98fda02e65
Previously the water shader was separate and executed on a different mesh. This adds the water shader as a separate fragment function (ws30-water.frag) and uses a material parameter passed in as a Uniform to use it in preference to the usual texel lookup. Performance testing found a slight performance improvement from having a single mesh, but a slight performance impact from the extra fragment shader complexity.
325 lines
11 KiB
C++
325 lines
11 KiB
C++
// WS30 FRAGMENT SHADER
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// -*-C++-*-
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#version 130
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#extension GL_EXT_texture_array : enable
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// written by Thorsten Renk, Oct 2011, based on default.frag
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//////////////////////////////////////////////////////////////////
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// TEST PHASE TOGGLES AND CONTROLS
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//
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// Development tools:
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// Reduce haze to almost zero, while preserving lighting. Useful for observing distant tiles.
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// Keeps the calculation overhead. This can be used for profiling.
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// Possible values: 0:Normal, 1:Reduced haze.
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const int reduce_haze_without_removing_calculation_overhead = 0;
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// Remove haze and lighting and shows just the texture.
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// Useful for checking texture rendering and scenery.
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// The compiler will likely optimise out the haze and lighting calculations.
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// Possible values: 0:Normal, 1:Just the texture.
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const int remove_haze_and_lighting = 0;
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// Use built-in water shader. Use for testing impact of ws30-water.frag
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const int water_shader = 1;
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//
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// End of test phase controls
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//////////////////////////////////////////////////////////////////
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// Ambient term comes in gl_Color.rgb.
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varying vec4 light_diffuse_comp;
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varying vec3 normal;
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varying vec3 relPos;
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varying vec2 ground_tex_coord;
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uniform sampler2D landclass;
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uniform sampler2DArray textureArray;
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varying float yprime_alt;
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varying float mie_angle;
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varying vec4 ecPosition;
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uniform float visibility;
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uniform float avisibility;
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uniform float scattering;
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uniform float terminator;
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uniform float terrain_alt;
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uniform float hazeLayerAltitude;
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uniform float overcast;
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uniform float eye_alt;
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uniform float cloud_self_shading;
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// Passed from VPBTechnique, not the Effect
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// Passed from VPBTechnique, not the Effect
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uniform float fg_tileWidth;
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uniform float fg_tileHeight;
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uniform bool fg_photoScenery;
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uniform vec4 fg_dimensionsArray[128];
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uniform vec4 fg_ambientArray[128];
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uniform vec4 fg_diffuseArray[128];
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uniform vec4 fg_specularArray[128];
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uniform vec4 fg_textureLookup1[128];
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uniform vec4 fg_textureLookup2[128];
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uniform vec4 fg_materialParams3[128];
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#define MAX_TEXTURES 8
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uniform mat4 fg_zUpTransform;
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uniform vec3 fg_modelOffset;
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const float EarthRadius = 5800000.0;
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const float terminator_width = 200000.0;
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float alt;
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float eShade;
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float fog_func (in float targ, in float alt);
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vec3 get_hazeColor(in float light_arg);
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vec3 filter_combined (in vec3 color) ;
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float shadow_func (in float x, in float y, in float noise, in float dist);
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float DotNoise2D(in vec2 coord, in float wavelength, in float fractionalMaxDotSize, in float dot_density);
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float Noise2D(in vec2 coord, in float wavelength);
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float Noise3D(in vec3 coord, in float wavelength);
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float SlopeLines2D(in vec2 coord, in vec2 gradDir, in float wavelength, in float steepness);
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float Strata3D(in vec3 coord, in float wavelength, in float variation);
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float fog_func (in float targ, in float alt);
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float rayleigh_in_func(in float dist, in float air_pollution, in float avisibility, in float eye_alt, in float vertex_alt);
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float alt_factor(in float eye_alt, in float vertex_alt);
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float light_distance_fading(in float dist);
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float fog_backscatter(in float avisibility);
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vec3 rayleigh_out_shift(in vec3 color, in float outscatter);
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vec3 get_hazeColor(in float light_arg);
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vec3 searchlight();
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vec3 landing_light(in float offset, in float offsetv);
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vec3 filter_combined (in vec3 color) ;
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float getShadowing();
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vec3 getClusteredLightsContribution(vec3 p, vec3 n, vec3 texel);
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vec4 generateWaterTexel();
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// Not used
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float luminance(vec3 color)
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{
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return dot(vec3(0.212671, 0.715160, 0.072169), color);
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}
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//////////////////////////
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// Test-phase code:
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// These should be sent as uniforms
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// Tile dimensions in meters
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// vec2 tile_size = vec2(tile_width , tile_height);
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// Testing: texture coords are sent flipped right now:
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// Note tile_size is defined in the shader include: ws30-landclass-search-functions.frag.
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// vec2 tile_size = vec2(tile_height , tile_width);
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// From noise.frag
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float rand2D(in vec2 co);
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// Create random landclasses without a texture lookup to stress test.
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// Each square of square_size in m is assigned a random landclass value.
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int get_random_landclass(in vec2 co, in vec2 tile_size);
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// End Test-phase code
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////////////////////////
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// These functions, and other function they depend on, are defined
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// in ws30-ALS-landclass-search.frag.
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// Lookup a ground texture at a point based on the landclass at that point, without visible
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// seams at coordinate discontinuities or at landclass boundaries where texture are switched.
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// The partial derivatives of the tile_coord at the fragment is needed to adjust for
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// the stretching of different textures, so that the correct mip-map level is looked
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// up and there are no seams.
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// Texture types: 0: base texture, 1: grain texture, 2: gradient texture, 3 dot texture,
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// 4: mix texture, 5: detail texture.
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vec4 lookup_ground_texture_array(in int texture_type, in vec2 ground_texture_coord, in int landclass_id,
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in vec4 dFdx_and_dFdy);
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// Look up the landclass id [0 .. 255] for this particular fragment.
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// Lookup id of any neighbouring landclass that is within the search distance.
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// Searches are performed in upto 4 directions right now, but only one landclass is looked up
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// Create a mix factor werighting the influences of nearby landclasses
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void get_landclass_id(in vec2 tile_coord, in vec4 dFdx_and_dFdy,
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out int landclass_id, out ivec4 neighbor_landclass_ids,
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out int num_unique_neighbors,out vec4 mix_factor
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);
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// Look up the texel of the specified texture type (e.g. grain or detail textures) for this fragment
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// and any neighbor texels, then mix.
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vec4 get_mixed_texel(in int texture_type, in vec2 g_texture_coord,
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in int landclass_id, in int num_unique_neighbors,
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in ivec4 neighbor_texel_landclass_ids, in vec4 neighbor_mix_factors,
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in vec4 dFdx_and_dFdy
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);
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// Determine the texel and material parameters for a particular fragment,
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// Taking into account photoscenery etc.
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void get_material(in int landclass,
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in vec2 ground_tex_coord,
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in vec4 dxdy_gc,
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out float mat_shininess,
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out vec4 mat_ambient,
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out vec4 mat_diffuse,
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out vec4 mat_specular,
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out vec4 dxdy,
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out vec2 st
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);
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// Apply the ALS haze model to a specific fragment
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vec4 applyHaze(inout vec4 fragColor,
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inout vec3 hazeColor,
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in vec3 secondary_light,
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in float ct,
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in float hazeLayerAltitude,
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in float visibility,
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in float avisibility,
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in float dist,
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in float lightArg,
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in float mie_angle);
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// Procedurally generate a water texel for this fragment
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vec4 generateWaterTexel();
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void main()
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{
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vec3 shadedFogColor = vec3(0.55, 0.67, 0.88);
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// this is taken from default.frag
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float NdotL, NdotHV, fogFactor;
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vec3 n = normalize(normal);
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vec3 lightDir = gl_LightSource[0].position.xyz;
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vec3 halfVector = gl_LightSource[0].halfVector.xyz;
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vec4 texel;
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vec4 fragColor;
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vec4 specular = vec4(0.0);
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float intensity;
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// Material/texel properties
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float mat_shininess;
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vec2 st;
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vec4 mat_ambient, mat_diffuse, mat_specular, dxdy;
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// Tile texture coordinates range [0..1] over the tile 'rectangle'
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vec2 tile_coord = gl_TexCoord[0].st;
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// Look up the landclass id [0 .. 255] for this particular fragment
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// and any neighbouring landclass that is close.
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// Each tile has 1 texture containing landclass ids stetched over it.
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// Landclass for current fragment, and up-to 4 neighboring landclasses - 2 used currently
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int lc;
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ivec4 lc_n;
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int num_unique_neighbors = 0;
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// Mix factor of base textures for 2 neighbour landclass(es)
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vec4 mfact;
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// Partial derivatives of s and t for this fragment,
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// with respect to window (screen space) x and y axes.
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// Used to pick mipmap LoD levels, and turn off unneeded procedural detail
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// dFdx and dFdy are packed in a vec4 so multiplying
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// to scale takes 1 instruction slot.
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vec4 dxdy_gc = vec4(dFdx(tile_coord) , dFdy(tile_coord));
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get_landclass_id(tile_coord, dxdy_gc, lc, lc_n, num_unique_neighbors, mfact);
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get_material(lc, ground_tex_coord, dxdy_gc, mat_shininess, mat_ambient, mat_diffuse, mat_specular, dxdy, st);
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if (fg_photoScenery) {
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texel = texture(landclass, vec2(gl_TexCoord[0].s, 1.0 - gl_TexCoord[0].t));
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} else {
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// Lookup the base texture texel for this fragment. No mixing at this quality level.
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texel = lookup_ground_texture_array(0, st, lc, dxdy);
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}
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if ((water_shader == 1) && (fg_photoScenery == false) && fg_materialParams3[lc].x > 0.5) {
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// This is a water fragment, so calculate the fragment color procedurally
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fragColor = generateWaterTexel();
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fragColor.rgb += getClusteredLightsContribution(ecPosition.xyz, n, fragColor.rgb);
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} else {
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// Photoscenery or land fragment, so determine the shading and color normally
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vec4 color = mat_ambient * (gl_LightModel.ambient + gl_LightSource[0].ambient);
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// Testing code:
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// Use rlc even when looking up textures to recreate the extra performance hit
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// so any performance difference between the two is due to the texture lookup
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// color = color+0.00001*float(get_random_landclass(tile_coord.st, tile_size));
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float effective_scattering = min(scattering, cloud_self_shading);
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vec4 light_specular = gl_LightSource[0].specular;
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// If gl_Color.a == 0, this is a back-facing polygon and the
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// normal should be reversed.
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//n = (2.0 * gl_Color.a - 1.0) * normal;
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NdotL = dot(n, lightDir);
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vec4 diffuse_term = light_diffuse_comp * mat_diffuse;
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if (NdotL > 0.0) {
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float shadowmap = getShadowing();
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vec4 diffuse_term = light_diffuse_comp * mat_diffuse;
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color += diffuse_term * NdotL * shadowmap;
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NdotHV = max(dot(n, halfVector), 0.0);
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if (mat_shininess > 0.0)
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specular.rgb = (mat_specular.rgb
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* light_specular.rgb
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* pow(NdotHV, gl_FrontMaterial.shininess)
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* shadowmap);
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}
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color.a = diffuse_term.a;
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// This shouldn't be necessary, but our lighting becomes very
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// saturated. Clamping the color before modulating by the texture
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// is closer to what the OpenGL fixed function pipeline does.
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color = clamp(color, 0.0, 1.0);
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// Testing code: mix with green to show values of variables at each point
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//vec4 green = vec4(0.0, 0.5, 0.0, 0.0);
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//texel = mix(texel, green, (mfact[2]));
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fragColor = color * texel + specular;
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fragColor.rgb += getClusteredLightsContribution(ecPosition.xyz, n, texel.rgb);
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}
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// angle with horizon
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float dist = length(relPos);
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float ct = dot(vec3(0.0, 0.0, 1.0), relPos)/dist;
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float lightArg = (terminator-yprime_alt)/100000.0;
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vec3 hazeColor = get_hazeColor(lightArg);
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gl_FragColor = applyHaze(fragColor, hazeColor, vec3(0.0), ct, hazeLayerAltitude, visibility, avisibility, dist, lightArg, mie_angle);
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// Testing phase controls:
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if (remove_haze_and_lighting == 1)
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{
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gl_FragColor = texel;
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}
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}
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