// -*-C++-*- #version 120 #extension GL_EXT_draw_instanced : enable // Shader that uses OpenGL state values to do per-pixel lighting // // The only light used is gl_LightSource[0], which is assumed to be // directional. // // Diffuse colors come from the gl_Color, ambient from the material. This is // equivalent to osg::Material::DIFFUSE. // Haze part added by Thorsten Renk, Oct. 2011 #define MODE_OFF 0 #define MODE_DIFFUSE 1 #define MODE_AMBIENT_AND_DIFFUSE 2 attribute vec3 instancePosition; // (x,y,z) attribute vec3 instanceScale; // (width, depth, height) attribute vec3 attrib1; // Generic packed attributes attribute vec3 attrib2; // The constant term of the lighting equation that doesn't depend on // the surface normal is passed in gl_{Front,Back}Color. The alpha // component is set to 1 for front, 0 for back in order to work around // bugs with gl_FrontFacing in the fragment shader. varying vec4 diffuse_term; varying vec3 normal; varying vec3 relPos; //varying float earthShade; //varying float yprime; //varying float vertex_alt; varying float yprime_alt; varying float mie_angle; uniform int colorMode; uniform float hazeLayerAltitude; uniform float terminator; uniform float terrain_alt; uniform float avisibility; uniform float visibility; uniform float overcast; //uniform float scattering; uniform float ground_scattering; uniform bool use_IR_vision; // This is the value used in the skydome scattering shader - use the same here for consistency? const float EarthRadius = 5800000.0; const float terminator_width = 200000.0; float earthShade; //float mie_angle; float light_func (in float x, in float a, in float b, in float c, in float d, in float e) { //x = x - 0.5; // use the asymptotics to shorten computations if (x < -15.0) {return 0.0;} return e / pow((1.0 + a * exp(-b * (x-c)) ),(1.0/d)); } const float c_precision = 128.0; const float c_precisionp1 = c_precision + 1.0; vec3 float2vec(float value) { vec3 val; val.x = mod(value, c_precisionp1) / c_precision; val.y = mod(floor(value / c_precisionp1), c_precisionp1) / c_precision; val.z = floor(value / (c_precisionp1 * c_precisionp1)) / c_precision; return val; } void main() { vec4 light_diffuse; vec4 light_ambient; float yprime; float lightArg; float intensity; float vertex_alt; float scattering; vec3 shadedFogColor = vec3(0.55, 0.67, 0.88); // Unpack generic attributes vec3 attr1 = float2vec(attrib1.x); vec3 attr2 = float2vec(attrib1.z); vec3 attr3 = float2vec(attrib2.x); // Determine the rotation for the building. float sr = sin(6.28 * attr1.x); float cr = cos(6.28 * attr1.x); vec3 position = gl_Vertex.xyz; // Adjust the very top of the roof to match the rooftop scaling. This shapes // the rooftop - gambled, gabled etc. These vertices are identified by gl_Color.z position.x = (1.0 - gl_Color.z) * position.x + gl_Color.z * ((position.x + 0.5) * attr3.z - 0.5); position.y = (1.0 - gl_Color.z) * position.y + gl_Color.z * (position.y * attrib2.y ); // Adjust pitch of roof to the correct height. These vertices are identified by gl_Color.z // Scale down by the building height (instanceScale.z) because // immediately afterwards we will scale UP the vertex to the correct scale. position.z = position.z + gl_Color.z * attrib1.y / instanceScale.z; position = position * instanceScale.xyz; // Rotation of the building and movement into position position.xy = vec2(dot(position.xy, vec2(cr, sr)), dot(position.xy, vec2(-sr, cr))); position = position + instancePosition.xyz; gl_Position = gl_ModelViewProjectionMatrix * vec4(position,1.0); // Texture coordinates are stored as: // - a separate offset (x0, y0) for the wall (wtex0x, wtex0y), and roof (rtex0x, rtex0y) // - a semi-shared (x1, y1) so that the front and side of the building can have // different texture mappings // // The vertex color value selects between them: // gl_Color.x=1 indicates front/back walls // gl_Color.y=1 indicates roof // gl_Color.z=1 indicates top roof vertexs (used above) // gl_Color.a=1 indicates sides // Finally, the roof texture is on the right of the texture sheet float wtex0x = attr1.y; // Front/Side texture X0 float wtex0y = attr1.z; // Front/Side texture Y0 float rtex0x = attr2.z; // Roof texture X0 float rtex0y = attr3.x; // Roof texture Y0 float wtex1x = attr2.x; // Front/Roof texture X1 float stex1x = attr3.y; // Side texture X1 float wtex1y = attr2.y; // Front/Roof/Side texture Y1 vec2 tex0 = vec2(sign(gl_MultiTexCoord0.x) * (gl_Color.x*wtex0x + gl_Color.y*rtex0x + gl_Color.a*wtex0x), gl_Color.x*wtex0y + gl_Color.y*rtex0y + gl_Color.a*wtex0y); vec2 tex1 = vec2(gl_Color.x*wtex1x + gl_Color.y*wtex1x + gl_Color.a*stex1x, wtex1y); gl_TexCoord[0].x = tex0.x + gl_MultiTexCoord0.x * tex1.x; gl_TexCoord[0].y = tex0.y + gl_MultiTexCoord0.y * tex1.y; // Rotate the normal. normal = gl_Normal; normal.xy = vec2(dot(normal.xy, vec2(cr, sr)), dot(normal.xy, vec2(-sr, cr))); normal = gl_NormalMatrix * normal; vec4 ambient_color, diffuse_color; if (colorMode == MODE_DIFFUSE) { diffuse_color = vec4(1.0,1.0,1.0,1.0); ambient_color = gl_FrontMaterial.ambient; } else if (colorMode == MODE_AMBIENT_AND_DIFFUSE) { diffuse_color = vec4(1.0,1.0,1.0,1.0); ambient_color = vec4(1.0,1.0,1.0,1.0); } else { diffuse_color = gl_FrontMaterial.diffuse; ambient_color = gl_FrontMaterial.ambient; } // here start computations for the haze layer // we need several geometrical quantities // first current altitude of eye position in model space vec4 ep = gl_ModelViewMatrixInverse * vec4(0.0,0.0,0.0,1.0); // and relative position to vector relPos = gl_Vertex.xyz + gl_Color.xyz - ep.xyz; // unfortunately, we need the distance in the vertex shader, although the more accurate version // is later computed in the fragment shader again float dist = length(relPos); // altitude of the vertex in question, somehow zero leads to artefacts, so ensure it is at least 100m vertex_alt = max(gl_Vertex.z + gl_Color.z,100.0); scattering = ground_scattering + (1.0 - ground_scattering) * smoothstep(hazeLayerAltitude -100.0, hazeLayerAltitude + 100.0, vertex_alt); // branch dependent on daytime if (terminator < 1000000.0) // the full, sunrise and sunset computation { // establish coordinates relative to sun position vec3 lightFull = (gl_ModelViewMatrixInverse * gl_LightSource[0].position).xyz; vec3 lightHorizon = normalize(vec3(lightFull.x,lightFull.y, 0.0)); // yprime is the distance of the vertex into sun direction yprime = -dot(relPos, lightHorizon); // this gets an altitude correction, higher terrain gets to see the sun earlier yprime_alt = yprime - sqrt(2.0 * EarthRadius * vertex_alt); // two times terminator width governs how quickly light fades into shadow // now the light-dimming factor earthShade = 0.6 * (1.0 - smoothstep(-terminator_width+ terminator, terminator_width + terminator, yprime_alt)) + 0.4; // parametrized version of the Flightgear ground lighting function lightArg = (terminator-yprime_alt)/100000.0; // directional scattering for low sun if (lightArg < 10.0) {mie_angle = (0.5 * dot(normalize(relPos), normalize(lightFull)) ) + 0.5;} else {mie_angle = 1.0;} 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 * 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; // correct ambient light intensity and hue before sunrise if (earthShade < 0.5) { //light_ambient = light_ambient * (0.4 + 0.6 * smoothstep(0.2, 0.5, earthShade)); intensity = length(light_ambient.rgb); light_ambient.rgb = intensity * normalize(mix(light_ambient.rgb, shadedFogColor, 1.0 -smoothstep(0.4, 0.8,earthShade) )); intensity = length(light_diffuse.rgb); light_diffuse.rgb = intensity * normalize(mix(light_diffuse.rgb, shadedFogColor, 1.0 -smoothstep(0.4, 0.7,earthShade) )); } // the haze gets the light at the altitude of the haze top if the vertex in view is below // but the light at the vertex if the vertex is above vertex_alt = max(vertex_alt,hazeLayerAltitude); if (vertex_alt > hazeLayerAltitude) { if (dist > 0.8 * avisibility) { vertex_alt = mix(vertex_alt, hazeLayerAltitude, smoothstep(0.8*avisibility, avisibility, dist)); yprime_alt = yprime -sqrt(2.0 * EarthRadius * vertex_alt); } } else { vertex_alt = hazeLayerAltitude; yprime_alt = yprime -sqrt(2.0 * EarthRadius * vertex_alt); } } else // the faster, full-day version without lightfields { //vertex_alt = max(gl_Vertex.z,100.0); earthShade = 1.0; mie_angle = 1.0; if (terminator > 3000000.0) {light_diffuse = vec4 (1.0, 1.0, 1.0, 1.0); light_ambient = vec4 (0.33, 0.4, 0.5, 1.0); } else { lightArg = (terminator/100000.0 - 10.0)/20.0; light_diffuse.b = 0.78 + lightArg * 0.21; light_diffuse.g = 0.907 + lightArg * 0.091; light_diffuse.r = 0.904 + lightArg * 0.092; light_diffuse.a = 1.0; light_ambient.r = 0.316 + lightArg * 0.016; 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; } light_diffuse = light_diffuse * scattering; yprime_alt = -sqrt(2.0 * EarthRadius * hazeLayerAltitude); } if (use_IR_vision) { light_ambient.rgb = max(light_ambient.rgb, vec3 (0.5, 0.5, 0.5)); } // default lighting based on texture and material using the light we have just computed diffuse_term = diffuse_color* light_diffuse; vec4 constant_term = gl_FrontMaterial.emission + ambient_color * (gl_LightModel.ambient + light_ambient); // Super hack: if diffuse material alpha is less than 1, assume a // transparency animation is at work if (gl_FrontMaterial.diffuse.a < 1.0) diffuse_term.a = gl_FrontMaterial.diffuse.a; else diffuse_term.a = 1.0; // Another hack for supporting two-sided lighting without using // gl_FrontFacing in the fragment shader. gl_FrontColor.rgb = constant_term.rgb; gl_BackColor.rgb = constant_term.rgb; //gl_FrontColor.a = mie_angle; gl_BackColor.a = mie_angle; }