public void testCompose1() {
AffineTransformation t0 = AffineTransformation.translationInstance(10, 0);
t0.rotate(Math.PI / 2);
t0.translate(0, -10);
AffineTransformation t1 = AffineTransformation.translationInstance(0, 0);
t1.rotate(Math.PI / 2);
checkTransformation(t0, t1);
}
public void testComposeRotation1() {
AffineTransformation t0 = AffineTransformation.rotationInstance(1, 10, 10);
AffineTransformation t1 = AffineTransformation.translationInstance(-10, -10);
t1.rotate(1);
t1.translate(10, 10);
checkTransformation(t0, t1);
}
/**
* Creates an AffineTransformation defined by a pair of control vectors. A control vector consists
* of a source point and a destination point, which is the image of the source point under the
* desired transformation. The computed transformation is a combination of one or more of a
* uniform scale, a rotation, and a translation (i.e. there is no shear component and no
* reflection)
*
* @param src0
* @param src1
* @param dest0
* @param dest1
* @return the computed transformation
* @return null if the control vectors do not determine a well-defined transformation
*/
public static AffineTransformation createFromControlVectors(
Coordinate src0, Coordinate src1, Coordinate dest0, Coordinate dest1) {
Coordinate rotPt = new Coordinate(dest1.x - dest0.x, dest1.y - dest0.y);
double ang = Angle.angleBetweenOriented(src1, src0, rotPt);
double srcDist = src1.distance(src0);
double destDist = dest1.distance(dest0);
if (srcDist == 0.0) return null;
double scale = destDist / srcDist;
AffineTransformation trans = AffineTransformation.translationInstance(-src0.x, -src0.y);
trans.rotate(ang);
trans.scale(scale, scale);
trans.translate(dest0.x, dest0.y);
return trans;
}
/**
* Creates an AffineTransformation defined by a maping between two baselines. The computed
* transformation consists of:
*
* <ul>
* <li>a translation from the start point of the source baseline to the start point of the
* destination baseline,
* <li>a rotation through the angle between the baselines fragment_about the destination start
* point,
* <li>and a scaling equal to the ratio of the baseline lengths.
* </ul>
*
* If the source baseline has zero length, an identity transformation is returned.
*
* @param src0 the start point of the source baseline
* @param src1 the end point of the source baseline
* @param dest0 the start point of the destination baseline
* @param dest1 the end point of the destination baseline
* @return the computed transformation
*/
public static AffineTransformation createFromBaseLines(
Coordinate src0, Coordinate src1, Coordinate dest0, Coordinate dest1) {
Coordinate rotPt = new Coordinate(src0.x + dest1.x - dest0.x, src0.y + dest1.y - dest0.y);
double ang = Angle.angleBetweenOriented(src1, src0, rotPt);
double srcDist = src1.distance(src0);
double destDist = dest1.distance(dest0);
// return identity if transformation would be degenerate
if (srcDist == 0.0) return new AffineTransformation();
double scale = destDist / srcDist;
AffineTransformation trans = AffineTransformation.translationInstance(-src0.x, -src0.y);
trans.rotate(ang);
trans.scale(scale, scale);
trans.translate(dest0.x, dest0.y);
return trans;
}
