757 lines
16 KiB
C
757 lines
16 KiB
C
#include "bsplib.h"
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/*
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each portal will have a list of all possible to see from first portal
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if (!thread->portalmightsee[portalnum])
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portal mightsee
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for p2 = all other portals in leaf
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get sperating planes
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for all portals that might be seen by p2
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mark as unseen if not present in seperating plane
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flood fill a new mightsee
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save as passagemightsee
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void CalcMightSee (leaf_t *leaf,
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*/
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int CountBits (byte *bits, int numbits)
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{
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int i;
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int c;
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c = 0;
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for (i=0 ; i<numbits ; i++)
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if (bits[i>>3] & (1<<(i&7)) )
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c++;
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return c;
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}
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int c_fullskip;
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int c_portalskip, c_leafskip;
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int c_vistest, c_mighttest;
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int c_chop, c_nochop;
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int active;
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void CheckStack (leaf_t *leaf, threaddata_t *thread)
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{
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pstack_t *p, *p2;
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for (p=thread->pstack_head.next ; p ; p=p->next)
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{
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if (p->leaf == leaf)
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Sys_Error ("CheckStack: leaf recursion");
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for (p2=thread->pstack_head.next ; p2 != p ; p2=p2->next)
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if (p2->leaf == p->leaf)
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Sys_Error ("CheckStack: late leaf recursion");
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}
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}
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viswinding_t *AllocStackWinding (pstack_t *stack)
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{
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int i;
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for (i=0 ; i<3 ; i++)
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{
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if (stack->freewindings[i])
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{
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stack->freewindings[i] = 0;
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return &stack->windings[i];
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}
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}
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Sys_Error ("AllocStackWinding: failed");
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return NULL;
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}
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void FreeStackWinding (viswinding_t *w, pstack_t *stack)
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{
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int i;
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i = w - stack->windings;
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if (i<0 || i>2)
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return; // not from local
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if (stack->freewindings[i])
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Sys_Error ("FreeStackWinding: allready free");
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stack->freewindings[i] = 1;
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}
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/*
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==============
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ChopWinding
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==============
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*/
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viswinding_t *ChopWinding (viswinding_t *in, pstack_t *stack, visplane_t *split)
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{
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vec_t dists[128];
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int sides[128];
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int counts[3];
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vec_t dot;
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int i, j;
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vec_t *p1, *p2;
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vec3_t mid;
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viswinding_t *neww;
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counts[0] = counts[1] = counts[2] = 0;
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// determine sides for each point
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for (i=0 ; i<in->numpoints ; i++)
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{
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dot = DotProduct (in->points[i], split->normal);
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dot -= split->dist;
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dists[i] = dot;
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if (dot > EQUAL_EPSILON)
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sides[i] = SIDE_FRONT;
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else if (dot < -EQUAL_EPSILON)
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sides[i] = SIDE_BACK;
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else
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{
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sides[i] = SIDE_ON;
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}
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counts[sides[i]]++;
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}
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if (!counts[1])
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return in; // completely on front side
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if (!counts[0])
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{
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FreeStackWinding (in, stack);
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return NULL;
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}
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sides[i] = sides[0];
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dists[i] = dists[0];
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neww = AllocStackWinding (stack);
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neww->numpoints = 0;
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for (i=0 ; i<in->numpoints ; i++)
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{
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p1 = in->points[i];
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if (neww->numpoints == 12)
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{
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FreeStackWinding (neww, stack);
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return in; // can't chop -- fall back to original
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}
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if (sides[i] == SIDE_ON)
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{
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VectorCopy (p1, neww->points[neww->numpoints]);
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neww->numpoints++;
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continue;
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}
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if (sides[i] == SIDE_FRONT)
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{
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VectorCopy (p1, neww->points[neww->numpoints]);
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neww->numpoints++;
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}
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if (sides[i+1] == SIDE_ON || sides[i+1] == sides[i])
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continue;
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if (neww->numpoints == 12)
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{
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FreeStackWinding (neww, stack);
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return in; // can't chop -- fall back to original
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}
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// generate a split point
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p2 = in->points[(i+1)%in->numpoints];
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dot = dists[i] / (dists[i]-dists[i+1]);
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for (j=0 ; j<3 ; j++)
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{ // avoid round off error when possible
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if (split->normal[j] == 1)
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mid[j] = split->dist;
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else if (split->normal[j] == -1)
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mid[j] = -split->dist;
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else
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mid[j] = p1[j] + dot*(p2[j]-p1[j]);
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}
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VectorCopy (mid, neww->points[neww->numpoints]);
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neww->numpoints++;
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}
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// free the original winding
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FreeStackWinding (in, stack);
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return neww;
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}
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/*
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==============
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ClipToSeperators
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Source, pass, and target are an ordering of portals.
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Generates seperating planes canidates by taking two points from source and one
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point from pass, and clips target by them.
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If target is totally clipped away, that portal can not be seen through.
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Normal clip keeps target on the same side as pass, which is correct if the
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order goes source, pass, target. If the order goes pass, source, target then
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flipclip should be set.
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==============
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*/
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viswinding_t *ClipToSeperators (viswinding_t *source, viswinding_t *pass, viswinding_t *target, bool flipclip, pstack_t *stack)
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{
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int i, j, k, l;
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visplane_t plane;
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vec3_t v1, v2;
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float d;
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vec_t length;
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int counts[3];
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bool fliptest;
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// check all combinations
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for (i=0 ; i<source->numpoints ; i++)
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{
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l = (i+1)%source->numpoints;
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VectorSubtract (source->points[l] , source->points[i], v1);
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// fing a vertex of pass that makes a plane that puts all of the
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// vertexes of pass on the front side and all of the vertexes of
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// source on the back side
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for (j=0 ; j<pass->numpoints ; j++)
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{
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VectorSubtract (pass->points[j], source->points[i], v2);
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plane.normal[0] = v1[1]*v2[2] - v1[2]*v2[1];
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plane.normal[1] = v1[2]*v2[0] - v1[0]*v2[2];
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plane.normal[2] = v1[0]*v2[1] - v1[1]*v2[0];
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// if points don't make a valid plane, skip it
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length = plane.normal[0] * plane.normal[0]
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+ plane.normal[1] * plane.normal[1]
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+ plane.normal[2] * plane.normal[2];
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if (length < EQUAL_EPSILON)
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continue;
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length = 1/sqrt(length);
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plane.normal[0] *= length;
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plane.normal[1] *= length;
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plane.normal[2] *= length;
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plane.dist = DotProduct (pass->points[j], plane.normal);
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//
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// find out which side of the generated seperating plane has the
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// source portal
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//
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#if 1
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fliptest = false;
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for (k=0 ; k<source->numpoints ; k++)
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{
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if (k == i || k == l)
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continue;
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d = DotProduct (source->points[k], plane.normal) - plane.dist;
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if (d < -EQUAL_EPSILON)
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{ // source is on the negative side, so we want all
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// pass and target on the positive side
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fliptest = false;
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break;
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}
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else if (d > EQUAL_EPSILON)
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{ // source is on the positive side, so we want all
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// pass and target on the negative side
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fliptest = true;
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break;
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}
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}
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if (k == source->numpoints)
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continue; // planar with source portal
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#else
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fliptest = flipclip;
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#endif
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//
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// flip the normal if the source portal is backwards
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//
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if (fliptest)
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{
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VectorSubtract (vec3_origin, plane.normal, plane.normal);
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plane.dist = -plane.dist;
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}
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#if 1
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//
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// if all of the pass portal points are now on the positive side,
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// this is the seperating plane
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//
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counts[0] = counts[1] = counts[2] = 0;
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for (k=0 ; k<pass->numpoints ; k++)
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{
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if (k==j)
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continue;
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d = DotProduct (pass->points[k], plane.normal) - plane.dist;
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if (d < -EQUAL_EPSILON)
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break;
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else if (d > EQUAL_EPSILON)
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counts[0]++;
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else
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counts[2]++;
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}
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if (k != pass->numpoints)
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continue; // points on negative side, not a seperating plane
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if (!counts[0])
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continue; // planar with seperating plane
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#else
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k = (j+1)%pass->numpoints;
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d = DotProduct (pass->points[k], plane.normal) - plane.dist;
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if (d < -EQUAL_EPSILON)
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continue;
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k = (j+pass->numpoints-1)%pass->numpoints;
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d = DotProduct (pass->points[k], plane.normal) - plane.dist;
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if (d < -EQUAL_EPSILON)
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continue;
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#endif
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//
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// flip the normal if we want the back side
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//
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if (flipclip)
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{
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VectorSubtract (vec3_origin, plane.normal, plane.normal);
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plane.dist = -plane.dist;
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}
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//
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// clip target by the seperating plane
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//
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target = ChopWinding (target, stack, &plane);
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if (!target)
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return NULL; // target is not visible
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}
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}
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return target;
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}
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/*
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==================
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RecursiveLeafFlow
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Flood fill through the leafs
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If src_portal is NULL, this is the originating leaf
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==================
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*/
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void RecursiveLeafFlow (int leafnum, threaddata_t *thread, pstack_t *prevstack)
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{
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pstack_t stack;
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visportal_t *p;
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visplane_t backplane;
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leaf_t *leaf;
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int i, j;
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long *test, *might, *vis, more;
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int pnum;
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thread->c_chains++;
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leaf = &leafs[leafnum];
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// CheckStack (leaf, thread);
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prevstack->next = &stack;
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stack.next = NULL;
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stack.leaf = leaf;
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stack.portal = NULL;
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might = (long *)stack.mightsee;
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vis = (long *)thread->base->portalvis;
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// check all portals for flowing into other leafs
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for (i=0 ; i<leaf->numportals ; i++)
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{
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p = leaf->portals[i];
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pnum = p - portals;
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if ( ! (prevstack->mightsee[pnum >> 3] & (1<<(pnum&7)) ) )
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{
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continue; // can't possibly see it
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}
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// if the portal can't see anything we haven't allready seen, skip it
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if (p->status == stat_done)
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{
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test = (long *)p->portalvis;
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}
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else
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{
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test = (long *)p->portalflood;
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}
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more = 0;
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for (j=0 ; j<portallongs ; j++)
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{
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might[j] = ((long *)prevstack->mightsee)[j] & test[j];
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more |= (might[j] & ~vis[j]);
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}
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if (!more &&
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(thread->base->portalvis[pnum>>3] & (1<<(pnum&7))) )
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{ // can't see anything new
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continue;
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}
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// get plane of portal, point normal into the neighbor leaf
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stack.portalplane = p->plane;
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VectorSubtract (vec3_origin, p->plane.normal, backplane.normal);
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backplane.dist = -p->plane.dist;
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// c_portalcheck++;
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stack.portal = p;
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stack.next = NULL;
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stack.freewindings[0] = 1;
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stack.freewindings[1] = 1;
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stack.freewindings[2] = 1;
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#if 1
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{
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float d;
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d = DotProduct (p->origin, thread->pstack_head.portalplane.normal);
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d -= thread->pstack_head.portalplane.dist;
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if (d < -p->radius)
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{
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continue;
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}
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else if (d > p->radius)
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{
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stack.pass = p->winding;
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}
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else
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{
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stack.pass = ChopWinding (p->winding, &stack, &thread->pstack_head.portalplane);
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if (!stack.pass)
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continue;
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}
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}
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#else
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stack.pass = ChopWinding (p->winding, &stack, &thread->pstack_head.portalplane);
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if (!stack.pass)
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continue;
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#endif
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#if 1
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{
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float d;
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d = DotProduct (thread->base->origin, p->plane.normal);
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d -= p->plane.dist;
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if (d > p->radius)
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{
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continue;
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}
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else if (d < -p->radius)
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{
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stack.source = prevstack->source;
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}
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else
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{
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stack.source = ChopWinding (prevstack->source, &stack, &backplane);
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if (!stack.source)
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continue;
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}
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}
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#else
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stack.source = ChopWinding (prevstack->source, &stack, &backplane);
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if (!stack.source)
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continue;
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#endif
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if (!prevstack->pass)
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{ // the second leaf can only be blocked if coplanar
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// mark the portal as visible
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thread->base->portalvis[pnum>>3] |= (1<<(pnum&7));
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RecursiveLeafFlow (p->leaf, thread, &stack);
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continue;
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}
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stack.pass = ClipToSeperators (stack.source, prevstack->pass, stack.pass, false, &stack);
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if (!stack.pass)
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continue;
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stack.pass = ClipToSeperators (prevstack->pass, stack.source, stack.pass, true, &stack);
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if (!stack.pass)
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continue;
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// mark the portal as visible
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thread->base->portalvis[pnum>>3] |= (1<<(pnum&7));
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// flow through it for real
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RecursiveLeafFlow (p->leaf, thread, &stack);
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}
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}
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/*
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===============
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PortalFlow
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generates the portalvis bit vector
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===============
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*/
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void PortalFlow (int portalnum)
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{
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threaddata_t data;
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int i;
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visportal_t *p;
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int c_might, c_can;
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p = sorted_portals[portalnum];
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p->status = stat_working;
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c_might = CountBits (p->portalflood, numportals*2);
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memset (&data, 0, sizeof(data));
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data.base = p;
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data.pstack_head.portal = p;
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data.pstack_head.source = p->winding;
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data.pstack_head.portalplane = p->plane;
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for (i=0 ; i<portallongs ; i++)
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((long *)data.pstack_head.mightsee)[i] = ((long *)p->portalflood)[i];
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RecursiveLeafFlow (p->leaf, &data, &data.pstack_head);
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p->status = stat_done;
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c_can = CountBits (p->portalvis, numportals*2);
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}
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/*
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===============================================================================
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This is a rough first-order aproximation that is used to trivially reject some
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of the final calculations.
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Calculates portalfront and portalflood bit vectors
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thinking about:
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typedef struct passage_s
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{
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struct passage_s *next;
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struct portal_s *to;
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stryct sep_s *seperators;
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byte *mightsee;
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} passage_t;
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typedef struct portal_s
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{
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struct passage_s *passages;
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int leaf; // leaf portal faces into
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} portal_s;
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leaf = portal->leaf
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clear
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for all portals
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calc portal visibility
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clear bit vector
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for all passages
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passage visibility
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for a portal to be visible to a passage, it must be on the front of
|
|
all seperating planes, and both portals must be behind the mew portal
|
|
|
|
===============================================================================
|
|
*/
|
|
|
|
int c_flood, c_vis;
|
|
|
|
|
|
/*
|
|
==================
|
|
SimpleFlood
|
|
|
|
==================
|
|
*/
|
|
void SimpleFlood (visportal_t *srcportal, int leafnum)
|
|
{
|
|
int i;
|
|
leaf_t *leaf;
|
|
visportal_t *p;
|
|
int pnum;
|
|
|
|
leaf = &leafs[leafnum];
|
|
|
|
for (i=0 ; i<leaf->numportals ; i++)
|
|
{
|
|
p = leaf->portals[i];
|
|
pnum = p - portals;
|
|
if ( ! (srcportal->portalfront[pnum>>3] & (1<<(pnum&7)) ) )
|
|
continue;
|
|
|
|
if (srcportal->portalflood[pnum>>3] & (1<<(pnum&7)) )
|
|
continue;
|
|
|
|
srcportal->portalflood[pnum>>3] |= (1<<(pnum&7));
|
|
|
|
SimpleFlood (srcportal, p->leaf);
|
|
}
|
|
}
|
|
|
|
/*
|
|
==============
|
|
BasePortalVis
|
|
==============
|
|
*/
|
|
void BasePortalVis (int portalnum)
|
|
{
|
|
int j, k;
|
|
visportal_t *tp, *p;
|
|
float d;
|
|
viswinding_t *w;
|
|
|
|
p = portals+portalnum;
|
|
|
|
p->portalfront = Malloc (portalbytes);
|
|
p->portalflood = Malloc (portalbytes);
|
|
p->portalvis = Malloc (portalbytes);
|
|
|
|
for (j=0, tp = portals ; j<numportals*2 ; j++, tp++)
|
|
{
|
|
if (j == portalnum)
|
|
continue;
|
|
w = tp->winding;
|
|
for (k=0 ; k<w->numpoints ; k++)
|
|
{
|
|
d = DotProduct (w->points[k], p->plane.normal)
|
|
- p->plane.dist;
|
|
if (d > EQUAL_EPSILON)
|
|
break;
|
|
}
|
|
if (k == w->numpoints)
|
|
continue; // no points on front
|
|
|
|
w = p->winding;
|
|
for (k=0 ; k<w->numpoints ; k++)
|
|
{
|
|
d = DotProduct (w->points[k], tp->plane.normal)
|
|
- tp->plane.dist;
|
|
if (d < -EQUAL_EPSILON)
|
|
break;
|
|
}
|
|
if (k == w->numpoints)
|
|
continue; // no points on front
|
|
|
|
p->portalfront[j>>3] |= (1<<(j&7));
|
|
}
|
|
|
|
SimpleFlood (p, p->leaf);
|
|
|
|
p->nummightsee = CountBits (p->portalflood, numportals*2);
|
|
c_flood += p->nummightsee;
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/*
|
|
===============================================================================
|
|
|
|
This is a second order aproximation
|
|
|
|
Calculates portalvis bit vector
|
|
|
|
WAAAAAAY too slow.
|
|
|
|
===============================================================================
|
|
*/
|
|
|
|
/*
|
|
==================
|
|
RecursiveLeafBitFlow
|
|
|
|
==================
|
|
*/
|
|
void RecursiveLeafBitFlow (int leafnum, byte *mightsee, byte *cansee)
|
|
{
|
|
visportal_t *p;
|
|
leaf_t *leaf;
|
|
int i, j;
|
|
long more;
|
|
int pnum;
|
|
byte newmight[MAX_PORTALS/8];
|
|
|
|
leaf = &leafs[leafnum];
|
|
|
|
// check all portals for flowing into other leafs
|
|
for (i=0 ; i<leaf->numportals ; i++)
|
|
{
|
|
p = leaf->portals[i];
|
|
pnum = p - portals;
|
|
|
|
// if some previous portal can't see it, skip
|
|
if (! (mightsee[pnum>>3] & (1<<(pnum&7)) ) )
|
|
continue;
|
|
|
|
// if this portal can see some portals we mightsee, recurse
|
|
more = 0;
|
|
for (j=0 ; j<portallongs ; j++)
|
|
{
|
|
((long *)newmight)[j] = ((long *)mightsee)[j]
|
|
& ((long *)p->portalflood)[j];
|
|
more |= ((long *)newmight)[j] & ~((long *)cansee)[j];
|
|
}
|
|
|
|
if (!more)
|
|
continue; // can't see anything new
|
|
|
|
cansee[pnum>>3] |= (1<<(pnum&7));
|
|
|
|
RecursiveLeafBitFlow (p->leaf, newmight, cansee);
|
|
}
|
|
}
|
|
|
|
/*
|
|
==============
|
|
BetterPortalVis
|
|
==============
|
|
*/
|
|
void BetterPortalVis (int portalnum)
|
|
{
|
|
visportal_t *p;
|
|
|
|
p = portals+portalnum;
|
|
|
|
RecursiveLeafBitFlow (p->leaf, p->portalflood, p->portalvis);
|
|
|
|
// build leaf vis information
|
|
p->nummightsee = CountBits (p->portalvis, numportals*2);
|
|
c_vis += p->nummightsee;
|
|
}
|
|
|
|
|