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{ RCSid $Id: klems_quarter.cal,v 1.3 2014/07/19 00:47:37 greg Exp $ } |
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{ |
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Compute interior bin for quarter Klems BSDF basis (0-40) |
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Returns -1 for wrong-side rays |
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|
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Modified from klems_full.cal |
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|
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7/18/2014 G. Ward |
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} |
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DEGREE : PI/180; |
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Acos(x) : if(x-1, 0, if(-1-x, PI, acos(x))) / DEGREE; |
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posangle(a) : if(-a, a + 2*PI, a) / DEGREE; |
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Atan2(y,x) : posangle(atan2(y,x)); |
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|
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kqpola(r) : select(r, 9, 27, 46, 66, 90); |
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kqnaz(r) : select(r, 1, 8, 12, 12, 8); |
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kqaccum(r) : if(r-.5, kqnaz(r) + kqaccum(r-1), 0); |
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kqfindrow(r, pol) : if(r-kqpola(0)+.5, r, |
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if(pol-kqpola(r), kqfindrow(r+1, pol), r) ); |
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|
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kqazn(azi,inc) : if((360-.5*inc)-azi, floor((azi+.5*inc)/inc), 0); |
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|
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kqbin2(pol,azi) = if(pol-90, -1, |
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select(kqfindrow(1, pol), |
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kqazn(azi,360/kqnaz(1)), |
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kqaccum(1) + kqazn(azi,360/kqnaz(2)), |
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kqaccum(2) + kqazn(azi,360/kqnaz(3)), |
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kqaccum(3) + kqazn(azi,360/kqnaz(4)), |
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kqaccum(4) + kqazn(azi,360/kqnaz(5)) |
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) ); |
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|
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kqbin(Nx,Ny,Nz,Ux,Uy,Uz) = kqbin2(Acos(-Dx*Nx-Dy*Ny-Dz*Nz), |
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Atan2(-Dx*Ux-Dy*Uy-Dz*Uz + (Nx*Dx+Ny*Dy+Nz*Dz)*(Nx*Ux+Ny*Uy+Nz*Uz), |
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-Dx*(Uy*Nz-Uz*Ny) - Dy*(Uz*Nx-Ux*Nz) - Dz*(Ux*Ny-Uy*Nx))); |
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|
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Nkqbins : kqaccum(kqnaz(0)); { Number of bins for one elevation } |
