// returns a surfID
static SurfaceHandle_t FindIntersectionSurfaceAtNode( mnode_t *node, float t,
Vector& c, LightVecState_t& state )
{
SurfaceHandle_t surfID = SurfaceHandleFromIndex( node->firstsurface );
for (int i=0 ; i<node->numsurfaces ; ++i, ++surfID)
{
// Don't immediately return when we hit sky;
// we may actually hit another surface
if (MSurf_Flags( surfID ) & SURFDRAW_SKY)
{
state.m_nSkySurfID = surfID;
continue;
}
// Don't let water surfaces affect us
if (MSurf_Flags( surfID ) & SURFDRAW_WATERSURFACE)
continue;
// Check this surface to see if there's an intersection
if (FindIntersectionAtSurface( surfID, t, c, state ))
{
return surfID;
}
}
return SURFACE_HANDLE_INVALID;
}
// returns surfID
static int FASTCALL FindIntersectionSurfaceAtLeaf( mleaf_t *pLeaf,
float start, float end, Vector& c, LightVecState_t& state )
{
Vector pt;
int closestSurfID = -1;
// Adds displacements in the leaf to a list of displacements to test at the end
AddDisplacementsInLeafToTestList( pLeaf, state );
// Add non-displacement surfaces
// Since there's no BSP tree here, we gotta test *all* surfaces! (blech)
for ( int i = 0; i < pLeaf->nummarksurfaces; i++ )
{
int surfID = host_state.worldmodel->brush.marksurfaces[pLeaf->firstmarksurface + i];
ASSERT_SURF_VALID( surfID );
// Don't add surfaces that have displacement; they are handled above
// In fact, don't even set the vis frame; we need it unset for translucent
// displacement code
if ( SurfaceHasDispInfo(surfID) )
continue;
if ( MSurf_Flags( surfID ) & (SURFDRAW_NODE | SURFDRAW_NODRAW | SURFDRAW_WATERSURFACE) )
continue;
cplane_t* pPlane = &MSurf_Plane( surfID );
// Backface cull...
if (DotProduct( pPlane->normal, state.m_Ray.m_Delta ) > 0.f)
continue;
float startDotN = DotProduct( state.m_Ray.m_Start, pPlane->normal );
float deltaDotN = DotProduct( state.m_Ray.m_Delta, pPlane->normal );
float front = startDotN + start * deltaDotN - pPlane->dist;
float back = startDotN + end * deltaDotN - pPlane->dist;
int side = front < 0.f;
// Blow it off if it doesn't split the plane...
if ( (back < 0.f) == side )
continue;
// Don't test a surface that is farther away from the closest found intersection
float frac = front / (front-back);
if (frac >= state.m_HitFrac)
continue;
float mid = start * (1.0f - frac) + end * frac;
// Check this surface to see if there's an intersection
if (FindIntersectionAtSurface( surfID, mid, c, state ))
{
closestSurfID = surfID;
}
}
// Return the closest surface hit
return closestSurfID;
}