/*
 * light.h
 *
 * Copyright (C) 1989, 1991, Craig E. Kolb
 * All rights reserved.
 *
 * This software may be freely copied, modified, and redistributed
 * provided that this copyright notice is preserved on all copies.
 *
 * You may not distribute this software, in whole or in part, as part of
 * any commercial product without the express consent of the authors.
 *
 * There is no warranty or other guarantee of fitness of this software
 * for any purpose.  It is provided solely "as is".
 *
 * $Id: light.h,v 4.0 91/07/17 14:35:10 kolb Exp Locker: kolb $
 *
 * $Log:	light.h,v $
 * Revision 4.0  91/07/17  14:35:10  kolb
 * Initial version.
 * 
 */
#ifndef LIGHT_H
#define LIGHT_H

#include "libobj/geom.h"

#define SHADOW_NONE	001
#define SHADOW_TRANSP	002
#define SHADOW_CSG	004
#define SHADOW_CACHE	010
#define SHADOW_BLUR	020

#define NOSHADOWS(f)	((f) & SHADOW_NONE)
#define SHADOWTRANSP(f)	((f) & SHADOW_TRANSP)
#define SHADOWCSG(f)	((f) & SHADOW_CSG)
#define SHADOWCACHE(f)	((f) & SHADOW_CACHE)
#define SHADOWBLUR(f)	((f) & SHADOW_BLUR)

#define SHADOW_EPSILON	(4. * EPSILON)

typedef char * LightRef;

typedef struct {
	struct Geom *obj;	/* Pointer to cached object */
	RSMatrix trans;	/* World-to-object transformation */
	char dotrans;		/* TRUE if above trans is non-identity */
} ShadowCache;

typedef struct {
	int	(*intens)();	/* intensity method */
	void	(*dir)(),	/* direction method */
		(*user)();	/* user-defined method */
} LightMethods;

typedef struct Light {
	Color color;		/* Light source color & intensity */
	int shadow;		/* Does light source cast shadows? */
	LightRef light;		/* Pointer to light information */
	LightMethods *methods;	/* Light source methods */
	ShadowCache *cache;	/* Shadow cache, if any */
	struct Light *next;	/* Next light in list */
} Light;

extern LightMethods	*LightMethodsCreate();
extern Light	*LightCreate();
extern void	LightAllocateCache(), LightAddToDefined();
extern int	LightIntens(), LightDirection();
extern void	ShadowSetOptions(), ShadowStats();

#endif /* LIGHT_H */