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fgdata/Shaders/light-ALS.frag
2016-02-03 09:13:30 +02:00

230 lines
5.4 KiB
C++

// -*-C++-*-
uniform sampler2D texture;
uniform float light_color_base_r;
uniform float light_color_base_g;
uniform float light_color_base_b;
uniform float light_color_center_r;
uniform float light_color_center_g;
uniform float light_color_center_b;
uniform float intensity_scale;
uniform float pointing_x;
uniform float pointing_y;
uniform float pointing_z;
uniform float outer_angle;
uniform float inner_angle;
uniform float zero_angle;
uniform float outer_gain;
uniform float visibility;
uniform float avisibility;
uniform float hazeLayerAltitude;
uniform float eye_alt;
uniform float terminator;
uniform float osg_SimulationTime;
uniform bool is_directional;
uniform bool is_strobe;
varying vec3 vertex;
varying vec3 relPos;
varying vec3 normal;
float Noise2D(in vec2 coord, in float wavelength);
float fog_func (in float targ, in float alt);
float shape (in vec3 coord, in float noise, in float fade, in float transmission, in float glare, in float lightArg)
{
float r = length (coord) / max(fade, 0.2);
float angle = noise * 6.2832;
float sinphi = dot(vec2 (sin(angle),cos(angle)), normalize(coord.yz));
float sinterm = sin(mod((sinphi-3.0) * (sinphi-3.0),6.2832));
float ray = 0.0;
if (sinterm == 0.0)
{ray = 0.0;}
else
{ray = clamp(pow(sinterm,10.0),0.0,1.0);
ray *= exp(-40.0 * r * r) * smoothstep(0.8, 1.0,fade) * smoothstep(0.7, 1.0, glare);
}
float base = exp(-80.0*r*r );
float halo = 0.2 * exp(-10.0 * r * r) * (1.0 - smoothstep(-5.0, 0.0, lightArg));
float fogEffect = (1.0-smoothstep(0.4,0.8,transmission));
//fogEffect = 1.0;
//float offset = 0.0;
//offset *=0.3;
//vec2 offset_vec = vec2 (1.0, 0.0);
//offset_vec *= offset;
// vec2 coord_reduced1 = vec2(coord.y- 1.2* offset_vec.x, coord.z - 1.2 * offset_vec.y);
//vec2 coord_reduced2 = vec2(coord.y- 2.0 * offset_vec.x, coord.z - 2.0 * offset_vec.y);
//vec3 coord_reduced = coord;
//r = min(length (coord_reduced1), 0.8* length(coord_reduced2));
//r /= 1.0 - 0.3 * smoothstep(0.0, 0.3, offset);
float intensity = clamp(base + halo + ray,0.0,1.0) + 0.2 * fogEffect * (1.0-smoothstep(0.3, 0.6,r));
intensity *=fade;
return intensity;
}
float directional_fade (in float direction)
{
float arg = clamp(direction, 0.0, 1.0);
float ia = (1.0 - inner_angle);
float oa = (1.0 - outer_angle);
float za = (1.0 - zero_angle);
if (direction > ia) {return 1.0;}
else if (direction > oa)
{return outer_gain + (1.0-outer_gain) * (direction - oa) / (ia - oa);}
else if (direction > za)
{return outer_gain * (direction - za) / (oa - za);}
else {return 0.0;}
}
float strobe_fade (in float fade)
{
float time_arg1 = sin(4.0 * osg_SimulationTime);
float time_arg2 = sin(4.0 * osg_SimulationTime - 0.4);
return fade * 0.825 * (pow(time_arg1, 40.0) + pow(time_arg2, 8.0));
}
void main()
{
float noise = 0.0;
vec3 light_color_base = vec3 (light_color_base_r, light_color_base_g, light_color_base_b);
vec3 light_color_center = vec3 (light_color_center_r, light_color_center_g, light_color_center_b);
vec3 pointing_vec = vec3 (pointing_x, pointing_y, pointing_z);
vec3 viewDir = normalize(relPos);
// fogging
float dist = length(relPos);
float delta_z = hazeLayerAltitude - eye_alt;
float transmission;
float vAltitude;
float delta_zv;
float H;
float distance_in_layer;
float transmission_arg;
// angle with horizon
float ct = dot(vec3(0.0, 0.0, 1.0), relPos)/dist;
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,min(visibility, avisibility)) * 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))
{
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);
}
else
{
transmission_arg = transmission_arg + (distance_in_layer/avisibility);
}
transmission = fog_func(transmission_arg, 0.0);
float lightArg = terminator/100000.0;
float r = length(vertex);
float mix_factor = 0.3 + 0.7 * smoothstep(0.0, 0.5, r);
// directionality
vec3 nViewDir = normalize(viewDir);
vec3 nPointingVec = normalize(pointing_vec);
float direction = dot (nViewDir, nPointingVec );
float fade;
vec2 offset = vec2 (0.0, 0.0);
if (is_directional)
{
fade = directional_fade(direction);
}
else
{fade = 1.0;}
// time evolution
if (is_strobe) {fade = strobe_fade (fade);}
fade *= intensity_scale;
// disc size correction for daylight
// shape of the light disc
float glare = length(light_color_center)/1.7321 * (1.0 - smoothstep(-5.0, 10.0, lightArg));
float intensity = shape(vertex, noise, fade, transmission, glare, lightArg);
// coloring of the light disc
vec3 light_color = mix(light_color_base, light_color_center, intensity*intensity);
gl_FragColor = vec4 (light_color.rgb, intensity * transmission );
}