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greg |
2.4 |
{ RCSid $Id: ambpos.cal,v 2.3 2014/05/01 03:00:59 greg Exp $ }
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| 2 |
greg |
2.1 |
{
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| 3 |
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Compute patterns for ambient position markers
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| 4 |
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}
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| 5 |
greg |
2.4 |
odd(n) : .5*n - floor(.5*n) - .25;
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| 6 |
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posangle(a) : if(-a, a + 2*PI, a) / DEGREE;
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| 7 |
greg |
2.1 |
{ Relative hit point }
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| 8 |
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rpx = Px - arg(1);
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| 9 |
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rpy = Py - arg(2);
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| 10 |
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rpz = Pz - arg(3);
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| 11 |
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| 12 |
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{ Calculation of directional gradient pattern }
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| 13 |
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ndx = arg(4); ndy = arg(5); ndz = arg(6);
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| 14 |
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dgx = arg(7); dgy = arg(8); dgz = arg(9);
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| 15 |
greg |
2.2 |
rdx = ndy*rpz - ndz*rpy;
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rdy = ndz*rpx - ndx*rpz;
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| 17 |
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rdz = ndx*rpy - ndy*rpx;
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| 18 |
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dgrad = (rdx*dgx + rdy*dgy + rdz*dgz)/sqrt(rpx*rpx + rpy*rpy + rpz*rpz);
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| 19 |
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dirfunc = bound(0, 1 + dgrad, 2);
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| 20 |
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| 21 |
greg |
2.1 |
{ Calculation of positional gradient pattern }
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| 22 |
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pgx = arg(4); pgy = arg(5); pgz = arg(6);
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| 23 |
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posfunc = bound(0, 1 + (pgx*rpx + pgy*rpy + pgz*rpz), 2);
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| 24 |
greg |
2.4 |
{ corral flags and associated pattern }
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| 25 |
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ux = arg(4); uy = arg(5); uz = arg(6);
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| 26 |
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cflags = arg(7);
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| 27 |
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vx = Ny*uz - Nz*uy;
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vy = Nz*ux - Nx*uz;
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| 29 |
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vz = Nx*uy - Ny*ux;
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| 30 |
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cflg(i) = if(odd(floor( cflags / 2^i )), 1, -1);
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| 31 |
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corralled = cflg(floor(32/360*posangle(
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| 32 |
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atan2(rpx*vx+rpy*vy+rpz*vz, rpx*ux+rpy*uy+rpz*uz) )));
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| 33 |
greg |
2.1 |
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| 34 |
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{ Calculation of ellipse stencil for base }
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| 35 |
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usx = arg(4); usy = arg(5); usz = arg(6);
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| 36 |
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vsx = arg(7); vsy = arg(8); vsz = arg(9);
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| 37 |
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ellipstencil = if(1 - sq(usx*rpx + usy*rpy + usz*rpz) - sq(vsx*rpx + vsy*rpy + vsz*rpz),
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| 38 |
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1, 0);
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