void clip(StringBlock block) {
        Rectangle bound = block.getTextBox();
        if (bound == null)
            return;

        // Clip the right x position and texture coordinate
        // to the string block
        float x1 = Math.min(bound.x + bound.width, x0 + width);
        float newWidth = x1 - x0;
        if (isRightToLeft()) newWidth = x1; // only the available space to the left
        if (newWidth == width)
            return;

        float rescale = newWidth / width;
        u1 = u0 + (u1 - u0) * rescale;
        width = newWidth;
    }
create letter and append to previous LetterQuad

@param c
@param prev previous character
jme3-core/src/main/java/com/jme3/font/LetterQuad.java