public void DrawTriangle(Vertex a, Vertex b, Vertex c)
{
a = SpaceToScreen(a);
b = SpaceToScreen(b);
c = SpaceToScreen(c);
if (a.Coordinate.Y > b.Coordinate.Y)
{
Swap(ref a, ref b);
}
if (a.Coordinate.Y > c.Coordinate.Y)
{
Swap(ref a, ref c);
}
if (b.Coordinate.Y > c.Coordinate.Y)
{
Swap(ref b, ref c);
}
Vertex left = new Vertex();
Vertex right = new Vertex();
Vertex point = new Vertex();
for (double y = a.Coordinate.Y; y < c.Coordinate.Y; ++y)
{
if (y < 0 || y > (Height - 1))
{
continue;
}
bool topHalf = y < b.Coordinate.Y;
var a0 = a;
var a1 = c;
Interpolate(a0, a1, (y - a0.Coordinate.Y) / (a1.Coordinate.Y - a0.Coordinate.Y), ref left);
var b0 = topHalf ? a : b;
var b1 = topHalf ? b : c;
Interpolate(b0, b1, (y - b0.Coordinate.Y) / (b1.Coordinate.Y - b0.Coordinate.Y), ref right);
if (left.Coordinate.X > right.Coordinate.X)
{
Swap(ref left, ref right);
}
for (double x = left.Coordinate.X; x < right.Coordinate.X; ++x)
{
if (x < 0 || x > (Width - 1))
{
continue;
}
Interpolate(left, right, (x - left.Coordinate.X) / (right.Coordinate.X - left.Coordinate.X), ref point);
if (point.Coordinate.Z > 1 || point.Coordinate.Z < -1)
{
continue;
}
if (point.Coordinate.Z < ZBuffer[(int)x, (int)y])
{
ZBuffer[(int)x, (int)y] = point.Coordinate.Z;
ColorBuffer.SetPixel((int)x, (int)y, point.Color);
}
}
}
}
private Vertex SpaceToScreen(Vertex vertex)
{
return(new Vertex(SpaceToScreenCoordinate(vertex.Coordinate), vertex.Normal, vertex.Color));
}
private void Interpolate(Vertex a, Vertex b, double f, ref Vertex v)
{
v.Coordinate = Interpolate(a.Coordinate, b.Coordinate, f);
v.Normal = Interpolate(a.Normal, b.Normal, f);
v.Color = Interpolate(a.Color, b.Color, f);
}