easy-osm2city-podman/full/fgdata/Shaders/tree-ALS-shadow.vert

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// -*-C++-*-
#version 120
// 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
// 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 vec3 relPos;
varying float yprime_alt;
varying float is_shadow;
varying float autumn_flag;
uniform int colorMode;
uniform int wind_effects;
uniform int forest_effects;
uniform int num_deciduous_trees;
uniform float hazeLayerAltitude;
uniform float terminator;
uniform float terrain_alt;
uniform float avisibility;
uniform float visibility;
uniform float overcast;
uniform float ground_scattering;
uniform float snow_level;
uniform float season;
uniform float forest_effect_size;
uniform float forest_effect_shape;
uniform float WindN;
uniform float WindE;
uniform bool use_tree_shadows;
uniform bool use_forest_effect;
uniform bool use_optimization;
uniform bool tree_patches;
uniform float osg_SimulationTime;
uniform int cloud_shadow_flag;
float earthShade;
float mie_angle;
float shadow_func (in float x, in float y, in float noise, in float dist);
float VoronoiNoise2D(in vec2 coord, in float wavelength, in float xrand, in float yrand);
// 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 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));
}
void main()
{
//vec4 light_diffuse;
vec4 light_ambient;
vec3 shadedFogColor = vec3(0.65, 0.67, 0.78);
float yprime;
float lightArg;
float intensity;
float vertex_alt;
float scattering;
is_shadow = -1.0;
// 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));
// eye position in model space
vec4 ep = gl_ModelViewMatrixInverse * vec4(0.0,0.0,0.0,1.0);
float rn_dist = length(gl_Color.xyz - ep.xyz) + 300.0 * mod(10.0 * gl_Color.x,1.0);
float rn = mod(100.0 * gl_Color.x + 100.0 * gl_Color.y,1.0);
float numVarieties = gl_Normal.z;
bool cull_flag = false;
float factor = 1.0;
float factor1 = 1.0;
if ((rn_dist > 2000.0) && (tree_patches == true) && (use_optimization == true))
{
if (rn > 0.15)
{cull_flag = true;}
else
{
numVarieties *=0.25;
factor = 5.2;
}
if (gl_FogCoord !=0.0) {cull_flag = true;}
}
if (cull_flag)
{
// move everything out of the view frustrum
gl_Position = vec4 (0.0,0.0,10.0,1.0);
gl_FrontColor.a = 0.0;
}
else
{
float texFract = floor(fract(gl_MultiTexCoord0.x) * numVarieties) / numVarieties;
// determine whether the tree changes color in autumn
if (texFract < float(num_deciduous_trees)/float(numVarieties)) {autumn_flag = 0.5 + fract(gl_Color.x);}
else {autumn_flag = 0.0;}
texFract += floor(gl_MultiTexCoord0.x) / numVarieties;
// Determine the rotation for the tree. The Fog Coordinate provides rotation information
// to rotate one of the quands by 90 degrees. We then apply an additional position seed
// so that trees aren't all oriented N/S
float sr;
float cr;
sr = sin(gl_FogCoord + gl_Color.x);
cr = cos(gl_FogCoord + gl_Color.x);
if (gl_FogCoord < 0.0)
{
sr = dot(lightHorizon.xy, vec2 (0.0,1.0));
cr = dot(lightHorizon.xy, vec2 (-1.0,0.0));
}
gl_TexCoord[0] = vec4(texFract, gl_MultiTexCoord0.y, 0.0, 0.0);
// Determine the y texture coordinate based on whether it's summer, winter, snowy.
gl_TexCoord[0].y = gl_TexCoord[0].y + 0.25 * step(snow_level, gl_Color.z) + 0.5 * season;
// scaling
vec3 position = gl_Vertex.xyz * gl_Normal.xxy;
// Rotation of the generic quad to specific one for the tree.
position.xy = factor * vec2(dot(position.xy, vec2(cr, sr)), dot(position.xy, vec2(-sr, cr)));
// Shear by wind. Note that this only applies to the top vertices
if (wind_effects > 0)
{
position.x = position.x + position.z * (sin(osg_SimulationTime * 1.8 + (gl_Color.x + gl_Color.y + gl_Color.z) * 0.01) + 1.0) * 0.0025 * WindN;
position.y = position.y + position.z * (sin(osg_SimulationTime * 1.8 + (gl_Color.x + gl_Color.y + gl_Color.z) * 0.01) + 1.0) * 0.0025 * WindE;
}
// Scale by random domains
float voronoi;
if ((forest_effects > 0)&& use_forest_effect)
{
voronoi = 0.5 + 1.0 * VoronoiNoise2D(gl_Color.xy, forest_effect_size, forest_effect_shape, forest_effect_shape);
position.xyz = position.xyz * voronoi;
}
// check if this is a shadow quad
if ((gl_FogCoord <0.0)&&(use_tree_shadows))
{
is_shadow = 1.0;
float sinAlpha = dot(lightFull, vec3 (0.0,0.0,1.0));
float cosAlpha = sqrt(1.0 - sinAlpha*sinAlpha);
float slope = dot(gl_SecondaryColor.xyz, vec3(0.0,0.0,1.0));
//float slope = 1.0;
position.x += position.z * clamp(cosAlpha/sinAlpha,-5.0,5.0) * -dot(lightHorizon.xy, vec2(1.0,0.0));
position.y += position.z * clamp(cosAlpha/sinAlpha,-5.0,5.0) * -dot(lightHorizon.xy, vec2 (0.0,1.0));
if (position.z > 3.0) // we deal with an upper vertex
{
vec3 terrainNormal = gl_SecondaryColor.xyz;
position.z = 0.4 + 10.0*(1.0 - slope) ;
float sinPhi = dot(terrainNormal, vec3(1.0,0.0,0.0));
float sinPsi = dot(terrainNormal, vec3(0.0,1.0,0.0));
position.z -= position.x * sinPhi;
position.z -= position.y * sinPsi;
}
else
{position.z = 0.4 + 10.0* (1.0-slope);}
}
// Move to correct location (stored in gl_Color)
position = position + gl_Color.xyz;
gl_Position = gl_ModelViewProjectionMatrix * vec4(position,1.0);
vec3 ecPosition = vec3(gl_ModelViewMatrix * vec4(position, 1.0));
//normal = normalize(-ecPosition);
//float n = dot(normalize(gl_LightSource[0].position.xyz), normalize(-ecPosition));
//vec4 diffuse_color = gl_FrontMaterial.diffuse * max(0.1, n);
//diffuse_color.a = 1.0;
vec4 ambient_color = gl_FrontMaterial.ambient;
// here start computations for the haze layer
// we need several geometrical quantities
relPos = position - 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(position.z,100.0);
scattering = ground_scattering + (1.0 - ground_scattering) * smoothstep(hazeLayerAltitude -100.0, hazeLayerAltitude + 100.0, vertex_alt);
// check whether we should see a shadow
if (is_shadow >0.0)
{
float view_angle = dot ((gl_SecondaryColor.xyz), normalize(relPos));
if (view_angle < 0.0) {is_shadow = -view_angle;}
else {is_shadow = 5.0;}
// the surface element will be in shadow
if (dot(normalize(lightFull),(gl_SecondaryColor.xyz)) < 0.0)
{ is_shadow = 5.0;}
}
// branch dependent on daytime
if (terminator < 1000000.0) // the full, sunrise and sunset computation
{
// 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_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(0.1, 0.8,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
{
earthShade = 1.0;
mie_angle = 1.0;
if (terminator > 3000000.0)
{light_ambient = vec4 (0.33, 0.4, 0.5, 1.0); }
else
{
lightArg = (terminator/100000.0 - 10.0)/20.0;
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;
}
yprime_alt = -sqrt(2.0 * EarthRadius * hazeLayerAltitude);
}
light_ambient.rgb = light_ambient.rgb * (1.0 + smoothstep(1000000.0, 3000000.0,terminator));
// tree shader lighting
if (cloud_shadow_flag == 1)
{light_ambient.rgb = light_ambient.rgb * (0.5 + 0.5 * shadow_func(relPos.x, relPos.y, 1.0, dist));}
gl_FrontColor = light_ambient * gl_FrontMaterial.ambient;
gl_FrontColor.a = mie_angle; gl_BackColor.a = mie_angle;
}
}