public PixelCollection BresenhamCircle(PixelCollection pixels, Point center,
double radius, Color colour)
{
double x = radius;
double y = 0;
double decition = 0;
while (x >= y)
{
if (decition <= 0)
{
y++;
decition += 2 * y + 1;
}
if (decition > 0)
{
x--;
decition -= 2 * x + 1;
}
pixels.SetPixel((int)(center.X + x), (int)(center.Y + y), colour);
pixels.SetPixel((int)(center.X + y), (int)(center.Y + x), colour);
pixels.SetPixel((int)(center.X - y), (int)(center.Y + x), colour);
pixels.SetPixel((int)(center.X - x), (int)(center.Y + y), colour);
pixels.SetPixel((int)(center.X - x), (int)(center.Y - y), colour);
pixels.SetPixel((int)(center.X - y), (int)(center.Y - x), colour);
pixels.SetPixel((int)(center.X + y), (int)(center.Y - x), colour);
pixels.SetPixel((int)(center.X + x), (int)(center.Y - y), colour);
}
return(pixels);
}
public PixelCollection FloodFill(PixelCollection pixels, Pixel fillPixel, Color targetColor, Color replacementColor)
{
if (targetColor.Equals(replacementColor))
{
return(pixels);
}
if (!fillPixel.Color.Equals(targetColor))
{
return(pixels);
}
var pixelQueue = new Queue <Pixel>();
pixels.SetPixel(fillPixel, replacementColor);
pixelQueue.Enqueue(fillPixel);
Pixel currentPixel;
while (pixelQueue.Count > 0)
{
currentPixel = pixelQueue.Dequeue();
var northPixel = pixels.GetPixelOrNull(currentPixel.Column, currentPixel.Row - 1);
var southPixel = pixels.GetPixelOrNull(currentPixel.Column, currentPixel.Row + 1);
var eastPixel = pixels.GetPixelOrNull(currentPixel.Column + 1, currentPixel.Row);
var westPixel = pixels.GetPixelOrNull(currentPixel.Column - 1, currentPixel.Row);
TryToColorPixel(pixels, pixelQueue, northPixel, targetColor, replacementColor);
TryToColorPixel(pixels, pixelQueue, southPixel, targetColor, replacementColor);
TryToColorPixel(pixels, pixelQueue, eastPixel, targetColor, replacementColor);
TryToColorPixel(pixels, pixelQueue, westPixel, targetColor, replacementColor);
}
return(pixels);
}
private void TryToColorPixel(PixelCollection pixels, Queue <Pixel> pixelQueue, Pixel currentPixel,
Color targetColor, Color replacementColor)
{
if (currentPixel != null && targetColor.Equals(currentPixel.Color))
{
pixels.SetPixel(currentPixel, replacementColor);
pixelQueue.Enqueue(currentPixel);
}
}
public PixelCollection Rectangle(PixelCollection pixels, Point startPoint, Point endPoint,
Color colour)
{
if (startPoint.X > endPoint.X)
{
Swapper.Swap(ref startPoint, ref endPoint);
}
for (int i = (int)startPoint.X; i < endPoint.X; i++)
{
pixels.SetPixel(i, (int)startPoint.Y, colour);
pixels.SetPixel(i, (int)endPoint.Y, colour);
}
if (startPoint.Y > endPoint.Y)
{
Swapper.Swap(ref startPoint, ref endPoint);
}
for (int i = (int)startPoint.Y; i < endPoint.Y; i++)
{
pixels.SetPixel((int)startPoint.X, i, colour);
pixels.SetPixel((int)endPoint.X, i, colour);
}
return(pixels);
}
public PixelCollection BresenhamLine(PixelCollection pixels, Point drawingStartPoint,
Point drawingEndPoint, Color colour)
{
int lineWidth = (int)drawingEndPoint.X - (int)drawingStartPoint.X;
int lineHeight = (int)drawingEndPoint.Y - (int)drawingStartPoint.Y;
int widthDifference1 = 0, heightDifference1 = 0, widthDifference2 = 0, heightDifference2 = 0;
if (lineWidth < 0)
{
widthDifference1 = -1;
}
else if (lineWidth > 0)
{
widthDifference1 = 1;
}
if (lineHeight < 0)
{
heightDifference1 = -1;
}
else if (lineHeight > 0)
{
heightDifference1 = 1;
}
if (lineWidth < 0)
{
widthDifference2 = -1;
}
else if (lineWidth > 0)
{
widthDifference2 = 1;
}
int longest = Math.Abs(lineWidth);
int shortest = Math.Abs(lineHeight);
if (!(longest > shortest))
{
longest = Math.Abs(lineHeight);
shortest = Math.Abs(lineWidth);
if (lineHeight < 0)
{
heightDifference2 = -1;
}
else if (lineHeight > 0)
{
heightDifference2 = 1;
}
widthDifference2 = 0;
}
int numerator = longest >> 1;
for (int i = 0; i <= longest; i++)
{
pixels.SetPixel((int)drawingStartPoint.X, (int)drawingStartPoint.Y, colour);
numerator += shortest;
if (!(numerator < longest))
{
numerator -= longest;
drawingStartPoint.X += widthDifference1;
drawingStartPoint.Y += heightDifference1;
}
else
{
drawingStartPoint.X += widthDifference2;
drawingStartPoint.Y += heightDifference2;
}
}
return(pixels);
}