[Cyan]<ISL>SolidViews>SVFancyRaysImpl.mesa!1

File: SVFancyRaysImpl.mesa

Author: Eric Bier on July 3, 1983 12:33 pm

Last edited by Bier on July 3, 1983 4:04 pm

Contents: Procedures implementing shadows (reflections and transparency to come).

DIRECTORY

CastRays,

CSG,

Matrix3d,

Shading,

SVFancyRays,

SVVector3d;

SVFancyRaysImpl: PROGRAM

IMPORTS CastRays, SVVector3d

EXPORTS SVFancyRays =

BEGIN

CSGTree: TYPE = REF CSGTreeObj;

CSGTreeObj: TYPE = CSG.CSGTreeObj;

LightSource: TYPE = Shading.LightSource;

LightSourceList: TYPE = Shading.LightSourceList;

Point3d: TYPE = Matrix3d.Point3d;

Ray: TYPE = CSG.Ray;

VisibleLights: PUBLIC PROC [allLights: LightSourceList, surfacePoint: Point3d, tree: CSGTree] RETURNS [visibleLights: LightSourceList] = {

surfaceToLightRay: Ray;

lightsource: LightSource;

hits: BOOL;

visibleLights ← NIL;

FOR l: LightSourceList ← allLights, l.rest UNTIL l = NIL DO

lightsource ← l.first;

surfaceToLightRay ← CastRays.GetRayFromPool[];

surfaceToLightRay.basePt ← surfacePoint;

surfaceToLightRay.direction ← SVVector3d.Difference[lightsource.position, surfacePoint];

hits ← CastRays.HitsTree[surfaceToLightRay, tree];

CastRays.ReturnRayToPool[surfaceToLightRay];

IF NOT hits THEN visibleLights ← CONS[lightsource, visibleLights];

ENDLOOP;

};

END.