31 lines
No EOL
1.6 KiB
PostScript
31 lines
No EOL
1.6 KiB
PostScript
#include "fluid_common.h"
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//////////////////////////////////////////////////////////////////////////////////////////
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// Pixel
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float4 main( p_fluidsim input ) : SV_Target
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{
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// Texture_tempvector contains the vorticity computed by PS_VORTICITY
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float4 omega = Texture_tempvector.SampleLevel( samPointClamp, input.texcoords, 0 );
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// Potential optimization: don't find length multiple times - do once for the entire texture
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float omegaL = length( Texture_tempvector.SampleLevel( samPointClamp, LEFTCELL, 0 ) );
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float omegaR = length( Texture_tempvector.SampleLevel( samPointClamp, RIGHTCELL, 0 ) );
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float omegaB = length( Texture_tempvector.SampleLevel( samPointClamp, BOTTOMCELL, 0 ) );
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float omegaT = length( Texture_tempvector.SampleLevel( samPointClamp, TOPCELL, 0 ) );
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float omegaD = length( Texture_tempvector.SampleLevel( samPointClamp, DOWNCELL, 0 ) );
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float omegaU = length( Texture_tempvector.SampleLevel( samPointClamp, UPCELL, 0 ) );
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float3 eta = 0.5 * float3( omegaR - omegaL,
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omegaT - omegaB,
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omegaU - omegaD );
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eta = normalize( eta + float3(0.001,0.001,0.001) );
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float4 force;
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force.xyz = timestep * epsilon * float3( eta.y * omega.z - eta.z * omega.y,
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eta.z * omega.x - eta.x * omega.z,
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eta.x * omega.y - eta.y * omega.x );
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// Note: the result is added to the current velocity at each cell using "additive blending"
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return force;
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} |