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/* Copyright (c) 1991 Regents of the University of California */ |
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/* Copyright (c) 1992 Regents of the University of California */ |
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#ifndef lint |
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static char SCCSid[] = "$SunId$ LBL"; |
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} |
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#define wrongsource(m, r) (r->rsrc>=0 && \ |
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source[r->rsrc].so!=r->ro && \ |
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(m->otype!=MAT_ILLUM || \ |
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objptr(source[r->rsrc].so->omod)->otype==MAT_ILLUM)) |
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/**************************************************************** |
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* The following macros were separated from the m_light() routine |
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* because they are very nasty and difficult to understand. |
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*/ |
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/* wrongillum * |
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* |
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* We cannot allow an illum to pass to another illum, because that |
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* would almost certainly constitute overcounting. |
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* However, we do allow an illum to pass to another illum |
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* that is actually going to relay to a virtual light source. |
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*/ |
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#define wrongillum(m, r) (!(source[r->rsrc].sflags&SVIRTUAL) && \ |
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objptr(source[r->rsrc].so->omod)->otype==MAT_ILLUM) |
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|
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/* wrongsource * |
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* |
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* This source is the wrong source (ie. overcounted) if we are |
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* aimed to a different source than the one we hit and the one |
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* we hit is not an illum which should be passed. |
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*/ |
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|
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#define wrongsource(m, r) (r->rsrc>=0 && source[r->rsrc].so!=r->ro && \ |
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(m->otype!=MAT_ILLUM || wrongillum(m,r))) |
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|
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/* distglow * |
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* |
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* A distant glow is an object that sometimes acts as a light source, |
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* but is too far away from the test point to be one in this case. |
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*/ |
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#define distglow(m, r) (m->otype==MAT_GLOW && \ |
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r->rot > m->oargs.farg[3]) |
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#define badambient(m, r) ((r->crtype&(AMBIENT|SHADOW))==AMBIENT && \ |
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!distglow(m, r)) |
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/* badcomponent * |
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* |
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* We must avoid counting light sources in the ambient calculation, |
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* since the direct component is handled separately. Therefore, any |
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* ambient ray which hits an active light source must be discarded. |
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* The same is true for stray specular samples, since the specular |
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* contribution from light sources is calculated separately. |
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*/ |
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#define badcomponent(m, r) (r->crtype&(AMBIENT|SPECULAR) && \ |
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!(r->crtype&SHADOW || distglow(m, r))) |
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|
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/* overcount * |
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* |
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* All overcounting possibilities are contained here. |
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*/ |
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#define overcount(m, r) (badcomponent(m,r) || wrongsource(m,r)) |
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/* passillum * |
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* |
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* An illum passes to another material type when we didn't hit it |
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* on purpose (as part of a direct calculation), or it is relaying |
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* a virtual light source. |
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*/ |
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#define passillum(m, r) (m->otype==MAT_ILLUM && \ |
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!(r->rsrc>=0&&source[r->rsrc].so==r->ro)) |
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(r->rsrc<0 || source[r->rsrc].so!=r->ro || \ |
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source[r->rsrc].sflags&SVIRTUAL)) |
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/* srcignore * |
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* |
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* The -di flag renders light sources invisible, and here is the test. |
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*/ |
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#define srcignore(m, r) (directinvis && !(r->crtype&SHADOW) && \ |
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!distglow(m, r)) |
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register RAY *r; |
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{ |
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/* check for over-counting */ |
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if (wrongsource(m, r) || badambient(m, r)) |
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if (overcount(m, r)) |
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return; |
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/* check for passed illum */ |
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if (passillum(m, r)) { |