private bool SelectColors(int targetColors)
{
int splitAxis;
ColorBox * splitBox, boxPtr = _boxes;
ARGBPixel * sPtr = _srcPixels;
ColorEntry **gPtr = _groupTable;
ColorEntry * entry;
ushort id;
//Create initial box
boxPtr->Initialize();
_boxCount = 1;
//Iterate through colors using ID generator
for (int i = 0; i < _size; i++)
{
_idFunc(*sPtr++, &id);
gPtr = _groupTable + id;
if ((entry = *gPtr) == null)
{
*gPtr = entry = ColorEntry.Create();
_idConv(&id, out entry->_color);
entry->_weight = 1;
boxPtr->_rootEntry->InsertPrev(entry);
}
else
{
entry->_weight++;
}
}
//If no quantization is necessary, then leave.
if (boxPtr->_colors <= targetColors)
{
return(false);
}
//Update initial box
boxPtr->Update(targetColors - 1);
//Split until we reach desired colors
while (_boxCount < targetColors)
{
//Find split candidate
splitBox = ColorBox.FindSplit(_boxes, _boxCount, targetColors, out splitAxis);
//Create new box
(++boxPtr)->Initialize();
//Move colors from one box to another using split axis
splitBox->Split(boxPtr, splitAxis);
//Update boxes
_boxCount++;
splitBox->Update(targetColors - _boxCount);
boxPtr->Update(targetColors - _boxCount);
}
return(true);
}
