/*
=======================
idRenderWorldLocal::FlowLightThroughPortals
Adds an arearef in each area that the light center flows into.
This can only be used for shadow casting lights that have a generated
prelight, because shadows are cast from back side which may not be in visible areas.
=======================
*/
void idRenderWorldLocal::FlowLightThroughPortals( idRenderLightLocal *light ) {
// if the light origin areaNum is not in a valid area,
// the light won't have any area refs
if ( light->areaNum == -1 ) {
return;
}
idPlane frustumPlanes[6];
idRenderMatrix::GetFrustumPlanes( frustumPlanes, light->baseLightProject, true, true );
portalStack_t ps;
memset( &ps, 0, sizeof( ps ) );
ps.numPortalPlanes = 6;
for ( int i = 0; i < 6; i++ ) {
ps.portalPlanes[i] = -frustumPlanes[i];
}
FloodLightThroughArea_r( light, light->areaNum, &ps );
}
/*
=======================
FlowLightThroughPortals
Adds an arearef in each area that the light center flows into.
This can only be used for shadow casting lights that have a generated
prelight, because shadows are cast from back side which may not be in visible areas.
=======================
*/
void idRenderWorldLocal::FlowLightThroughPortals( idRenderLightLocal *light ) {
portalStack_t ps;
int i;
// if the light origin areaNum is not in a valid area,
// the light won't have any area refs
if ( light->areaNum == -1 ) {
return;
}
memset( &ps, 0, sizeof( ps ) );
ps.numPortalPlanes = 6;
for ( i = 0 ; i < 6 ; i++ ) {
ps.portalPlanes[i] = light->frustum[i];
}
FloodLightThroughArea_r( light, light->areaNum, &ps );
}
/*
===================
FloodLightThroughArea_r
===================
*/
void idRenderWorldLocal::FloodLightThroughArea_r( idRenderLightLocal *light, int areaNum,
const struct portalStack_s *ps ) {
portal_t* p;
float d;
portalArea_t * area;
const portalStack_t *check, *firstPortalStack;
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 ];
// add an areaRef
AddLightRefToArea( light, area );
// go through all the portals
for ( p = area->portals; p; p = p->next ) {
// make sure this portal is facing away from the view
d = p->plane.Distance( light->globalLightOrigin );
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 ) {
firstPortalStack = check;
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;
FloodLightThroughArea_r( light, 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
}
// also always clip to the original light planes, because they aren't
// necessarily extending to infinitiy like a view frustum
for ( j = 0; j < firstPortalStack->numPortalPlanes; j++ ) {
if ( !w.ClipInPlace( -firstPortalStack->portalPlanes[j], 0 ) ) {
break;
}
}
if ( !w.GetNumPoints() ) {
continue; // portal not visible
}
// go through this portal
newStack.p = p;
newStack.next = ps;
// 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 = light->globalLightOrigin - w[i].ToVec3();
v2 = light->globalLightOrigin - 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( light->globalLightOrigin );
newStack.numPortalPlanes++;
}
FloodLightThroughArea_r( light, p->intoArea, &newStack );
}
}
