/****************************************************************************
* planes.c
*
* This module implements functions that manipulate planes.
*
* from Persistence of Vision(tm) Ray Tracer
* Copyright 1996 Persistence of Vision Team
*---------------------------------------------------------------------------
* NOTICE: This source code file is provided so that users may experiment
* with enhancements to POV-Ray and to port the software to platforms other
* than those supported by the POV-Ray Team. There are strict rules under
* which you are permitted to use this file. The rules are in the file
* named POVLEGAL.DOC which should be distributed with this file. If
* POVLEGAL.DOC is not available or for more info please contact the POV-Ray
* Team Coordinator by leaving a message in CompuServe's Graphics Developer's
* Forum. The latest version of POV-Ray may be found there as well.
*
* This program is based on the popular DKB raytracer version 2.12.
* DKBTrace was originally written by David K. Buck.
* DKBTrace Ver 2.0-2.12 were written by David K. Buck & Aaron A. Collins.
*
*****************************************************************************/
#include "frame.h"
#include "povray.h"
#include "vector.h"
#include "povproto.h"
#include "matrices.h"
#include "objects.h"
#include "planes.h"
/*****************************************************************************
* Local preprocessor defines
******************************************************************************/
#define DEPTH_TOLERANCE 1.0e-6
/*****************************************************************************
* Static functions
******************************************************************************/
static int Intersect_Plane PARAMS((RAY *Ray, PLANE *Plane, DBL *Depth));
static int All_Plane_Intersections PARAMS((OBJECT *Object, RAY *Ray, ISTACK *Depth_Stack));
static int Inside_Plane PARAMS((VECTOR point, OBJECT *Object));
static void Plane_Normal PARAMS((VECTOR Result, OBJECT *Object, INTERSECTION *Inter));
static void *Copy_Plane PARAMS((OBJECT *Object));
static void Translate_Plane PARAMS((OBJECT *Object, VECTOR Vector, TRANSFORM *Trans));
static void Rotate_Plane PARAMS((OBJECT *Object, VECTOR Vector, TRANSFORM *Trans));
static void Scale_Plane PARAMS((OBJECT *Object, VECTOR Vector, TRANSFORM *Trans));
static void Transform_Plane PARAMS((OBJECT *Object, TRANSFORM *Trans));
static void Invert_Plane PARAMS((OBJECT *Object));
static void Destroy_Plane PARAMS((OBJECT *Object));
/*****************************************************************************
* Local variables
******************************************************************************/
METHODS Plane_Methods =
{
All_Plane_Intersections,
Inside_Plane, Plane_Normal,
Copy_Plane,
Translate_Plane, Rotate_Plane,
Scale_Plane, Transform_Plane, Invert_Plane, Destroy_Plane
};
/*****************************************************************************
*
* FUNCTION
*
* All_Plane_Intersections
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* POV-Ray Team
*
* DESCRIPTION
*
* -
*
* CHANGES
*
* -
*
******************************************************************************/
static int All_Plane_Intersections (Object, Ray, Depth_Stack)
OBJECT *Object;
RAY *Ray;
ISTACK *Depth_Stack;
{
DBL Depth;
VECTOR IPoint;
if (Intersect_Plane(Ray, (PLANE *)Object, &Depth))
{
VEvaluateRay(IPoint, Ray->Initial, Depth, Ray->Direction);
if (Point_In_Clip(IPoint, Object->Clip))
{
push_entry(Depth,IPoint,Object,Depth_Stack);
return(TRUE);
}
}
return(FALSE);
}
/*****************************************************************************
*
* FUNCTION
*
* Intersect_Plane
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* POV-Ray Team
*
* DESCRIPTION
*
* -
*
* CHANGES
*
* -
*
******************************************************************************/
static int Intersect_Plane (Ray, Plane, Depth)
RAY *Ray;
PLANE *Plane;
DBL *Depth;
{
DBL NormalDotOrigin, NormalDotDirection;
VECTOR P, D;
Increase_Counter(stats[Ray_Plane_Tests]);
if (Plane->Trans == NULL)
{
VDot(NormalDotDirection, Plane->Normal_Vector, Ray->Direction);
if (fabs(NormalDotDirection) < EPSILON)
{
return(FALSE);
}
VDot(NormalDotOrigin, Plane->Normal_Vector, Ray->Initial);
}
else
{
MInvTransPoint(P, Ray->Initial, Plane->Trans);
MInvTransDirection(D, Ray->Direction, Plane->Trans);
VDot(NormalDotDirection, Plane->Normal_Vector, D);
if (fabs(NormalDotDirection) < EPSILON)
{
return(FALSE);
}
VDot(NormalDotOrigin, Plane->Normal_Vector, P);
}
*Depth = -(NormalDotOrigin + Plane->Distance) / NormalDotDirection;
if ((*Depth >= DEPTH_TOLERANCE) && (*Depth <= Max_Distance))
{
Increase_Counter(stats[Ray_Plane_Tests_Succeeded]);
return (TRUE);
}
else
{
return (FALSE);
}
}
/*****************************************************************************
*
* FUNCTION
*
* Inside_Plane
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* POV-Ray Team
*
* DESCRIPTION
*
* -
*
* CHANGES
*
* -
*
******************************************************************************/
static int Inside_Plane (IPoint, Object)
VECTOR IPoint;
OBJECT *Object;
{
DBL Temp;
VECTOR P;
if (((PLANE *)Object)->Trans == NULL)
{
VDot (Temp, IPoint, ((PLANE *)Object)->Normal_Vector);
}
else
{
MInvTransPoint(P, IPoint, ((PLANE *)Object)->Trans);
VDot (Temp, P, ((PLANE *)Object)->Normal_Vector);
}
return((Temp + ((PLANE *)Object)->Distance) < EPSILON);
}
/*****************************************************************************
*
* FUNCTION
*
* Plane_Normal
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* POV-Ray Team
*
* DESCRIPTION
*
* -
*
* CHANGES
*
* -
*
******************************************************************************/
static void Plane_Normal (Result, Object, Inter)
OBJECT *Object;
VECTOR Result;
INTERSECTION *Inter;
{
Assign_Vector(Result,((PLANE *)Object)->Normal_Vector);
if (((PLANE *)Object)->Trans != NULL)
{
MTransNormal(Result, Result, ((PLANE *)Object)->Trans);
VNormalize(Result, Result);
}
}
/*****************************************************************************
*
* FUNCTION
*
* Translate_Plane
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* POV-Ray Team
*
* DESCRIPTION
*
* -
*
* CHANGES
*
* -
*
******************************************************************************/
static void Translate_Plane (Object, Vector, Trans)
OBJECT *Object;
VECTOR Vector;
TRANSFORM *Trans;
{
VECTOR Translation;
PLANE *Plane = (PLANE *)Object;
if (Plane->Trans == NULL)
{
VEvaluate (Translation, ((PLANE *)Object)->Normal_Vector, Vector);
((PLANE *)Object)->Distance -= Translation[X] + Translation[Y] + Translation[Z];
Compute_Plane_BBox((PLANE *)Object);
}
else
{
Transform_Plane(Object, Trans);
}
}
/*****************************************************************************
*
* FUNCTION
*
* Rotate_Plane
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* POV-Ray Team
*
* DESCRIPTION
*
* -
*
* CHANGES
*
* -
*
******************************************************************************/
static void Rotate_Plane (Object, Vector, Trans)
OBJECT *Object;
VECTOR Vector;
TRANSFORM *Trans;
{
if (((PLANE *)Object)->Trans == NULL)
{
MTransDirection(((PLANE *)Object)->Normal_Vector, ((PLANE *)Object)->Normal_Vector, Trans);
Compute_Plane_BBox(((PLANE *)Object));
}
else
{
Transform_Plane (Object, Trans);
}
}
/*****************************************************************************
*
* FUNCTION
*
* Scale_Plane
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* POV-Ray Team
*
* DESCRIPTION
*
* -
*
* CHANGES
*
* -
*
******************************************************************************/
static void Scale_Plane (Object, Vector, Trans)
OBJECT *Object;
VECTOR Vector;
TRANSFORM *Trans;
{
DBL Length;
PLANE *Plane = (PLANE *) Object;
if (Plane->Trans == NULL)
{
VDivEq(Plane->Normal_Vector, Vector);
VLength(Length, ((PLANE *)Object)->Normal_Vector);
VInverseScaleEq (((PLANE *)Object)->Normal_Vector, Length);
((PLANE *)Object)->Distance /= Length;
Compute_Plane_BBox(Plane);
}
else
{
Transform_Plane (Object, Trans);
}
}
/*****************************************************************************
*
* FUNCTION
*
* Invert_Plane
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* POV-Ray Team
*
* DESCRIPTION
*
* -
*
* CHANGES
*
* -
*
******************************************************************************/
static void Invert_Plane (Object)
OBJECT *Object;
{
VScaleEq(((PLANE *)Object)->Normal_Vector, -1.0);
((PLANE *)Object)->Distance *= -1.0;
}
/*****************************************************************************
*
* FUNCTION
*
* Transform_Plane
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* POV-Ray Team
*
* DESCRIPTION
*
* -
*
* CHANGES
*
* -
*
******************************************************************************/
static void Transform_Plane(Object, Trans)
OBJECT *Object;
TRANSFORM *Trans;
{
PLANE *Plane = (PLANE *) Object;
if (Plane->Trans == NULL)
{
Plane->Trans = Create_Transform();
}
Compose_Transforms(Plane->Trans, Trans);
Compute_Plane_BBox(Plane);
}
/*****************************************************************************
*
* FUNCTION
*
* Create_Plane
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* POV-Ray Team
*
* DESCRIPTION
*
* -
*
* CHANGES
*
* -
*
******************************************************************************/
PLANE *Create_Plane()
{
PLANE *New;
New = (PLANE *)POV_MALLOC(sizeof (PLANE), "plane");
INIT_OBJECT_FIELDS(New,PLANE_OBJECT,&Plane_Methods)
Make_Vector(New->Normal_Vector, 0.0, 1.0, 0.0);
New ->Distance = 0.0;
New->Trans = NULL;
return(New);
}
/*****************************************************************************
*
* FUNCTION
*
* Copy_Plane
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* POV-Ray Team
*
* DESCRIPTION
*
* -
*
* CHANGES
*
* -
*
******************************************************************************/
static void *Copy_Plane (Object)
OBJECT *Object;
{
PLANE *New;
New = Create_Plane();
Destroy_Transform(New->Trans);
*New = *((PLANE *)Object);
New->Trans = Copy_Transform(((PLANE *)Object)->Trans);
return(New);
}
/*****************************************************************************
*
* FUNCTION
*
* Destroy_Plane
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* POV-Ray Team
*
* DESCRIPTION
*
* -
*
* CHANGES
*
* -
*
******************************************************************************/
static void Destroy_Plane(Object)
OBJECT *Object;
{
Destroy_Transform(((PLANE *)Object)->Trans);
POV_FREE(Object);
}
/*****************************************************************************
*
* FUNCTION
*
* Compute_Plane_BBox
*
* INPUT
*
* Plane - Plane
*
* OUTPUT
*
* Plane
*
* RETURNS
*
* AUTHOR
*
* Dieter Bayer
*
* DESCRIPTION
*
* Calculate the bounding box of a plane (it's always infinite).
*
* CHANGES
*
* Aug 1994 : Creation.
*
******************************************************************************/
void Compute_Plane_BBox(Plane)
PLANE *Plane;
{
Make_BBox(Plane->BBox, -BOUND_HUGE/2, -BOUND_HUGE/2, -BOUND_HUGE/2,
BOUND_HUGE, BOUND_HUGE, BOUND_HUGE);
if (Plane->Clip != NULL)
{
Plane->BBox = Plane->Clip->BBox;
}
}
