private void DrawLine(FastBitmap bitmap, double[,] buffer, Point3D start, Point3D end, Color color)
{
double dx = end.X - start.X;
double dy = end.Y - start.Y;
if (Math.Abs(dx) > Math.Abs(dy))
{
if (dx < 0)
{
MathHelp.Swap(ref start, ref end);
}
double[] ys = MathHelp.Interpolate(start.X, start.Y, end.X, end.Y);
double[] zs = MathHelp.Interpolate(start.X, start.Z, end.X, end.Z);
Parallel.For((int)start.X, (int)end.X, x =>
{
int y = (int)ys[(int)(x - start.X)];
double z = zs[(int)(x - start.X)];
if (IsOnImage((int)x, y) && buffer[(int)x, y] >= z)
{
buffer[(int)x, y] = z;
bitmap.SetPixel((int)x, y, color);
}
});
}
else
{
if (dy < 0)
{
MathHelp.Swap(ref start, ref end);
}
double[] xs = MathHelp.Interpolate(start.Y, start.X, end.Y, end.X);
double[] zs = MathHelp.Interpolate(start.Y, start.Z, end.Y, end.Z);
Parallel.For((int)start.Y, (int)end.Y, y =>
{
int x = (int)xs[(int)(y - start.Y)];
double z = zs[(int)(y - start.Y)];
if (IsOnImage(x, (int)y) && buffer[x, (int)y] >= z)
{
buffer[x, (int)y] = z;
bitmap.SetPixel(x, (int)y, color);
}
});
}
}
private void Triangle(Vector3D p0, Vector3D p1, Vector3D p2, Color color, FastBitmap bitmap, double[,] buffer)
{
if (p0.Y != p1.Y || p0.Y != p2.Y)
{
if (p0.Y > p1.Y)
{
MathHelp.Swap(ref p0, ref p1);
}
if (p0.Y > p2.Y)
{
MathHelp.Swap(ref p0, ref p2);
}
if (p1.Y > p2.Y)
{
MathHelp.Swap(ref p1, ref p2);
}
int totalHeight = (int)Math.Round(p2.Y - p0.Y);
Parallel.For(0, totalHeight - 1, i =>
{
bool secondHalf = i > p1.Y - p0.Y || p1.Y == p0.Y;
int segmentHeight = (int)Math.Round(secondHalf ? p2.Y - p1.Y : p1.Y - p0.Y);
double alpha = (double)i / totalHeight;
double beta = (i - (secondHalf ? p1.Y - p0.Y : 0.0)) / segmentHeight;
Vector3D a = p0 + (p2 - p0) * alpha;
Vector3D b = (secondHalf ? p1 + (p2 - p1) * beta : p0 + (p1 - p0) * beta);
if (a.X > b.X)
{
MathHelp.Swap(ref a, ref b);
}
for (int j = (int)Math.Round(a.X); j <= (int)Math.Round(b.X); ++j)
{
double scale = (a.X == b.X) ? 1 : (j - a.X) / (b.X - a.X);
Vector3D p = a + (b - a) * scale;
int x = (int)Math.Round(p.X);
int y = (int)Math.Round(p.Y);
if (IsOnImage(x, y) && buffer[x, y] >= p.Z)
{
buffer[x, y] = p.Z;
bitmap.SetPixel(x, y, color);
}
}
});
}
}