affinetransform.java

Hecl编程语言是一个高层次的脚本语言的Java实现。其用意是要小

	    m01 = Tx.m01;
	    m10 = Tx.m10;
	    m11 = 0.0;
	    state = APPLY_TRANSLATE | APPLY_SHEAR;
	    type = TYPE_UNKNOWN;
	    return;
	}
	// If Tx has more than one attribute, it is not worth optimizing
	// all of those cases...
	T00 = Tx.m00; T01 = Tx.m01; T02 = Tx.m02;
	T10 = Tx.m10; T11 = Tx.m11; T12 = Tx.m12;
	switch (mystate) {
	  default:
	    stateError();
	    return;
	    /* NOTREACHED */
	  case (APPLY_SHEAR | APPLY_SCALE):
	    state = mystate | txstate;
	    /* NOBREAK */
	  case (APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
	    M0 = m00;
	    M1 = m01;
	    m00  = T00 * M0 + T10 * M1;
	    m01  = T01 * M0 + T11 * M1;
	    m02 += T02 * M0 + T12 * M1;

	    M0 = m10;
	    M1 = m11;
	    m10  = T00 * M0 + T10 * M1;
	    m11  = T01 * M0 + T11 * M1;
	    m12 += T02 * M0 + T12 * M1;
	    type = TYPE_UNKNOWN;
	    return;

	case (APPLY_SHEAR | APPLY_TRANSLATE):
	case (APPLY_SHEAR):
	    M0 = m01;
	    m00  = T10 * M0;
	    m01  = T11 * M0;
	    m02 += T12 * M0;

	    M0 = m10;
	    m10  = T00 * M0;
	    m11  = T01 * M0;
	    m12 += T02 * M0;
	    break;

	case (APPLY_SCALE | APPLY_TRANSLATE):
	case (APPLY_SCALE):
	    M0 = m00;
	    m00  = T00 * M0;
	    m01  = T01 * M0;
	    m02 += T02 * M0;

	    M0 = m11;
	    m10  = T10 * M0;
	    m11  = T11 * M0;
	    m12 += T12 * M0;
	    break;

	case (APPLY_TRANSLATE):
	    m00  = T00;
	    m01  = T01;
	    m02 += T02;

	    m10  = T10;
	    m11  = T11;
	    m12 += T12;
	    state = txstate | APPLY_TRANSLATE;
	    type = TYPE_UNKNOWN;
	    return;
	}
	updateState();
    }

    /**
     * Concatenates an <code>AffineTransform</code> <code>Tx</code> to
     * this <code>AffineTransform</code> Cx
     * in a less commonly used way such that <code>Tx</code> modifies the
     * coordinate transformation relative to the absolute pixel
     * space rather than relative to the existing user space.
     * Cx is updated to perform the combined transformation.
     * Transforming a point p by the updated transform Cx' is
     * equivalent to first transforming p by the original transform
     * Cx and then transforming the result by 
     * <code>Tx</code> like this: 
     * Cx'(p) = Tx(Cx(p))  
     * In matrix notation, if this transform Cx
     * is represented by the matrix [this] and <code>Tx</code> is
     * represented by the matrix [Tx] then this method does the
     * following:
     * <pre>
     *		[this] = [Tx] x [this]
     * </pre>
     * @param Tx the <code>AffineTransform</code> object to be
     * concatenated with this <code>AffineTransform</code> object.
     * @see #concatenate
     */
    public void preConcatenate(AffineTransform Tx) {
	double M0, M1;
	double T00, T01, T10, T11;
	double T02, T12;
	int mystate = state;
	int txstate = Tx.state;
	switch ((txstate << HI_SHIFT) | mystate) {
	case (HI_IDENTITY | APPLY_IDENTITY):
	case (HI_IDENTITY | APPLY_TRANSLATE):
	case (HI_IDENTITY | APPLY_SCALE):
	case (HI_IDENTITY | APPLY_SCALE | APPLY_TRANSLATE):
	case (HI_IDENTITY | APPLY_SHEAR):
	case (HI_IDENTITY | APPLY_SHEAR | APPLY_TRANSLATE):
	case (HI_IDENTITY | APPLY_SHEAR | APPLY_SCALE):
	case (HI_IDENTITY | APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
	    // Tx is IDENTITY...
	    return;

	case (HI_TRANSLATE | APPLY_IDENTITY):
	case (HI_TRANSLATE | APPLY_SCALE):
	case (HI_TRANSLATE | APPLY_SHEAR):
	case (HI_TRANSLATE | APPLY_SHEAR | APPLY_SCALE):
	    // Tx is TRANSLATE, this has no TRANSLATE
	    m02 = Tx.m02;
	    m12 = Tx.m12;
	    state = mystate | APPLY_TRANSLATE;
	    type |= TYPE_TRANSLATION;
	    return;

	case (HI_TRANSLATE | APPLY_TRANSLATE):
	case (HI_TRANSLATE | APPLY_SCALE | APPLY_TRANSLATE):
	case (HI_TRANSLATE | APPLY_SHEAR | APPLY_TRANSLATE):
	case (HI_TRANSLATE | APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
	    // Tx is TRANSLATE, this has one too
	    m02 = m02 + Tx.m02;
	    m12 = m12 + Tx.m12;
	    return;

	case (HI_SCALE | APPLY_TRANSLATE):
	case (HI_SCALE | APPLY_IDENTITY):
	    // Only these two existing states need a new state
	    state = mystate | APPLY_SCALE;
	    /* NOBREAK */
	case (HI_SCALE | APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
	case (HI_SCALE | APPLY_SHEAR | APPLY_SCALE):
	case (HI_SCALE | APPLY_SHEAR | APPLY_TRANSLATE):
	case (HI_SCALE | APPLY_SHEAR):
	case (HI_SCALE | APPLY_SCALE | APPLY_TRANSLATE):
	case (HI_SCALE | APPLY_SCALE):
	    // Tx is SCALE, this is anything
	    T00 = Tx.m00;
	    T11 = Tx.m11;
	    if ((mystate & APPLY_SHEAR) != 0) {
		m01 = m01 * T00;
		m10 = m10 * T11;
		if ((mystate & APPLY_SCALE) != 0) {
		    m00 = m00 * T00;
		    m11 = m11 * T11;
		}
	    } else {
		m00 = m00 * T00;
		m11 = m11 * T11;
	    }
	    if ((mystate & APPLY_TRANSLATE) != 0) {
		m02 = m02 * T00;
		m12 = m12 * T11;
	    }
	    type = TYPE_UNKNOWN;
	    return;
	case (HI_SHEAR | APPLY_SHEAR | APPLY_TRANSLATE):
	case (HI_SHEAR | APPLY_SHEAR):
	    mystate = mystate | APPLY_SCALE;
	    /* NOBREAK */
	case (HI_SHEAR | APPLY_TRANSLATE):
	case (HI_SHEAR | APPLY_IDENTITY):
	case (HI_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
	case (HI_SHEAR | APPLY_SCALE):
	    state = mystate ^ APPLY_SHEAR;
	    /* NOBREAK */
	case (HI_SHEAR | APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
	case (HI_SHEAR | APPLY_SHEAR | APPLY_SCALE):
	    // Tx is SHEAR, this is anything
	    T01 = Tx.m01;
	    T10 = Tx.m10;

	    M0 = m00;
	    m00 = m10 * T01;
	    m10 = M0 * T10;

	    M0 = m01;
	    m01 = m11 * T01;
	    m11 = M0 * T10;

	    M0 = m02;
	    m02 = m12 * T01;
	    m12 = M0 * T10;
	    type = TYPE_UNKNOWN;
	    return;
	}
	// If Tx has more than one attribute, it is not worth optimizing
	// all of those cases...
	T00 = Tx.m00; T01 = Tx.m01; T02 = Tx.m02;
	T10 = Tx.m10; T11 = Tx.m11; T12 = Tx.m12;
	switch (mystate) {
	  default:
	    stateError();
	    return;
	    /* NOTREACHED */
	  case (APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
	    M0 = m02;
	    M1 = m12;
	    T02 += M0 * T00 + M1 * T01;
	    T12 += M0 * T10 + M1 * T11;

	    /* NOBREAK */
	  case (APPLY_SHEAR | APPLY_SCALE):
	    m02 = T02;
	    m12 = T12;

	    M0 = m00;
	    M1 = m10;
	    m00 = M0 * T00 + M1 * T01;
	    m10 = M0 * T10 + M1 * T11;

	    M0 = m01;
	    M1 = m11;
	    m01 = M0 * T00 + M1 * T01;
	    m11 = M0 * T10 + M1 * T11;
	    break;

	  case (APPLY_SHEAR | APPLY_TRANSLATE):
	    M0 = m02;
	    M1 = m12;
	    T02 += M0 * T00 + M1 * T01;
	    T12 += M0 * T10 + M1 * T11;

	    /* NOBREAK */
	  case (APPLY_SHEAR):
	    m02 = T02;
	    m12 = T12;

	    M0 = m10;
	    m00 = M0 * T01;
	    m10 = M0 * T11;

	    M0 = m01;
	    m01 = M0 * T00;
	    m11 = M0 * T10;
	    break;

	  case (APPLY_SCALE | APPLY_TRANSLATE):
	    M0 = m02;
	    M1 = m12;
	    T02 += M0 * T00 + M1 * T01;
	    T12 += M0 * T10 + M1 * T11;

	    /* NOBREAK */
	  case (APPLY_SCALE):
	    m02 = T02;
	    m12 = T12;

	    M0 = m00;
	    m00 = M0 * T00;
	    m10 = M0 * T10;

	    M0 = m11;
	    m01 = M0 * T01;
	    m11 = M0 * T11;
	    break;

	  case (APPLY_TRANSLATE):
	    M0 = m02;
	    M1 = m12;
	    T02 += M0 * T00 + M1 * T01;
	    T12 += M0 * T10 + M1 * T11;

	    /* NOBREAK */
	  case (APPLY_IDENTITY):
	    m02 = T02;
	    m12 = T12;

	    m00 = T00;
	    m10 = T10;

	    m01 = T01;
	    m11 = T11;

	    state = mystate | txstate;
	    type = TYPE_UNKNOWN;
	    return;
	}
	updateState();
    }

    /**
     * Returns an <code>AffineTransform</code> object representing the
     * inverse transformation.
     * The inverse transform Tx' of this transform Tx 
     * maps coordinates transformed by Tx back
     * to their original coordinates.
     * In other words, Tx'(Tx(p)) = p = Tx(Tx'(p)).
     * <p>
     * If this transform maps all coordinates onto a point or a line
     * then it will not have an inverse, since coordinates that do
     * not lie on the destination point or line will not have an inverse
     * mapping.
     * The <code>getDeterminant</code> method can be used to determine if this
     * transform has no inverse, in which case an exception will be
     * thrown if the <code>createInverse</code> method is called.
     * @return a new <code>AffineTransform</code> object representing the
     * inverse transformation.
     * @see #getDeterminant
     * @exception NoninvertibleTransformException
     * if the matrix cannot be inverted.
     */
    public AffineTransform createInverse()
	throws NoninvertibleTransformException {
	double det;
	switch (state) {
	  default:
	    stateError();
	    return null;
	    /* NOTREACHED */
	  case (APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
	    det = m00 * m11 - m01 * m10;
	    if (Math.abs(det) <= Double.MIN_VALUE) {
		throw new NoninvertibleTransformException("Determinant is "+
							  det);
	    }
	    return new AffineTransform( m11 / det, -m10 / det,
					-m01 / det,  m00 / det,
					(m01 * m12 - m11 * m02) / det,
					(m10 * m02 - m00 * m12) / det,
					(APPLY_SHEAR |
					 APPLY_SCALE |
					 APPLY_TRANSLATE));
	  case (APPLY_SHEAR | APPLY_SCALE):
	    det = m00 * m11 - m01 * m10;
	    if (Math.abs(det) <= Double.MIN_VALUE) {
		throw new NoninvertibleTransformException("Determinant is "+
							  det);
	    }
	    return new AffineTransform( m11 / det, -m10 / det,
					-m01 / det,  m00 / det,
				        0.0,        0.0,
					(APPLY_SHEAR | APPLY_SCALE));
	  case (APPLY_SHEAR | APPLY_TRANSLATE):
	    if (m01 == 0.0 || m10 == 0.0) {
		throw new NoninvertibleTransformException("Determinant is 0");
	    }
	    return new AffineTransform( 0.0,        1.0 / m01,
				        1.0 / m10,  0.0,
					-m12 / m10, -m02 / m01,
					(APPLY_SHEAR | APPLY_TRANSLATE));
	  case (APPLY_SHEAR):
	    if (m01 == 0.0 || m10 == 0.0) {
		throw new NoninvertibleTransformException("Determinant is 0");
	    }
	    return new AffineTransform(0.0,       1.0 / m01,
				       1.0 / m10, 0.0,
				       0.0,       0.0,
				       (APPLY_SHEAR));
	  case (APPLY_SCALE | APPLY_TRANSLATE):
	    if (m00 == 0.0 || m11 == 0.0) {
		throw new NoninvertibleTransformException("Determinant is 0");
	    }
	    return new AffineTransform( 1.0 / m00,  0.0,
				        0.0,        1.0 / m11,
					-m02 / m00, -m12 / m11,
					(APPLY_SCALE | APPLY_TRANSLATE));
	  case (APPLY_SCALE):
	    if (m00 == 0.0 || m11 == 0.0) {
		throw new NoninvertibleTransformException("Determinant is 0");
	    }
	    return new AffineTransform(1.0 / m00, 0.0,
				       0.0,       1.0 / m11,
				       0.0,       0.0,
				       (APPLY_SCALE));
	case (APPLY_TRANSLATE):
	    return new AffineTransform( 1.0,  0.0,
				        0.0,  1.0,
				       -m02, -m12,
				       (APPLY_TRANSLATE));
	case (APPLY_IDENTITY):
	    return new AffineTransform();
	}

	/* NOTREACHED */
    }

    /**
     * Transforms the specified <code>ptSrc</code> and stores the result
     * in <code>ptDst</code>.
     * If <code>ptDst</code> is <code>null</code>, a new {@link Point2D}
     * object is allocated and then the result of the transformation is
     * stored in this object.
     * In either case, <code>ptDst</code>, which contains the
     * transformed point, is returned for convenience.
     * If <code>ptSrc</code> and <code>ptDst</code> are the same
     * object, the input point is correctly overwritten with
     * the transformed point.
     * @param ptSrc the specified <code>Point2D</code> to be transformed
     * @param ptDst the specified <code>Point2D</code> that stores the
     * result of transforming <code>ptSrc</code>
     * @return the <code>ptDst</code> after transforming
     * <code>ptSrc</code> and stroring the result in <code>ptDst</code>.
     */
    public Point2D transform(Point2D ptSrc, Point2D ptDst) {
	if (ptDst == null) {
	    if (ptSrc instanceof Point2D.Double) {
		ptDst = new Point2D.Double();
	    } else {
		ptDst = new Point2D.Float();
	    }
	}
	// Copy source coords into local variables in case src == dst
	double x = ptSrc.getX();
	double y = ptS