--- /dev/null
+/*
+===========================================================================
+Copyright (C) 1997-2006 Id Software, Inc.
+
+This file is part of Quake 2 Tools source code.
+
+Quake 2 Tools source code is free software; you can redistribute it
+and/or modify it under the terms of the GNU General Public License as
+published by the Free Software Foundation; either version 2 of the License,
+or (at your option) any later version.
+
+Quake 2 Tools source code is distributed in the hope that it will be
+useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with Quake 2 Tools source code; if not, write to the Free Software
+Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+===========================================================================
+*/
+#include "vis.h"
+
+/*
+
+ each portal will have a list of all possible to see from first portal
+
+ if (!thread->portalmightsee[portalnum])
+
+ portal mightsee
+
+ for p2 = all other portals in leaf
+ get sperating planes
+ for all portals that might be seen by p2
+ mark as unseen if not present in seperating plane
+ flood fill a new mightsee
+ save as passagemightsee
+
+
+ void CalcMightSee (leaf_t *leaf,
+*/
+
+int CountBits (byte *bits, int numbits)
+{
+ int i;
+ int c;
+
+ c = 0;
+ for (i=0 ; i<numbits ; i++)
+ if (bits[i>>3] & (1<<(i&7)) )
+ c++;
+
+ return c;
+}
+
+int c_fullskip;
+int c_portalskip, c_leafskip;
+int c_vistest, c_mighttest;
+
+int c_chop, c_nochop;
+
+int active;
+
+void CheckStack (leaf_t *leaf, threaddata_t *thread)
+{
+ pstack_t *p, *p2;
+
+ for (p=thread->pstack_head.next ; p ; p=p->next)
+ {
+// printf ("=");
+ if (p->leaf == leaf)
+ Error ("CheckStack: leaf recursion");
+ for (p2=thread->pstack_head.next ; p2 != p ; p2=p2->next)
+ if (p2->leaf == p->leaf)
+ Error ("CheckStack: late leaf recursion");
+ }
+// printf ("\n");
+}
+
+
+winding_t *AllocStackWinding (pstack_t *stack)
+{
+ int i;
+
+ for (i=0 ; i<3 ; i++)
+ {
+ if (stack->freewindings[i])
+ {
+ stack->freewindings[i] = 0;
+ return &stack->windings[i];
+ }
+ }
+
+ Error ("AllocStackWinding: failed");
+
+ return NULL;
+}
+
+void FreeStackWinding (winding_t *w, pstack_t *stack)
+{
+ int i;
+
+ i = w - stack->windings;
+
+ if (i<0 || i>2)
+ return; // not from local
+
+ if (stack->freewindings[i])
+ Error ("FreeStackWinding: allready free");
+ stack->freewindings[i] = 1;
+}
+
+/*
+==============
+ChopWinding
+
+==============
+*/
+winding_t *ChopWinding (winding_t *in, pstack_t *stack, plane_t *split)
+{
+ vec_t dists[128];
+ int sides[128];
+ int counts[3];
+ vec_t dot;
+ int i, j;
+ vec_t *p1, *p2;
+ vec3_t mid;
+ winding_t *neww;
+
+ counts[0] = counts[1] = counts[2] = 0;
+
+// determine sides for each point
+ for (i=0 ; i<in->numpoints ; i++)
+ {
+ dot = DotProduct (in->points[i], split->normal);
+ dot -= split->dist;
+ dists[i] = dot;
+ if (dot > ON_EPSILON)
+ sides[i] = SIDE_FRONT;
+ else if (dot < -ON_EPSILON)
+ sides[i] = SIDE_BACK;
+ else
+ {
+ sides[i] = SIDE_ON;
+ }
+ counts[sides[i]]++;
+ }
+
+ if (!counts[1])
+ return in; // completely on front side
+
+ if (!counts[0])
+ {
+ FreeStackWinding (in, stack);
+ return NULL;
+ }
+
+ sides[i] = sides[0];
+ dists[i] = dists[0];
+
+ neww = AllocStackWinding (stack);
+
+ neww->numpoints = 0;
+
+ for (i=0 ; i<in->numpoints ; i++)
+ {
+ p1 = in->points[i];
+
+ if (neww->numpoints == MAX_POINTS_ON_FIXED_WINDING)
+ {
+ FreeStackWinding (neww, stack);
+ return in; // can't chop -- fall back to original
+ }
+
+ if (sides[i] == SIDE_ON)
+ {
+ VectorCopy (p1, neww->points[neww->numpoints]);
+ neww->numpoints++;
+ continue;
+ }
+
+ if (sides[i] == SIDE_FRONT)
+ {
+ VectorCopy (p1, neww->points[neww->numpoints]);
+ neww->numpoints++;
+ }
+
+ if (sides[i+1] == SIDE_ON || sides[i+1] == sides[i])
+ continue;
+
+ if (neww->numpoints == MAX_POINTS_ON_FIXED_WINDING)
+ {
+ FreeStackWinding (neww, stack);
+ return in; // can't chop -- fall back to original
+ }
+
+ // generate a split point
+ p2 = in->points[(i+1)%in->numpoints];
+
+ dot = dists[i] / (dists[i]-dists[i+1]);
+ for (j=0 ; j<3 ; j++)
+ { // avoid round off error when possible
+ if (split->normal[j] == 1)
+ mid[j] = split->dist;
+ else if (split->normal[j] == -1)
+ mid[j] = -split->dist;
+ else
+ mid[j] = p1[j] + dot*(p2[j]-p1[j]);
+ }
+
+ VectorCopy (mid, neww->points[neww->numpoints]);
+ neww->numpoints++;
+ }
+
+// free the original winding
+ FreeStackWinding (in, stack);
+
+ return neww;
+}
+
+
+/*
+==============
+ClipToSeperators
+
+Source, pass, and target are an ordering of portals.
+
+Generates seperating planes canidates by taking two points from source and one
+point from pass, and clips target by them.
+
+If target is totally clipped away, that portal can not be seen through.
+
+Normal clip keeps target on the same side as pass, which is correct if the
+order goes source, pass, target. If the order goes pass, source, target then
+flipclip should be set.
+==============
+*/
+winding_t *ClipToSeperators (winding_t *source, winding_t *pass, winding_t *target, qboolean flipclip, pstack_t *stack)
+{
+ int i, j, k, l;
+ plane_t plane;
+ vec3_t v1, v2;
+ float d;
+ vec_t length;
+ int counts[3];
+ qboolean fliptest;
+
+// check all combinations
+ for (i=0 ; i<source->numpoints ; i++)
+ {
+ l = (i+1)%source->numpoints;
+ VectorSubtract (source->points[l] , source->points[i], v1);
+
+ // fing a vertex of pass that makes a plane that puts all of the
+ // vertexes of pass on the front side and all of the vertexes of
+ // source on the back side
+ for (j=0 ; j<pass->numpoints ; j++)
+ {
+ VectorSubtract (pass->points[j], source->points[i], v2);
+
+ plane.normal[0] = v1[1]*v2[2] - v1[2]*v2[1];
+ plane.normal[1] = v1[2]*v2[0] - v1[0]*v2[2];
+ plane.normal[2] = v1[0]*v2[1] - v1[1]*v2[0];
+
+ // if points don't make a valid plane, skip it
+
+ length = plane.normal[0] * plane.normal[0]
+ + plane.normal[1] * plane.normal[1]
+ + plane.normal[2] * plane.normal[2];
+
+ if (length < ON_EPSILON)
+ continue;
+
+ length = 1/sqrt(length);
+
+ plane.normal[0] *= length;
+ plane.normal[1] *= length;
+ plane.normal[2] *= length;
+
+ plane.dist = DotProduct (pass->points[j], plane.normal);
+
+ //
+ // find out which side of the generated seperating plane has the
+ // source portal
+ //
+#if 1
+ fliptest = false;
+ for (k=0 ; k<source->numpoints ; k++)
+ {
+ if (k == i || k == l)
+ continue;
+ d = DotProduct (source->points[k], plane.normal) - plane.dist;
+ if (d < -ON_EPSILON)
+ { // source is on the negative side, so we want all
+ // pass and target on the positive side
+ fliptest = false;
+ break;
+ }
+ else if (d > ON_EPSILON)
+ { // source is on the positive side, so we want all
+ // pass and target on the negative side
+ fliptest = true;
+ break;
+ }
+ }
+ if (k == source->numpoints)
+ continue; // planar with source portal
+#else
+ fliptest = flipclip;
+#endif
+ //
+ // flip the normal if the source portal is backwards
+ //
+ if (fliptest)
+ {
+ VectorSubtract (vec3_origin, plane.normal, plane.normal);
+ plane.dist = -plane.dist;
+ }
+#if 1
+ //
+ // if all of the pass portal points are now on the positive side,
+ // this is the seperating plane
+ //
+ counts[0] = counts[1] = counts[2] = 0;
+ for (k=0 ; k<pass->numpoints ; k++)
+ {
+ if (k==j)
+ continue;
+ d = DotProduct (pass->points[k], plane.normal) - plane.dist;
+ if (d < -ON_EPSILON)
+ break;
+ else if (d > ON_EPSILON)
+ counts[0]++;
+ else
+ counts[2]++;
+ }
+ if (k != pass->numpoints)
+ continue; // points on negative side, not a seperating plane
+
+ if (!counts[0])
+ continue; // planar with seperating plane
+#else
+ k = (j+1)%pass->numpoints;
+ d = DotProduct (pass->points[k], plane.normal) - plane.dist;
+ if (d < -ON_EPSILON)
+ continue;
+ k = (j+pass->numpoints-1)%pass->numpoints;
+ d = DotProduct (pass->points[k], plane.normal) - plane.dist;
+ if (d < -ON_EPSILON)
+ continue;
+#endif
+ //
+ // flip the normal if we want the back side
+ //
+ if (flipclip)
+ {
+ VectorSubtract (vec3_origin, plane.normal, plane.normal);
+ plane.dist = -plane.dist;
+ }
+
+ //
+ // clip target by the seperating plane
+ //
+ target = ChopWinding (target, stack, &plane);
+ if (!target)
+ return NULL; // target is not visible
+ }
+ }
+
+ return target;
+}
+
+
+
+/*
+==================
+RecursiveLeafFlow
+
+Flood fill through the leafs
+If src_portal is NULL, this is the originating leaf
+==================
+*/
+void RecursiveLeafFlow (int leafnum, threaddata_t *thread, pstack_t *prevstack)
+{
+ pstack_t stack;
+ portal_t *p;
+ plane_t backplane;
+ leaf_t *leaf;
+ int i, j;
+ long *test, *might, *vis, more;
+ int pnum;
+
+ thread->c_chains++;
+
+ leaf = &leafs[leafnum];
+// CheckStack (leaf, thread);
+
+ prevstack->next = &stack;
+
+ stack.next = NULL;
+ stack.leaf = leaf;
+ stack.portal = NULL;
+
+ might = (long *)stack.mightsee;
+ vis = (long *)thread->base->portalvis;
+
+// check all portals for flowing into other leafs
+ for (i=0 ; i<leaf->numportals ; i++)
+ {
+ p = leaf->portals[i];
+ pnum = p - portals;
+
+ if ( ! (prevstack->mightsee[pnum >> 3] & (1<<(pnum&7)) ) )
+ {
+ continue; // can't possibly see it
+ }
+
+ // if the portal can't see anything we haven't allready seen, skip it
+ if (p->status == stat_done)
+ {
+ test = (long *)p->portalvis;
+ }
+ else
+ {
+ test = (long *)p->portalflood;
+ }
+
+ more = 0;
+ for (j=0 ; j<portallongs ; j++)
+ {
+ might[j] = ((long *)prevstack->mightsee)[j] & test[j];
+ more |= (might[j] & ~vis[j]);
+ }
+
+ if (!more &&
+ (thread->base->portalvis[pnum>>3] & (1<<(pnum&7))) )
+ { // can't see anything new
+ continue;
+ }
+
+ // get plane of portal, point normal into the neighbor leaf
+ stack.portalplane = p->plane;
+ VectorSubtract (vec3_origin, p->plane.normal, backplane.normal);
+ backplane.dist = -p->plane.dist;
+
+// c_portalcheck++;
+
+ stack.portal = p;
+ stack.next = NULL;
+ stack.freewindings[0] = 1;
+ stack.freewindings[1] = 1;
+ stack.freewindings[2] = 1;
+
+#if 1
+{
+float d;
+
+ d = DotProduct (p->origin, thread->pstack_head.portalplane.normal);
+ d -= thread->pstack_head.portalplane.dist;
+ if (d < -p->radius)
+ {
+ continue;
+ }
+ else if (d > p->radius)
+ {
+ stack.pass = p->winding;
+ }
+ else
+ {
+ stack.pass = ChopWinding (p->winding, &stack, &thread->pstack_head.portalplane);
+ if (!stack.pass)
+ continue;
+ }
+}
+#else
+ stack.pass = ChopWinding (p->winding, &stack, &thread->pstack_head.portalplane);
+ if (!stack.pass)
+ continue;
+#endif
+
+
+#if 1
+{
+float d;
+
+ d = DotProduct (thread->base->origin, p->plane.normal);
+ d -= p->plane.dist;
+ if (d > p->radius)
+ {
+ continue;
+ }
+ else if (d < -p->radius)
+ {
+ stack.source = prevstack->source;
+ }
+ else
+ {
+ stack.source = ChopWinding (prevstack->source, &stack, &backplane);
+ if (!stack.source)
+ continue;
+ }
+}
+#else
+ stack.source = ChopWinding (prevstack->source, &stack, &backplane);
+ if (!stack.source)
+ continue;
+#endif
+
+ if (!prevstack->pass)
+ { // the second leaf can only be blocked if coplanar
+
+ // mark the portal as visible
+ thread->base->portalvis[pnum>>3] |= (1<<(pnum&7));
+
+ RecursiveLeafFlow (p->leaf, thread, &stack);
+ continue;
+ }
+
+ stack.pass = ClipToSeperators (stack.source, prevstack->pass, stack.pass, false, &stack);
+ if (!stack.pass)
+ continue;
+
+ stack.pass = ClipToSeperators (prevstack->pass, stack.source, stack.pass, true, &stack);
+ if (!stack.pass)
+ continue;
+
+ // mark the portal as visible
+ thread->base->portalvis[pnum>>3] |= (1<<(pnum&7));
+
+ // flow through it for real
+ RecursiveLeafFlow (p->leaf, thread, &stack);
+ }
+}
+
+
+/*
+===============
+PortalFlow
+
+generates the portalvis bit vector
+===============
+*/
+void PortalFlow (int portalnum)
+{
+ threaddata_t data;
+ int i;
+ portal_t *p;
+ int c_might, c_can;
+
+ p = sorted_portals[portalnum];
+ p->status = stat_working;
+
+ c_might = CountBits (p->portalflood, numportals*2);
+
+ memset (&data, 0, sizeof(data));
+ data.base = p;
+
+ data.pstack_head.portal = p;
+ data.pstack_head.source = p->winding;
+ data.pstack_head.portalplane = p->plane;
+ for (i=0 ; i<portallongs ; i++)
+ ((long *)data.pstack_head.mightsee)[i] = ((long *)p->portalflood)[i];
+ RecursiveLeafFlow (p->leaf, &data, &data.pstack_head);
+
+ p->status = stat_done;
+
+ c_can = CountBits (p->portalvis, numportals*2);
+
+ qprintf ("portal:%4i mightsee:%4i cansee:%4i (%i chains)\n",
+ (int)(p - portals), c_might, c_can, data.c_chains);
+}
+
+
+/*
+===============================================================================
+
+This is a rough first-order aproximation that is used to trivially reject some
+of the final calculations.
+
+
+Calculates portalfront and portalflood bit vectors
+
+thinking about:
+
+typedef struct passage_s
+{
+ struct passage_s *next;
+ struct portal_s *to;
+ stryct sep_s *seperators;
+ byte *mightsee;
+} passage_t;
+
+typedef struct portal_s
+{
+ struct passage_s *passages;
+ int leaf; // leaf portal faces into
+} portal_s;
+
+leaf = portal->leaf
+clear
+for all portals
+
+
+calc portal visibility
+ clear bit vector
+ for all passages
+ passage visibility
+
+
+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 (portal_t *srcportal, int leafnum)
+{
+ int i;
+ leaf_t *leaf;
+ portal_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;
+ portal_t *tp, *p;
+ float d;
+ winding_t *w;
+
+ p = portals+portalnum;
+
+ p->portalfront = malloc (portalbytes);
+ memset (p->portalfront, 0, portalbytes);
+
+ p->portalflood = malloc (portalbytes);
+ memset (p->portalflood, 0, portalbytes);
+
+ p->portalvis = malloc (portalbytes);
+ memset (p->portalvis, 0, 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 > ON_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 < -ON_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);
+// printf ("portal %i: %i mightsee\n", portalnum, p->nummightsee);
+ 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)
+{
+ portal_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)
+{
+ portal_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;
+}
+
+
projects / xonotic / netradiant.git / blobdiff