void ClipWindingEpsilon (winding_t *in, vec3_t normal, vec_t dist,
vec_t epsilon, winding_t **front, winding_t **back)
{
ClipWindingEpsilonStrict(in, normal, dist, epsilon, front, back);
/* apparently most code expects that in the winding-on-plane case, the back winding is the original winding */
if(!*front && !*back)
*back = CopyWinding(in);
}
void SplitBrush( brush_t *brush, int planenum, brush_t **front, brush_t **back ){
brush_t *b[2];
int i, j;
winding_t *w, *cw[2], *midwinding;
plane_t *plane, *plane2;
side_t *s, *cs;
float d, d_front, d_back;
*front = NULL;
*back = NULL;
plane = &mapplanes[planenum];
// check all points
d_front = d_back = 0;
for ( i = 0 ; i < brush->numsides ; i++ )
{
w = brush->sides[i].winding;
if ( !w ) {
continue;
}
for ( j = 0 ; j < w->numpoints ; j++ )
{
d = DotProduct( w->p[j], plane->normal ) - plane->dist;
if ( d > 0 && d > d_front ) {
d_front = d;
}
if ( d < 0 && d < d_back ) {
d_back = d;
}
}
}
if ( d_front < 0.1 ) { // PLANESIDE_EPSILON)
// only on back
*back = CopyBrush( brush );
return;
}
if ( d_back > -0.1 ) { // PLANESIDE_EPSILON)
// only on front
*front = CopyBrush( brush );
return;
}
// create a new winding from the split plane
w = BaseWindingForPlane( plane->normal, plane->dist );
for ( i = 0 ; i < brush->numsides && w ; i++ )
{
plane2 = &mapplanes[brush->sides[i].planenum ^ 1];
ChopWindingInPlace( &w, plane2->normal, plane2->dist, 0 ); // PLANESIDE_EPSILON);
}
if ( !w || WindingIsTiny( w ) ) { // the brush isn't really split
int side;
side = BrushMostlyOnSide( brush, plane );
if ( side == PSIDE_FRONT ) {
*front = CopyBrush( brush );
}
if ( side == PSIDE_BACK ) {
*back = CopyBrush( brush );
}
return;
}
if ( WindingIsHuge( w ) ) {
Sys_FPrintf( SYS_VRB,"WARNING: huge winding\n" );
}
midwinding = w;
// split it for real
for ( i = 0 ; i < 2 ; i++ )
{
b[i] = AllocBrush( brush->numsides + 1 );
memcpy( b[i], brush, sizeof( brush_t ) - sizeof( brush->sides ) );
b[i]->numsides = 0;
b[i]->next = NULL;
b[i]->original = brush->original;
}
// split all the current windings
for ( i = 0 ; i < brush->numsides ; i++ )
{
s = &brush->sides[i];
w = s->winding;
if ( !w ) {
continue;
}
/* strict, in parallel case we get the face back because it also is the midwinding */
ClipWindingEpsilonStrict( w, plane->normal, plane->dist,
0 /*PLANESIDE_EPSILON*/, &cw[0], &cw[1] );
for ( j = 0 ; j < 2 ; j++ )
{
if ( !cw[j] ) {
continue;
}
cs = &b[j]->sides[b[j]->numsides];
b[j]->numsides++;
*cs = *s;
cs->winding = cw[j];
}
}
// see if we have valid polygons on both sides
for ( i = 0 ; i < 2 ; i++ )
{
if ( b[i]->numsides < 3 || !BoundBrush( b[i] ) ) {
if ( b[i]->numsides >= 3 ) {
Sys_FPrintf( SYS_VRB,"bogus brush after clip\n" );
}
FreeBrush( b[i] );
b[i] = NULL;
}
}
if ( !( b[0] && b[1] ) ) {
if ( !b[0] && !b[1] ) {
Sys_FPrintf( SYS_VRB,"split removed brush\n" );
}
else{
Sys_FPrintf( SYS_VRB,"split not on both sides\n" );
}
if ( b[0] ) {
FreeBrush( b[0] );
*front = CopyBrush( brush );
}
if ( b[1] ) {
FreeBrush( b[1] );
*back = CopyBrush( brush );
}
return;
}
// add the midwinding to both sides
for ( i = 0 ; i < 2 ; i++ )
{
cs = &b[i]->sides[b[i]->numsides];
b[i]->numsides++;
cs->planenum = planenum ^ i ^ 1;
cs->shaderInfo = NULL;
if ( i == 0 ) {
cs->winding = CopyWinding( midwinding );
}
else{
cs->winding = midwinding;
}
}
{
vec_t v1;
int i;
for ( i = 0 ; i < 2 ; i++ )
{
v1 = BrushVolume( b[i] );
if ( v1 < 1.0 ) {
FreeBrush( b[i] );
b[i] = NULL;
// Sys_FPrintf (SYS_VRB,"tiny volume after clip\n");
}
}
}
*front = b[0];
*back = b[1];
}
qboolean ChopFaceSurfaceByBrush( entity_t *e, mapDrawSurface_t *ds, brush_t *b ){
int i, j;
side_t *s;
plane_t *plane;
winding_t *w;
winding_t *front, *back;
winding_t *outside[ MAX_BRUSH_SIDES ];
int numOutside;
mapDrawSurface_t *newds;
/* dummy check */
if ( ds->sideRef == NULL || ds->sideRef->side == NULL ) {
return qfalse;
}
/* initial setup */
w = WindingFromDrawSurf( ds );
numOutside = 0;
/* chop by each brush side */
for ( i = 0; i < b->numsides; i++ )
{
/* get brush side and plane */
s = &b->sides[ i ];
plane = &mapplanes[ s->planenum ];
/* handle coplanar outfacing (don't fog) */
if ( ds->sideRef->side->planenum == s->planenum ) {
return qfalse;
}
/* handle coplanar infacing (keep inside) */
if ( ( ds->sideRef->side->planenum ^ 1 ) == s->planenum ) {
continue;
}
/* general case */
ClipWindingEpsilonStrict( w, plane->normal, plane->dist, ON_EPSILON, &front, &back ); /* strict; if plane is "almost identical" to face, both ways to continue can be wrong, so we better not fog it */
FreeWinding( w );
if ( back == NULL ) {
/* nothing actually contained inside */
for ( j = 0; j < numOutside; j++ )
FreeWinding( outside[ j ] );
return qfalse;
}
if ( front != NULL ) {
if ( numOutside == MAX_BRUSH_SIDES ) {
Error( "MAX_BRUSH_SIDES" );
}
outside[ numOutside ] = front;
numOutside++;
}
w = back;
}
/* fixme: celshaded surface fragment errata */
/* all of outside fragments become seperate drawsurfs */
numFogFragments += numOutside;
s = ds->sideRef->side;
for ( i = 0; i < numOutside; i++ )
{
newds = DrawSurfaceForSide( e, ds->mapBrush, s, outside[ i ] );
newds->fogNum = ds->fogNum;
FreeWinding( outside[ i ] );
}
/* ydnar: the old code neglected to snap to 0.125 for the fragment
inside the fog brush, leading to sparklies. this new code does
the right thing and uses the original surface's brush side */
/* build a drawsurf for it */
newds = DrawSurfaceForSide( e, ds->mapBrush, s, w );
if ( newds == NULL ) {
return qfalse;
}
/* copy new to original */
ClearSurface( ds );
memcpy( ds, newds, sizeof( mapDrawSurface_t ) );
/* didn't really add a new drawsurface... :) */
numMapDrawSurfs--;
/* return ok */
return qtrue;
}
void BuildFaceTree_r( node_t *node, face_t *list ){
face_t *split;
face_t *next;
int side;
plane_t *plane;
face_t *newFace;
face_t *childLists[2];
winding_t *frontWinding, *backWinding;
int i;
int splitPlaneNum, compileFlags;
/* count faces left */
i = CountFaceList( list );
/* select the best split plane */
SelectSplitPlaneNum( node, list, &splitPlaneNum, &compileFlags );
/* if we don't have any more faces, this is a node */
if ( splitPlaneNum == -1 ) {
node->planenum = PLANENUM_LEAF;
node->has_structural_children = qfalse;
c_faceLeafs++;
return;
}
/* partition the list */
node->planenum = splitPlaneNum;
node->compileFlags = compileFlags;
node->has_structural_children = !( compileFlags & C_DETAIL ) && !node->opaque;
plane = &mapplanes[ splitPlaneNum ];
childLists[0] = NULL;
childLists[1] = NULL;
for ( split = list; split; split = next )
{
/* set next */
next = split->next;
/* don't split by identical plane */
if ( split->planenum == node->planenum ) {
FreeBspFace( split );
continue;
}
/* determine which side the face falls on */
side = WindingOnPlaneSide( split->w, plane->normal, plane->dist );
/* switch on side */
if ( side == SIDE_CROSS ) {
/* strict; if no winding is left, we have a "virtually identical" plane and don't want to split by it */
ClipWindingEpsilonStrict( split->w, plane->normal, plane->dist, CLIP_EPSILON * 2,
&frontWinding, &backWinding );
if ( frontWinding ) {
newFace = AllocBspFace();
newFace->w = frontWinding;
newFace->next = childLists[0];
newFace->planenum = split->planenum;
newFace->priority = split->priority;
newFace->compileFlags = split->compileFlags;
childLists[0] = newFace;
}
if ( backWinding ) {
newFace = AllocBspFace();
newFace->w = backWinding;
newFace->next = childLists[1];
newFace->planenum = split->planenum;
newFace->priority = split->priority;
newFace->compileFlags = split->compileFlags;
childLists[1] = newFace;
}
FreeBspFace( split );
}
else if ( side == SIDE_FRONT ) {
split->next = childLists[0];
childLists[0] = split;
}
else if ( side == SIDE_BACK ) {
split->next = childLists[1];
childLists[1] = split;
}
}
// recursively process children
for ( i = 0 ; i < 2 ; i++ ) {
node->children[i] = AllocNode();
node->children[i]->parent = node;
VectorCopy( node->mins, node->children[i]->mins );
VectorCopy( node->maxs, node->children[i]->maxs );
}
for ( i = 0 ; i < 3 ; i++ ) {
if ( plane->normal[i] == 1 ) {
node->children[0]->mins[i] = plane->dist;
node->children[1]->maxs[i] = plane->dist;
break;
}
if ( plane->normal[i] == -1 ) {
node->children[0]->maxs[i] = -plane->dist;
node->children[1]->mins[i] = -plane->dist;
break;
}
}
for ( i = 0 ; i < 2 ; i++ ) {
BuildFaceTree_r( node->children[i], childLists[i] );
node->has_structural_children |= node->children[i]->has_structural_children;
}
}
