317 lines
11 KiB
GLSL
317 lines
11 KiB
GLSL
|
// -*-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 vec4 ecPosition;
|
||
|
|
|
||
|
|
//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;
|
||
|
|
|
||
|
|
void setupShadows(vec4 eyeSpacePos);
|
||
|
|
|
||
|
|
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;
|
||
|
|
|
||
|
|
ecPosition = gl_ModelViewMatrix * vec4(position, 1.0);
|
||
|
|
setupShadows(ecPosition);
|
||
|
|
}
|