ref: 63e826c1a177368305ce9e89c0b7bc3b13e158d5
dir: /libmemlayer/lorigin.c/
#include <u.h> #include <libc.h> #include <draw.h> #include <memdraw.h> #include <memlayer.h> /* * Place i so i->r.min = log, i->layer->screenr.min == scr. */ int memlorigin(Memimage *i, Point log, Point scr) { Memlayer *l; Memscreen *s; Memimage *t, *shad, *nsave; Rectangle x, newr, oldr; Point delta; int overlap, eqlog, eqscr, wasclear; l = i->layer; s = l->screen; oldr = l->screenr; newr = Rect(scr.x, scr.y, scr.x+Dx(oldr), scr.y+Dy(oldr)); eqscr = eqpt(scr, oldr.min); eqlog = eqpt(log, i->r.min); if(eqscr && eqlog) return 0; nsave = nil; if(eqlog==0 && l->save!=nil){ nsave = allocmemimage(Rect(log.x, log.y, log.x+Dx(oldr), log.y+Dy(oldr)), i->chan); if(nsave == nil) return -1; } /* * Bring it to front and move logical coordinate system. */ memltofront(i); wasclear = l->clear; if(nsave){ if(!wasclear) memimagedraw(nsave, nsave->r, l->save, l->save->r.min, nil, Pt(0,0), S); freememimage(l->save); l->save = nsave; } delta = subpt(log, i->r.min); i->r = rectaddpt(i->r, delta); i->clipr = rectaddpt(i->clipr, delta); l->delta = subpt(l->screenr.min, i->r.min); if(eqscr) return 0; /* * To clean up old position, make a shadow window there, don't paint it, * push it behind this one, and (later) delete it. Because the refresh function * for this fake window is a no-op, this will cause no graphics action except * to restore the background and expose the windows previously hidden. */ shad = memlalloc(s, oldr, memlnorefresh, nil, DNofill); if(shad == nil) return -1; s->frontmost = i; if(s->rearmost == i) s->rearmost = shad; else l->rear->layer->front = shad; shad->layer->front = i; shad->layer->rear = l->rear; l->rear = shad; l->front = nil; shad->layer->clear = 0; /* * Shadow is now holding down the fort at the old position. * Move the window and hide things obscured by new position. */ for(t=l->rear->layer->rear; t!=nil; t=t->layer->rear){ x = newr; overlap = rectclip(&x, t->layer->screenr); if(overlap){ memlhide(t, x); t->layer->clear = 0; } } l->screenr = newr; l->delta = subpt(scr, i->r.min); l->clear = rectinrect(newr, l->screen->image->clipr); /* * Everything's covered. Copy to new position and delete shadow window. */ if(wasclear) memdraw(s->image, newr, s->image, oldr.min, nil, Pt(0,0), S); else memlexpose(i, newr); memldelete(shad); return 1; } void memlnorefresh(Memimage *l, Rectangle r, void *v) { USED(l); USED(r.min.x); USED(v); }