public ColorCoordinateSet(Drawable drawable, int cellSize)
{
_cellSize2 = cellSize * cellSize;
_backgroundColor = new Pixel(Context.Background.Bytes);
var pf = new PixelFetcher(drawable, false);
_width = drawable.Width;
_height = drawable.Height;
int nrOfCells = (int)(2.5 * _width * _height / _cellSize2);
_matrixColumns = (int)Math.Sqrt(nrOfCells * _width / 8.0 / _height);
_matrixRows = _matrixColumns * _height / _width;
_matrixColumns = Math.Max(_matrixColumns, 1);
_matrixRows = Math.Max(_matrixRows, 1);
_matrix = new List <ColorCoordinate> [_matrixRows, _matrixColumns];
foreach (var c in new RandomCoordinateGenerator(_width - 1, _height - 1,
nrOfCells))
{
int x = c.X;
int y = c.Y;
var color = pf.GetPixel(c);
color.AddNoise(5);
var coordinate = new ColorCoordinate(c, color);
Add(coordinate);
int row = y * _matrixRows / _height;
int col = x * _matrixColumns / _width;
Add(row, col, coordinate);
int top = row * _height / _matrixRows;
int left = col * _width / _matrixColumns;
int bottom = (row + 1) * _height / _matrixRows;
int right = (col + 1) * _width / _matrixColumns;
Intersects(left, top, col - 1, row - 1, coordinate);
Intersects(x, top, col, row - 1, coordinate);
Intersects(right, top, col + 1, row - 1, coordinate);
Intersects(left, y, col - 1, row, coordinate);
Intersects(right, y, col + 1, row, coordinate);
Intersects(left, bottom, col - 1, row + 1, coordinate);
Intersects(x, bottom, col, row + 1, coordinate);
Intersects(right, bottom, col + 1, row + 1, coordinate);
}
pf.Dispose();
}
void Intersects(int x, int y, int col, int row, ColorCoordinate coordinate)
{
if (col < 0 || col >= _matrixColumns || row < 0 || row >= _matrixRows)
{
return;
}
if (coordinate.Distance(x, y) < _cellSize2 / 4)
{
Add(row, col, coordinate);
}
}
Pixel GetNearestColor(List <ColorCoordinate> list, IntCoordinate c)
{
int distance = int.MaxValue;
ColorCoordinate closest = null;
list.ForEach(coordinate =>
{
int d = coordinate.Distance(c);
if (d < distance)
{
distance = d;
closest = coordinate;
}
});
return(distance < _cellSize2 / 4 ? closest.Color : _backgroundColor);
}
void Add(int row, int col, ColorCoordinate coordinate)
{
_matrix[row, col] = _matrix[row, col] ?? new List <ColorCoordinate>();
_matrix[row, col].Add(coordinate);
}
