sys/src/libmemlayer/lalloc.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include <draw.h>
   4 #include <memdraw.h>
   5 #include <memlayer.h>
   6
   7 Memimage*
   8 memlalloc(Memscreen *s, Rectangle screenr, Refreshfn refreshfn, void *refreshptr, ulong val)
   9 {
  10         Memlayer *l;
  11         Memimage *n;
  12         static Memimage *paint;
  13
  14         if(paint == nil){
  15                 paint = allocmemimage(Rect(0,0,1,1), RGBA32);
  16                 if(paint == nil)
  17                         return nil;
  18                 paint->flags |= Frepl;
  19                 paint->clipr = Rect(-0x3FFFFFF, -0x3FFFFFF, 0x3FFFFFF, 0x3FFFFFF);
  20         }
  21
  22         n = allocmemimaged(screenr, s->image->chan, s->image->data);
  23         if(n == nil)
  24                 return nil;
  25         l = malloc(sizeof(Memlayer));
  26         if(l == nil){
  27                 free(n);
  28                 return nil;
  29         }
  30
  31         l->screen = s;
  32         if(refreshfn)
  33                 l->save = nil;
  34         else{
  35                 l->save = allocmemimage(screenr, s->image->chan);
  36                 if(l->save == nil){
  37                         free(l);
  38                         free(n);
  39                         return nil;
  40                 }
  41                 /* allocmemimage doesn't initialize memory; this paints save area */
  42                 if(val != DNofill)
  43                         memfillcolor(l->save, val);
  44         }
  45         l->refreshfn = refreshfn;
  46         l->refreshptr = nil;    /* don't set it until we're done */
  47         l->screenr = screenr;
  48         l->delta = Pt(0,0);
  49
  50         n->data->ref++;
  51         n->zero = s->image->zero;
  52         n->width = s->image->width;
  53         n->layer = l;
  54
  55         /* start with new window behind all existing ones */
  56         l->front = s->rearmost;
  57         l->rear = nil;
  58         if(s->rearmost)
  59                 s->rearmost->layer->rear = n;
  60         s->rearmost = n;
  61         if(s->frontmost == nil)
  62                 s->frontmost = n;
  63         l->clear = 0;
  64
  65         /* now pull new window to front */
  66         _memltofrontfill(n, val != DNofill);
  67         l->refreshptr = refreshptr;
  68
  69         /*
  70          * paint with requested color; previously exposed areas are already right
  71          * if this window has backing store, but just painting the whole thing is simplest.
  72          */
  73         if(val != DNofill){
  74                 memsetchan(paint, n->chan);
  75                 memfillcolor(paint, val);
  76                 memdraw(n, n->r, paint, n->r.min, nil, n->r.min, S);
  77         }
  78         return n;
  79 }