procedure sbrod

This subroutine plots a diffusively-shaded coloured rod. All (x,y,z) values are taken to be given in world coordinates. The z-component of the eye-poisition should be positive and that of the rod-ends should be negative (< -radius); the viewing-screen is fixed at z=0.

Syntax
sbrod EYE,END1,END2,RADIUS,IC1,IC2,LIGHT,NSIDES,LEND

Arguments

ARGUMENT    TYPE I/O DIMENSION DESCRIPTION

EYE:   R*4 I 3 (x,y,z) coordinate of eye-position.

END1:   R*4 I 3 (x,y,z) coordinate of rod-end 1.

END2:   R*4 I 3 (x,y,z) coordinate of rod-end 2.

RADIUS:   R*4 I - Radius of cylinderical rod.

IC1,IC2:   I*4 I - Lowest & highest colour-index to be

   used for the shading.

LIGHT:   R*4 I 3 (x,y,z) direction of flood-light.

NSIDES:   I*4 I - The order of the polygon to be used

   for the cross-section of the rod.

LEND:   L*1 I - If true, plot the end of the rod.

ARGUMENT	TYPE I/O DIMENSION DESCRIPTION
EYE:	R*4 I 3 (x,y,z) coordinate of eye-position.
END1:	R*4 I 3 (x,y,z) coordinate of rod-end 1.
END2:	R*4 I 3 (x,y,z) coordinate of rod-end 2.
RADIUS:	R*4 I - Radius of cylinderical rod.
IC1,IC2:	I*4 I - Lowest & highest colour-index to be
	used for the shading.
LIGHT:	R*4 I 3 (x,y,z) direction of flood-light.
NSIDES:	I*4 I - The order of the polygon to be used
	for the cross-section of the rod.
LEND:	L*1 I - If true, plot the end of the rod.