/*
=======================
idRenderWorldLocal::FlowViewThroughPortals
Finds viewLights and viewEntities by flowing from an origin through the visible
portals that the origin point can see into. The planes array defines a volume with
the planes pointing outside the volume. Zero planes assumes an unbounded volume.
=======================
*/
void idRenderWorldLocal::FlowViewThroughPortals( const idVec3& origin, int numPlanes, const idPlane* planes )
{
portalStack_t ps;
ps.next = NULL;
ps.p = NULL;
assert( numPlanes <= MAX_PORTAL_PLANES );
for( int i = 0; i < numPlanes; i++ )
{
ps.portalPlanes[i] = planes[i];
}
ps.numPortalPlanes = numPlanes;
ps.rect = tr.viewDef->scissor;
// if outside the world, mark everything
if( tr.viewDef->areaNum < 0 )
{
for( int i = 0; i < numPortalAreas; i++ )
{
areaScreenRect[i] = tr.viewDef->scissor;
AddAreaToView( i, &ps );
}
}
else
{
// flood out through portals, setting area viewCount
FloodViewThroughArea_r( origin, tr.viewDef->areaNum, &ps );
}
}
/*
=============
idRenderWorldLocal::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.
Entities and lights can have cached viewEntities / viewLights that
will be used if the viewCount variable matches.
=============
*/
void idRenderWorldLocal::FindViewLightsAndEntities() {
SCOPED_PROFILE_EVENT( "FindViewLightsAndEntities" );
// bumping this counter invalidates cached viewLights / viewEntities,
// when a light or entity is next considered, it will create a new
// viewLight / viewEntity
tr.viewCount++;
// clear the visible lightDef and entityDef lists
tr.viewDef->viewLights = NULL;
tr.viewDef->viewEntitys = NULL;
// all areas are initially not visible, but each portal
// chain that leads to them will expand the visible rectangle
for ( int i = 0; i < numPortalAreas; i++ ) {
areaScreenRect[i].Clear();
}
// 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();
// 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 ) {
static int lastPrintedAreaNum;
if ( tr.viewDef->areaNum != lastPrintedAreaNum ) {
lastPrintedAreaNum = tr.viewDef->areaNum;
common->Printf( "entering portal area %i\n", tr.viewDef->areaNum );
}
portalStack_t ps;
for ( int i = 0; i < 5; i++ ) {
ps.portalPlanes[i] = tr.viewDef->frustum[i];
}
ps.numPortalPlanes = 5;
ps.rect = tr.viewDef->scissor;
AddAreaToView( 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 );
}
}
/*
===================
idRenderWorldLocal::FloodViewThroughArea_r
===================
*/
void idRenderWorldLocal::FloodViewThroughArea_r( const idVec3 & origin, int areaNum, const portalStack_t *ps ) {
portalArea_t * area = &portalAreas[ areaNum ];
// cull models and lights to the current collection of planes
AddAreaToView( areaNum, ps );
if ( areaScreenRect[areaNum].IsEmpty() ) {
areaScreenRect[areaNum] = ps->rect;
} else {
areaScreenRect[areaNum].Union( ps->rect );
}
// go through all the portals
for ( const portal_t * p = area->portals; p != NULL; 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
const float 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
const portalStack_t * check = ps;
for ( ; check != NULL; 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
portalStack_t newStack;
newStack = *ps;
newStack.p = p;
newStack.next = ps;
FloodViewThroughArea_r( origin, p->intoArea, &newStack );
continue;
}
// clip the portal winding to all of the planes
idFixedWinding w; // we won't overflow because MAX_PORTAL_PLANES = 20
w = *p->w;
for ( int 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
portalStack_t newStack;
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
int addPlanes = w.GetNumPoints();
if ( addPlanes > MAX_PORTAL_PLANES ) {
addPlanes = MAX_PORTAL_PLANES;
}
newStack.numPortalPlanes = 0;
for ( int i = 0; i < addPlanes; i++ ) {
int j = i + 1;
if ( j == w.GetNumPoints() ) {
j = 0;
}
const idVec3 & v1 = origin - w[i].ToVec3();
const idVec3 & 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 );
}
}
