eic-opticks/CSG/csg_tranche.h

0001 #pragma once
0002
0003 #if defined(__CUDACC__) || defined(__CUDABE__)
0004 #    define TRANCHE_FUNC __forceinline__ __device__
0005 #else
0006 #    define TRANCHE_FUNC inline
0007 #endif
0008
0009 /**1
0010 csg_tranche.h : struct Tranche
0011 -------------------------------------------
0012
0013 Postorder Tranch storing a stack of slices into the postorder sequence.
0014
0015 slice
0016    32 bit unsigned holding a pair of begin and end indices
0017    specifying a range over the postorder traversal sequence
0018
0019 tranche_push
0020     push (slice, tmin) onto the small stack
0021
0022 tranche_pop
0023     pops off (slice, tmin)
0024
0025 tranche_repr
0026     representation of the stack of slices packed into a 64 bit unsigned long long
0027
0028 1**/
0029
0030 #define TRANCHE_STACK_SIZE 4
0031
0032
0033 struct Tranche
0034 {
0035     float      tmin[TRANCHE_STACK_SIZE] ;
0036     unsigned  slice[TRANCHE_STACK_SIZE] ;
0037     int curr ;
0038 };
0039
0040
0041 TRANCHE_FUNC
0042 int tranche_push(Tranche& tr, const unsigned slice, const float tmin)
0043 {
0044     if(tr.curr >= TRANCHE_STACK_SIZE - 1) return ERROR_TRANCHE_OVERFLOW ;
0045     tr.curr++ ;
0046     tr.slice[tr.curr] = slice  ;
0047     tr.tmin[tr.curr] = tmin ;
0048     return 0 ;
0049 }
0050
0051 TRANCHE_FUNC
0052 int tranche_pop(Tranche& tr, unsigned& slice, float& tmin)
0053 {
0054     if(tr.curr < 0) return ERROR_POP_EMPTY  ;
0055     slice = tr.slice[tr.curr] ;
0056     tmin = tr.tmin[tr.curr] ;
0057     tr.curr-- ;
0058     return 0 ;
0059 }
0060
0061 TRANCHE_FUNC
0062 unsigned long long tranche_repr(Tranche& tr)
0063 {
0064     unsigned long long val = 0ull ;
0065     if(tr.curr == -1) return val ;
0066
0067     unsigned long long c = tr.curr ;
0068     val |= ((c+1ull)&0xfull)  ;     // count at lsb, contents from msb
0069
0070     do {
0071         unsigned long long x = tr.slice[c] & 0xffff ;
0072         val |=  x << ((4ull-c-1ull)*16ull) ;
0073     }
0074     while(c--) ;
0075
0076     return val ;
0077 }
0078
0079
0080