gtkradiant/tools/quake2/q2map/flow.c

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/*
Copyright (C) 1999-2007 id Software, Inc. and contributors.
For a list of contributors, see the accompanying CONTRIBUTORS file.
This file is part of GtkRadiant.
GtkRadiant 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.
GtkRadiant 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 GtkRadiant; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "qvis.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;
}
/*
==============
Vis_ChopWinding
==============
*/
winding_t *Vis_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 = Vis_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 = Vis_ChopWinding( p->winding, &stack, &thread->pstack_head.portalplane );
if ( !stack.pass ) {
continue;
}
}
}
#else
stack.pass = Vis_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 = Vis_ChopWinding( prevstack->source, &stack, &backplane );
if ( !stack.source ) {
continue;
}
}
}
#else
stack.source = Vis_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 );
Sys_FPrintf( SYS_VRB, "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;
}