/// <summary>
/// Calculates the triangles position on the screen and adds them to the screens collection of triangles.
/// </summary>
public void ProjectToScreen()
{
screen.ClearTriangles();
//Used for angle calculation.
Vect3D toPointVector;
Vect3D toPointVerticalPlaneNormalVector;
Vect3D toPointHorizontalPlaneNormalVector;
//Angles.
double angleLeft;
double angleTop;
//Position on screen: 0 = left/top, 1 = right/bottom.
double screenScalar;
Point[] triangleCoordinatesOnScreen;
BackFaceCulling();
foreach (int triangleIndex in trianglesOnScreenIndex)
{
triangleCoordinatesOnScreen = new Point[3];
for (int i = 0; i < 3; i++)
{
toPointVector = new Vect3D(CameraPosition, triangles[triangleIndex].coordinates[i]);
toPointVerticalPlaneNormalVector = Vect3D.VectorProduct(toPointVector, cameraVerticalUnitVector);
toPointHorizontalPlaneNormalVector = Vect3D.VectorProduct(toPointVector, cameraHorizontalUnitVector);
angleLeft = Relation3D.AngleBetween(toPointVerticalPlaneNormalVector, cameraLeftPlaneNormalVector);
angleTop = Relation3D.AngleBetween(toPointHorizontalPlaneNormalVector, cameraTopPlaneNormalVector);
toPointVerticalPlaneNormalVector.SwitchOrientation();
toPointHorizontalPlaneNormalVector.SwitchOrientation();
screenScalar = widthScalar * Math.Sin(angleLeft) / Math.Sin(Math.PI - angleLeft - (Math.PI - CameraFieldOfView) / 2);
if (Relation3D.AngleBetween(toPointVerticalPlaneNormalVector, cameraRightPlaneNormalVector) > CameraFieldOfView)
{
screenScalar *= -1;
}
triangleCoordinatesOnScreen[i].X = Math.Round(screenScalar * screen.Width, 0);
screenScalar = heightScalar * Math.Sin(angleTop) / Math.Sin(Math.PI - angleTop - (Math.PI - (CameraFieldOfView / AspectRatio)) / 2);
if (Relation3D.AngleBetween(toPointHorizontalPlaneNormalVector, cameraBottomPlaneNormalVector) > CameraFieldOfView / AspectRatio)
{
screenScalar *= -1;
}
triangleCoordinatesOnScreen[i].Y = Math.Round(screenScalar * screen.Height, 0);
}
screen.AddTriangleToScreen(triangleCoordinatesOnScreen);
}
}
public void BackFaceCulling()
{
Stack <int> trianglesIndex = new Stack <int>();
Vect3D camToCorner;
Vect3D cornerVector1;
Vect3D cornerVector2;
foreach (int index in trianglesOnScreenIndex)
{
cornerVector1 = new Vect3D(triangles[index].coordinates[0], triangles[index].coordinates[1]);
cornerVector2 = new Vect3D(triangles[index].coordinates[0], triangles[index].coordinates[2]);
camToCorner = new Vect3D(CameraPosition, triangles[index].coordinates[0]);
if (Vect3D.VectorProduct(cornerVector1, cornerVector2) * camToCorner >= 0.0)
{
trianglesIndex.Push(index);
}
}
trianglesOnScreenIndex = trianglesIndex.ToArray();
}
