/*
=======================
FlowViewThroughPortals
Finds viewLights and viewEntities by flowing from an origin through the visible portals.
origin point can see into. The planes array defines a volume (positive
sides facing in) that should contain the origin, such as a view frustum or a point light box.
Zero planes assumes an unbounded volume.
=======================
*/
void idRenderWorldLocal::FlowViewThroughPortals( const idVec3 origin, int numPlanes, const idPlane *planes ) {
portalStack_t ps;
int i;
ps.next = NULL;
ps.p = NULL;
for ( i = 0 ; i < numPlanes ; i++ ) {
ps.portalPlanes[i] = planes[i];
}
ps.numPortalPlanes = numPlanes;
ps.rect = tr.viewDef->scissor;
if ( tr.viewDef->areaNum < 0 ){
for ( i = 0; i < numPortalAreas; i++ ) {
areaScreenRect[i] = tr.viewDef->scissor;
}
// if outside the world, mark everything
for ( i = 0 ; i < numPortalAreas ; i++ ) {
AddAreaRefs( i, &ps );
}
} else {
for ( i = 0; i < numPortalAreas; i++ ) {
areaScreenRect[i].Clear();
}
// flood out through portals, setting area viewCount
FloodViewThroughArea_r( origin, tr.viewDef->areaNum, &ps );
}
}
/*
=============
FindViewLightsAndEntites
All the modelrefs and lightrefs that are in visible areas
will have viewEntitys and viewLights created for them.
The scissorRects on the viewEntitys and viewLights may be empty if
they were considered, but not actually visible.
=============
*/
void idRenderWorldLocal::FindViewLightsAndEntities(void)
{
// clear the visible lightDef and entityDef lists
tr.viewDef->viewLights = NULL;
tr.viewDef->viewEntitys = NULL;
// find the area to start the portal flooding in
if (!r_usePortals.GetBool()) {
// debug tool to force no portal culling
tr.viewDef->areaNum = -1;
} else {
tr.viewDef->areaNum = PointInArea(tr.viewDef->initialViewAreaOrigin);
}
// determine all possible connected areas for
// light-behind-door culling
BuildConnectedAreas();
// bump the view count, invalidating all
// visible areas
tr.viewCount++;
// flow through all the portals and add models / lights
if (r_singleArea.GetBool()) {
// if debugging, only mark this area
// if we are outside the world, don't draw anything
if (tr.viewDef->areaNum >= 0) {
portalStack_t ps;
int i;
static int lastPrintedAreaNum;
if (tr.viewDef->areaNum != lastPrintedAreaNum) {
lastPrintedAreaNum = tr.viewDef->areaNum;
common->Printf("entering portal area %i\n", tr.viewDef->areaNum);
}
for (i = 0 ; i < 5 ; i++) {
ps.portalPlanes[i] = tr.viewDef->frustum[i];
}
ps.numPortalPlanes = 5;
ps.rect = tr.viewDef->scissor;
AddAreaRefs(tr.viewDef->areaNum, &ps);
}
} else {
// note that the center of projection for flowing through portals may
// be a different point than initialViewAreaOrigin for subviews that
// may have the viewOrigin in a solid/invalid area
FlowViewThroughPortals(tr.viewDef->renderView.vieworg, 5, tr.viewDef->frustum);
}
}
/*
===================
FloodViewThroughArea_r
===================
*/
void idRenderWorldLocal::FloodViewThroughArea_r( const idVec3 origin, int areaNum,
const struct portalStack_s *ps ) {
portal_t* p;
float d;
portalArea_t * area;
const portalStack_t *check;
portalStack_t newStack;
int i, j;
idVec3 v1, v2;
int addPlanes;
idFixedWinding w; // we won't overflow because MAX_PORTAL_PLANES = 20
area = &portalAreas[ areaNum ];
// cull models and lights to the current collection of planes
AddAreaRefs( areaNum, ps );
if ( areaScreenRect[areaNum].IsEmpty() ) {
areaScreenRect[areaNum] = ps->rect;
} else {
areaScreenRect[areaNum].Union( ps->rect );
}
// go through all the portals
for ( p = area->portals; p; p = p->next ) {
// an enclosing door may have sealed the portal off
if ( p->doublePortal->blockingBits & PS_BLOCK_VIEW ) {
continue;
}
// make sure this portal is facing away from the view
d = p->plane.Distance( origin );
if ( d < -0.1f ) {
continue;
}
// make sure the portal isn't in our stack trace,
// which would cause an infinite loop
for ( check = ps; check; check = check->next ) {
if ( check->p == p ) {
break; // don't recursively enter a stack
}
}
if ( check ) {
continue; // already in stack
}
// if we are very close to the portal surface, don't bother clipping
// it, which tends to give epsilon problems that make the area vanish
if ( d < 1.0f ) {
// go through this portal
newStack = *ps;
newStack.p = p;
newStack.next = ps;
FloodViewThroughArea_r( origin, p->intoArea, &newStack );
continue;
}
// clip the portal winding to all of the planes
w = *p->w;
for ( j = 0; j < ps->numPortalPlanes; j++ ) {
if ( !w.ClipInPlace( -ps->portalPlanes[j], 0 ) ) {
break;
}
}
if ( !w.GetNumPoints() ) {
continue; // portal not visible
}
// see if it is fogged out
if ( PortalIsFoggedOut( p ) ) {
continue;
}
// go through this portal
newStack.p = p;
newStack.next = ps;
// find the screen pixel bounding box of the remaining portal
// so we can scissor things outside it
newStack.rect = ScreenRectFromWinding( &w, &tr.identitySpace );
// slop might have spread it a pixel outside, so trim it back
newStack.rect.Intersect( ps->rect );
// generate a set of clipping planes that will further restrict
// the visible view beyond just the scissor rect
addPlanes = w.GetNumPoints();
if ( addPlanes > MAX_PORTAL_PLANES ) {
addPlanes = MAX_PORTAL_PLANES;
}
newStack.numPortalPlanes = 0;
for ( i = 0; i < addPlanes; i++ ) {
j = i+1;
if ( j == w.GetNumPoints() ) {
j = 0;
}
v1 = origin - w[i].ToVec3();
v2 = origin - w[j].ToVec3();
newStack.portalPlanes[newStack.numPortalPlanes].Normal().Cross( v2, v1 );
// if it is degenerate, skip the plane
if ( newStack.portalPlanes[newStack.numPortalPlanes].Normalize() < 0.01f ) {
continue;
}
newStack.portalPlanes[newStack.numPortalPlanes].FitThroughPoint( origin );
newStack.numPortalPlanes++;
}
// the last stack plane is the portal plane
newStack.portalPlanes[newStack.numPortalPlanes] = p->plane;
newStack.numPortalPlanes++;
FloodViewThroughArea_r( origin, p->intoArea, &newStack );
}
}
