HLua/utils/visx2/flow.c

688 lines
14 KiB
C

/***
*
* Copyright (c) 1996-2002, Valve LLC. All rights reserved.
*
* This product contains software technology licensed from Id
* Software, Inc. ("Id Technology"). Id Technology (c) 1996 Id Software, Inc.
* All Rights Reserved.
*
****/
#include "vis.h"
int c_fullskip;
int c_chains;
int c_portalskip, c_leafskip;
int c_vistest, c_mighttest;
int active;
void CheckStack (leaf_t *leaf, threaddata_t *thread)
{
pstack_t *p;
for (p=thread->pstack_head.next ; p ; p=p->next)
{
// printf ("=");
if (p->leaf == leaf)
Error ("CheckStack: 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;
int maxpts;
counts[0] = counts[1] = counts[2] = 0;
if ( in->numpoints > (sizeof(sides)/sizeof(*sides)) )
Error("Winding with too many sides!");
// 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;
}
/*
==============
InTheBallpark
Build a bounding box using the start and end windings
then verify that the clip winding bounding box touches
the start/end bounding box.
==============
*/
int
InTheBallpark( winding_t *start, winding_t *clip, winding_t *end )
{
int d,p;
vec3_t bmin = {9999,9999,9999}, bmax = {-9999,-9999,-9999};
vec3_t cmin = {9999,9999,9999}, cmax = {-9999,-9999,-9999};
vec3_t bcenter, bsize;
vec3_t ccenter, csize;
for(d=0; d<3; d++)
{
// Establish a bounding box based on start winding
for (p=0; p<start->numpoints; p++)
{
if (start->points[p][d] < bmin[d])
bmin[d] = start->points[p][d];
if (start->points[p][d] > bmax[d])
bmax[d] = start->points[p][d];
}
// Extend this bounding box based on end winding
for (p=0; p<end->numpoints; p++)
{
if (end->points[p][d] < bmin[d])
bmin[d] = end->points[p][d];
if (end->points[p][d] > bmax[d])
bmax[d] = end->points[p][d];
}
// Establish a second box based on clip winding
for (p=0; p<clip->numpoints; p++)
{
if (clip->points[p][d] < cmin[d])
cmin[d] = clip->points[p][d];
if (clip->points[p][d] > cmax[d])
cmax[d] = clip->points[p][d];
}
// Calculate the center of each bounding box
bcenter[d] = (bmax[d]+bmin[d]); // Optimized out /2;
ccenter[d] = (cmax[d]+cmin[d]); // Optimized out /2;
// Calculate the distances from center to the edges
bsize[d] = (bmax[d] - bmin[d]); // Optimized out /2;
csize[d] = (cmax[d] - cmin[d]); // Optimized out /2;
// Are the centers further apart than the distance to the edges
if ( fabs(bcenter[d]-ccenter[d]) > bsize[d]+csize[d]+ON_EPSILON )
return 0;
}
return 1;
}
/*
==============
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;
c_chains++;
leaf = &leafs[leafnum];
// CheckStack (leaf, thread);
// mark the leaf as visible
if (! (thread->leafvis[leafnum>>3] & (1<<(leafnum&7)) ) )
{
thread->leafvis[leafnum>>3] |= 1<<(leafnum&7);
thread->base->numcansee++;
}
prevstack->next = &stack;
stack.next = NULL;
stack.leaf = leaf;
stack.portal = NULL;
might = (long *)stack.mightsee;
vis = (long *)thread->leafvis;
// check all portals for flowing into other leafs
for (i=0 ; i<leaf->numportals ; i++)
{
p = leaf->portals[i];
if ( ! (prevstack->mightsee[p->leaf>>3] & (1<<(p->leaf&7)) ) )
{
c_leafskip++;
continue; // can't possibly see it
}
#if 0
pnum = p - portals;
if ( (thread->fullportal[pnum>>3] & (1<<(pnum&7)) ) )
{
c_fullskip++;
continue; // allready have full vis info
}
#endif
// if the portal can't see anything we haven't allready seen, skip it
if (p->status == stat_done)
{
c_vistest++;
test = (long *)p->visbits;
}
else
{
c_mighttest++;
test = (long *)p->mightsee;
}
more = 0;
for (j=0 ; j<bitlongs ; j++)
{
might[j] = ((long *)prevstack->mightsee)[j] & test[j];
more |= (might[j] & ~vis[j]);
}
if (!more)
{ // can't see anything new
c_portalskip++;
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;
if (VectorCompare (prevstack->portalplane.normal, backplane.normal) )
continue; // can't go out a coplanar face
c_portalcheck++;
stack.portal = p;
stack.next = NULL;
stack.freewindings[0] = 1;
stack.freewindings[1] = 1;
stack.freewindings[2] = 1;
stack.pass = ChopWinding (p->winding, &stack, &thread->pstack_head.portalplane);
if (!stack.pass)
continue;
stack.source = ChopWinding (prevstack->source, &stack, &backplane);
if (!stack.source)
continue;
if (!prevstack->pass)
{ // the second leaf can only be blocked if coplanar
RecursiveLeafFlow (p->leaf, thread, &stack);
continue;
}
stack.pass = ChopWinding (stack.pass, &stack, &prevstack->portalplane);
if (!stack.pass)
continue;
c_portaltest++;
#ifdef NOT_BROKEN
if (!InTheBallpark(stack.source, prevstack->pass, stack.pass))
{
FreeStackWinding (stack.pass, &stack);
stack.pass = NULL;
continue;
}
#endif
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;
c_portalpass++;
#if 0
if (stack.pass == p->winding)
{
thread->fullportal[pnum>>3] |= (1<<(pnum&7));
FreeStackWinding (stack.source, &stack);
stack.source = ChopWinding (thread->base->winding, &stack, &backplane);
for (j=0 ; j<bitlongs ; j++)
might[j] = ((long *)thread->pstack_head.mightsee)[j] & test[j];
}
#endif
// flow through it for real
RecursiveLeafFlow (p->leaf, thread, &stack);
}
}
/*
===============
PortalFlow
===============
*/
void PortalFlow (portal_t *p)
{
threaddata_t data;
int i;
if (p->status != stat_working)
Error ("PortalFlow: reflowed");
p->status = stat_working;
p->visbits = malloc (bitbytes);
memset (p->visbits, 0, bitbytes);
memset (&data, 0, sizeof(data));
data.leafvis = p->visbits;
data.base = p;
data.pstack_head.portal = p;
data.pstack_head.source = p->winding;
data.pstack_head.portalplane = p->plane;
for (i=0 ; i<bitlongs ; i++)
((long *)data.pstack_head.mightsee)[i] = ((long *)p->mightsee)[i];
RecursiveLeafFlow (p->leaf, &data, &data.pstack_head);
p->status = stat_done;
}
/*
===============================================================================
This is a rough first-order aproximation that is used to trivially reject some
of the final calculations.
===============================================================================
*/
void SimpleFlood (portal_t *srcportal, int leafnum, byte *portalsee, int *c_leafsee)
{
int i;
leaf_t *leaf;
portal_t *p;
if (srcportal->mightsee[leafnum>>3] & (1<<(leafnum&7)) )
return;
srcportal->mightsee[leafnum>>3] |= (1<<(leafnum&7));
(*c_leafsee)++;
leaf = &leafs[leafnum];
for (i=0 ; i<leaf->numportals ; i++)
{
p = leaf->portals[i];
if ( !portalsee[ p - portals ] )
continue;
SimpleFlood (srcportal, p->leaf, portalsee, c_leafsee);
}
}
/*
==============
BasePortalVis
==============
*/
void BasePortalVis (int threadnum)
{
int i, j, k;
portal_t *tp, *p;
float d;
winding_t *w;
byte portalsee[MAX_PORTALS];
int c_leafsee;
while (1)
{
i = GetThreadWork ();
if (i == -1)
break;
p = portals+i;
p->mightsee = malloc (bitbytes);
memset (p->mightsee, 0, bitbytes);
memset (portalsee, 0, numportals*2);
for (j=0, tp = portals ; j<numportals*2 ; j++, tp++)
{
if (j == i)
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
portalsee[j] = 1;
}
c_leafsee = 0;
SimpleFlood (p, p->leaf, portalsee, &c_leafsee);
p->nummightsee = c_leafsee;
// printf ("portal:%4i c_leafsee:%4i \n", i, c_leafsee);
}
}