register row, col;
register int row, col;
PointToRowCol(y, x, r, c)    register int y, x;    int *r, *c;/* Convert pixel coordinates to character coordinates.   Rows are clipped between firstValidRow and lastValidRow.   Columns are clipped between to be 0 or greater, but are not clipped to some       maximum value. */{	register TScreen *screen = &term->screen;	register row, col;	row = (y - screen->border) / FontHeight(screen);	if(row < firstValidRow)		row = firstValidRow;	else if(row > lastValidRow)		row = lastValidRow;	col = (x - OriginX(screen)) / FontWidth(screen);	if(col < 0)		col = 0;	else if(col > screen->max_col+1) {		col = screen->max_col+1;	}	*r = row;	*c = col;}