/// <summary>
/// Calculates which triangles are within the camera's field of view.
/// </summary>
public void DetermineTrianglesInRange()
{
//TODO can be heavly optimized by reading directly from the objects verticies. CREATE BACKUP WHEN EDITING.
Vect3D toPointVector;
Stack <int> trianglesIndex = new Stack <int>();
foreach (Triangle3D triangle in triangles)
{
foreach (Point3D point in triangle.coordinates)
{
toPointVector = new Vect3D(CameraPosition, point);
if (Relation3D.AngleBetween(toPointVector, cameraLeftPlaneNormalVector) > Math.PI / 2)
{
continue;
}
if (Relation3D.AngleBetween(toPointVector, cameraRightPlaneNormalVector) > Math.PI / 2)
{
continue;
}
if (Relation3D.AngleBetween(toPointVector, cameraTopPlaneNormalVector) > Math.PI / 2)
{
continue;
}
if (Relation3D.AngleBetween(toPointVector, cameraBottomPlaneNormalVector) > Math.PI / 2)
{
continue;
}
trianglesIndex.Push(Array.IndexOf(triangles, triangle));
break;
}
}
trianglesOnScreenIndex = trianglesIndex.ToArray();
}
/// <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);
}
}
