public Matrix3fStack pushMatrix() {
        if (curr == mats.length) {
            throw new IllegalStateException("max stack size of " + (curr + 1) + " reached"); //$NON-NLS-1$ //$NON-NLS-2$
        }
        mats[curr++].set(this);
        return this;
    }
public Matrix3fStack pushMatrix ( ) { if ( curr == mats . length ) { throw new IllegalStateException ( "max stack size of " + ( curr + 1 ) + " reached" ) ; } mats [ curr ++ ] . set ( this ) ; return this ; }
Increment the stack pointer by one and set the values of the new current matrix to the one directly below it.

@return this