/// <summary>
/// Return the palette index for the passed color
/// </summary>
/// <param name="pixel">The <see cref="TColor"/> representing the pixel.</param>
/// <param name="level">The level.</param>
/// <returns>
/// The <see cref="int"/> representing the index of the pixel in the palette.
/// </returns>
public int GetPaletteIndex(TColor pixel, int level)
{
int index = this.paletteIndex;
if (!this.leaf)
{
int shift = 7 - level;
Color color = new Color(pixel.ToVector4());
int pixelIndex = ((color.A & Mask[0]) >> (shift - 3)) |
((color.B & Mask[level + 1]) >> (shift - 2)) |
((color.G & Mask[level + 1]) >> (shift - 1)) |
((color.R & Mask[level + 1]) >> shift);
if (this.children[pixelIndex] != null)
{
index = this.children[pixelIndex].GetPaletteIndex(pixel, level + 1);
}
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>
public void AddColor(TColor pixel, int colorBits, int level, Octree octree)
{
// Update the color information if this is a leaf
if (this.leaf)
{
this.Increment(pixel);
// Setup the previous node
octree.TrackPrevious(this);
}
else
{
// Go to the next level down in the tree
int shift = 7 - level;
Color color = new Color(pixel.ToVector4());
int index = ((color.A & Mask[0]) >> (shift - 3)) |
((color.B & Mask[level + 1]) >> (shift - 2)) |
((color.G & Mask[level + 1]) >> (shift - 1)) |
((color.R & Mask[level + 1]) >> 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);
}
}
/// <summary>
/// Increment the pixel count and add to the color information
/// </summary>
/// <param name="pixel">
/// The pixel to add.
/// </param>
public void Increment(TColor pixel)
{
this.pixelCount++;
Color color = new Color(pixel.ToVector4());
this.red += color.R;
this.green += color.G;
this.blue += color.B;
this.alpha += color.A;
}