61 lines
1.6 KiB
Plaintext
61 lines
1.6 KiB
Plaintext
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uniform float4 fog_depths : $fogDepths;
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$if ( r_megaDrawMethod == 0 )
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uniform float4 fog_parameters : $fogParams;
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uniform float3 fog_eyePos : $viewOriginWorld;
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$endif
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uniform float3 fog_viewOrigin : $viewOrigin;
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$if ( r_megaDrawMethod == 0 )
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uniform float4 fog_matrix_x : $transposedModelMatrix_x;
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uniform float4 fog_matrix_y : $transposedModelMatrix_y;
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uniform float4 fog_matrix_z : $transposedModelMatrix_z;
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$endif
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//MAD result.color.secondary, _F1.x, $fogDepths.z, $fogDepths.w;
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float2 Extinction(float3 inpos) {
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$if ( r_megaDrawMethod != 0 )
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float3 diff = inpos - fog_viewOrigin;
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float d = length( diff );
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return 1.f-saturate( d * fog_depths.z + fog_depths.w );
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$else
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float3 eye = fog_eyePos;
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float4 iP = float4(inpos,1);
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float3 pos;
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pos.x = dot( iP, fog_matrix_x );
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pos.y = dot( iP, fog_matrix_y );
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pos.z = dot( iP, fog_matrix_z );
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float oneOverA = fog_parameters.x;
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float oneOverB = fog_parameters.y;
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float C = fog_parameters.z;
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//Cheap clutch for horizontal rays
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if (abs(eye.z-pos.z) < 100) {
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eye.z = pos.z + 100;
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}
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float3 ray = (pos - eye);
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//Deviation from the vertical ray
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float3 rayn = normalize(ray);
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float3 up = float3(0,0,1);
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float costheta = dot(up, rayn);
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float z1 = max(pos.z+C,0);
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float z2 = max(eye.z+C,0);
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//Integrate along a vertical ray
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float dens = pow(0.5,z2*oneOverB)-pow(0.5,z1*oneOverB);
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//Correct for horizontal rays
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dens = dens/costheta;
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//Multiply with distance
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float thick = dens*(length(ray)*oneOverA);
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float T = pow(0.5, thick);
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return float2(T, rayn.z);
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$endif
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} |