/// <summary>
/// Keep track of the previous node that was quantized
/// </summary>
/// <param name="node">The node last quantized</param>
public void TrackPrevious( OctreeNode node )
{
_previousNode = node;
}
/// <summary>
/// Construct the octree
/// </summary>
/// <param name="maxColourBits">
/// The maximum number of significant bits in the image
/// </param>
public Octree( int maxColourBits )
{
_maxColorBits = maxColourBits;
_reducibleNodes = new OctreeNode[9];
_root = new OctreeNode( 0, _maxColorBits, this );
}
/// <summary>
/// Reduce the depth of the tree
/// </summary>
private void Reduce()
{
int index;
// Find the deepest level containing at least one reducible node
for(
index = _maxColorBits - 1;
( index > 0 ) && ( null == _reducibleNodes[index] );
index--
);
// Reduce the node most recently added to the list at level 'index'
OctreeNode node = _reducibleNodes[index];
_reducibleNodes[index] = node.NextReducible;
// Decrement the leaf count after reducing the node
_leafCount -= node.Reduce();
// And just in case I've reduced the last color to be added,
// and the next color to be added is the same, invalidate the
// previousNode...
_previousNode = null;
}
public void AddColour( Colour32* pixel,
int colourBits,
int level,
Octree octree )
{
// Update the color information if this is a leaf
if( _leaf )
{
Increment( pixel );
// Setup the previous node
octree.TrackPrevious( this );
}
else
{
// Go to the next level down in the tree
// FXCOP: Correct the potential overflow in the operation '7-level' in 'OctreeNode.AddColour(Colour32*, Int32, Int32, Octree):Void'. (CA2233)
int shift = 7 - level;
int index = ( ( pixel->Red & mask[level] ) >> ( shift - 2 ) ) |
( ( pixel->Green & mask[level] ) >> ( shift - 1 ) ) |
( ( pixel->Blue & mask[level] ) >> ( shift ) );
OctreeNode child = _children[index];
if( null == child )
{
// Create a new child node & store in the array
// FXCOP: Correct the potential overflow in the operation 'level+1' in 'OctreeNode.AddColour(Colour32*, Int32, Int32, Octree):Void'. (CA2233)
child = new OctreeNode( level + 1, colourBits, octree );
_children[index] = child;
}
// Add the color to the child node
// FXCOP: Correct the potential overflow in the operation 'level+1' in 'OctreeNode.AddColour(Colour32*, Int32, Int32, Octree):Void'. (CA2233)
child.AddColour( pixel, colourBits, level + 1, octree );
}
}
public OctreeNode( int level, int colourBits, Octree octree )
{
if( octree == null )
{
// TESTME: constructor null argument
throw new ArgumentNullException( "octree" );
}
// Construct the new node
_leaf = ( level == colourBits );
_red = _green = _blue = 0;
// If a leaf, increment the leaf count
if( _leaf )
{
octree.Leaves++;
}
else
{
// Otherwise add this to the reducible nodes
_nextReducible = octree.ReducibleNodes[level];
octree.ReducibleNodes[level] = this;
_children = new OctreeNode[8];
}
}
/// <summary>
/// Construct the octree
/// </summary>
/// <param name="maxColourBits">
/// The maximum number of significant bits in the image
/// </param>
public Octree(int maxColourBits)
{
_maxColorBits = maxColourBits;
_reducibleNodes = new OctreeNode[9];
_root = new OctreeNode(0, _maxColorBits, this);
}
/// <summary>
/// Keep track of the previous node that was quantized
/// </summary>
/// <param name="node">The node last quantized</param>
public void TrackPrevious(OctreeNode node)
{
_previousNode = node;
}
