public int GetPaletteIndex(ref TPixel pixel, int level)
{
int index = this.paletteIndex;
if (!this.leaf)
{
int shift = 7 - level;
Rgba32 rgba = default;
pixel.ToRgba32(ref rgba);
int pixelIndex = ((rgba.B & Mask[level]) >> (shift - 2))
| ((rgba.G & Mask[level]) >> (shift - 1))
| ((rgba.R & Mask[level]) >> shift);
OctreeNode child = this.children[pixelIndex];
if (child != null)
{
index = child.GetPaletteIndex(ref pixel, level + 1);
}
else
{
throw new Exception($"Cannot retrieve a pixel at the given index {pixelIndex}.");
}
}
return(index);
}
/// <summary>
/// Add a color into the tree
/// </summary>
/// <param name="pixel">The pixel 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(ref TPixel pixel, int colorBits, int level, Octree octree)
{
// Update the color information if this is a leaf
if (this.leaf)
{
this.Increment(ref pixel);
// Setup the previous node
octree.TrackPrevious(this);
}
else
{
// Go to the next level down in the tree
int shift = 7 - level;
Rgba32 rgba = default;
pixel.ToRgba32(ref rgba);
int index = ((rgba.B & Mask[level]) >> (shift - 2))
| ((rgba.G & Mask[level]) >> (shift - 1))
| ((rgba.R & Mask[level]) >> shift);
OctreeNode child = this.children[index];
if (child is 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(ref pixel, colorBits, level + 1, octree);
}
}
public void Invoke(int y)
{
Rgba32 rgb = default;
Span <TPixel> pixelRow = this.source.GetPixelRowSpan(y);
for (int x = this.startX; x < this.endX; x++)
{
TPixel pixel = pixelRow[x];
pixel.ToRgba32(ref rgb);
var x1 = Math.Max(x - this.startX - this.clusterSize + 1, 0);
var x2 = Math.Min(x - this.startX + this.clusterSize + 1, this.bounds.Width - 1);
var y1 = Math.Max(y - this.startY - this.clusterSize + 1, 0);
var y2 = Math.Min(y - this.startY + this.clusterSize + 1, this.bounds.Height - 1);
var count = (uint)((x2 - x1) * (y2 - y1));
var sum = (long)Math.Min(this.intImage[x2, y2] - this.intImage[x1, y2] - this.intImage[x2, y1] + this.intImage[x1, y1], long.MaxValue);
if ((rgb.R + rgb.G + rgb.B) * count <= sum * this.thresholdLimit)
{
this.source[x, y] = this.lower;
}
else
{
this.source[x, y] = this.upper;
}
}
}
/// <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="rgba">The color to map to.</param>
/// <returns>
/// The <see cref="int"/> representing the index of the pixel in the palette.
/// </returns>
public int GetPaletteIndex(TPixel pixel, int level, ref Rgba32 rgba)
{
int index = this.paletteIndex;
if (!this.leaf)
{
int shift = 7 - level;
pixel.ToRgba32(ref rgba);
int pixelIndex = ((rgba.B & Mask[level]) >> (shift - 2)) |
((rgba.G & Mask[level]) >> (shift - 1)) |
((rgba.R & Mask[level]) >> shift);
if (this.children[pixelIndex] != null)
{
index = this.children[pixelIndex].GetPaletteIndex(pixel, level + 1, ref rgba);
}
else
{
throw new Exception($"Cannot retrive a pixel at the given index {pixelIndex}.");
}
}
return(index);
}
public void Increment(ref TPixel pixel, ref Rgba32 rgba)
{
pixel.ToRgba32(ref rgba);
this.pixelCount++;
this.red += rgba.R;
this.green += rgba.G;
this.blue += rgba.B;
}
