sys/src/libmemlayer/ltorear.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include <draw.h>
   4 #include <memdraw.h>
   5 #include <memlayer.h>
   6
   7 void
   8 _memltorear(Memimage *i, Memimage *rear)
   9 {
  10         Memlayer *l;
  11         Memscreen *s;
  12         Memimage *f, *r, *rr;
  13         Rectangle x;
  14         int overlap;
  15
  16         l = i->layer;
  17         s = l->screen;
  18         while(l->rear != rear){
  19                 r = l->rear;
  20                 x = l->screenr;
  21                 overlap = rectclip(&x, r->layer->screenr);
  22                 if(overlap){
  23                         memlhide(i, x);
  24                         l->clear = 0;
  25                 }
  26                 /* swap l and r in screen's list */
  27                 rr = r->layer->rear;
  28                 f = l->front;
  29                 if(rr == nil)
  30                         s->rearmost = i;
  31                 else
  32                         rr->layer->front = i;
  33                 if(f == nil)
  34                         s->frontmost = r;
  35                 else
  36                         f->layer->rear = r;
  37                 l->rear = rr;
  38                 l->front = r;
  39                 r->layer->rear = i;
  40                 r->layer->front = f;
  41                 if(overlap)
  42                         memlexpose(r, x);
  43         }
  44 }
  45
  46 void
  47 memltorear(Memimage *i)
  48 {
  49         _memltorear(i, nil);
  50         _memlsetclear(i->layer->screen);
  51 }
  52
  53 void
  54 memltorearn(Memimage **ip, int n)
  55 {
  56         Memimage *i, *rear;
  57         Memscreen *s;
  58
  59         if(n == 0)
  60                 return;
  61         rear = nil;
  62         while(--n >= 0){
  63                 i = *ip++;
  64                 _memltorear(i, rear);
  65                 rear = i;
  66         }
  67         s = rear->layer->screen;
  68         _memlsetclear(s);
  69 }