/// <summary>
/// Return the palette index for the passed color
/// </summary>
/// <param name="pixel">The pixel data.</param>
/// <param name="level">The level.</param>
/// <param name="buffer">The buffer array.</param>
/// <returns>
/// The <see cref="int"/> representing the index of the pixel in the palette.
/// </returns>
public int GetPaletteIndex(TPixel pixel, int level, byte[] buffer)
{
int index = this.paletteIndex;
if (!this.leaf)
{
int shift = 7 - level;
pixel.ToXyzwBytes(buffer, 0);
int pixelIndex = ((buffer[2] & Mask[level]) >> (shift - 2)) |
((buffer[1] & Mask[level]) >> (shift - 1)) |
((buffer[0] & Mask[level]) >> shift);
if (this.children[pixelIndex] != null)
{
index = this.children[pixelIndex].GetPaletteIndex(pixel, level + 1, buffer);
}
else
{
throw new Exception($"Cannot retrive a pixel at the given index {pixelIndex}.");
}
}
return(index);
}
/// <summary>
/// Add a color into the tree
/// </summary>
/// <param name="pixel">The color</param>
/// <param name="colorBits">The number of significant color bits</param>
/// <param name="level">The level in the tree</param>
/// <param name="octree">The tree to which this node belongs</param>
/// <param name="buffer">The buffer array.</param>
public void AddColor(TPixel pixel, int colorBits, int level, Octree octree, byte[] buffer)
{
// Update the color information if this is a leaf
if (this.leaf)
{
this.Increment(pixel, buffer);
// Setup the previous node
octree.TrackPrevious(this);
}
else
{
// Go to the next level down in the tree
int shift = 7 - level;
pixel.ToXyzwBytes(buffer, 0);
int index = ((buffer[2] & Mask[level]) >> (shift - 2)) |
((buffer[1] & Mask[level]) >> (shift - 1)) |
((buffer[0] & Mask[level]) >> shift);
OctreeNode child = this.children[index];
if (child == null)
{
// Create a new child node and store it in the array
child = new OctreeNode(level + 1, colorBits, octree);
this.children[index] = child;
}
// Add the color to the child node
child.AddColor(pixel, colorBits, level + 1, octree, buffer);
}
}
/// <summary>
/// Increment the pixel count and add to the color information
/// </summary>
/// <param name="pixel">The pixel to add.</param>
/// <param name="buffer">The buffer array.</param>
public void Increment(TPixel pixel, byte[] buffer)
{
pixel.ToXyzwBytes(buffer, 0);
this.pixelCount++;
this.red += buffer[0];
this.green += buffer[1];
this.blue += buffer[2];
}
