/// <summary>
/// Convert the world coordinates to pixel coordinates.
/// </summary>
/// <remarks>
/// TODO: There is conversion between Point3D and Vector3D because
/// matrix multiplication doesn't work nicely with the Vector3D class.
/// http://stackoverflow.com/questions/34097628/use-of-offsets-for-translation-in-matrix3d
/// </remarks>
/// <param name="worldCoords">The world coordinates.</param>
/// <returns>A list of pixel coords.</returns>
private List <Point> GetRasterPoints(List <Point3D> worldCoords)
{
// Setup camera position in the world.
// The camera will look down the negative z axis.
Matrix3D cameraToWorld = new Matrix3D();
cameraToWorld.Rotate(new Quaternion(new Vector3D(0, 1, 0), 180));
cameraToWorld.Translate(new Vector3D(0, 2, 0.5));
// Create the world to camera coordinates matrix.
cameraToWorld.Invert();
Matrix3D worldToCamera = cameraToWorld;
// Convert the Point3D to Vector3D so the spline can do vector operations.
List <Vector3D> quadCoords = new List <Vector3D>();
foreach (Point3D point in worldCoords)
{
quadCoords.Add((Vector3D)point);
}
NaturalSpline airfoilSpline = new NaturalSpline(quadCoords);
// Convert the Vector3D back to Point3D.
worldCoords.Clear();
foreach (Vector3D point in airfoilSpline.Points)
{
worldCoords.Add((Point3D)point);
}
// Compute the final pixel coordinates.
List <Point> rasterCoords = new List <Point>();
foreach (Point3D worldCoord in worldCoords)
{
Point3D raster = worldToCamera.ComputePixelCoordinates(
worldCoord,
canvasWidth,
canvasHeight,
DrawRegion.Width,
DrawRegion.Height);
rasterCoords.Add(new Point((int)raster.X, (int)raster.Y));
}
return(rasterCoords);
}