CHAR_HEIGHT
int32 startY = max_c(0, (int32)(updateRect.top / CHAR_HEIGHT));
int32 endY = min_c(fRows - 1, (int32)(updateRect.bottom / CHAR_HEIGHT) + 1);
y *= CHAR_HEIGHT;
InvertRect(BRect(x, y, x + CHAR_WIDTH, y + CHAR_HEIGHT));
height *= CHAR_HEIGHT;
srcy *= CHAR_HEIGHT;
desty *= CHAR_HEIGHT;
BPoint where(x * CHAR_WIDTH, (y + 1) * CHAR_HEIGHT - 3);
FillRect(BRect(x * CHAR_WIDTH, y * CHAR_HEIGHT,
(x + 1) * CHAR_WIDTH, (y + 1) * CHAR_HEIGHT),
fRows(frame.IntegerHeight() / CHAR_HEIGHT),
fRows = (int32)height / CHAR_HEIGHT;