653    png_size_t         readpos;  /* Position in *next */  member
735    ps->readpos = 0;  in store_init()
1155       if (cbAvail > ps->readpos)  in store_read_buffer_avail()
1156          return cbAvail - ps->readpos;  in store_read_buffer_avail()
1176          ps->readpos = 0;  in store_read_buffer_next()
1197       size_t cbAvail = store_read_buffer_size(ps) - ps->readpos;  in store_read_imp()
1202          memcpy(pb, ps->next->buffer + ps->readpos, cbAvail);  in store_read_imp()
1205          ps->readpos += cbAvail;  in store_read_imp()
1236       if (ps->readpos != 0)  in store_progressive_read()
1608    ps->readpos = 0;  in store_read_reset()
2739        pm->this.readpos < pm->this.current->datacount)  in modifier_progressive_read()