{ RCSid $Id: bsdf2rad.cal,v 2.5 2017/04/11 02:34:10 greg Exp $ }
{
	Calculation of false color scale for bsdf2rad.

	Greg Ward	April 2017
}
		{ Compute lines of latitude and longitude }
LATSTEP : 15*DEGREE;
LONGSTEP : 30*DEGREE;		{ must divide evenly into 90 degrees }
LATWIDTH : 0.7*DEGREE;
LONGWIDTH : 1.*DEGREE;

mylong = atan2(Ny,Nx);

latlong = if(LATWIDTH-mod(Acos(Nz)+LATWIDTH/2,LATSTEP), .05,
		if(LONGWIDTH-mod(mylong+LONGWIDTH/2,90*DEGREE), .01,
		if(LONGWIDTH-mod(mylong+LONGWIDTH/2,LONGSTEP), .3, 1)));

		{ Compute up vector corresponding to sphere position }
ur2 = Nx*Nx + Ny*Ny;
upx = Nx*Ny*(Nz - 1);
upy = if(ur2 - FTINY, Nx*Nx + Ny*Ny*Nz, 1);
upz = -Ny*ur2;

interp_arr2`(i,x,f):(i+1-x)*f(i)+(x-i)*f(i+1);
interp_arr`(x,f):if(x-1,if(f(0)-x,interp_arr2(floor(x),x,f),f(f(0))),f(1));

def_redp(i):select(i,0.18848,0.05468174,
0.00103547,8.311144e-08,7.449763e-06,0.0004390987,0.001367254,
0.003076,0.01376382,0.06170773,0.1739422,0.2881156,0.3299725,
0.3552663,0.372552,0.3921184,0.4363976,0.6102754,0.7757267,
0.9087369,1,1,0.9863);
sca_red(x):interp_arr(x/0.0454545+1,def_redp);

def_grnp(i):select(i,0.0009766,2.35501e-05,
0.0008966244,0.0264977,0.1256843,0.2865799,0.4247083,0.4739468,
0.4402732,0.3671876,0.2629843,0.1725325,0.1206819,0.07316644,
0.03761026,0.01612362,0.004773749,6.830967e-06,0.00803605,
0.1008085,0.3106831,0.6447838,0.9707);
sca_grn(x):interp_arr(x/0.0454545+1,def_grnp);

def_blup(i):select(i,0.2666,0.3638662,0.4770437,
0.5131397,0.5363797,0.5193677,0.4085123,0.1702815,0.05314236,
0.05194055,0.08564082,0.09881395,0.08324373,0.06072902,
0.0391076,0.02315354,0.01284458,0.005184709,0.001691774,
2.432735e-05,1.212949e-05,0.006659406,0.02539);
sca_blu(x):interp_arr(x/0.0454545+1,def_blup);

{ BSDF scale is based on distance from the origin }

dist_orig = sqrt(Px*Px + Py*Py + Pz*Pz);
bsdf_red = sca_red(dist_orig);
bsdf_grn = sca_grn(dist_orig);
bsdf_blu = sca_blu(dist_orig);