// WS30 FRAGMENT SHADER
// -*-C++-*-
#version 130
#extension GL_EXT_texture_array : enable
// written by Thorsten Renk, Oct 2011, based on default.frag
//////////////////////////////////////////////////////////////////
// TEST PHASE TOGGLES AND CONTROLS
//
// Development tools:
// Reduce haze to almost zero, while preserving lighting. Useful for observing distant tiles.
// Keeps the calculation overhead. This can be used for profiling.
// Possible values: 0:Normal, 1:Reduced haze.
const int reduce_haze_without_removing_calculation_overhead = 0;
// Remove haze and lighting and shows just the texture.
// Useful for checking texture rendering and scenery.
// The compiler will likely optimise out the haze and lighting calculations.
// Possible values: 0:Normal, 1:Just the texture.
const int remove_haze_and_lighting = 0;
//
// End of test phase controls
//////////////////////////////////////////////////////////////////
// Ambient term comes in gl_Color.rgb.
varying vec4 light_diffuse_comp;
varying vec3 normal;
varying vec3 relPos;
varying vec2 ground_tex_coord;
uniform sampler2D landclass;
uniform sampler2DArray textureArray;
varying float yprime_alt;
varying float mie_angle;
varying vec4 ecPosition;
uniform float visibility;
uniform float avisibility;
uniform float scattering;
uniform float terminator;
uniform float terrain_alt;
uniform float hazeLayerAltitude;
uniform float overcast;
uniform float eye_alt;
uniform float cloud_self_shading;
// Passed from VPBTechnique, not the Effect
// Passed from VPBTechnique, not the Effect
uniform float fg_tileWidth;
uniform float fg_tileHeight;
uniform bool fg_photoScenery;
uniform vec4 fg_dimensionsArray[128];
uniform vec4 fg_ambientArray[128];
uniform vec4 fg_diffuseArray[128];
uniform vec4 fg_specularArray[128];
uniform vec4 fg_textureLookup1[128];
uniform vec4 fg_textureLookup2[128];
#define MAX_TEXTURES 8
uniform mat4 fg_zUpTransform;
uniform vec3 fg_modelOffset;
const float EarthRadius = 5800000.0;
const float terminator_width = 200000.0;
float alt;
float eShade;
float fog_func (in float targ, in float alt);
vec3 get_hazeColor(in float light_arg);
vec3 filter_combined (in vec3 color) ;
float shadow_func (in float x, in float y, in float noise, in float dist);
float DotNoise2D(in vec2 coord, in float wavelength, in float fractionalMaxDotSize, in float dot_density);
float Noise2D(in vec2 coord, in float wavelength);
float Noise3D(in vec3 coord, in float wavelength);
float SlopeLines2D(in vec2 coord, in vec2 gradDir, in float wavelength, in float steepness);
float Strata3D(in vec3 coord, in float wavelength, in float variation);
float fog_func (in float targ, in float alt);
float rayleigh_in_func(in float dist, in float air_pollution, in float avisibility, in float eye_alt, in float vertex_alt);
float alt_factor(in float eye_alt, in float vertex_alt);
float light_distance_fading(in float dist);
float fog_backscatter(in float avisibility);
vec3 rayleigh_out_shift(in vec3 color, in float outscatter);
vec3 get_hazeColor(in float light_arg);
vec3 searchlight();
vec3 landing_light(in float offset, in float offsetv);
vec3 filter_combined (in vec3 color) ;
float getShadowing();
vec3 getClusteredLightsContribution(vec3 p, vec3 n, vec3 texel);
// Not used
float luminance(vec3 color)
{
return dot(vec3(0.212671, 0.715160, 0.072169), color);
}
//////////////////////////
// Test-phase code:
// These should be sent as uniforms
// Tile dimensions in meters
// vec2 tile_size = vec2(tile_width , tile_height);
// Testing: texture coords are sent flipped right now:
// Note tile_size is defined in the shader include: ws30-landclass-search-functions.frag.
// vec2 tile_size = vec2(tile_height , tile_width);
// From noise.frag
float rand2D(in vec2 co);
// These functions, and other function they depend on, are defined
// in ws30-ALS-landclass-search.frag.
// Create random landclasses without a texture lookup to stress test.
// Each square of square_size in m is assigned a random landclass value.
int get_random_landclass(in vec2 co, in vec2 tile_size);
// Lookup a ground texture at a point based on the landclass at that point, without visible
// seams at coordinate discontinuities or at landclass boundaries where texture are switched.
// The partial derivatives of the tile_coord at the fragment is needed to adjust for
// the stretching of different textures, so that the correct mip-map level is looked
// up and there are no seams.
// Texture types: 0: base texture, 1: grain texture, 2: gradient texture, 3 dot texture,
// 4: mix texture, 5: detail texture.
vec4 lookup_ground_texture_array(in int texture_type, in vec2 ground_texture_coord, in int landclass_id,
in vec4 dFdx_and_dFdy);
// Look up the landclass id [0 .. 255] for this particular fragment.
// Lookup id of any neighbouring landclass that is within the search distance.
// Searches are performed in upto 4 directions right now, but only one landclass is looked up
// Create a mix factor werighting the influences of nearby landclasses
void get_landclass_id(in vec2 tile_coord, in vec4 dFdx_and_dFdy,
out int landclass_id, out ivec4 neighbor_landclass_ids,
out int num_unique_neighbors,out vec4 mix_factor
);
// Look up the texel of the specified texture type (e.g. grain or detail textures) for this fragment
// and any neighbor texels, then mix.
vec4 get_mixed_texel(in int texture_type, in vec2 g_texture_coord,
in int landclass_id, in int num_unique_neighbors,
in ivec4 neighbor_texel_landclass_ids, in vec4 neighbor_mix_factors,
in vec4 dFdx_and_dFdy
);
// Determine the texel and material parameters for a particular fragment,
// Taking into account photoscenery etc.
void get_material(in int landclass,
in vec2 ground_tex_coord,
in vec4 dxdy_gc,
out float mat_shininess,
out vec4 mat_ambient,
out vec4 mat_diffuse,
out vec4 mat_specular,
out vec4 dxdy,
out vec2 st
);
// Apply the ALS haze model to a specific fragment
vec4 applyHaze(inout vec4 fragColor,
inout vec3 hazeColor,
in vec3 secondary_light,
in float ct,
in float hazeLayerAltitude,
in float visibility,
in float avisibility,
in float dist,
in float lightArg,
in float mie_angle);
// End Test-phase code
////////////////////////
void main()
{
vec3 shadedFogColor = vec3(0.55, 0.67, 0.88);
// this is taken from default.frag
vec3 n;
float NdotL, NdotHV, fogFactor;
vec3 lightDir = gl_LightSource[0].position.xyz;
vec3 halfVector = gl_LightSource[0].halfVector.xyz;
vec4 texel;
vec4 fragColor;
vec4 specular = vec4(0.0);
float intensity;
// Material/texel properties
float mat_shininess;
vec2 st;
vec4 mat_ambient, mat_diffuse, mat_specular, dxdy;
// Oct 27 2021:
// Geometry is in the form of roughly rectangular 'tiles'
// with a mesh forming a grid with regular spacing.
// Each vertex in the mesh is given an elevation
// Tile dimensions in m
// Testing: created from two float uniforms in global scope. Should be sent as a vec2
// vec2 tile_size
// Tile texture coordinates range [0..1] over the tile 'rectangle'
vec2 tile_coord = gl_TexCoord[0].st;
// Test phase: Constants and toggles for transitions between landlcasses are defined at
// the top of this file.
// Look up the landclass id [0 .. 255] for this particular fragment
// and any neighbouring landclass that is close.
// Each tile has 1 texture containing landclass ids stetched over it.
// Landclass for current fragment, and up-to 4 neighboring landclasses - 2 used currently
int lc;
ivec4 lc_n;
int num_unique_neighbors = 0;
// Mix factor of base textures for 2 neighbour landclass(es)
vec4 mfact;
// Partial derivatives of s and t for this fragment,
// with respect to window (screen space) x and y axes.
// Used to pick mipmap LoD levels, and turn off unneeded procedural detail
// dFdx and dFdy are packed in a vec4 so multiplying
// to scale takes 1 instruction slot.
vec4 dxdy_gc = vec4(dFdx(tile_coord) , dFdy(tile_coord));
get_landclass_id(tile_coord, dxdy_gc, lc, lc_n, num_unique_neighbors, mfact);
get_material(lc, ground_tex_coord, dxdy_gc, mat_shininess, mat_ambient, mat_diffuse, mat_specular, dxdy, st);
if (fg_photoScenery) {
texel = texture(landclass, vec2(gl_TexCoord[0].s, 1.0 - gl_TexCoord[0].t));
} else {
// Lookup the base texture texel for this fragment. No mixing at this quality level.
texel = lookup_ground_texture_array(0, st, lc, dxdy);
}
vec4 color = mat_ambient * (gl_LightModel.ambient + gl_LightSource[0].ambient);
// Testing code:
// Use rlc even when looking up textures to recreate the extra performance hit
// so any performance difference between the two is due to the texture lookup
// color = color+0.00001*float(get_random_landclass(tile_coord.st, tile_size));
float effective_scattering = min(scattering, cloud_self_shading);
vec4 light_specular = gl_LightSource[0].specular;
// If gl_Color.a == 0, this is a back-facing polygon and the
// normal should be reversed.
//n = (2.0 * gl_Color.a - 1.0) * normal;
n = normalize(normal);
NdotL = dot(n, lightDir);
vec4 diffuse_term = light_diffuse_comp * mat_diffuse;
if (NdotL > 0.0) {
float shadowmap = getShadowing();
vec4 diffuse_term = light_diffuse_comp * mat_diffuse;
color += diffuse_term * NdotL * shadowmap;
NdotHV = max(dot(n, halfVector), 0.0);
if (mat_shininess > 0.0)
specular.rgb = (mat_specular.rgb
* light_specular.rgb
* pow(NdotHV, gl_FrontMaterial.shininess)
* shadowmap);
}
color.a = diffuse_term.a;
// This shouldn't be necessary, but our lighting becomes very
// saturated. Clamping the color before modulating by the texture
// is closer to what the OpenGL fixed function pipeline does.
color = clamp(color, 0.0, 1.0);
// Testing code: mix with green to show values of variables at each point
//vec4 green = vec4(0.0, 0.5, 0.0, 0.0);
//texel = mix(texel, green, (mfact[2]));
fragColor = color * texel + specular;
fragColor.rgb += getClusteredLightsContribution(ecPosition.xyz, n, texel.rgb);
float dist = length(relPos);
// angle with horizon
float ct = dot(vec3(0.0, 0.0, 1.0), relPos)/dist;
float lightArg = (terminator-yprime_alt)/100000.0;
vec3 hazeColor = get_hazeColor(lightArg);
gl_FragColor = applyHaze(fragColor, hazeColor, vec3(0.0), ct, hazeLayerAltitude, visibility, avisibility, dist, lightArg, mie_angle);
// Testing phase controls:
if (remove_haze_and_lighting == 1)
{
gl_FragColor = texel;
}
}