private void VertexToEdge(ref List <AEL> Edges, List <Point> Vertex, out int ymin, out int ymax)
{
AEL temp;
ymin = Vertex[0].Y;
ymax = Vertex[0].Y;
Vertex.Add(Vertex[0]);
Vertex.Add(Vertex[1]);
Vertex.Insert(0, Vertex[Vertex.Count - 3]);
for (int i = 1; i <= Vertex.Count - 3; i++)
{
temp = new AEL();
temp.yUpper = Math.Max(Vertex[i].Y, Vertex[i + 1].Y);
temp.yLower = Math.Min(Vertex[i].Y, Vertex[i + 1].Y);
if (Vertex[i].Y > Vertex[i + 1].Y)
{
temp.xIntersect = Vertex[i + 1].X;
}
else
{
temp.xIntersect = Vertex[i].X;
}
if (temp.yLower == temp.yUpper)
{
temp.reciSlope = 0;
}
else
{
temp.reciSlope = (Vertex[i].X - Vertex[i + 1].X) * 1.0 / (Vertex[i].Y - Vertex[i + 1].Y) * 1.0;
}
//Trường hợp điểm giao nhau không phải là cực trị
if (Vertex[i + 1].Y < Vertex[i].Y && Vertex[i].Y < Vertex[i - 1].Y)
{
temp.yUpper--;
}
else
if (Vertex[i + 2].Y > Vertex[i + 1].Y && Vertex[i + 1].Y > Vertex[i].Y)
{
temp.yUpper--;
}
Edges.Add(temp);
ymin = Math.Min(ymin, Vertex[i + 1].Y);
ymax = Math.Max(ymax, Vertex[i + 1].Y);
}
Vertex.RemoveAt(0);
Vertex.RemoveAt(Vertex.Count - 1);
Vertex.RemoveAt(Vertex.Count - 1);
}
public double ScanFill(Shape shape, Color fillColor)
{
Stopwatch stopWatch = new Stopwatch();
stopWatch.Start();
TimeSpan ts;
shape.fillType = FillType.SCANLINE;
int yMin, yMax;
if (shape.type == ShapeType.CIRCLE || shape.type == ShapeType.ELLIPSE)
{
List <Point> fillVertex = new List <Point>();
fillVertex.AddRange(shape.vertexs);
yMin = fillVertex[0].Y;
yMax = yMin;
foreach (var v in fillVertex)
{
if (v.Y > yMax)
{
yMax = v.Y;
}
if (v.Y < yMin)
{
yMin = v.Y;
}
}
for (int y = yMin; y <= yMax; y++)
{
List <Point> line = new List <Point>();
line.AddRange(fillVertex.Where(v => v.Y == y));
line = line.OrderBy(v => v.X).ToList();
int xmin = -1, xmax = -1;
for (int i = 0; i < line.Count - 1; i++)
{
if (Math.Abs(line[i].X - line[i + 1].X) > 1)
{
xmin = line[i].X;
xmax = line[i + 1].X;
break;
}
}
if (xmax < 0)
{
continue;
}
gl.Color(fillColor.R / 255.0, fillColor.G / 255.0, fillColor.B / 255.0);
gl.Begin(OpenGL.GL_LINES);
gl.Vertex(xmin, y);
gl.Vertex(xmax, y);
gl.End();
}
gl.Flush();
shape.Draw(gl);
stopWatch.Stop();
ts = stopWatch.Elapsed;
return(ts.TotalMilliseconds);
}
List <List <AEL> > edgeTable = new List <List <AEL> >();
List <AEL> begList = new List <AEL>();
List <AEL> edges = new List <AEL>();
VertexToEdge(ref edges, shape.vertexs, out yMin, out yMax);
//Tạo Edge Table
for (int y = yMin; y <= yMax; y++)
{
List <AEL> subList = new List <AEL>();
edgeTable.Add(subList);
}
for (int i = 0; i < edges.Count; i++)
{
if (edges[i].yLower != edges[i].yUpper)
{
int id = edges[i].yLower - yMin;
edgeTable[id].Add(edges[i]);
}
}
for (int y = yMin; y <= yMax; y++)
{
begList.AddRange(edgeTable[y - yMin]);
//Sắp xếp các giao điểm theo x
begList = begList.OrderBy(v => v.xIntersect).ToList();
//Tô màu cho dòng hiện tại
if (y != yMin && y != yMax)
{
gl.Color(fillColor.R / 255.0, fillColor.G / 255.0, fillColor.B / 255.0);
gl.Begin(OpenGL.GL_LINES);
for (int i = 0; i < begList.Count; i += 2)
{
if (i + 1 < begList.Count)
{
gl.Vertex(begList[i].xIntersect, y);
gl.Vertex(begList[i + 1].xIntersect, y);
}
}
gl.End();
}
gl.Flush();
//Xoá các cạnh đã ở dưới scan line
int j = 0;
while (j < begList.Count)
{
if (begList[j].yUpper == y)
{
begList.RemoveAt(j);
}
else
{
j++;
}
}
for (int i = 0; i < begList.Count; i++)
{
AEL t = new AEL();
t.reciSlope = begList[i].reciSlope;
t.yLower = begList[i].yLower;
t.yUpper = begList[i].yUpper;
t.xIntersect = begList[i].xIntersect + begList[i].reciSlope;
begList[i] = t;
}
}
shape.Draw(gl);
stopWatch.Stop();
ts = stopWatch.Elapsed;
return(ts.TotalMilliseconds);
}
