home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Info-Mac 4
/
Info_Mac IV CD-ROM (Pacific HiTech Inc.)(August 1994).iso
/
Development
/
Source
/
POVSRC
/
SOURCE
/
RAY.C
< prev
next >
Wrap
Text File
|
1993-07-29
|
3KB
|
102 lines
/****************************************************************************
* ray.c
*
* This module implements the code pertaining to rays.
*
* from Persistence of Vision Raytracer
* Copyright 1993 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 "vector.h"
#include "povproto.h"
#define Mix(a,b,c) { \
(a).x = (b).x * (c).y; \
(a).y = (b).x * (c).z; \
(a).z = (b).y * (c).z; }
void Make_Ray(r)
RAY *r;
{
VECTOR Temp_Init_Dir;
VSquareTerms (r -> Initial_2, r -> Initial);
VSquareTerms (r -> Direction_2, r -> Direction);
VEvaluate (r -> Initial_Direction, r -> Initial, r -> Direction);
Mix (r -> Mixed_Initial_Initial, r -> Initial, r -> Initial);
Mix (r -> Mixed_Dir_Dir, r -> Direction, r -> Direction);
Mix (Temp_Init_Dir, r -> Initial, r -> Direction);
Mix (r -> Mixed_Init_Dir, r -> Direction, r -> Initial);
VAdd (r -> Mixed_Init_Dir, r -> Mixed_Init_Dir, Temp_Init_Dir);
r -> Quadric_Constants_Cached = TRUE;
}
void Initialize_Ray_Containers (Ray)
RAY *Ray;
{
Ray -> Containing_Index = -1;
}
void Copy_Ray_Containers (Dest_Ray, Source_Ray)
RAY *Dest_Ray, *Source_Ray;
{
register int i;
if ((Dest_Ray -> Containing_Index = Source_Ray -> Containing_Index)
>= MAX_CONTAINING_OBJECTS)
{
fprintf (stderr, "ERROR - Containing Index too high\n");
close_all();
exit (1);
}
for (i = 0 ; i < MAX_CONTAINING_OBJECTS ; i++)
{
Dest_Ray -> Containing_Textures[i] = Source_Ray -> Containing_Textures[i];
Dest_Ray -> Containing_IORs[i] = Source_Ray -> Containing_IORs[i];
}
}
void Ray_Enter (ray, texture)
RAY *ray;
TEXTURE *texture;
{
register int index;
if ((index = ++(ray -> Containing_Index)) >= MAX_CONTAINING_OBJECTS)
{
fprintf (stderr, "Too many nested refracting objects\n");
close_all();
exit(1);
}
ray -> Containing_Textures [index] = texture;
ray -> Containing_IORs [index] = texture->Finish->Index_Of_Refraction;
}
void Ray_Exit (ray)
RAY *ray;
{
if (--(ray -> Containing_Index) < -1)
{
fprintf (stderr, "Too many exits from refractions\n");
close_all();
exit(1);
}
}