quakequest/Projects/Android/jni/darkplaces/bih.h
2021-02-02 22:53:37 +00:00

91 lines
2.4 KiB
C

// This code written in 2010 by Forest Hale (lordhavoc ghdigital com), and placed into public domain.
// Based on information in http://zach.in.tu-clausthal.de/papers/vrst02.html (in particular vrst02_boxtree.pdf)
#ifndef BIH_H
#define BIH_H
#define BIH_MAXUNORDEREDCHILDREN 8
typedef enum biherror_e
{
BIHERROR_OK, // no error, be happy
BIHERROR_OUT_OF_NODES // could not produce complete hierarchy, maxnodes too low (should be roughly half of numleafs)
}
biherror_t;
typedef enum bih_nodetype_e
{
BIH_SPLITX = 0,
BIH_SPLITY = 1,
BIH_SPLITZ = 2,
BIH_UNORDERED = 3,
}
bih_nodetype_t;
typedef enum bih_leaftype_e
{
BIH_BRUSH = 4,
BIH_COLLISIONTRIANGLE = 5,
BIH_RENDERTRIANGLE = 6
}
bih_leaftype_t;
typedef struct bih_node_s
{
bih_nodetype_t type; // = BIH_SPLITX and similar values
// TODO: store just one float for distance, and have BIH_SPLITMINX and BIH_SPLITMAXX distinctions, to reduce memory footprint and traversal time, as described in the paper (vrst02_boxtree.pdf)
// TODO: move bounds data to parent node and remove it from leafs?
float mins[3];
float maxs[3];
// node indexes of children (always > this node's index)
int front;
int back;
// interval of children
float frontmin; // children[0]
float backmax; // children[1]
// BIH_UNORDERED uses this for a list of leafindex (all >= 0), -1 = end of list
int children[BIH_MAXUNORDEREDCHILDREN];
}
bih_node_t;
typedef struct bih_leaf_s
{
bih_leaftype_t type; // = BIH_BRUSH And similar values
float mins[3];
float maxs[3];
// data past this point is generic and entirely up to the caller...
int textureindex;
int surfaceindex;
int itemindex; // triangle or brush index
}
bih_leaf_t;
typedef struct bih_s
{
// permanent fields
// leafs are constructed by caller before calling BIH_Build
int numleafs;
bih_leaf_t *leafs;
// nodes are constructed by BIH_Build
int numnodes;
bih_node_t *nodes;
int rootnode; // 0 if numnodes > 0, -1 otherwise
// bounds calculated by BIH_Build
float mins[3];
float maxs[3];
// fields used only during BIH_Build:
int maxnodes;
int error; // set to a value if an error occurs in building (such as numnodes == maxnodes)
int *leafsort;
int *leafsortscratch;
}
bih_t;
int BIH_Build(bih_t *bih, int numleafs, bih_leaf_t *leafs, int maxnodes, bih_node_t *nodes, int *temp_leafsort, int *temp_leafsortscratch);
int BIH_GetTriangleListForBox(const bih_t *bih, int maxtriangles, int *trianglelist_idx, int *trianglelist_surf, const float *mins, const float *maxs);
#endif