private static Box[] SplitData(ref int colorCount, ColorMoment[, , ,] moments)
{
--colorCount;
int next = 0;
float[] volumeVariance = new float[colorCount];
Box[] cubes = new Box[colorCount];
cubes[0].AlphaMaximum = MaxSideIndex;
cubes[0].RedMaximum = MaxSideIndex;
cubes[0].GreenMaximum = MaxSideIndex;
cubes[0].BlueMaximum = MaxSideIndex;
for (int cubeIndex = 1; cubeIndex < colorCount; ++cubeIndex)
{
if (Cut(moments, ref cubes[next], ref cubes[cubeIndex]))
{
volumeVariance[next] = cubes[next].Size > 1 ? CalculateVariance(moments, cubes[next]) : 0.0f;
volumeVariance[cubeIndex] = cubes[cubeIndex].Size > 1 ? CalculateVariance(moments, cubes[cubeIndex]) : 0.0f;
}
else
{
volumeVariance[next] = 0.0f;
cubeIndex--;
}
next = 0;
float temp = volumeVariance[0];
for (int index = 1; index <= cubeIndex; ++index)
{
if (volumeVariance[index] <= temp)
{
continue;
}
temp = volumeVariance[index];
next = index;
}
if (temp > 0.0)
{
continue;
}
colorCount = cubeIndex + 1;
break;
}
return cubes.Take(colorCount).ToArray();
}
private static Color32[] BuildLookups(Box[] cubes, ColorMoment[, , ,] moments)
{
Color32[] lookups = new Color32[cubes.Length];
for (int cubeIndex = 0; cubeIndex < cubes.Length; cubeIndex++)
{
ColorMoment volume = Volume(moments, cubes[cubeIndex]);
if (volume.Weight <= 0)
{
continue;
}
Color32 lookup = new Color32
{
A = (byte)(volume.Alpha / volume.Weight),
R = (byte)(volume.Red / volume.Weight),
G = (byte)(volume.Green / volume.Weight),
B = (byte)(volume.Blue / volume.Weight)
};
lookups[cubeIndex] = lookup;
}
return lookups;
}
private static ColorMoment Volume(ColorMoment[, , ,] moments, Box cube)
{
return (moments[cube.AlphaMaximum, cube.RedMaximum, cube.GreenMaximum, cube.BlueMaximum] -
moments[cube.AlphaMaximum, cube.RedMaximum, cube.GreenMinimum, cube.BlueMaximum] -
moments[cube.AlphaMaximum, cube.RedMinimum, cube.GreenMaximum, cube.BlueMaximum] +
moments[cube.AlphaMaximum, cube.RedMinimum, cube.GreenMinimum, cube.BlueMaximum] -
moments[cube.AlphaMinimum, cube.RedMaximum, cube.GreenMaximum, cube.BlueMaximum] +
moments[cube.AlphaMinimum, cube.RedMaximum, cube.GreenMinimum, cube.BlueMaximum] +
moments[cube.AlphaMinimum, cube.RedMinimum, cube.GreenMaximum, cube.BlueMaximum] -
moments[cube.AlphaMinimum, cube.RedMinimum, cube.GreenMinimum, cube.BlueMaximum]) -
(moments[cube.AlphaMaximum, cube.RedMaximum, cube.GreenMaximum, cube.BlueMinimum] -
moments[cube.AlphaMinimum, cube.RedMaximum, cube.GreenMaximum, cube.BlueMinimum] -
moments[cube.AlphaMaximum, cube.RedMaximum, cube.GreenMinimum, cube.BlueMinimum] +
moments[cube.AlphaMinimum, cube.RedMaximum, cube.GreenMinimum, cube.BlueMinimum] -
moments[cube.AlphaMaximum, cube.RedMinimum, cube.GreenMaximum, cube.BlueMinimum] +
moments[cube.AlphaMinimum, cube.RedMinimum, cube.GreenMaximum, cube.BlueMinimum] +
moments[cube.AlphaMaximum, cube.RedMinimum, cube.GreenMinimum, cube.BlueMinimum] -
moments[cube.AlphaMinimum, cube.RedMinimum, cube.GreenMinimum, cube.BlueMinimum]);
}
private static float CalculateVariance(ColorMoment[, , ,] moments, Box cube)
{
ColorMoment volume = Volume(moments, cube);
return volume.Variance();
}
private static bool Cut(ColorMoment[, , ,] moments, ref Box first, ref Box second)
{
int direction;
ColorMoment whole = Volume(moments, first);
CubeCut maxAlpha = Maximize(moments, first, Alpha, (byte)(first.AlphaMinimum + 1), first.AlphaMaximum, whole);
CubeCut maxRed = Maximize(moments, first, Red, (byte)(first.RedMinimum + 1), first.RedMaximum, whole);
CubeCut maxGreen = Maximize(moments, first, Green, (byte)(first.GreenMinimum + 1), first.GreenMaximum, whole);
CubeCut maxBlue = Maximize(moments, first, Blue, (byte)(first.BlueMinimum + 1), first.BlueMaximum, whole);
if ((maxAlpha.Value >= maxRed.Value) && (maxAlpha.Value >= maxGreen.Value) && (maxAlpha.Value >= maxBlue.Value))
{
direction = Alpha;
if (maxAlpha.Position == null)
{
return false;
}
}
else if ((maxRed.Value >= maxAlpha.Value) && (maxRed.Value >= maxGreen.Value)
&& (maxRed.Value >= maxBlue.Value))
{
direction = Red;
}
else
{
if ((maxGreen.Value >= maxAlpha.Value) && (maxGreen.Value >= maxRed.Value)
&& (maxGreen.Value >= maxBlue.Value))
{
direction = Green;
}
else
{
direction = Blue;
}
}
second.AlphaMaximum = first.AlphaMaximum;
second.RedMaximum = first.RedMaximum;
second.GreenMaximum = first.GreenMaximum;
second.BlueMaximum = first.BlueMaximum;
switch (direction)
{
case Alpha:
if (maxAlpha.Position == null)
{
return false;
}
second.AlphaMinimum = first.AlphaMaximum = (byte)maxAlpha.Position;
second.RedMinimum = first.RedMinimum;
second.GreenMinimum = first.GreenMinimum;
second.BlueMinimum = first.BlueMinimum;
break;
case Red:
if (maxRed.Position == null)
{
return false;
}
second.RedMinimum = first.RedMaximum = (byte)maxRed.Position;
second.AlphaMinimum = first.AlphaMinimum;
second.GreenMinimum = first.GreenMinimum;
second.BlueMinimum = first.BlueMinimum;
break;
case Green:
if (maxGreen.Position == null)
{
return false;
}
second.GreenMinimum = first.GreenMaximum = (byte)maxGreen.Position;
second.AlphaMinimum = first.AlphaMinimum;
second.RedMinimum = first.RedMinimum;
second.BlueMinimum = first.BlueMinimum;
break;
case Blue:
if (maxBlue.Position == null)
{
return false;
}
second.BlueMinimum = first.BlueMaximum = (byte)maxBlue.Position;
second.AlphaMinimum = first.AlphaMinimum;
second.RedMinimum = first.RedMinimum;
second.GreenMinimum = first.GreenMinimum;
break;
}
first.Size = (first.AlphaMaximum - first.AlphaMinimum) * (first.RedMaximum - first.RedMinimum) * (first.GreenMaximum - first.GreenMinimum) * (first.BlueMaximum - first.BlueMinimum);
second.Size = (second.AlphaMaximum - second.AlphaMinimum) * (second.RedMaximum - second.RedMinimum) * (second.GreenMaximum - second.GreenMinimum) * (second.BlueMaximum - second.BlueMinimum);
return true;
}
private static CubeCut Maximize(ColorMoment[, , ,] moments, Box cube, int direction, byte first, byte last, ColorMoment whole)
{
ColorMoment bottom = Bottom(cube, direction, moments);
float result = 0.0f;
byte? cutPoint = null;
for (byte position = first; position < last; ++position)
{
ColorMoment half = bottom + Top(cube, direction, position, moments);
if (half.Weight == 0)
{
continue;
}
long temp = half.WeightedDistance();
half = whole - half;
if (half.Weight != 0)
{
temp += half.WeightedDistance();
if (temp > result)
{
result = temp;
cutPoint = position;
}
}
}
return new CubeCut(cutPoint, result);
}
private static ColorMoment Bottom(Box cube, int direction, ColorMoment[, , ,] moment)
{
switch (direction)
{
case Alpha:
return (-moment[cube.AlphaMinimum, cube.RedMaximum, cube.GreenMaximum, cube.BlueMaximum] +
moment[cube.AlphaMinimum, cube.RedMaximum, cube.GreenMinimum, cube.BlueMaximum] +
moment[cube.AlphaMinimum, cube.RedMinimum, cube.GreenMaximum, cube.BlueMaximum] -
moment[cube.AlphaMinimum, cube.RedMinimum, cube.GreenMinimum, cube.BlueMaximum]) -
(-moment[cube.AlphaMinimum, cube.RedMaximum, cube.GreenMaximum, cube.BlueMinimum] +
moment[cube.AlphaMinimum, cube.RedMaximum, cube.GreenMinimum, cube.BlueMinimum] +
moment[cube.AlphaMinimum, cube.RedMinimum, cube.GreenMaximum, cube.BlueMinimum] -
moment[cube.AlphaMinimum, cube.RedMinimum, cube.GreenMinimum, cube.BlueMinimum]);
case Red:
return (-moment[cube.AlphaMaximum, cube.RedMinimum, cube.GreenMaximum, cube.BlueMaximum] +
moment[cube.AlphaMaximum, cube.RedMinimum, cube.GreenMinimum, cube.BlueMaximum] +
moment[cube.AlphaMinimum, cube.RedMinimum, cube.GreenMaximum, cube.BlueMaximum] -
moment[cube.AlphaMinimum, cube.RedMinimum, cube.GreenMinimum, cube.BlueMaximum]) -
(-moment[cube.AlphaMaximum, cube.RedMinimum, cube.GreenMaximum, cube.BlueMinimum] +
moment[cube.AlphaMaximum, cube.RedMinimum, cube.GreenMinimum, cube.BlueMinimum] +
moment[cube.AlphaMinimum, cube.RedMinimum, cube.GreenMaximum, cube.BlueMinimum] -
moment[cube.AlphaMinimum, cube.RedMinimum, cube.GreenMinimum, cube.BlueMinimum]);
case Green:
return (-moment[cube.AlphaMaximum, cube.RedMaximum, cube.GreenMinimum, cube.BlueMaximum] +
moment[cube.AlphaMaximum, cube.RedMinimum, cube.GreenMinimum, cube.BlueMaximum] +
moment[cube.AlphaMinimum, cube.RedMaximum, cube.GreenMinimum, cube.BlueMaximum] -
moment[cube.AlphaMinimum, cube.RedMinimum, cube.GreenMinimum, cube.BlueMaximum]) -
(-moment[cube.AlphaMaximum, cube.RedMaximum, cube.GreenMinimum, cube.BlueMinimum] +
moment[cube.AlphaMaximum, cube.RedMinimum, cube.GreenMinimum, cube.BlueMinimum] +
moment[cube.AlphaMinimum, cube.RedMaximum, cube.GreenMinimum, cube.BlueMinimum] -
moment[cube.AlphaMinimum, cube.RedMinimum, cube.GreenMinimum, cube.BlueMinimum]);
case Blue:
return (-moment[cube.AlphaMaximum, cube.RedMaximum, cube.GreenMaximum, cube.BlueMinimum] +
moment[cube.AlphaMaximum, cube.RedMaximum, cube.GreenMinimum, cube.BlueMinimum] +
moment[cube.AlphaMaximum, cube.RedMinimum, cube.GreenMaximum, cube.BlueMinimum] -
moment[cube.AlphaMaximum, cube.RedMinimum, cube.GreenMinimum, cube.BlueMinimum]) -
(-moment[cube.AlphaMinimum, cube.RedMaximum, cube.GreenMaximum, cube.BlueMinimum] +
moment[cube.AlphaMinimum, cube.RedMaximum, cube.GreenMinimum, cube.BlueMinimum] +
moment[cube.AlphaMinimum, cube.RedMinimum, cube.GreenMaximum, cube.BlueMinimum] -
moment[cube.AlphaMinimum, cube.RedMinimum, cube.GreenMinimum, cube.BlueMinimum]);
default:
return new ColorMoment();
}
}