Data Members

Point position

Private variable

The location of the Focus in the world coordinate system.

Point direction

Private variable

The direction of view from position into the scene.

Point up

Private variable

The direction that will be at the top of the projected drawing.

real distance

Private variable

The distance of the Focus from the plane of projection.

real angle

Private variable

Used for determining the up direction.

char axis

Private variable

The main axis onto which the Focus is transformed in order to perform the perspective projection, z by default. It will normally not matter which axis is used, but it might be advantageous to use a particular axis in some special situations.

Transform transform

Private variable

The Transform, which will be applied to the Shapes on the Picture, when the latter is output. The effect of this is equivalent to transforming the Focus, so that it lies on a major axis. Focus f(5, 5, -10, 2, 4, 10, 10, 180); => f.transform == 0.989 -0.00733 -0.148 0 0 0.999 -0.0494 0 0.148 0.0488 0.988 0 -3.4 -4.47 0.865 1

Transform persp

Private variable

The Transform representing the perspective transformation for a particular Focus. Let d stand for distance, then persp == 1 0 0 0 0 1 0 0 0 0 0 1/d 0 0 0 1