ref: d9591a54d23e99daa351ed8a76b0a8c3bcf2690a
dir: /sys/src/libmemlayer/lalloc.c/
#include <u.h> #include <libc.h> #include <draw.h> #include <memdraw.h> #include <memlayer.h> Memimage* memlalloc(Memscreen *s, Rectangle screenr, Refreshfn refreshfn, void *refreshptr, ulong val) { Memlayer *l; Memimage *n; static Memimage *paint; if(paint == nil){ paint = allocmemimage(Rect(0,0,1,1), RGBA32); if(paint == nil) return nil; paint->flags |= Frepl; paint->clipr = Rect(-0x3FFFFFF, -0x3FFFFFF, 0x3FFFFFF, 0x3FFFFFF); } n = allocmemimaged(screenr, s->image->chan, s->image->data); if(n == nil) return nil; l = malloc(sizeof(Memlayer)); if(l == nil){ free(n); return nil; } l->screen = s; if(refreshfn) l->save = nil; else{ l->save = allocmemimage(screenr, s->image->chan); if(l->save == nil){ free(l); free(n); return nil; } /* allocmemimage doesn't initialize memory; this paints save area */ if(val != DNofill) memfillcolor(l->save, val); } l->refreshfn = refreshfn; l->refreshptr = nil; /* don't set it until we're done */ l->screenr = screenr; l->delta = Pt(0,0); n->data->ref++; n->zero = s->image->zero; n->width = s->image->width; n->layer = l; /* start with new window behind all existing ones */ l->front = s->rearmost; l->rear = nil; if(s->rearmost) s->rearmost->layer->rear = n; s->rearmost = n; if(s->frontmost == nil) s->frontmost = n; l->clear = 0; /* now pull new window to front */ _memltofrontfill(n, val != DNofill); l->refreshptr = refreshptr; /* * paint with requested color; previously exposed areas are already right * if this window has backing store, but just painting the whole thing is simplest. */ if(val != DNofill){ memsetchan(paint, n->chan); memfillcolor(paint, val); memdraw(n, n->r, paint, n->r.min, nil, n->r.min, S); } return n; }