719 lines
21 KiB
GLSL
719 lines
21 KiB
GLSL
// This shader is mostly an adaptation of the shader found at
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// http://www.bonzaisoftware.com/water_tut.html and its glsl conversion
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// available at http://forum.bonzaisoftware.com/viewthread.php?tid=10
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// © Michael Horsch - 2005
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// Major update and revisions - 2011-10-07
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// © Emilian Huminiuc and Vivian Meazza
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// ported to ALS Thorsten Renk 2012
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#version 120
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uniform sampler2D water_normalmap;
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uniform sampler2D water_dudvmap;
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uniform sampler2D sea_foam;
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uniform sampler2D perlin_normalmap;
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uniform sampler2D ice_texture;
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uniform sampler2D topo_map;
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uniform float saturation, Overcast, WindE, WindN;
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uniform float osg_SimulationTime;
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varying vec4 waterTex1; //moving texcoords
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varying vec4 waterTex2; //moving texcoords
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varying vec4 waterTex4; //viewts
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varying vec3 viewerdir;
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varying vec3 lightdir;
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varying vec3 relPos;
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varying vec3 rawPos;
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varying vec2 TopoUV;
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varying float earthShade;
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varying float yprime_alt;
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varying float mie_angle;
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varying float steepness;
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uniform float WaveFreq ;
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uniform float WaveAmp ;
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uniform float WaveSharp ;
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uniform float WaveAngle ;
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uniform float WaveFactor ;
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uniform float WaveDAngle ;
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uniform float normalmap_dds;
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uniform float hazeLayerAltitude;
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uniform float terminator;
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uniform float terrain_alt;
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uniform float avisibility;
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uniform float visibility;
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uniform float overcast;
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uniform float scattering;
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uniform float ground_scattering;
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uniform float cloud_self_shading;
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uniform float eye_alt;
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uniform float fogstructure;
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uniform float ice_cover;
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uniform float sea_r;
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uniform float sea_g;
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uniform float sea_b;
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uniform float air_pollution;
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uniform float landing_light1_offset;
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uniform float landing_light2_offset;
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uniform float landing_light3_offset;
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uniform int quality_level;
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uniform int tquality_level;
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uniform int ocean_flag;
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uniform int cloud_shadow_flag;
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uniform int use_searchlight;
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uniform int use_landing_light;
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uniform int use_alt_landing_light;
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vec3 specular_light;
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const float terminator_width = 200000.0;
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const float EarthRadius = 5800000.0;
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////included functions /////
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float Noise3D(in vec3 coord, in float wavelength);
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float Noise2D(in vec2 coord, in float wavelength);
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float shadow_func (in float x, in float y, in float noise, in float dist);
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float fog_func (in float targ, in float alt);
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float rayleigh_in_func(in float dist, in float air_pollution, in float avisibility, in float eye_alt, in float vertex_alt);
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float alt_factor(in float eye_alt, in float vertex_alt);
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float light_distance_fading(in float dist);
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float fog_backscatter(in float avisibility);
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vec3 rayleigh_out_shift(in vec3 color, in float outscatter);
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vec3 get_hazeColor(in float light_arg);
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vec3 searchlight();
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vec3 landing_light(in float offset, in float offsetv);
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vec3 filter_combined (in vec3 color) ;
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//////////////////////
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/////// functions /////////
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void rotationmatrix(in float angle, out mat4 rotmat)
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{
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rotmat = mat4( cos( angle ), -sin( angle ), 0.0, 0.0,
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sin( angle ), cos( angle ), 0.0, 0.0,
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0.0 , 0.0 , 1.0, 0.0,
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0.0 , 0.0 , 0.0, 1.0 );
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}
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// wave functions ///////////////////////
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struct Wave {
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float freq; // 2*PI / wavelength
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float amp; // amplitude
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float phase; // speed * 2*PI / wavelength
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vec2 dir;
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};
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Wave wave0 = Wave(1.0, 1.0, 0.5, vec2(0.97, 0.25));
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Wave wave1 = Wave(2.0, 0.5, 1.3, vec2(0.97, -0.25));
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Wave wave2 = Wave(1.0, 1.0, 0.6, vec2(0.95, -0.3));
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Wave wave3 = Wave(2.0, 0.5, 1.4, vec2(0.99, 0.1));
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float evaluateWave(in Wave w, vec2 pos, float t)
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{
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return w.amp * sin( dot(w.dir, pos) * w.freq + t * w.phase);
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}
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// derivative of wave function
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float evaluateWaveDeriv(Wave w, vec2 pos, float t)
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{
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return w.freq * w.amp * cos( dot(w.dir, pos)*w.freq + t*w.phase);
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}
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// sharp wave functions
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float evaluateWaveSharp(Wave w, vec2 pos, float t, float k)
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{
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return w.amp * pow(sin( dot(w.dir, pos)*w.freq + t*w.phase)* 0.5 + 0.5 , k);
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}
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float evaluateWaveDerivSharp(Wave w, vec2 pos, float t, float k)
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{
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return k*w.freq*w.amp * pow(sin( dot(w.dir, pos)*w.freq + t*w.phase)* 0.5 + 0.5 , k - 1) * cos( dot(w.dir, pos)*w.freq + t*w.phase);
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}
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void sumWaves(float angle, float dangle, float windScale, float factor, out float ddx, float ddy)
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{
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mat4 RotationMatrix;
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float deriv;
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vec4 P = waterTex1 * 1024;
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rotationmatrix(radians(angle + dangle * windScale + 0.6 * sin(P.x * factor)), RotationMatrix);
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P *= RotationMatrix;
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P.y += evaluateWave(wave0, P.xz, osg_SimulationTime);
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deriv = evaluateWaveDeriv(wave0, P.xz, osg_SimulationTime );
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ddx = deriv * wave0.dir.x;
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ddy = deriv * wave0.dir.y;
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P.y += evaluateWave(wave1, P.xz, osg_SimulationTime);
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deriv = evaluateWaveDeriv(wave1, P.xz, osg_SimulationTime);
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ddx += deriv * wave1.dir.x;
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ddy += deriv * wave1.dir.y;
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P.y += evaluateWaveSharp(wave2, P.xz, osg_SimulationTime, WaveSharp);
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deriv = evaluateWaveDerivSharp(wave2, P.xz, osg_SimulationTime, WaveSharp);
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ddx += deriv * wave2.dir.x;
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ddy += deriv * wave2.dir.y;
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P.y += evaluateWaveSharp(wave3, P.xz, osg_SimulationTime, WaveSharp);
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deriv = evaluateWaveDerivSharp(wave3, P.xz, osg_SimulationTime, WaveSharp);
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ddx += deriv * wave3.dir.x;
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ddy += deriv * wave3.dir.y;
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}
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float light_func (in float x, in float a, in float b, in float c, in float d, in float e)
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{
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x = x - 0.5;
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// use the asymptotics to shorten computations
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if (x > 30.0) {return e;}
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if (x < -15.0) {return 0.0;}
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return e / pow((1.0 + a * exp(-b * (x-c)) ),(1.0/d));
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}
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// this determines how light is attenuated in the distance
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// physically this should be exp(-arg) but for technical reasons we use a sharper cutoff
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// for distance > visibility
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void main(void)
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{
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vec3 shadedFogColor = vec3(0.55, 0.67, 0.88);
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float effective_scattering = min(scattering, cloud_self_shading);
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float dist = length(relPos);
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const vec4 sca = vec4(0.005, 0.005, 0.005, 0.005);
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const vec4 sca2 = vec4(0.02, 0.02, 0.02, 0.02);
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const vec4 tscale = vec4(0.25, 0.25, 0.25, 0.25);
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float noise_50m = Noise3D(rawPos.xyz, 50.0);
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float noise_250m = Noise3D(rawPos.xyz,250.0);
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float noise_500m = Noise3D(rawPos.xyz,500.0);
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float noise_1500m = Noise3D(rawPos.xyz,1500.0);
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float noise_2000m = Noise3D(rawPos.xyz,2000.0);
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float noise_2500m = Noise3D(rawPos.xyz, 2500.0);
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// get depth map
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vec4 topoTexel = texture2D(topo_map, TopoUV);
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float floorMixFactor = smoothstep(0.3, 0.985, topoTexel.a);
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vec3 floorColour = topoTexel.rgb;
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mat4 RotationMatrix;
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// compute direction to viewer
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vec3 E = normalize(viewerdir);
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// compute direction to light source
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vec3 L = lightdir; // normalize(lightdir);
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// half vector
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vec3 Hv = normalize(L + E);
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//vec3 Normal = normalize(normal);
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vec3 Normal = vec3 (0.0, 0.0, 1.0);
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const float water_shininess = 240.0;
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// approximate cloud cover
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//float cover = 0.0;
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//bool Status = true;
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float windEffect = sqrt( WindE*WindE + WindN*WindN ) * 0.6; //wind speed in kt
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float windScale = 15.0/(3.0 + windEffect); //wave scale
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float windEffect_low = 0.3 + 0.7 * smoothstep(0.0, 5.0, windEffect); //low windspeed wave filter
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float waveRoughness = 0.01 + smoothstep(0.0, 40.0, windEffect); //wave roughness filter
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float mixFactor = 0.2 + 0.02 * smoothstep(0.0, 50.0, windEffect);
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//mixFactor = 0.2;
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mixFactor = clamp(mixFactor, 0.3, 0.8);
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// there's no need to do wave patterns or foam for pixels which are so far away that we can't actually see them
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// we only need detail in the near zone or where the sun reflection is
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int detail_flag;
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if ((dist > 15000.0) && (dot(normalize(vec3 (lightdir.x, lightdir.y, 0.0) ), normalize(relPos)) < 0.7 )) {detail_flag = 0;}
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else {detail_flag = 1;}
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//detail_flag = 1;
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// sine waves
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float ddx, ddx1, ddx2, ddx3, ddy, ddy1, ddy2, ddy3;
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float angle;
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ddx = 0.0, ddy = 0.0;
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ddx1 = 0.0, ddy1 = 0.0;
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ddx2 = 0.0, ddy2 = 0.0;
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ddx3 = 0.0, ddy3 = 0.0;
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if (detail_flag == 1)
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{
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angle = 0.0;
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wave0.freq = WaveFreq ;
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wave0.amp = WaveAmp;
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wave0.dir = vec2 (0.0, 1.0); //vec2(cos(radians(angle)), sin(radians(angle)));
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angle -= 45;
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wave1.freq = WaveFreq * 2.0 ;
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wave1.amp = WaveAmp * 1.25;
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wave1.dir = vec2(0.70710, -0.7071); //vec2(cos(radians(angle)), sin(radians(angle)));
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angle += 30;
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wave2.freq = WaveFreq * 3.5;
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wave2.amp = WaveAmp * 0.75;
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wave2.dir = vec2(0.96592, -0.2588);// vec2(cos(radians(angle)), sin(radians(angle)));
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angle -= 50;
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wave3.freq = WaveFreq * 3.0 ;
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wave3.amp = WaveAmp * 0.75;
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wave3.dir = vec2(0.42261, -0.9063); //vec2(cos(radians(angle)), sin(radians(angle)));
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// sum waves
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sumWaves(WaveAngle, -1.5, windScale, WaveFactor, ddx, ddy);
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sumWaves(WaveAngle, 1.5, windScale, WaveFactor, ddx1, ddy1);
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//reset the waves
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angle = 0.0;
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float waveamp = WaveAmp * 0.75;
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wave0.freq = WaveFreq ;
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wave0.amp = waveamp;
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wave0.dir = vec2 (0.0, 1.0); //vec2(cos(radians(angle)), sin(radians(angle)));
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angle -= 20;
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wave1.freq = WaveFreq * 2.0 ;
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wave1.amp = waveamp * 1.25;
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wave1.dir = vec2(0.93969, -0.34202);// vec2(cos(radians(angle)), sin(radians(angle)));
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angle += 35;
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wave2.freq = WaveFreq * 3.5;
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wave2.amp = waveamp * 0.75;
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wave2.dir = vec2(0.965925, 0.25881); //vec2(cos(radians(angle)), sin(radians(angle)));
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angle -= 45;
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wave3.freq = WaveFreq * 3.0 ;
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wave3.amp = waveamp * 0.75;
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wave3.dir = vec2(0.866025, -0.5); //vec2(cos(radians(angle)), sin(radians(angle)));
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sumWaves(WaveAngle + WaveDAngle, -1.5, windScale, WaveFactor, ddx2, ddy2);
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sumWaves(WaveAngle + WaveDAngle, 1.5, windScale, WaveFactor, ddx3, ddy3);
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}
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// end sine stuff
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//cover = 5.0 * smoothstep(0.6, 1.0, scattering);
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//cover = 5.0 * ground_scattering;
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vec4 viewt = normalize(waterTex4);
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vec4 disdis = texture2D(water_dudvmap, vec2(waterTex2 * tscale)* windScale) * 2.0 - 1.0;
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vec4 vNorm;
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//normalmaps
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vec4 nmap = texture2D(water_normalmap, vec2(waterTex1 + disdis * sca2) * windScale) * 2.0 - 1.0;
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vec4 nmap1 = texture2D(perlin_normalmap, vec2(waterTex1 + disdis * sca2) * windScale) * 2.0 - 1.0;
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rotationmatrix(radians(3.0 * sin(osg_SimulationTime * 0.0075)), RotationMatrix);
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nmap += texture2D(water_normalmap, vec2(waterTex2 * RotationMatrix * tscale) * windScale) * 2.0 - 1.0;
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nmap1 += texture2D(perlin_normalmap, vec2(waterTex2 * RotationMatrix * tscale) * windScale) * 2.0 - 1.0;
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nmap *= windEffect_low;
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nmap1 *= windEffect_low;
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// mix water and noise, modulated by factor
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vNorm = normalize(mix(nmap, nmap1, mixFactor) * waveRoughness);
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vNorm.r += ddx + ddx1 + ddx2 + ddx3;
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if (normalmap_dds > 0)
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{vNorm = -vNorm;} //dds fix
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vNorm = vNorm * (0.5 + 0.5 * noise_250m);
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//load reflection
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vec4 refl ;
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refl.r = sea_r;
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refl.g = sea_g;
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refl.b = sea_b;
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refl.a = 1.0;
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refl.g = refl.g * (0.9 + 0.2* noise_2500m);
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// the depth map works perfectly fine for both ocean and inland water texels
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refl.rgb = mix(refl.rgb, 0.65* floorColour, floorMixFactor);
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refl.rgb = refl.rgb * (0.5 + 0.5 * smoothstep(0.0,0.3,topoTexel.a));
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float intensity;
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// de-saturate for reduced light
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refl.rgb = mix(refl.rgb, vec3 (0.248, 0.248, 0.248), 1.0 - smoothstep(0.1, 0.8, ground_scattering));
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// de-saturate light for overcast haze
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intensity = length(refl.rgb);
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refl.rgb = mix(refl.rgb, intensity * vec3 (1.0, 1.0, 1.0), 0.5 * smoothstep(0.1, 0.9, overcast));
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vec3 N;
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vec3 N0 = vec3(texture2D(water_normalmap, vec2(waterTex1 + disdis * sca2) * windScale) * 2.0 - 1.0);
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vec3 N1 = vec3(texture2D(perlin_normalmap, vec2(waterTex1 + disdis * sca) * windScale) * 2.0 - 1.0);
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N0 += vec3(texture2D(water_normalmap, vec2(waterTex1 * tscale) * windScale) * 2.0 - 1.0);
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N1 += vec3(texture2D(perlin_normalmap, vec2(waterTex2 * tscale) * windScale) * 2.0 - 1.0);
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rotationmatrix(radians(2.0 * sin(osg_SimulationTime * 0.005)), RotationMatrix);
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N0 += vec3(texture2D(water_normalmap, vec2(waterTex2 * RotationMatrix * (tscale + sca2)) * windScale) * 2.0 - 1.0);
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N1 += vec3(texture2D(perlin_normalmap, vec2(waterTex2 * RotationMatrix * (tscale + sca2)) * windScale) * 2.0 - 1.0);
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rotationmatrix(radians(-4.0 * sin(osg_SimulationTime * 0.003)), RotationMatrix);
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N0 += vec3(texture2D(water_normalmap, vec2(waterTex1 * RotationMatrix + disdis * sca2) * windScale) * 2.0 - 1.0);
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N1 += vec3(texture2D(perlin_normalmap, vec2(waterTex1 * RotationMatrix + disdis * sca) * windScale) * 2.0 - 1.0);
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N0 *= windEffect_low;
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N1 *= windEffect_low;
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N0.r += (ddx + ddx1 + ddx2 + ddx3);
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N0.g += (ddy + ddy1 + ddy2 + ddy3);
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N = normalize(mix(Normal + N0, Normal + N1, mixFactor) * waveRoughness);
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if (normalmap_dds > 0)
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{N = -N;} //dds fix
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// primary reflection of the sun
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specular_light = gl_Color.rgb * earthShade;
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vec3 specular_color = vec3(specular_light)
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* pow(max(0.0, dot(N, Hv)), water_shininess) * 6.0;
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// secondary reflection of sky irradiance
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vec3 ER = E - 2.0 * N * dot(E,N);
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float ctrefl = dot(vec3(0.0,0.0,1.0), -normalize(ER));
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//float fresnel = -0.5 + 8.0 * (1.0-smoothstep(0.0,0.4, dot(E,N)));
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float fresnel = 8.0 * (1.0-smoothstep(0.0,0.4, dot(E,N)));
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//specular_color += (ctrefl*ctrefl) * fresnel* specular_light.rgb;
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specular_color += ((0.15*(1.0-ctrefl* ctrefl) * fresnel) - 0.3) * specular_light.rgb;
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vec4 specular = vec4(specular_color, 0.5);
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specular = specular * saturation * 0.3 * earthShade ;
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//calculate fresnel
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vec4 invfres = vec4( dot(vNorm, viewt) );
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vec4 fres = vec4(1.0) + invfres;
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refl *= fres;
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vec4 ambient_light;
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//intensity = length(specular_light.rgb);
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ambient_light.rgb = max(specular_light.rgb, vec3(0.05, 0.05, 0.05));
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//ambient_light.rgb = max(intensity * normalize(vec3 (0.33, 0.4, 0.5)), vec3 (0.1,0.1,0.1));
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ambient_light.a = 1.0;
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vec4 finalColor;
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// compute cloud shadow effect
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float shadowValue;
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if (cloud_shadow_flag == 1)
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{
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shadowValue = shadow_func(relPos.x, relPos.y, 0.3 * noise_250m + 0.5 * noise_500m+0.2 * noise_1500m, dist);
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specular = specular * shadowValue;
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refl = refl * (0.7 + 0.3 *shadowValue);
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}
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// compute secondary light effect
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vec3 secondary_light = vec3 (0.0,0.0,0.0);
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if ((quality_level >5)&&(tquality_level > 5))
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{
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if (use_searchlight == 1)
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{
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secondary_light += searchlight();
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}
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if (use_landing_light == 1)
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{
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secondary_light += landing_light(landing_light1_offset, landing_light3_offset);
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}
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if (use_alt_landing_light == 1)
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{
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secondary_light += landing_light(landing_light2_offset, landing_light3_offset);
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}
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}
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finalColor = refl + specular * smoothstep(0.3, 0.6, ground_scattering) + vec4 (secondary_light, 0.0) * light_distance_fading(dist) * 2.0 * pow(max(0.0,dot(E,N)), water_shininess);
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finalColor = clamp(finalColor, 0.0,1.0);
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//add foam
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vec4 foam_texel = texture2D(sea_foam, vec2(waterTex2 * tscale) * 25.0);
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if (dist < 10000.0)
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{
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float foamSlope = 0.10 + 0.1 * windScale;
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float waveSlope = N.g;
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float surfFact = 0.0;
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if ((windEffect >= 8.0) || (steepness < 0.999) || (topoTexel.a > 0.98))
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{
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if ((waveSlope > 0.0) && (ocean_flag ==1))
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{
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surfFact = surfFact +(1.0 -smoothstep(0.97,1.0,steepness));
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surfFact += 0.5 * smoothstep(0.98,1.0,topoTexel.a);
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waveSlope = waveSlope + 2.0 * surfFact;
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}
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if (waveSlope >= foamSlope){
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finalColor = mix(finalColor, max(finalColor, finalColor + foam_texel), smoothstep(0.01, 0.50, N.g+0.2 * surfFact));
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}
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}
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}
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// add ice
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vec4 ice_texel = texture2D(ice_texture, vec2(waterTex2) * 0.2 );
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float nSum = 0.5 * (noise_250m + noise_50m);
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float mix_factor = smoothstep(1.0 - ice_cover, 1.04-ice_cover, nSum);
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finalColor = mix(finalColor, ice_texel, mix_factor * ice_texel.a);
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finalColor.a = 1.0;
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finalColor *= vec4 (ambient_light.rgb + secondary_light * light_distance_fading(dist), ambient_light.a);
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|
|
|
float lightArg = (terminator-yprime_alt)/100000.0;
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vec3 hazeColor = get_hazeColor(lightArg); ;
|
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|
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// Rayleigh color shift due to out-scattering
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|
|
|
float rayleigh_length;
|
|
float outscatter;
|
|
|
|
if ((quality_level > 5) && (tquality_level > 5))
|
|
{
|
|
rayleigh_length = 0.4 * avisibility * (2.5 - 1.9 * air_pollution)/alt_factor(eye_alt, eye_alt+relPos.z);
|
|
outscatter = 1.0-exp(-dist/rayleigh_length);
|
|
finalColor.rgb = rayleigh_out_shift(finalColor.rgb,outscatter);
|
|
}
|
|
|
|
// Rayleigh color shift due to in-scattering
|
|
|
|
if ((quality_level > 5) && (tquality_level > 5))
|
|
{
|
|
float rShade = 1.0 - 0.9 * smoothstep(-terminator_width+ terminator, terminator_width + terminator, yprime_alt+420000.0);
|
|
//float lightIntensity = length(gl_Color.rgb* gl_FrontMaterial.diffuse.rgb)/1.73 * rShade;
|
|
float lightIntensity = length(hazeColor * effective_scattering) * rShade;
|
|
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);
|
|
finalColor.rgb = mix(finalColor.rgb, rayleighColor, rayleighStrength);
|
|
}
|
|
|
|
|
|
// here comes the terrain haze model
|
|
|
|
|
|
float delta_z = hazeLayerAltitude - eye_alt;
|
|
float mvisibility = min(visibility,avisibility);
|
|
|
|
if (dist > 0.04 * mvisibility)
|
|
{
|
|
|
|
|
|
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;
|
|
|
|
|
|
// we solve the geometry what part of the light path is attenuated normally and what is through the haze layer
|
|
|
|
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;
|
|
}
|
|
}
|
|
|
|
|
|
// ground haze cannot be thinner than aloft visibility in the model,
|
|
// so we need to use aloft visibility otherwise
|
|
|
|
|
|
transmission_arg = (dist-distance_in_layer)/avisibility;
|
|
|
|
|
|
float eqColorFactor;
|
|
|
|
if (visibility < avisibility)
|
|
{
|
|
if (quality_level > 3)
|
|
{
|
|
transmission_arg = transmission_arg + (distance_in_layer/(1.0 * visibility + 1.0 * visibility * fogstructure * 0.06 * (noise_1500m + noise_2000m -1.0) ));
|
|
}
|
|
else
|
|
{
|
|
transmission_arg = transmission_arg + (distance_in_layer/visibility);
|
|
}
|
|
// this combines the Weber-Fechner intensity
|
|
eqColorFactor = 1.0 - 0.1 * delta_zv/visibility - (1.0 -effective_scattering);
|
|
}
|
|
else
|
|
{
|
|
if (quality_level > 3)
|
|
{
|
|
transmission_arg = transmission_arg + (distance_in_layer/(1.0 * avisibility + 1.0 * avisibility * fogstructure * 0.06 * (noise_1500m + noise_2000m - 1.0) ));
|
|
}
|
|
else
|
|
{
|
|
transmission_arg = transmission_arg + (distance_in_layer/avisibility);
|
|
}
|
|
// this combines the Weber-Fechner intensity
|
|
eqColorFactor = 1.0 - 0.1 * delta_zv/avisibility - (1.0 -effective_scattering);
|
|
}
|
|
|
|
|
|
transmission = fog_func(transmission_arg, eye_alt);
|
|
|
|
// there's always residual intensity, we should never be driven to zero
|
|
if (eqColorFactor < 0.2) eqColorFactor = 0.2;
|
|
|
|
|
|
|
|
|
|
// now dim the light for haze
|
|
float eShade = 1.0 - 0.9 * smoothstep(-terminator_width+ terminator, terminator_width + terminator, yprime_alt);
|
|
|
|
// Mie-like factor
|
|
|
|
if (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)) );
|
|
}
|
|
|
|
// high altitude desaturation of the haze color
|
|
|
|
intensity = length(hazeColor);
|
|
|
|
|
|
if (intensity > 0.0) // this needs to be a condition, because otherwise hazeColor doesn't come out correctly
|
|
{
|
|
hazeColor = intensity * normalize (mix(hazeColor, intensity * vec3 (1.0,1.0,1.0), 0.7* smoothstep(5000.0, 50000.0, eye_alt)));
|
|
|
|
// blue hue of haze
|
|
|
|
hazeColor.x = hazeColor.x * 0.83;
|
|
hazeColor.y = hazeColor.y * 0.9;
|
|
|
|
|
|
// additional blue in indirect light
|
|
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,eShade) ));
|
|
|
|
// change haze color to blue hue for strong fogging
|
|
hazeColor = intensity * normalize(mix(hazeColor, shadedFogColor, (1.0-smoothstep(0.5,0.9,eqColorFactor))));
|
|
}
|
|
|
|
|
|
// 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 * eShade;
|
|
hazeColor.rgb = max(hazeColor.rgb, minLight.rgb);
|
|
|
|
finalColor.rgb = mix(hazeColor +secondary_light * fog_backscatter(mvisibility), finalColor.rgb,transmission);
|
|
}
|
|
|
|
finalColor.rgb = filter_combined(finalColor.rgb);
|
|
|
|
|
|
|
|
gl_FragColor = finalColor;
|
|
|
|
|
|
}
|