ortho(3G) ortho(3G)
NAME
ortho, ortho2 - define an orthographic projection
transformation
SPECIFICATION
C ortho(left, right, bottom, top, near, far)
Coord left, right, bottom, top, near, far;
ortho2(left, right, bottom, top)
Coord left, right, bottom, top;
FORTRAN subroutine ortho(left, right, bottom, top, near, far)
real left, right, bottom, top, near, far
subroutine ortho2(left, right, bottom, top)
real left, right, bottom, top
DESCRIPTION
ortho specifies a box-shaped enclosure in the eye coordinate
system that is mapped to the viewport. left, right, bottom,
top are the x and y clipping planes. near and far are
distances along the line of sight from the eye space origin,
and can be negative. The z clipping planes are at -near and
-far.
ortho2 defines a 2-D clipping rectangle. When you use
ortho2 with 3-D world coordinates, the z values are not
transformed. When ortho2 is specified, objects with z
values outside the range -1<z<1 are clipped out.
Both ortho and ortho2 load a matrix onto the transformation
stack, overwriting what was there.
SEE ALSO
perspective, window
Programming Guide, Section 4.3, Projection Transformations
Page 1 (printed 8/20/87)