1// -*-C++-*- 2#version 120 3 4varying vec2 rawPos; 5varying vec2 nPos; 6varying vec3 vertPos; 7varying vec3 normal; 8varying vec3 light_diffuse; 9varying vec3 refl_vec; 10varying float splash_angle; 11varying float Mie; 12varying float ambient_fraction; 13 14varying float flogz; 15 16uniform float ground_scattering; 17uniform float hazeLayerAltitude; 18uniform float moonlight; 19uniform float terminator; 20uniform float splash_x; 21uniform float splash_y; 22uniform float splash_z; 23 24const float EarthRadius = 5800000.0; 25const float terminator_width = 200000.0; 26 27float light_func (in float x, in float a, in float b, in float c, in float d, in float e) 28{ 29//x = x - 0.5; 30 31// use the asymptotics to shorten computations 32if (x < -15.0) {return 0.0;} 33 34return e / pow((1.0 + a * exp(-b * (x-c)) ),(1.0/d)); 35} 36 37 38void main() 39{ 40 41vec3 shadedFogColor = vec3(0.55, 0.67, 0.88); 42vec3 moonLightColor = vec3 (0.095, 0.095, 0.15) * moonlight; 43 44// geometry for lighting 45vec4 ep = gl_ModelViewMatrixInverse * vec4(0.0,0.0,0.0,1.0); 46vec3 relPos = gl_Vertex.xyz - ep.xyz; 47vec3 lightFull = (gl_ModelViewMatrixInverse * gl_LightSource[0].position).xyz; 48vec3 lightHorizon = normalize(vec3(lightFull.x,lightFull.y, 0.0)); 49float dist = length(relPos); 50float vertex_alt = max(gl_Vertex.z,100.0); 51float scattering = ground_scattering + (1.0 - ground_scattering) * smoothstep(hazeLayerAltitude -100.0, hazeLayerAltitude + 100.0, vertex_alt); 52float yprime_alt = - sqrt(2.0 * EarthRadius * vertex_alt); 53float earthShade = 0.6 * (1.0 - smoothstep(-terminator_width+ terminator, terminator_width + terminator, yprime_alt)) + 0.4; 54float lightArg = (terminator-yprime_alt)/100000.0; 55 56// light computation 57 58vec3 light_ambient; 59 60light_diffuse.b = light_func(lightArg, 1.330e-05, 0.264, 3.827, 1.08e-05, 1.0); 61light_diffuse.g = light_func(lightArg, 3.931e-06, 0.264, 3.827, 7.93e-06, 1.0); 62light_diffuse.r = light_func(lightArg, 8.305e-06, 0.161, 3.827, 3.04e-05, 1.0); 63light_diffuse = light_diffuse * scattering; 64 65 66light_ambient.r = light_func(lightArg, 0.236, 0.253, 1.073, 0.572, 0.33); 67light_ambient.g = light_ambient.r * 0.4/0.33; 68light_ambient.b = light_ambient.r * 0.5/0.33; 69 70float intensity; 71 72if (earthShade < 0.5) 73 { 74 intensity = length(light_ambient.xyz); 75 76 light_ambient.rgb = intensity * normalize(mix(light_ambient.rgb, shadedFogColor, 1.0 -smoothstep(0.4, 0.8,earthShade) )); 77 light_ambient.rgb = light_ambient.rgb + moonLightColor * (1.0 - smoothstep(0.4, 0.5, earthShade)); 78 79 intensity = length(light_diffuse.xyz); 80 light_diffuse.rgb = intensity * normalize(mix(light_diffuse.rgb, shadedFogColor, 1.0 -smoothstep(0.4, 0.7,earthShade) )); 81 } 82 83 84float MieFactor = dot(normalize(lightFull), normalize(relPos)); 85Mie = smoothstep(0.9,1.0, MieFactor) * earthShade * earthShade * scattering; 86 87 88// get a reflection vector for cube map 89 90vec4 ecPosition = gl_ModelViewMatrix * gl_Vertex; 91normal = normalize(gl_NormalMatrix * gl_Normal); 92vec4 reflect_eye = vec4(reflect(ecPosition.xyz, normal), 0.0); 93vec3 reflVec_stat = normalize(gl_ModelViewMatrixInverse * reflect_eye).xyz; 94refl_vec = reflVec_stat; 95 96// get a projection plane orthogonal to the splash vector 97 98vec3 splash_vec = vec3 (splash_x, splash_y, splash_z); 99vec3 corrected_splash = normalize(splash_vec); 100 101float angle = abs(dot(corrected_splash, gl_Normal)); 102 103 104//corrected_splash = normalize(corrected_splash + 0.4* gl_Normal ); 105 106 107vec3 base_1 = vec3 (-corrected_splash.y, corrected_splash.x, 0.0); 108vec3 base_2 = cross (corrected_splash, base_1); 109 110base_1 = normalize(base_1); 111base_2 = normalize(base_2); 112 113rawPos = vec2 (dot(gl_Vertex.xyz, base_1), dot(gl_Vertex.xyz, base_2)); 114 115base_1 = vec3 (-gl_Normal.y, gl_Normal.x, 0.0); 116base_2 = cross(gl_Normal, base_1); 117 118base_1 = normalize(base_1); 119base_2 = normalize(base_2); 120 121nPos = vec2 (dot(gl_Vertex.xyz, base_1), dot(gl_Vertex.xyz, base_2)); 122 123vertPos = gl_Vertex.xyz; 124 125splash_angle = dot(gl_Normal, corrected_splash); 126 127ambient_fraction = length(light_ambient.rgb)/(length(light_diffuse.rgb +light_ambient.rgb ) + 0.01); 128 129 130gl_Position = ftransform(); 131// logarithmic depth 132flogz = 1.0 + gl_Position.w; 133 134vec4 diffuse_color = gl_FrontMaterial.diffuse; 135vec4 ambient_color = gl_FrontMaterial.ambient; 136 137vec4 constant_term = gl_FrontMaterial.emission + ambient_color * vec4 (light_diffuse.rgb + light_ambient.rgb,1.0); 138constant_term.a = min(diffuse_color.a, ambient_color.a); 139 140gl_FrontColor = constant_term; 141gl_BackColor = gl_FrontColor; 142 143} 144