account for margins in sixel/kitty_destroy() #1588

src/lib/kitty.c

@@ -571,12 +571,13 @@ int kitty_destroy(const notcurses* nc, const ncpile* p, FILE* out, sprixel* s){
     return -1;
   }
 //fprintf(stderr, "FROM: %d/%d state: %d s->n: %p\n", s->movedfromy, s->movedfromx, s->invalidated, s->n);
+  const ncplane* stdn = notcurses_stdplane_const(nc);
   for(int yy = s->movedfromy ; yy < s->movedfromy + s->dimy && yy < p->dimy ; ++yy){
     for(int xx = s->movedfromx ; xx < s->movedfromx + s->dimx && xx < p->dimx ; ++xx){
-      struct crender *r = &p->crender[yy * p->dimx + xx];
+      const int ridx = (yy - stdn->absy) * p->dimx + (xx - stdn->absx);
+      struct crender *r = &p->crender[ridx];
       if(!r->sprixel){
         if(s->n){
-          const ncplane* stdn = notcurses_stdplane_const(nc);
 //fprintf(stderr, "CHECKING %d/%d\n", yy - s->movedfromy, xx - s->movedfromx);
           sprixcell_e state = sprixel_state(s, yy - s->movedfromy + s->n->absy - stdn->absy,
                                               xx - s->movedfromx + s->n->absx - stdn->absx);

src/lib/sixel.c

@@ -693,9 +693,11 @@ int sixel_destroy(const notcurses* nc, const ncpile* p, FILE* out, sprixel* s){
   (void)out;
   int starty = s->movedfromy;
   int startx = s->movedfromx;
+  const ncplane* stdn = notcurses_stdplane_const(nc);
   for(int yy = starty ; yy < starty + s->dimy && yy < p->dimy ; ++yy){
     for(int xx = startx ; xx < startx + s->dimx && xx < p->dimx ; ++xx){
-      struct crender *r = &p->crender[yy * p->dimx + xx];
+      int ridx = (yy - stdn->absy) * p->dimx + (xx - stdn->absx);
+      struct crender *r = &p->crender[ridx];
       // FIXME this probably overdoes it -- look at kitty_destroy()
       if(!r->sprixel){
         r->s.damaged = 1;