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Use std::sort for object rendering distance

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This commit is contained in:
Kp 2014-11-13 03:07:58 +00:00
parent dc772c693d
commit 30e988fc5f
1 changed files with 10 additions and 98 deletions
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108
similar/main/render.cpp
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@ -1135,90 +1135,6 @@ static void add_obj_to_seglist(render_state_t &rstate, objnum_t objnum,int listn
}
}
#ifdef __sun__
// the following is a drop-in replacement for the broken libc qsort on solaris
// taken from http://www.snippets.org/snippets/portable/RG_QSORT+C.php3
#define qsort qsort_dropin
/******************************************************************/
/* qsort.c -- Non-Recursive ANSI Quicksort function */
/* Public domain by Raymond Gardner, Englewood CO February 1991 */
/******************************************************************/
#define COMP(a, b) ((*comp)((void *)(a), (void *)(b)))
#define T 7 // subfiles of <= T elements will be insertion sorteded (T >= 3)
#define SWAP(a, b) (swap_bytes((char *)(a), (char *)(b), size))
static void swap_bytes(char *a, char *b, size_t nbytes)
{
char tmp;
do {
tmp = *a; *a++ = *b; *b++ = tmp;
} while ( --nbytes );
}
void qsort(void *basep, size_t nelems, size_t size,
int (*comp)(const void *, const void *))
{
char *stack[40], **sp; /* stack and stack pointer */
char *i, *j, *limit; /* scan and limit pointers */
size_t thresh; /* size of T elements in bytes */
char *base; /* base pointer as char * */
base = (char *)basep; /* set up char * base pointer */
thresh = T * size; /* init threshold */
sp = stack; /* init stack pointer */
limit = base + nelems * size;/* pointer past end of array */
for ( ;; ) { /* repeat until break... */
if ( limit - base > thresh ) { /* if more than T elements */
/* swap base with middle */
SWAP((((limit-base)/size)/2)*size+base, base);
i = base + size; /* i scans left to right */
j = limit - size; /* j scans right to left */
if ( COMP(i, j) > 0 ) /* Sedgewick's */
SWAP(i, j); /* three-element sort */
if ( COMP(base, j) > 0 ) /* sets things up */
SWAP(base, j); /* so that */
if ( COMP(i, base) > 0 ) /* *i <= *base <= *j */
SWAP(i, base); /* *base is pivot element */
for ( ;; ) { /* loop until break */
do /* move i right */
i += size; /* until *i >= pivot */
while ( COMP(i, base) < 0 );
do /* move j left */
j -= size; /* until *j <= pivot */
while ( COMP(j, base) > 0 );
if ( i > j ) /* if pointers crossed */
break; /* break loop */
SWAP(i, j); /* else swap elements, keep scanning*/
}
SWAP(base, j); /* move pivot into correct place */
if ( j - base > limit - i ) { /* if left subfile larger */
sp[0] = base; /* stack left subfile base */
sp[1] = j; /* and limit */
base = i; /* sort the right subfile */
} else { /* else right subfile larger*/
sp[0] = i; /* stack right subfile base */
sp[1] = limit; /* and limit */
limit = j; /* sort the left subfile */
}
sp += 2; /* increment stack pointer */
} else { /* else subfile is small, use insertion sort */
for ( j = base, i = j+size; i < limit; j = i, i += size )
for ( ; COMP(j, j+size) > 0; j -= size ) {
SWAP(j, j+size);
if ( j == base )
break;
}
if ( sp != stack ) { /* if any entries on stack */
sp -= 2; /* pop the base and limit */
base = sp[0];
limit = sp[1];
} else /* else stack empty, done */
break;
}
}
}
#endif // __sun__ qsort drop-in replacement
#if defined(DXX_BUILD_DESCENT_I)
#define SORT_LIST_SIZE 50
@ -1232,19 +1148,14 @@ struct sort_item
fix64 dist_squared;
};
static sort_item sort_list[SORT_LIST_SIZE];
static int n_sort_items;
//compare function for object sort.
static int sort_func(const sort_item *a,const sort_item *b)
static bool compare_func(const sort_item &a,const sort_item &b)
{
fix64 delta_dist_squared = a->dist_squared - b->dist_squared;
fix64 delta_dist_squared = a.dist_squared - b.dist_squared;
#if defined(DXX_BUILD_DESCENT_II)
object *obj_a,*obj_b;
obj_a = &Objects[a->objnum];
obj_b = &Objects[b->objnum];
const auto obj_a = &Objects[a.objnum];
const auto obj_b = &Objects[b.objnum];
auto abs_delta_dist_squared = std::abs(delta_dist_squared);
fix combined_size = obj_a->size + obj_b->size;
@ -1261,16 +1172,16 @@ static int sort_func(const sort_item *a,const sort_item *b)
if (obj_a->type == OBJ_WEAPON || (obj_a->type == OBJ_FIREBALL && obj_a->id != VCLIP_AFTERBURNER_BLOB))
if (!(obj_b->type == OBJ_WEAPON || obj_b->type == OBJ_FIREBALL))
return -1; //a is weapon, b is not, so say a is closer
return true; //a is weapon, b is not, so say a is closer
else; //both are weapons
else
if (obj_b->type == OBJ_WEAPON || (obj_b->type == OBJ_FIREBALL && obj_b->id != VCLIP_AFTERBURNER_BLOB))
return 1; //b is weapon, a is not, so say a is farther
return false; //b is weapon, a is not, so say a is farther
//no special case, fall through to normal return
}
#endif
return (delta_dist_squared < 0) ? -1 : (delta_dist_squared > 0); //return distance
return delta_dist_squared < 0; //return distance
}
static void build_object_lists(render_state_t &rstate)
@ -1352,6 +1263,8 @@ static void build_object_lists(render_state_t &rstate)
for (nn=0;nn < rstate.N_render_segs;nn++) {
segnum_t segnum = rstate.Render_list[nn];
if (segnum != segment_none) {
array<sort_item, SORT_LIST_SIZE> sort_list;
uint_fast32_t n_sort_items;
int t,lookn,i,n;
//first count the number of objects & copy into sort list
@ -1418,8 +1331,7 @@ static void build_object_lists(render_state_t &rstate)
#endif
//now call qsort
qsort(sort_list,n_sort_items,sizeof(*sort_list),
(int (*)(const void*,const void*))sort_func);
std::sort(sort_list.begin(), std::next(sort_list.begin(), n_sort_items), compare_func);
//now copy back into list