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*/ |
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#include <stdio.h> |
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#include <stdlib.h> |
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#include <math.h> |
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#include "ccolor.h" |
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|
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#undef frand |
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#define frand() (rand()*(1./(RAND_MAX+.5))) |
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|
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/* Sharp primary matrix */ |
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float XYZtoSharp[3][3] = { |
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{ 1.2694, -0.0988, -0.1706}, |
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|
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const C_COLOR c_dfcolor = C_DEFCOLOR; |
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|
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const C_CHROMA c_dfchroma = 49750; /* c_encodeChroma(&c_dfcolor) */ |
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|
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/* CIE 1931 Standard Observer curves */ |
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const C_COLOR c_x31 = { 1, NULL, C_CDSPEC|C_CSSPEC|C_CSXY|C_CSEFF, |
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{14,42,143,435,1344,2839,3483,3362,2908,1954,956, |
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{ |
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double xyz[3], sf; |
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|
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xyz[0] = XYZfromSharp[0][0]*cin[0] + XYZfromSharp[0][1]*cin[1] + |
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XYZfromSharp[0][2]*cin[2]; |
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xyz[1] = XYZfromSharp[1][0]*cin[0] + XYZfromSharp[1][1]*cin[1] + |
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XYZfromSharp[1][2]*cin[2]; |
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if (xyz[1] <= 1e-6) { |
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*cout = c_dfcolor; /* punting, here... */ |
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return xyz[1]; |
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} |
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xyz[0] = XYZfromSharp[0][0]*cin[0] + XYZfromSharp[0][1]*cin[1] + |
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XYZfromSharp[0][2]*cin[2]; |
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xyz[2] = XYZfromSharp[2][0]*cin[0] + XYZfromSharp[2][1]*cin[1] + |
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XYZfromSharp[2][2]*cin[2]; |
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sf = 1./(xyz[0] + xyz[1] + xyz[2]); |
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|
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cout->cx = xyz[0] * sf; |
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return(xyz[1]); |
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} |
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/* assign arbitrary spectrum */ |
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/* assign arbitrary spectrum and return Y value */ |
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double |
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c_sset(C_COLOR *clr, double wlmin, double wlmax, const float spec[], int nwl) |
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{ |
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wlmax -= wlstep; |
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--nwl; |
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} |
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if ((nwl <= 1) | (wlmin >= wlmax)) |
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return(0.); |
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imax = nwl; /* box filter if necessary */ |
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boxpos = 0; |
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boxstep = 1; |
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pos++; |
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} |
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if ((wl+1e-7 >= wl0) & (wl-1e-7 <= wl0)) |
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clr->ssamp[i] = scale*va[pos] + .5; |
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clr->ssamp[i] = scale*va[pos] + frand(); |
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else /* interpolate if necessary */ |
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clr->ssamp[i] = .5 + scale / wlstep * |
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clr->ssamp[i] = frand() + scale / wlstep * |
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( va[pos]*(wl0+wlstep - wl) + |
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va[pos+1]*(wl - wl0) ); |
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clr->ssum += clr->ssamp[i]; |
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y /= (double)c_y31.ssum; |
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z /= (double)c_z31.ssum; |
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z += x + y; |
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clr->cx = x / z; |
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clr->cy = y / z; |
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if (z > 1e-6) { |
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clr->cx = x / z; |
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clr->cy = y / z; |
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} else |
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clr->cx = clr->cy = 1./3.; |
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clr->flags |= C_CSXY; |
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} else if (fl & C_CSSPEC) { /* cxy -> cspec */ |
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} |
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if (fl & C_CSSPEC) { /* cxy -> cspec */ |
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x = clr->cx; |
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y = clr->cy; |
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z = 1. - x - y; |
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clr->ssum = 0; |
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for (i = 0; i < C_CNSS; i++) { |
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clr->ssamp[i] = x*cie_xp.ssamp[i] + y*cie_yp.ssamp[i] |
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+ z*cie_zp.ssamp[i] + .5; |
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+ z*cie_zp.ssamp[i] + frand(); |
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if (clr->ssamp[i] < 0) /* out of gamut! */ |
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clr->ssamp[i] = 0; |
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else |
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y = 0.; |
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for (i = 0; i < C_CNSS; i++) |
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y += c_y31.ssamp[i] * clr->ssamp[i]; |
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clr->eff = C_CLPWM * y / clr->ssum; |
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clr->eff = C_CLPWM * y / (clr->ssum + 0.0001); |
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} else /* clr->flags & C_CSXY */ { /* from (x,y) */ |
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clr->eff = clr->cx*c_x31.eff + clr->cy*c_y31.eff + |
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(1. - clr->cx - clr->cy)*c_z31.eff; |
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double scale; |
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int i; |
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|
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if (w1 == 0) { |
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*cres = *c2; |
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return; |
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} |
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if (w2 == 0) { |
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*cres = *c1; |
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return; |
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} |
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if ((c1->flags|c2->flags) & C_CDSPEC) { /* spectral mixing */ |
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float cmix[C_CNSS]; |
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|
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c_ccvt(c1, C_CSSPEC|C_CSEFF); |
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c_ccvt(c2, C_CSSPEC|C_CSEFF); |
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if (c1->ssum*c2->ssum == 0) { |
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*cres = c_dfcolor; |
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return; |
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} |
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w1 /= c1->eff*c1->ssum; |
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w2 /= c2->eff*c2->ssum; |
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scale = 0.; |
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scale = C_CMAXV / scale; |
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cres->ssum = 0; |
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for (i = 0; i < C_CNSS; i++) |
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cres->ssum += cres->ssamp[i] = scale*cmix[i] + .5; |
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cres->ssum += cres->ssamp[i] = scale*cmix[i] + frand(); |
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cres->flags = C_CDSPEC|C_CSSPEC; |
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} else { /* CIE xy mixing */ |
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c_ccvt(c1, C_CSXY); |
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cres->ssum += cres->ssamp[i] = cmix[i] / cmax; |
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cres->flags = C_CDSPEC|C_CSSPEC; |
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|
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c_ccvt(cres, C_CSEFF); /* don't touch below */ |
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c_ccvt(cres, C_CSEFF); /* below is correct */ |
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yres = y1 * y2 * c_y31.ssum * C_CLPWM / |
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(c1->eff*c1->ssum * c2->eff*c2->ssum) * |
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cres->eff*( cres->ssum*(double)cmax + |
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clr->ssum = 0; |
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for (i = 0; i < C_CNSS; i++) { |
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wl = (C_CMINWL + i*C_CWLI)*1e-9; |
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clr->ssum += clr->ssamp[i] = sf*bbsp(wl,tk) + .5; |
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clr->ssum += clr->ssamp[i] = sf*bbsp(wl,tk) + frand(); |
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} |
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clr->flags = C_CDSPEC|C_CSSPEC; |
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return(1); |
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#undef C2 |
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#undef bbsp |
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#undef bblm |
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|
415 |
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#define UV_NORMF 410. |
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|
417 |
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/* encode (x,y) chromaticity */ |
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C_CHROMA |
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c_encodeChroma(C_COLOR *clr) |
420 |
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{ |
421 |
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double df; |
422 |
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int ub, vb; |
423 |
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|
424 |
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c_ccvt(clr, C_CSXY); |
425 |
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df = UV_NORMF/(-2.*clr->cx + 12.*clr->cy + 3.); |
426 |
+ |
ub = 4.*clr->cx*df + frand(); |
427 |
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if (ub > 0xff) ub = 0xff; |
428 |
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else ub *= (ub > 0); |
429 |
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vb = 9.*clr->cy*df + frand(); |
430 |
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if (vb > 0xff) vb = 0xff; |
431 |
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else vb *= (vb > 0); |
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|
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return(vb<<8 | ub); |
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} |
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|
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/* decode (x,y) chromaticity */ |
437 |
+ |
void |
438 |
+ |
c_decodeChroma(C_COLOR *cres, C_CHROMA ccode) |
439 |
+ |
{ |
440 |
+ |
double up = (ccode & 0xff)*(1./UV_NORMF); |
441 |
+ |
double vp = (ccode>>8 & 0xff)*(1./UV_NORMF); |
442 |
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double df = 1./(6.*up - 16.*vp + 12.); |
443 |
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|
444 |
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cres->cx = 9.*up * df; |
445 |
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cres->cy = 4.*vp * df; |
446 |
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cres->flags = C_CDXY|C_CSXY; |
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} |
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|
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#undef UV_NORMF |