//-----------------------------------------------------------------------------
// Recursively checks the scene's leaves against the given object.
//-----------------------------------------------------------------------------
void SceneManager::RecursiveBuildCollisionArray( SceneLeaf *leaf, SceneObject *object )
{
// Only process the leaves if the object's bounding box intesects with it.
// NOTE: Test both ways to ensure smaller nodes are accepted for intersection.
if( !IsBoxInBox( object->GetBoundingBox()->min, object->GetBoundingBox()->max, leaf->GetBoundingBox()->min, leaf->GetBoundingBox()->max ) && !IsBoxInBox( leaf->GetBoundingBox()->min, leaf->GetBoundingBox()->max, object->GetBoundingBox()->min, object->GetBoundingBox()->max ) )
return;
// Recursively build collision array from each of the leaf's children.
for( char c = 0; c < 8; c++ )
if( leaf->children[c] != NULL )
RecursiveBuildCollisionArray( leaf->children[c], object );
// Add the faces in this leaf to the array of possible collision faces.
for( unsigned long f = 0; f < leaf->totalFaces; f++ )
{
if( m_totalCollisionFaces == m_totalFaces )
return;
m_collisionFaces[m_totalCollisionFaces] = &m_faces[leaf->faces[f]];
m_totalCollisionFaces++;
}
}
//-----------------------------------------------------------------------------
// Recursively builds the scene.
//-----------------------------------------------------------------------------
void SceneManager::RecursiveSceneBuild( SceneLeaf *leaf, D3DXVECTOR3 translation, float halfSize )
{
// Build a bounding volume around this leaf.
leaf->SetBoundingBox( D3DXVECTOR3( translation.x - halfSize, translation.y - halfSize, translation.z - halfSize ), D3DXVECTOR3( translation.x + halfSize, translation.y + halfSize, translation.z + halfSize ) );
leaf->SetBoundingSphere( translation, (float)sqrt( halfSize * halfSize + halfSize * halfSize + halfSize * halfSize ) );
// Count the number of face in this leaf.
unsigned long totalFaces = 0;
for( unsigned long f = 0; f < m_totalFaces; f++ )
if( IsFaceInBox( &m_vertices[m_faces[f].vertex0], &m_vertices[m_faces[f].vertex1], &m_vertices[m_faces[f].vertex2], leaf->GetBoundingBox()->min, leaf->GetBoundingBox()->max ) == true )
totalFaces++;
// Only divide the leaf up if it is too big and contains too many faces.
if( halfSize > m_maxHalfSize && totalFaces > m_maxFaces )
{
// Go through all the child leaves.
for( char c = 0; c < 8; c++ )
{
D3DXVECTOR3 newTranslation, newMin, newMax;
float newHalfSize = halfSize / 2.0f;
float mod;
// Calculate the translation of the new leaf on the x axis.
mod = 1.0f;
if( c % 2 < 1 )
mod = -1.0f;
newTranslation.x = translation.x + newHalfSize * mod;
// Calculate the translation of the new leaf on the y axis.
mod = 1.0f;
if( c % 4 < 2 )
mod = -1.0f;
newTranslation.y = translation.y + newHalfSize * mod;
// Calculate the translation of the new leaf on the z axis.
mod = 1.0f;
if( c % 8 < 4 )
mod = -1.0f;
newTranslation.z = translation.z + newHalfSize * mod;
// Calculate the bounding box around the new leaf.
newMin = D3DXVECTOR3( newTranslation.x - newHalfSize, newTranslation.y - newHalfSize, newTranslation.z - newHalfSize );
newMax = D3DXVECTOR3( newTranslation.x + newHalfSize, newTranslation.y + newHalfSize, newTranslation.z + newHalfSize );
// Check if the new scene leaf will have at least one face in it.
for( f = 0; f < m_totalFaces; f++ )
{
if( IsFaceInBox( &m_vertices[m_faces[f].vertex0], &m_vertices[m_faces[f].vertex1], &m_vertices[m_faces[f].vertex2], newMin, newMax ) == true )
{
// A face has been found that is inside the new child scene
// leaf, so create the scene leaf. Then recurse through the
// scene leaf's branch of the scene hierarchy.
leaf->children[c] = new SceneLeaf;
RecursiveSceneBuild( leaf->children[c], newTranslation, halfSize / 2.0f );
break;
}
}
}
return;
}
// Create the leaf's array of face indices.
leaf->totalFaces = totalFaces;
leaf->faces = new unsigned long[totalFaces];
// If any face is contained in the leaf's bounding box, then store
// the index of the face in the leaf's face index array.
totalFaces = 0;
for( f = 0; f < m_totalFaces; f++ )
if( IsFaceInBox( &m_vertices[m_faces[f].vertex0], &m_vertices[m_faces[f].vertex1], &m_vertices[m_faces[f].vertex2], leaf->GetBoundingBox()->min, leaf->GetBoundingBox()->max ) == true )
leaf->faces[totalFaces++] = f;
// Store pointers to any occluding objects in the leaf.
m_occludingObjects->Iterate( true );
while( m_occludingObjects->Iterate() )
if( IsBoxInBox( m_occludingObjects->GetCurrent()->GetBoundingBox()->min, m_occludingObjects->GetCurrent()->GetBoundingBox()->max, leaf->GetBoundingBox()->min, leaf->GetBoundingBox()->max ) == true )
leaf->occluders->Add( m_occludingObjects->GetCurrent() );
}
