/// <summary>
/// Scan each row of the shape to update shape data between the contour values..
/// </summary>
/// <param name="pixels"></param>
private void PopulatePixels(PixelCollection pixels)
{
foreach (var row in pixels.Rows)
{
var keys = row.Value.Keys;
int index = 0;
int y = row.Key;
while (keys[index] != keys[^ 1])
{
int start = keys[index];
int end = keys[index + 1];
for (int x = start + 1; x < end; x++)
{
if (!_pixelMap.PixelInShape(x, y))
{
break;
}
// Update data.
pixels.AddPixel(x, y);
_pixelMap.SetVisited(x, y);
}
index++;
}
}
}
public Shape(List <Point> contour,
PixelCollection pixels,
List <Line> lines,
List <Corner> corners)
{
Contour = contour;
Pixels = pixels;
Lines = lines;
Corners = corners;
}
/// <summary>
/// Crawl around the contour of a shape in an image.
/// </summary>
/// <param name="x"></param>
/// <param name="y"></param>
/// <param name="pixels"></param>
/// <returns></returns>
private List <Point> DefineContour(int x, int y, PixelCollection pixels)
{
// Define contour.
var contour = new List <Point>();
// Start from the end of the top line.
while (_pixelMap.PixelInShape(x + 1, y))
{
x += 1;
}
var initial = new Point(x, y);
// Initialise data.
contour.Add(initial);
pixels.AddPixel(initial);
_pixelMap.SetVisited(x, y);
// Used to hold the previous pixel co-ords.
var last = initial;
// Initialise current to be the next pixel along the edge.
// Next pixel will be on the next line.
y = last.Y + 1;
// If line does not have a pixel to the bottom right then it must be below
// initial pixel.
x = _pixelMap.PixelInShape(last.X + 1, y) ? last.X + 1 : last.X;
var current = new Point(x, y);
// Crawl around contour until back at start.
while (current != initial)
{
// Update data.
contour.Add(current);
pixels.AddPixel(current);
_pixelMap.SetVisited(current.X, current.Y);
// Find the position of the first empty pixel next to the previous one
// in a clockwise direction.
Zone initialSearchZone = FindSearchZone(current, last);
// Search in a clockwise direction until the first shape pixel is found.
Point found = FindNextPixel(initialSearchZone, current);
// Increment
last = current;
current = found;
}
return(contour);
}
/// <summary>
/// Scan around a shape contour in an image and collect data.
/// </summary>
/// <param name="x"></param>
/// <param name="y"></param>
/// <returns></returns>
public ShapeData Scan(int x, int y)
{
var pixels = new PixelCollection(x, y);
List <Point> contour = DefineContour(x, y, pixels);
// Populate visited array.
PopulatePixels(pixels);
return(new ShapeData()
{
Contour = contour,
Pixels = pixels
});
}
public Triangle(List <Point> contour,
PixelCollection pixels,
List <Line> lines,
List <Corner> corners) : base(contour, pixels, lines, corners)
{
}
public Quadralateral(List <Point> contour,
PixelCollection pixels,
List <Line> lines,
List <Corner> corners) : base(contour, pixels, lines, corners)
{
}
