[Indigo]<Solidviews>SolidModeler>SVFaces.mesa!5

File: SVFaces.mesa

Last edited by Bier on September 24, 1987 12:17:20 pm PDT

Contents: Definitions of various face types such as Cone, Disk Ring, and Cylinder and procedures which make them from simpler data

DIRECTORY

SV2d, SV3d, SVBasicTypes, SVModelTypes;

SVFaces: CEDAR DEFINITIONS =

BEGIN

BoundBox: TYPE = SVBasicTypes.BoundBox;

Sphere: TYPE = SV3d.Sphere;

BoundHedron: TYPE = SVBasicTypes.BoundHedron;

TrigLineSeg: TYPE = SV2d.TrigLineSeg;

Vector3d: TYPE = SV3d.Vector3d;

The cone described here is revolute around the y-axis. Otherwise it is very general, allowing for an arbitrary apex point (on the y-axis) and an arbitrary spread ratio.

Cone: TYPE = REF ConeObj;

ConeObj: TYPE = RECORD [

h: REAL,-- y at the apex

M: REAL,-- r/|y-h|

yHi, yLo: REAL,

normalPointsOut: BOOL,

noseIsUp: BOOL,

boundHedron: BoundHedron,

boundBox: BoundBox,

boundSphere: Sphere];

The disk ring described here is revolute around the y-axis. Otherwise it is very general. It may be in an arbitrary horizontal plane (y = yPlane), may have any two radii, rIn and rOut subject to rIn, rOut >= 0 AND rOut > rIn, and may have an upward or downward pointing normal.

DiskRing: TYPE = REF DiskRingObj;

DiskRingObj: TYPE = RECORD [

yPlane: REAL,

normal: Vector3d,

rInSquared, rOutSquared: REAL,

boundHedron: BoundHedron,

boundBox: BoundBox,

boundSphere: Sphere];

The cylinder described here is revolute around the y-axis. Otherwise it is very general. It may have its top and bottom in arbitrary horizontal planes (y = yHigh and y = yLow) subject to yHigh > yLow and may have an arbitrary radius r.

Cylinder: TYPE = REF CylinderObj;

CylinderObj: TYPE = RECORD [

yHi, yLo: REAL,

r: REAL,

rSquared: REAL,

normalPointsOut: BOOL,

boundHedron: BoundHedron,

boundBox: BoundBox,

boundSphere: Sphere];

The edge on rectangle has a surface normal parallel to the xy plane. That is, it is edge on when viewed from the z direction.

EdgeOnRect: TYPE = REF EdgeOnRectObj;

EdgeOnRectObj: TYPE = RECORD [

frontZ, backZ: REAL,

A, B, D: REAL,-- plane equation Ax + By + D = 0.

normal: Vector3d,

valHi, valLo: REAL,

valIsY: BOOL, -- valHi and valLo will be y values if the edge on rectangle is more closely verical than horizontal and x values otherwise

boundHedron: BoundHedron,

boundBox: BoundBox,

boundSphere: Sphere

];

ConeFromTrigLineSeg: PROC [seg: TrigLineSeg] RETURNS [cone: Cone];

AttemptToCreateDegenerateCone: ERROR;

DiskRingFromTrigLineSeg: PROC [seg: TrigLineSeg] RETURNS [diskRing: DiskRing];

AttemptToCreateDegenerateDiskRing: ERROR;

CylinderFromTrigLineSeg: PROC [seg: TrigLineSeg] RETURNS [cylinder: Cylinder];

AttemptToCreateDegenerateCylinder: ERROR;

EdgeOnRectFromTrigLineSeg: PROC [seg: TrigLineSeg, frontZ, backZ: REAL] RETURNS [edgeOnRect: EdgeOnRect];

AttemptToCreateDegenerateEdgeOnRect: ERROR;

END.