rayintersection.h

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/*
 * $Id: rayintersection.h 35233 2011-02-27 19:31:27Z jesterking $
 *
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version. 
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2007 Blender Foundation.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): André Pinto.
 *
 * ***** END GPL LICENSE BLOCK *****
 * RE_raytrace.h: ray tracing api, can be used independently from the renderer. 
 */

#ifndef __RENDER_RAYINTERSECTION_H__
#define __RENDER_RAYINTERSECTION_H__

#ifdef __cplusplus
extern "C" {
#endif

struct RayObject;

/* Ray Hints */

#define RE_RAY_LCTS_MAX_SIZE    256
#define RT_USE_LAST_HIT                 /* last shadow hit is reused before raycasting on whole tree */
//#define RT_USE_HINT                   /* last hit object is reused before raycasting on whole tree */

typedef struct LCTSHint {
        int size;
        struct RayObject *stack[RE_RAY_LCTS_MAX_SIZE];
} LCTSHint;

typedef struct RayHint {
        union { LCTSHint lcts; } data;
} RayHint;

/* Ray Intersection */

typedef struct Isect {
        /* ray start, direction (normalized vector), and max distance. on hit,
           the distance is modified to be the distance to the hit point. */
        float start[3];
        float dir[3];
        float dist;

        /* precomputed values to accelerate bounding box intersection */
        int bv_index[6];
        float idot_axis[3];

        /* intersection options */
        int mode;                               /* RE_RAY_SHADOW, RE_RAY_MIRROR, RE_RAY_SHADOW_TRA */
        int lay;                                /* -1 default, set for layer lamps */
        int skip;                               /* skip flags */
        int check;                              /* check flags */
        void *userdata;                 /* used by bake check */

        /* hit information */
        float u, v;
        int isect;                              /* which half of quad */
        
        struct {
                void *ob;
                void *face;
        } hit, orig;
        
        /* last hit optimization */
        struct RayObject *last_hit;

        /* hints */
#ifdef RT_USE_HINT
        RayTraceHint *hint, *hit_hint;
#endif
        RayHint *hint;
        
        /* ray counter */
#ifdef RE_RAYCOUNTER
        RayCounter *raycounter;
#endif
} Isect;

/* ray types */
#define RE_RAY_SHADOW 0
#define RE_RAY_MIRROR 1
#define RE_RAY_SHADOW_TRA 2

/* skip options */
#define RE_SKIP_CULLFACE                (1 << 0)
/* if using this flag then *face should be a pointer to a VlakRen */
#define RE_SKIP_VLR_NEIGHBOUR           (1 << 1)

/* check options */
#define RE_CHECK_VLR_NONE               0
#define RE_CHECK_VLR_RENDER             1
#define RE_CHECK_VLR_NON_SOLID_MATERIAL 2
#define RE_CHECK_VLR_BAKE               3

/* arbitrary, but can't use e.g. FLT_MAX because of precision issues */
#define RE_RAYTRACE_MAXDIST     1e15f
#define RE_RAYTRACE_EPSILON 0.0f

#ifdef __cplusplus
}
#endif

#endif /* __RENDER_RAYINTERSECTION_H__ */