mirror of https://github.com/minetest/minetest.git
458 lines
14 KiB
GLSL
458 lines
14 KiB
GLSL
uniform sampler2D baseTexture;
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uniform vec3 dayLight;
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uniform vec4 skyBgColor;
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uniform float fogDistance;
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uniform vec3 eyePosition;
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// The cameraOffset is the current center of the visible world.
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uniform vec3 cameraOffset;
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uniform float animationTimer;
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#ifdef ENABLE_DYNAMIC_SHADOWS
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// shadow texture
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uniform sampler2D ShadowMapSampler;
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// shadow uniforms
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uniform vec3 v_LightDirection;
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uniform float f_textureresolution;
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uniform mat4 m_ShadowViewProj;
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uniform float f_shadowfar;
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uniform float f_shadow_strength;
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uniform vec4 CameraPos;
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uniform float xyPerspectiveBias0;
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uniform float xyPerspectiveBias1;
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varying float adj_shadow_strength;
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varying float cosLight;
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varying float f_normal_length;
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varying vec3 shadow_position;
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varying float perspective_factor;
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#endif
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varying vec3 vNormal;
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varying vec3 vPosition;
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// World position in the visible world (i.e. relative to the cameraOffset.)
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// This can be used for many shader effects without loss of precision.
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// If the absolute position is required it can be calculated with
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// cameraOffset + worldPosition (for large coordinates the limits of float
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// precision must be considered).
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varying vec3 worldPosition;
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varying lowp vec4 varColor;
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#ifdef GL_ES
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varying mediump vec2 varTexCoord;
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#else
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centroid varying vec2 varTexCoord;
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#endif
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varying vec3 eyeVec;
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varying float nightRatio;
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varying vec3 tsEyeVec;
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varying vec3 lightVec;
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varying vec3 tsLightVec;
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const float fogStart = FOG_START;
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const float fogShadingParameter = 1.0 / ( 1.0 - fogStart);
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#ifdef ENABLE_DYNAMIC_SHADOWS
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// assuming near is always 1.0
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float getLinearDepth()
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{
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return 2.0 * f_shadowfar / (f_shadowfar + 1.0 - (2.0 * gl_FragCoord.z - 1.0) * (f_shadowfar - 1.0));
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}
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vec3 getLightSpacePosition()
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{
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return shadow_position * 0.5 + 0.5;
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}
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// custom smoothstep implementation because it's not defined in glsl1.2
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// https://docs.gl/sl4/smoothstep
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float mtsmoothstep(in float edge0, in float edge1, in float x)
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{
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float t = clamp((x - edge0) / (edge1 - edge0), 0.0, 1.0);
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return t * t * (3.0 - 2.0 * t);
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}
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#ifdef COLORED_SHADOWS
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// c_precision of 128 fits within 7 base-10 digits
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const float c_precision = 128.0;
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const float c_precisionp1 = c_precision + 1.0;
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float packColor(vec3 color)
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{
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return floor(color.b * c_precision + 0.5)
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+ floor(color.g * c_precision + 0.5) * c_precisionp1
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+ floor(color.r * c_precision + 0.5) * c_precisionp1 * c_precisionp1;
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}
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vec3 unpackColor(float value)
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{
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vec3 color;
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color.b = mod(value, c_precisionp1) / c_precision;
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color.g = mod(floor(value / c_precisionp1), c_precisionp1) / c_precision;
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color.r = floor(value / (c_precisionp1 * c_precisionp1)) / c_precision;
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return color;
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}
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vec4 getHardShadowColor(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
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{
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vec4 texDepth = texture2D(shadowsampler, smTexCoord.xy).rgba;
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float visibility = step(0.0, realDistance - texDepth.r);
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vec4 result = vec4(visibility, vec3(0.0,0.0,0.0));//unpackColor(texDepth.g));
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if (visibility < 0.1) {
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visibility = step(0.0, realDistance - texDepth.b);
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result = vec4(visibility, unpackColor(texDepth.a));
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}
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return result;
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}
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#else
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float getHardShadow(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
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{
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float texDepth = texture2D(shadowsampler, smTexCoord.xy).r;
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float visibility = step(0.0, realDistance - texDepth);
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return visibility;
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}
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#endif
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#if SHADOW_FILTER == 2
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#define PCFBOUND 2.0 // 5x5
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#define PCFSAMPLES 25
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#elif SHADOW_FILTER == 1
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#define PCFBOUND 1.0 // 3x3
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#define PCFSAMPLES 9
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#else
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#define PCFBOUND 0.0
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#define PCFSAMPLES 1
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#endif
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#ifdef COLORED_SHADOWS
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float getHardShadowDepth(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
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{
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vec4 texDepth = texture2D(shadowsampler, smTexCoord.xy);
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float depth = max(realDistance - texDepth.r, realDistance - texDepth.b);
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return depth;
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}
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#else
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float getHardShadowDepth(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
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{
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float texDepth = texture2D(shadowsampler, smTexCoord.xy).r;
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float depth = realDistance - texDepth;
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return depth;
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}
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#endif
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#define BASEFILTERRADIUS 1.0
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float getPenumbraRadius(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
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{
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// Return fast if sharp shadows are requested
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if (PCFBOUND == 0.0 || SOFTSHADOWRADIUS <= 0.0)
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return 0.0;
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vec2 clampedpos;
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float y, x;
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float depth = getHardShadowDepth(shadowsampler, smTexCoord.xy, realDistance);
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// A factor from 0 to 1 to reduce blurring of short shadows
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float sharpness_factor = 1.0;
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// conversion factor from shadow depth to blur radius
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float depth_to_blur = f_shadowfar / SOFTSHADOWRADIUS / xyPerspectiveBias0;
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if (depth > 0.0 && f_normal_length > 0.0)
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// 5 is empirical factor that controls how fast shadow loses sharpness
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sharpness_factor = clamp(5 * depth * depth_to_blur, 0.0, 1.0);
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depth = 0.0;
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float world_to_texture = xyPerspectiveBias1 / perspective_factor / perspective_factor
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* f_textureresolution / 2.0 / f_shadowfar;
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float world_radius = 0.2; // shadow blur radius in world float coordinates, e.g. 0.2 = 0.02 of one node
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return max(BASEFILTERRADIUS * f_textureresolution / 4096.0, sharpness_factor * world_radius * world_to_texture * SOFTSHADOWRADIUS);
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}
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#ifdef POISSON_FILTER
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const vec2[64] poissonDisk = vec2[64](
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vec2(0.170019, -0.040254),
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vec2(-0.299417, 0.791925),
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vec2(0.645680, 0.493210),
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vec2(-0.651784, 0.717887),
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vec2(0.421003, 0.027070),
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vec2(-0.817194, -0.271096),
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vec2(-0.705374, -0.668203),
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vec2(0.977050, -0.108615),
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vec2(0.063326, 0.142369),
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vec2(0.203528, 0.214331),
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vec2(-0.667531, 0.326090),
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vec2(-0.098422, -0.295755),
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vec2(-0.885922, 0.215369),
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vec2(0.566637, 0.605213),
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vec2(0.039766, -0.396100),
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vec2(0.751946, 0.453352),
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vec2(0.078707, -0.715323),
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vec2(-0.075838, -0.529344),
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vec2(0.724479, -0.580798),
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vec2(0.222999, -0.215125),
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vec2(-0.467574, -0.405438),
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vec2(-0.248268, -0.814753),
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vec2(0.354411, -0.887570),
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vec2(0.175817, 0.382366),
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vec2(0.487472, -0.063082),
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vec2(0.355476, 0.025357),
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vec2(-0.084078, 0.898312),
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vec2(0.488876, -0.783441),
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vec2(0.470016, 0.217933),
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vec2(-0.696890, -0.549791),
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vec2(-0.149693, 0.605762),
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vec2(0.034211, 0.979980),
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vec2(0.503098, -0.308878),
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vec2(-0.016205, -0.872921),
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vec2(0.385784, -0.393902),
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vec2(-0.146886, -0.859249),
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vec2(0.643361, 0.164098),
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vec2(0.634388, -0.049471),
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vec2(-0.688894, 0.007843),
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vec2(0.464034, -0.188818),
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vec2(-0.440840, 0.137486),
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vec2(0.364483, 0.511704),
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vec2(0.034028, 0.325968),
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vec2(0.099094, -0.308023),
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vec2(0.693960, -0.366253),
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vec2(0.678884, -0.204688),
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vec2(0.001801, 0.780328),
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vec2(0.145177, -0.898984),
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vec2(0.062655, -0.611866),
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vec2(0.315226, -0.604297),
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vec2(-0.780145, 0.486251),
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vec2(-0.371868, 0.882138),
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vec2(0.200476, 0.494430),
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vec2(-0.494552, -0.711051),
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vec2(0.612476, 0.705252),
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vec2(-0.578845, -0.768792),
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vec2(-0.772454, -0.090976),
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vec2(0.504440, 0.372295),
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vec2(0.155736, 0.065157),
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vec2(0.391522, 0.849605),
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vec2(-0.620106, -0.328104),
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vec2(0.789239, -0.419965),
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vec2(-0.545396, 0.538133),
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vec2(-0.178564, -0.596057)
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);
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#ifdef COLORED_SHADOWS
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vec4 getShadowColor(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
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{
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float radius = getPenumbraRadius(shadowsampler, smTexCoord, realDistance);
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if (radius < 0.1) {
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// we are in the middle of even brightness, no need for filtering
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return getHardShadowColor(shadowsampler, smTexCoord.xy, realDistance);
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}
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vec2 clampedpos;
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vec4 visibility = vec4(0.0);
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float scale_factor = radius / f_textureresolution;
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int samples = (1 + 1 * int(SOFTSHADOWRADIUS > 1.0)) * PCFSAMPLES; // scale max samples for the soft shadows
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samples = int(clamp(pow(4.0 * radius + 1.0, 2.0), 1.0, float(samples)));
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int init_offset = int(floor(mod(((smTexCoord.x * 34.0) + 1.0) * smTexCoord.y, 64.0-samples)));
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int end_offset = int(samples) + init_offset;
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for (int x = init_offset; x < end_offset; x++) {
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clampedpos = poissonDisk[x] * scale_factor + smTexCoord.xy;
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visibility += getHardShadowColor(shadowsampler, clampedpos.xy, realDistance);
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}
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return visibility / samples;
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}
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#else
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float getShadow(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
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{
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float radius = getPenumbraRadius(shadowsampler, smTexCoord, realDistance);
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if (radius < 0.1) {
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// we are in the middle of even brightness, no need for filtering
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return getHardShadow(shadowsampler, smTexCoord.xy, realDistance);
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}
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vec2 clampedpos;
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float visibility = 0.0;
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float scale_factor = radius / f_textureresolution;
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int samples = (1 + 1 * int(SOFTSHADOWRADIUS > 1.0)) * PCFSAMPLES; // scale max samples for the soft shadows
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samples = int(clamp(pow(4.0 * radius + 1.0, 2.0), 1.0, float(samples)));
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int init_offset = int(floor(mod(((smTexCoord.x * 34.0) + 1.0) * smTexCoord.y, 64.0-samples)));
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int end_offset = int(samples) + init_offset;
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for (int x = init_offset; x < end_offset; x++) {
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clampedpos = poissonDisk[x] * scale_factor + smTexCoord.xy;
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visibility += getHardShadow(shadowsampler, clampedpos.xy, realDistance);
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}
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return visibility / samples;
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}
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#endif
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#else
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/* poisson filter disabled */
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#ifdef COLORED_SHADOWS
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vec4 getShadowColor(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
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{
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float radius = getPenumbraRadius(shadowsampler, smTexCoord, realDistance);
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if (radius < 0.1) {
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// we are in the middle of even brightness, no need for filtering
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return getHardShadowColor(shadowsampler, smTexCoord.xy, realDistance);
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}
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vec2 clampedpos;
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vec4 visibility = vec4(0.0);
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float x, y;
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float bound = (1 + 0.5 * int(SOFTSHADOWRADIUS > 1.0)) * PCFBOUND; // scale max bound for soft shadows
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bound = clamp(0.5 * (4.0 * radius - 1.0), 0.5, bound);
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float scale_factor = radius / bound / f_textureresolution;
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float n = 0.0;
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// basic PCF filter
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for (y = -bound; y <= bound; y += 1.0)
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for (x = -bound; x <= bound; x += 1.0) {
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clampedpos = vec2(x,y) * scale_factor + smTexCoord.xy;
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visibility += getHardShadowColor(shadowsampler, clampedpos.xy, realDistance);
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n += 1.0;
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}
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return visibility / max(n, 1.0);
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}
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#else
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float getShadow(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
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{
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float radius = getPenumbraRadius(shadowsampler, smTexCoord, realDistance);
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if (radius < 0.1) {
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// we are in the middle of even brightness, no need for filtering
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return getHardShadow(shadowsampler, smTexCoord.xy, realDistance);
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}
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vec2 clampedpos;
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float visibility = 0.0;
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float x, y;
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float bound = (1 + 0.5 * int(SOFTSHADOWRADIUS > 1.0)) * PCFBOUND; // scale max bound for soft shadows
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bound = clamp(0.5 * (4.0 * radius - 1.0), 0.5, bound);
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float scale_factor = radius / bound / f_textureresolution;
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float n = 0.0;
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// basic PCF filter
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for (y = -bound; y <= bound; y += 1.0)
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for (x = -bound; x <= bound; x += 1.0) {
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clampedpos = vec2(x,y) * scale_factor + smTexCoord.xy;
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visibility += getHardShadow(shadowsampler, clampedpos.xy, realDistance);
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n += 1.0;
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}
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return visibility / max(n, 1.0);
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}
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#endif
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#endif
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#endif
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void main(void)
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{
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vec3 color;
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vec2 uv = varTexCoord.st;
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vec4 base = texture2D(baseTexture, uv).rgba;
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// If alpha is zero, we can just discard the pixel. This fixes transparency
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// on GPUs like GC7000L, where GL_ALPHA_TEST is not implemented in mesa,
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// and also on GLES 2, where GL_ALPHA_TEST is missing entirely.
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#ifdef USE_DISCARD
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if (base.a == 0.0)
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discard;
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#endif
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#ifdef USE_DISCARD_REF
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if (base.a < 0.5)
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discard;
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#endif
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color = base.rgb;
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vec4 col = vec4(color.rgb * varColor.rgb, 1.0);
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#ifdef ENABLE_DYNAMIC_SHADOWS
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if (f_shadow_strength > 0.0) {
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float shadow_int = 0.0;
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vec3 shadow_color = vec3(0.0, 0.0, 0.0);
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vec3 posLightSpace = getLightSpacePosition();
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float distance_rate = (1.0 - pow(clamp(2.0 * length(posLightSpace.xy - 0.5),0.0,1.0), 10.0));
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if (max(abs(posLightSpace.x - 0.5), abs(posLightSpace.y - 0.5)) > 0.5)
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distance_rate = 0.0;
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float f_adj_shadow_strength = max(adj_shadow_strength-mtsmoothstep(0.9,1.1, posLightSpace.z),0.0);
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if (distance_rate > 1e-7) {
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#ifdef COLORED_SHADOWS
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vec4 visibility;
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if (cosLight > 0.0 || f_normal_length < 1e-3)
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visibility = getShadowColor(ShadowMapSampler, posLightSpace.xy, posLightSpace.z);
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else
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visibility = vec4(1.0, 0.0, 0.0, 0.0);
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shadow_int = visibility.r;
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shadow_color = visibility.gba;
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#else
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if (cosLight > 0.0 || f_normal_length < 1e-3)
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shadow_int = getShadow(ShadowMapSampler, posLightSpace.xy, posLightSpace.z);
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else
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shadow_int = 1.0;
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#endif
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shadow_int *= distance_rate;
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shadow_int = clamp(shadow_int, 0.0, 1.0);
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}
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// turns out that nightRatio falls off much faster than
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// actual brightness of artificial light in relation to natual light.
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// Power ratio was measured on torches in MTG (brightness = 14).
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float adjusted_night_ratio = pow(max(0.0, nightRatio), 0.6);
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// Apply self-shadowing when light falls at a narrow angle to the surface
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// Cosine of the cut-off angle.
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const float self_shadow_cutoff_cosine = 0.035;
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if (f_normal_length != 0 && cosLight < self_shadow_cutoff_cosine) {
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shadow_int = max(shadow_int, 1 - clamp(cosLight, 0.0, self_shadow_cutoff_cosine)/self_shadow_cutoff_cosine);
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shadow_color = mix(vec3(0.0), shadow_color, min(cosLight, self_shadow_cutoff_cosine)/self_shadow_cutoff_cosine);
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}
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shadow_int *= f_adj_shadow_strength;
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// calculate fragment color from components:
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col.rgb =
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adjusted_night_ratio * col.rgb + // artificial light
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(1.0 - adjusted_night_ratio) * ( // natural light
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col.rgb * (1.0 - shadow_int * (1.0 - shadow_color)) + // filtered texture color
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dayLight * shadow_color * shadow_int); // reflected filtered sunlight/moonlight
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}
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#endif
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// Due to a bug in some (older ?) graphics stacks (possibly in the glsl compiler ?),
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// the fog will only be rendered correctly if the last operation before the
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// clamp() is an addition. Else, the clamp() seems to be ignored.
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// E.g. the following won't work:
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// float clarity = clamp(fogShadingParameter
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// * (fogDistance - length(eyeVec)) / fogDistance), 0.0, 1.0);
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// As additions usually come for free following a multiplication, the new formula
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// should be more efficient as well.
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// Note: clarity = (1 - fogginess)
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float clarity = clamp(fogShadingParameter
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- fogShadingParameter * length(eyeVec) / fogDistance, 0.0, 1.0);
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col = mix(skyBgColor, col, clarity);
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col = vec4(col.rgb, base.a);
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gl_FragData[0] = col;
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}
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