File: SVSlices.mesa
Last edited by: Eric Bier on August 19, 1984 6:28:52 pm PDT
Copyright © 1984 by Xerox Corporation. All rights reserved.
Contents: A scanline data structure representing a ray-traced slice thru a 3D scene. Can be shown in 3D by drawing the endpoints in perspective or in 2D by rotating the slicing plane into the viewing plane.
DIRECTORY
Graphics,
Imager,
SV2d,
SV3d,
SVModelTypes,
SVRayTypes,
SVSceneTypes;
SVSlices: CEDAR DEFINITIONS =
BEGIN
Camera: TYPE = SVModelTypes.Camera;
Classification: TYPE = SVRayTypes.Classification;
CoordSystem: TYPE = SVModelTypes.CoordSystem;
CSGTree: TYPE = SVRayTypes.CSGTree;
FrameBlock: TYPE = SVSceneTypes.FrameBlock;
Point2d: TYPE = SV2d.Point2d;
Point3d: TYPE = SV3d.Point3d;
Ray: TYPE = SVRayTypes.Ray;
SliceScanLine: TYPE = REF SliceScanLineObj;
SliceScanLineObj:
TYPE =
RECORD [
lineVal: REAL,
hits: ARRAY [1..SVRayTypes.maxSceneDepth] OF Point3d,
classifs: ARRAY [1..SVRayTypes.maxSceneDepth] OF BOOL,
count: NAT];
Slice: TYPE = REF SliceObj;
SliceObj:
TYPE =
RECORD [
coordSys: CoordSystem, frame: FrameBlock, plane: NAT, seq: SEQUENCE maxScans: NAT OF SliceScanLine];
CreateSlice: PROC [maxScans: NAT, coordSys: CoordSystem, frame: FrameBlock, plane: NAT] RETURNS [slice: Slice];
UpdateSlice: PROC [slice: Slice, coordSys: CoordSystem, frame: FrameBlock, plane: NAT];
ChangeSlicePlane: PROC [slice: Slice, plane: NAT];
RayTraceTheSlice: PROC [slice: Slice, tree: CSGTree, camera: Camera];
WidthAndHeight:
PROC [slice: Slice]
RETURNS [width, height:
REAL];
Uses the dimensions of the framebox and the current plane to determine the size of the rectangle this slice will project to in the chosen plane.
DrawSlice:
PROC [dc: Imager.Context, slice: Slice, origin: Point2d];
Draw the slice in a 2d window such as the scratchpad.
DrawSlice3d:
PROC [dc: Graphics.Context, slice: Slice, camera: Camera];
Draw the outline of the slice in with a set of solid objects.
END.