * rtype_traffic_density);
texel.rgb = mix(texel.rgb, snow_texel.rgb, snow_texel.a* smoothstep(snowlevel, snowlevel+200.0, 1.0 * (relPos.z + eye_alt)+ (noise_2000m + 0.1 * noise_10m -0.55) *400.0));
float cTag = 0.0;
float cPresent = 0.0;
if (road_traffic_enabled == 1)
{
float cSign = 1.0;
if (roadCoords.s > 0.5) {cSign = -1.0;}
cSign *= road_traffic_direction;
float total_traffic_density = road_traffic_density * rtype_traffic_density;
float cCoord = roadCoords.t;
cCoord += 0.3 * osg_SimulationTime * cSign * rtype_traffic_speed * (1.0 - (0.9 * smoothstep(1.0, 2.5, total_traffic_density)));
cCoord *= 5.0;
cTag = fract(cCoord);
float cDomain = cCoord - cTag;
float cRnd = rand2D(vec2 (cDomain, cSign));
cPresent = 0.0;
float cDisc = 0.2 * total_traffic_density;
if (cRnd > 1.0 - cDisc) {cPresent = 1.0;}
float cColorRnd = (cRnd - 1.0 + cDisc)/ max(cDisc, 0.05);
float cColorRnd2 = rand2D(vec2 (cDomain, 0.5));
vec3 cColor = vec3 (0.8 * (1.0 - cColorRnd), 0.8 * 2.0 * (0.5 - abs(cColorRnd - 0.5)) , 0.8 * cColorRnd);
cColor *= cColorRnd2;
float cPos = cTag;
if (cSign > 0.0) {cPos = 1.0 - cPos;}
float cShape = smoothstep(0.0, 0.05, cPos) * (1.0-smoothstep(0.35, 0.4, cPos));
float laneShape = smoothstep(0.25, 0.28, roadCoords.s) * (1.0-smoothstep(0.42, 0.45, roadCoords.s));
laneShape += smoothstep(0.65, 0.68, roadCoords.s) * (1.0-smoothstep(0.82, 0.85, roadCoords.s));
cShape *= laneShape;
texel.rgb = mix(texel.rgb, cColor, cPresent * cShape);
}
/// END procedural cars
vec3 reflVecN;
///BEGIN bump
if (nmap_enabled > 0){
N = nmap.rgb * 2.0 - 1.0;
// this is exact only for viewing under 90 degrees but much faster than the real solution
reflVecN = normalize (N.x * VTangent + N.y * VBinormal + N.z * reflVec);
N = normalize(N.x * VTangent + N.y * VBinormal + N.z * VNormal);
if (nmap_dds > 0)
N = -N;
} else {
N = normalize(VNormal);
reflVecN = reflVec;
}
///END bump
vec4 reflection = textureCube(Environment, reflVecN );
vec3 viewVec = normalize(vViewVec);
float v = abs(dot(viewVec, normalize(VNormal)));// Map a rainbowish color
vec4 fresnel = texture2D(ReflGradientsTex, vec2(v, 0.75));
vec4 rainbow = texture2D(ReflGradientsTex, vec2(v, 0.25));
float nDotVP = max(0.0, dot(N, normalize(gl_LightSource[0].position.xyz)));
//float nDotHV = max(0.0, dot(N, normalize(gl_LightSource[0].halfVector.xyz)));
float nDotHV = max(0.0, dot(N,HV));
//glare on the backside of tranparent objects
if ((gl_FrontMaterial.diffuse.a < 1.0 || texel.a < 1.0)
&& dot(N, normalize(gl_LightSource[0].position.xyz)) < 0.0) {
nDotVP = max(0.0, dot(-N, normalize(gl_LightSource[0].position.xyz)) * (1.0 -texel.a) );
nDotHV = max(0.0, dot(-N, HV) * (1.0 -texel.a) );
}
float nDotVP1 = 0.0;
float nDotHV1 = 0.0;
// try specular reflection of sky irradiance
nDotVP1 = max(0.0, dot(N, up));
nDotHV1 = max(0.0, dot(N, normalize(normalize(up) + normalize(-vertVec))));
if (nDotVP == 0.0)
{pf = 0.0;}
else
{pf = pow(nDotHV, gl_FrontMaterial.shininess);}
if (nDotVP1 == 0.0)
{pf1 = 0.0;}
else
{pf1 = pow(nDotHV1, 0.5*gl_FrontMaterial.shininess);}
if (cloud_shadow_flag == 1)
{
light_diffuse = light_diffuse * shadow_func(relPos.x, relPos.y, 1.0, dist);
}
vec3 secondary_light = vec3 (0.0,0.0,0.0);
if (use_searchlight == 1)
{
secondary_light += searchlight();
}
if (use_landing_light == 1)
{
secondary_light += landing_light(landing_light1_offset, landing_light3_offset);
}
if (use_alt_landing_light == 1)
{
secondary_light += landing_light(landing_light2_offset, landing_light3_offset);
}
vec4 Diffuse = light_diffuse * nDotVP;
Diffuse.rgb += secondary_light * light_distance_fading(dist);
if (use_IR_vision)
{
Diffuse.rgb = max(Diffuse.rgb, vec3 (0.5, 0.5, 0.5));
}
vec4 Specular = gl_FrontMaterial.specular * light_diffuse * pf + gl_FrontMaterial.specular * light_ambient * pf1;
Specular+= gl_FrontMaterial.specular * pow(max(0.0,-dot(N,normalize(vertVec))),gl_FrontMaterial.shininess) * vec4(secondary_light,1.0);
//vec4 color = gl_Color + Diffuse * gl_FrontMaterial.diffuse;
vec4 color = Diffuse;// * gl_FrontMaterial.diffuse;
color = clamp( color, 0.0, 1.0 );
////////////////////////////////////////////////////////////////////
//BEGIN reflect
////////////////////////////////////////////////////////////////////
if (refl_enabled > 0){
float reflFactor = 0.0;
float transparency_offset = clamp(refl_correction, -1.0, 1.0);// set the user shininess offset
if(refl_map > 0){
// map the shininess of the object with user input
//float pam = (map.a * -2) + 1; //reverse map
reflFactor = reflmap.a + transparency_offset;
} else if (nmap_enabled > 0) {
// set the reflectivity proportional to shininess with user input
reflFactor = gl_FrontMaterial.shininess * 0.0078125 * nmap.a + transparency_offset;
} else {
reflFactor = gl_FrontMaterial.shininess* 0.0078125 + transparency_offset;
}
// enhance low angle reflection by a fresnel term
float fresnel_enhance = (1.0-smoothstep(0.0,0.4, dot(N,-normalize(vertVec)))) * refl_fresnel_factor;
reflFactor+=fresnel_enhance;
reflFactor = clamp(reflFactor, 0.0, 1.0);
// add fringing fresnel and rainbow effects and modulate by reflection
vec4 reflcolor = mix(reflection, rainbow, refl_rainbow * v);
//vec4 reflcolor = reflection;
vec4 reflfrescolor = mix(reflcolor, fresnel, refl_fresnel * v);
vec4 noisecolor = mix(reflfrescolor, noisevec, refl_noise);
//vec4 raincolor = vec4(noisecolor.rgb * reflFactor, 1.0);
vec4 raincolor = vec4(noisecolor.rgb, 1.0);
raincolor += Specular;
raincolor *= light_diffuse;
if (refl_type == 1)
{mixedcolor = mix(texel, raincolor, reflFactor).rgb;}
else if (refl_type == 2)
{mixedcolor = ((texel +(reflcolor * reflFactor))-(0.5*reflFactor)).rgb;}
} else {
mixedcolor = texel.rgb;
}
/////////////////////////////////////////////////////////////////////
//END reflect
/////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////
//begin DIRT
//////////////////////////////////////////////////////////////////////
if (dirt_enabled >= 1){
vec3 dirtFactorIn = vec3 (dirt_r_factor, dirt_g_factor, dirt_b_factor);
vec3 dirtFactor = reflmap.rgb * dirtFactorIn.rgb;
//dirtFactor.r = smoothstep(0.0, 1.0, dirtFactor.r);
mixedcolor.rgb = mix(mixedcolor.rgb, dirt_r_color, smoothstep(0.0, 1.0, dirtFactor.r));
if (dirt_multi > 0) {
//dirtFactor.g = smoothstep(0.0, 1.0, dirtFactor.g);
//dirtFactor.b = smoothstep(0.0, 1.0, dirtFactor.b);
mixedcolor.rgb = mix(mixedcolor.rgb, dirt_g_color, smoothstep(0.0, 1.0, dirtFactor.g));
mixedcolor.rgb = mix(mixedcolor.rgb, dirt_b_color, smoothstep(0.0, 1.0, dirtFactor.b));
}
}
//////////////////////////////////////////////////////////////////////
//END Dirt
//////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////
//begin WETNESS
//////////////////////////////////////////////////////////////////////
if (rain_enabled >0.0)
{
texel.rgb = texel.rgb * (1.0 - 0.6 * wetness);
float rain_factor = 0.0;
float rain_orientation = max(dot(VNormal, up),0.0);
if ((rain_norm > 0.0) && (rain_orientation > 0.0))
{
rain_factor += DotNoise2D(rawpos.xy, 0.2 ,0.5, rain_norm) * abs(sin(6.0*osg_SimulationTime));
rain_factor += DotNoise2D(rawpos.xy, 0.3 ,0.4, rain_norm) * abs(sin(6.0*osg_SimulationTime + 2.094));
rain_factor += DotNoise2D(rawpos.xy, 0.4 ,0.3, rain_norm)* abs(sin(6.0*osg_SimulationTime + 4.188));
}
// secondary reflection of sky irradiance in water film
float fresnelW = ((0.8 * wetness) ) * (1.0-smoothstep(0.0,0.4, dot(N,-normalize(vertVec)) * 1.0 - 0.2 * rain_factor * wetness));
float sky_factor = (1.0-ct*ct);
vec3 sky_light = vec3 (1.0,1.0,1.0) * length(light_diffuse.rgb) * (1.0-effective_scattering);
Specular.rgb += sky_factor * fresnelW * sky_light;
}
/////////////////////////////////////////////////////////////////////
//end WETNESS
//////////////////////////////////////////////////////////////////////
// set ambient adjustment to remove bluiness with user input
float ambient_offset = clamp(amb_correction, -1.0, 1.0);
vec4 ambient = gl_LightModel.ambient + light_ambient;
vec4 ambient_Correction = vec4(ambient.rg, ambient.b * 0.6, 1.0)
* ambient_offset ;
ambient_Correction = clamp(ambient_Correction, -1.0, 1.0);
color += ambient;
color.a = texel.a * alpha;
vec4 fragColor = vec4(color.rgb * mixedcolor + ambient_Correction.rgb, color.a);
fragColor += Specular * nmap.a;
//////////////////////////////////////////////////////////////////////
// BEGIN procedural lightmap
//////////////////////////////////////////////////////////////////////
vec3 pLMColor = streetlight_color;//vec3 (0.941, 0.682, 0.086);
float pLMIntensity = smoothstep(0.0, 0.4, roadCoords.s) * (1.0 - smoothstep(0.6, 1.0, roadCoords.s));
pLMIntensity = 0.5 * rtype_base_illumination + 0.1 * max(0.0,sin(4.0 * roadCoords.t)) * streetlight_factor;
if (gl_FrontMaterial.diffuse.r == 0.0) {pLMIntensity =0.0;}
pLMColor *= pLMIntensity;
if (road_traffic_enabled == 1)
{
vec3 pCLColor = vec3 (0.95, 1.0, 1.0);
float pCLIntensity = smoothstep(0.4, 0.6, cTag) * (1.0-smoothstep(0.6, 0.8, cTag));
float laneFact = smoothstep(0.25, 0.3, roadCoords.s) * (1.0-smoothstep(0.3, 0.35, roadCoords.s));
laneFact += smoothstep(0.35, 0.4, roadCoords.s) * (1.0-smoothstep(0.4, 0.45, roadCoords.s));
laneFact += smoothstep(0.65, 0.7, roadCoords.s) * (1.0-smoothstep(0.7, 0.75, roadCoords.s));
laneFact += smoothstep(0.75, 0.8, roadCoords.s) * (1.0-smoothstep(0.8, 0.85, roadCoords.s));
pCLIntensity = pCLIntensity * laneFact * cPresent;
pCLColor = pCLColor *= pCLIntensity;
pLMColor = max(pLMColor,pCLColor);
}
//fragColor.rgb = max(fragColor.rgb, pLMColor * gl_FrontMaterial.diffuse.rgb * smoothstep(0.0, 1.0, mixedcolor*.5 + pLMColor*.5));
fragColor.rgb = max(fragColor.rgb, pLMColor * smoothstep(0.0, 1.0, mixedcolor*.5 + pLMColor*.5));
//////////////////////////////////////////////////////////////////////
// END procedural lightmap
//////////////////////////////////////////////////////////////////////
/// BEGIN fog amount
float transmission;
float vAltitude;
float delta_zv;
float H;
float distance_in_layer;
float transmission_arg;
float eqColorFactor;
float delta_z = hazeLayerAltitude - eye_alt;
float mvisibility = min(visibility, avisibility);
if (dist > 0.04 * mvisibility)
{
if (delta_z > 0.0) // we're inside the layer
{
if (ct < 0.0) // we look down
{
distance_in_layer = dist;
vAltitude = min(distance_in_layer,mvisibility) * ct;
delta_zv = delta_z - vAltitude;
}
else // we may look through upper layer edge
{
H = dist * ct;
if (H > delta_z) {distance_in_layer = dist/H * delta_z;}
else {distance_in_layer = dist;}
vAltitude = min(distance_in_layer,visibility) * ct;
delta_zv = delta_z - vAltitude;
}
}
else // we see the layer from above, delta_z < 0.0
{
H = dist * -ct;
if (H < (-delta_z)) // we don't see into the layer at all, aloft visibility is the only fading
{
distance_in_layer = 0.0;
delta_zv = 0.0;
}
else
{
vAltitude = H + delta_z;
distance_in_layer = vAltitude/H * dist;
vAltitude = min(distance_in_layer,visibility) * (-ct);
delta_zv = vAltitude;
}
}
transmission_arg = (dist-distance_in_layer)/avisibility;
if (visibility < avisibility)
{
transmission_arg = transmission_arg + (distance_in_layer/visibility);
eqColorFactor = 1.0 - 0.1 * delta_zv/visibility - (1.0 -effective_scattering);
}
else
{
transmission_arg = transmission_arg + (distance_in_layer/avisibility);
eqColorFactor = 1.0 - 0.1 * delta_zv/avisibility - (1.0 -effective_scattering);
}
transmission = fog_func(transmission_arg, alt);
if (eqColorFactor < 0.2) eqColorFactor = 0.2;
}
else
{
eqColorFactor = 1.0;
transmission = 1.0;
}
/// END fog amount
/// BEGIN fog color
vec3 hazeColor = get_hazeColor(fog_lightArg);
float rShade = 1.0 - 0.9 * smoothstep(-terminator_width+ terminator, terminator_width + terminator, yprime_alt + 420000.0);
float lightIntensity = length(hazeColor * effective_scattering) * rShade;
if (transmission< 1.0)
{
if (fog_lightArg < 10.0)
{
intensity = length(hazeColor);
float mie_magnitude = 0.5 * smoothstep(350000.0, 150000.0, terminator-sqrt(2.0 * EarthRadius * terrain_alt));
hazeColor = intensity * ((1.0 - mie_magnitude) + mie_magnitude * mie_angle) * normalize(mix(hazeColor, vec3 (0.5, 0.58, 0.65), mie_magnitude * (0.5 - 0.5 * mie_angle)) );
}
intensity = length(hazeColor);
hazeColor = intensity * normalize (mix(hazeColor, intensity * vec3 (1.0,1.0,1.0), 0.7* smoothstep(5000.0, 50000.0, alt)));
hazeColor.r = hazeColor.r * 0.83;
hazeColor.g = hazeColor.g * 0.9;
float fade_out = max(0.65 - 0.3 *overcast, 0.45);
intensity = length(hazeColor);
hazeColor = intensity * normalize(mix(hazeColor, 1.5* shadedFogColor, 1.0 -smoothstep(0.25, fade_out,fog_earthShade) ));
hazeColor = intensity * normalize(mix(hazeColor, shadedFogColor, (1.0-smoothstep(0.5,0.9,eqColorFactor))));
float shadow = mix( min(1.0 + dot(VNormal,gl_LightSource[0].position.xyz),1.0), 1.0, 1.0-smoothstep(0.1, 0.4, transmission));
hazeColor = mix(shadow * hazeColor, hazeColor, 0.3 + 0.7* smoothstep(250000.0, 400000.0, terminator));
}
else
{
hazeColor = vec3 (1.0, 1.0, 1.0);
}
/// END fog color
fragColor = clamp(fragColor, 0.0, 1.0);
hazeColor = clamp(hazeColor, 0.0, 1.0);
///BEGIN Rayleigh fog ///
// Rayleigh color shift due to out-scattering
float rayleigh_length = 0.5 * avisibility * (2.5 - 1.9 * air_pollution)/alt_factor(eye_alt, eye_alt+relPos.z);
float outscatter = 1.0-exp(-dist/rayleigh_length);
fragColor.rgb = rayleigh_out_shift(fragColor.rgb,outscatter);
vec3 rayleighColor = vec3 (0.17, 0.52, 0.87) * lightIntensity;
float rayleighStrength = rayleigh_in_func(dist, air_pollution, avisibility/max(lightIntensity,0.05), eye_alt, eye_alt + relPos.z);
fragColor.rgb = mix(fragColor.rgb, rayleighColor,rayleighStrength);
/// END Rayleigh fog
// don't let the light fade out too rapidly
lightArg = (terminator + 200000.0)/100000.0;
float minLightIntensity = min(0.2,0.16 * lightArg + 0.5);
vec3 minLight = minLightIntensity * vec3 (0.2, 0.3, 0.4);
hazeColor *= eqColorFactor * fog_earthShade;
hazeColor.rgb = max(hazeColor.rgb, minLight.rgb);
fragColor.rgb = mix(hazeColor +secondary_light * fog_backscatter(mvisibility), fragColor.rgb,transmission);
fragColor.rgb = filter_combined(fragColor.rgb);
//gl_FragColor = vec4 (1.0, 0.0, 0.0,1.0);
gl_FragColor = fragColor;
}