Resizes or translates a Shape
/**
*
* JFreeReport : a free Java reporting library
*
*
* Project Info: http://reporting.pentaho.org/
*
* (C) Copyright 2001-2007, by Object Refinery Ltd, Pentaho Corporation and Contributors.
*
* This library is free software; you can redistribute it and/or modify it under the terms
* of the GNU Lesser General Public License as published by the Free Software Foundation;
* either version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307, USA.
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.]
*
* ------------
* ShapeTransform.java
* ------------
* (C) Copyright 2001-2007, by Object Refinery Ltd, Pentaho Corporation and Contributors.
*/
import java.awt.Dimension;
import java.awt.Shape;
import java.awt.geom.AffineTransform;
import java.awt.geom.Area;
import java.awt.geom.Dimension2D;
import java.awt.geom.GeneralPath;
import java.awt.geom.Line2D;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.awt.geom.RectangularShape;
/**
* Utility class, which resizes or translates a Shape. The class contains
* special handlers for Rectangles and Lines.
*
* @author Thomas Morgner
*/
public final strictfp class ShapeTransform {
// some constants for the cohenen-algorithmus
/**
* Flag for point lying left of clipping area.
*/
public static final int LEFT = 0x01;
/**
* Flag for point lying between horizontal bounds of area.
*/
public static final int H_CENTER = 0x02;
/**
* Flag for point lying right of clipping area.
*/
public static final int RIGHT = 0x04;
/**
* Flag for point lying "below" clipping area.
*/
public static final int BELOW = 0x10;
/**
* Flag for point lying between vertical bounds of clipping area.
*/
public static final int V_CENTER = 0x20;
/**
* Flag for point lying "above" clipping area.
*/
public static final int ABOVE = 0x40;
/** A simple way to handle rounding errors. */
private static final double DELTA = 0.000001;
/**
* Mask for points which are inside.
*/
public static final int INSIDE = H_CENTER | V_CENTER;
/**
* Mask for points which are outside.
*/
public static final int OUTSIDE = LEFT | RIGHT | BELOW | ABOVE;
/**
* Default constructor.
*/
private ShapeTransform() {
}
/**
* Resizes a line. Instead of creating a GeneralPath (as AffineTransform's
* scale would do) we modify the line itself.
*
* @param line
* the line that should be scaled
* @param width
* the new width of the line bounds
* @param height
* the new height of the line bounds
* @return the scale Line2D object.
*/
private static Line2D resizeLine(final Line2D line, final double width, final double height) {
final Line2D newLine = getNormalizedLine(line);
final Point2D p1 = newLine.getP1();
final Point2D p2 = newLine.getP2();
final double normPointX = (p1.getX() - p2.getX());
final double normPointY = (p1.getY() - p2.getY());
final double scaleX = (normPointX == 0) ? 1 : width / Math.abs(normPointX);
final double scaleY = (normPointY == 0) ? 1 : height / Math.abs(normPointY);
p2.setLocation((p2.getX() - p1.getX()) * scaleX + p1.getX(), (p2.getY() - p1.getY()) * scaleY
+ p1.getY());
newLine.setLine(p1, p2);
return newLine;
}
/**
* Normalize the line; the point with the lowest X is the primary point, if
* both points have the same X, that point with the lowest Y value wins.
*
* @param line
* the original line
* @return the normalized line
*/
private static Line2D getNormalizedLine(final Line2D line) {
final Line2D lineClone = (Line2D) line.clone();
final Point2D p1 = line.getP1();
final Point2D p2 = line.getP2();
if (p1.getX() < p2.getX()) {
return lineClone;
}
if (p1.getX() > p2.getX()) {
lineClone.setLine(p2, p1);
return lineClone;
}
if (p1.getY() < p2.getY()) {
return lineClone;
}
lineClone.setLine(p2, p1);
return lineClone;
}
/**
* Resizes a shape, so that the shape has the given width and height, but the
* origin of the shape does not change. <p/> Unlike the AffineTransform, this
* method tries to preserve the Shape's Type.
*
* @param s
* the shape
* @param width
* the new width
* @param height
* the new height
* @return the resized shape.
*/
public static Shape resizeShape(final Shape s, final float width, final float height) {
if (s instanceof Line2D) {
return resizeLine((Line2D) s, width, height);
}
if (s instanceof RectangularShape) {
return resizeRect((RectangularShape) s, width, height);
}
return transformShape(s, true, false, new Dimension((int) width, (int) height));
}
/**
* Resizes a rectangle. This works for real rectangles and produces funny
* results for RoundRects etc ..
*
* @param rectangularShape
* the rectangle
* @param width
* the new width of the rectangle
* @param height
* the new height of the rectangle.
* @return the resized rectangle.
*/
public static Shape resizeRect(final RectangularShape rectangularShape, final double width,
final double height) {
final RectangularShape retval = (RectangularShape) rectangularShape.clone();
retval.setFrame(retval.getX(), retval.getY(), width, height);
return retval;
}
/**
* Translates the given shape. The shape is translated to the origin supplied
* in <code>point</code>. If scaling is requested, the shape will also be
* scaled using an AffineTransform.
*
* @param s
* the shape that should be transformed
* @param scale
* true, if the shape should be scaled, false otherwise
* @param keepAR
* true, if the scaled shape should keep the aspect ratio
* @param width
* the target width.
* @param height
* the target height.
* @return the transformed shape
*/
public static Shape transformShape(final Shape s, final boolean scale, final boolean keepAR,
final double width, final double height) {
/**
* Always scale to the maximum bounds ...
*/
if (scale) {
final Rectangle2D boundsShape = s.getBounds2D();
final double w = boundsShape.getWidth();
final double h = boundsShape.getHeight();
double scaleX = 1;
if (w != 0) {
scaleX = width / w;
}
double scaleY = 1;
if (h != 0) {
scaleY = height / h;
}
if (scaleX != 1 || scaleY != 1) {
if (s instanceof RectangularShape) {
return ShapeTransform.resizeRect((RectangularShape) s, w * scaleX, h * scaleY);
}
if (s instanceof Line2D) {
return ShapeTransform.resizeLine((Line2D) s, w * scaleX, h * scaleY);
}
if (keepAR) {
final double scaleFact = Math.min(scaleX, scaleY);
return performDefaultTransformation(s, scaleFact, scaleFact);
} else {
return performDefaultTransformation(s, scaleX, scaleY);
}
}
}
return s;
}
/**
* Translates the given shape. The shape is translated to the origin supplied
* in <code>point</code>. If scaling is requested, the shape will also be
* scaled using an AffineTransform.
*
* @param s
* the shape that should be transformed
* @param scale
* true, if the shape should be scaled, false otherwise
* @param keepAR
* true, if the scaled shape should keep the aspect ratio
* @param dim
* the target dimension.
* @return the transformed shape
*/
public static Shape transformShape(final Shape s, final boolean scale, final boolean keepAR,
final Dimension2D dim) {
return transformShape(s, scale, keepAR, dim.getWidth(), dim.getHeight());
}
/**
* Clips the given shape to the given bounds. If the shape is a Line2D, manual
* clipping is performed, as the built in Area does not handle lines.
*
* @param s
* the shape to be clipped
* @param bounds
* the bounds to which the shape should be clipped
* @return the clipped shape.
*/
public static Shape performCliping(final Shape s, final Rectangle2D bounds) {
if (s instanceof Line2D) {
final Line2D line = (Line2D) s;
final Point2D[] clipped = getClipped(line.getX1(), line.getY1(), line.getX2(), line.getY2(),
-DELTA, DELTA + bounds.getWidth(), -DELTA, DELTA + bounds.getHeight());
if (clipped == null) {
return new GeneralPath();
}
return new Line2D.Float(clipped[0], clipped[1]);
}
final Rectangle2D boundsCorrected = bounds.getBounds2D();
boundsCorrected.setRect(-DELTA, -DELTA, DELTA + boundsCorrected.getWidth(), DELTA
+ boundsCorrected.getHeight());
final Area a = new Area(boundsCorrected);
if (a.isEmpty()) {
// don't clip ... Area does not like lines
// operations with lines always result in an empty Bounds:(0,0,0,0) area
return new GeneralPath();
}
final Area clipArea = new Area(s);
a.intersect(clipArea);
return a;
}
/**
* Scales a given shape. The shape is first normalized, then scaled and
* finally brought back into its original position.
*
* @param shape
* the shape to be scaled
* @param scaleX
* the horizontal scaling factor
* @param scaleY
* the vertical scaling factor
* @return the scaled shape
*/
private static Shape performDefaultTransformation(final Shape shape, final double scaleX,
final double scaleY) {
/**
* Apply the normalisation shape transform ... bring the shape to pos (0,0)
*/
final Rectangle2D bounds = shape.getBounds2D();
AffineTransform af = AffineTransform.getTranslateInstance(0 - bounds.getX(), 0 - bounds.getY());
// apply normalisation translation ...
Shape s = af.createTransformedShape(shape);
af = AffineTransform.getScaleInstance(scaleX, scaleY);
// apply scaling ...
s = af.createTransformedShape(s);
// now retranslate the shape to its original position ...
af = AffineTransform.getTranslateInstance(bounds.getX(), bounds.getY());
return af.createTransformedShape(s);
}
/**
* Translates a given shape. Special care is taken to preserve the shape's
* original class, if the shape is a rectangle or a line.
*
* @param s
* the shape
* @param x
* the x coordinate where the shape is translated to
* @param y
* the y coordinate where the shape is translated to
* @return the translated shape
*/
public static Shape translateShape(final Shape s, final double x, final double y) {
if (s instanceof RectangularShape) {
final RectangularShape rect = (RectangularShape) s;
final RectangularShape retval = (RectangularShape) rect.clone();
retval.setFrame(retval.getX() + x, retval.getY() + y, retval.getWidth(), retval.getHeight());
return retval;
}
if (s instanceof Line2D) {
final Line2D line = (Line2D) s;
final Line2D retval = (Line2D) line.clone();
retval
.setLine(retval.getX1() + x, retval.getY1() + y, retval.getX2() + x, retval.getY2() + y);
return retval;
}
final AffineTransform af = AffineTransform.getTranslateInstance(x, y);
return af.createTransformedShape(s);
}
/**
* Calculate the clipping points of a line with a rectangle.
*
* @param x1
* starting x of line
* @param y1
* starting y of line
* @param x2
* ending x of line
* @param y2
* ending y of line
* @param xmin
* lower left x of rectangle
* @param xmax
* upper right x of rectangle
* @param ymin
* lower left y of rectangle
* @param ymax
* upper right y of rectangle
* @return <code>null</code> (does not clip) or array of two points
*/
public static Point2D[] getClipped(final double x1, final double y1, final double x2,
final double y2, final double xmin, final double xmax, final double ymin, final double ymax) {
int mask1 = 0; // position mask for first point
if (x1 < xmin) {
mask1 |= LEFT;
} else if (x1 > xmax) {
mask1 |= RIGHT;
} else {
mask1 |= H_CENTER;
}
if (y1 < ymin) {
// btw: I know that in AWT y runs from down but I more used to
// y pointing up and it makes no difference for the algorithms
mask1 |= BELOW;
} else if (y1 > ymax) {
mask1 |= ABOVE;
} else {
mask1 |= V_CENTER;
}
int mask2 = 0; // position mask for second point
if (x2 < xmin) {
mask2 |= LEFT;
} else if (x2 > xmax) {
mask2 |= RIGHT;
} else {
mask2 |= H_CENTER;
}
if (y2 < ymin) {
mask2 |= BELOW;
} else if (y2 > ymax) {
mask2 |= ABOVE;
} else {
mask2 |= V_CENTER;
}
final int mask = mask1 | mask2;
if ((mask & OUTSIDE) == 0) {
// fine. everything's internal
final Point2D[] ret = new Point2D[2];
ret[0] = new Point2D.Double(x1, y1);
ret[1] = new Point2D.Double(x2, y2);
return ret;
} else if ((mask & (H_CENTER | LEFT)) == 0 || // everything's right
(mask & (H_CENTER | RIGHT)) == 0 || // everything's left
(mask & (V_CENTER | BELOW)) == 0 || // everything's above
(mask & (V_CENTER | ABOVE)) == 0) { // everything's below
// nothing to do
return null;
} else {
// need clipping
return getClipped(x1, y1, mask1, x2, y2, mask2, xmin, xmax, ymin, ymax);
}
}
/**
* Calculate the clipping points of a line with a rectangle.
*
* @param x1
* starting x of line
* @param y1
* starting y of line
* @param mask1
* clipping info mask for starting point
* @param x2
* ending x of line
* @param y2
* ending y of line
* @param mask2
* clipping info mask for ending point
* @param xmin
* lower left x of rectangle
* @param ymin
* lower left y of rectangle
* @param xmax
* upper right x of rectangle
* @param ymax
* upper right y of rectangle
* @return <code>null</code> (does not clip) or array of two points
*/
private static Point2D[] getClipped(final double x1, final double y1, final int mask1,
final double x2, final double y2, final int mask2, final double xmin, final double xmax,
final double ymin, final double ymax) {
final int mask = mask1 ^ mask2;
Point2D p1 = null;
if (mask1 == INSIDE) {
// point 1 is internal
p1 = new Point2D.Double(x1, y1);
if (mask == 0) {
// both masks are the same, so the second point is inside, too
final Point2D[] ret = new Point2D[2];
ret[0] = p1;
ret[1] = new Point2D.Double(x2, y2);
return ret;
}
} else if (mask2 == INSIDE) {
// point 2 is internal
p1 = new Point2D.Double(x2, y2);
}
if ((mask & LEFT) != 0) {
// System.out.println("Trying left");
// try to calculate intersection with left line
final Point2D p = intersect(x1, y1, x2, y2, xmin, ymin, xmin, ymax);
if (p != null) {
if (p1 == null) {
p1 = p;
} else {
final Point2D[] ret = new Point2D[2];
ret[0] = p1;
ret[1] = p;
return ret;
}
}
}
if ((mask & RIGHT) != 0) {
// System.out.println("Trying right");
// try to calculate intersection with left line
final Point2D p = intersect(x1, y1, x2, y2, xmax, ymin, xmax, ymax);
if (p != null) {
if (p1 == null) {
p1 = p;
} else {
final Point2D[] ret = new Point2D[2];
ret[0] = p1;
ret[1] = p;
return ret;
}
}
}
if (mask1 == (LEFT | BELOW) || mask1 == (RIGHT | BELOW)) {
// for exactly these two special cases use different sequence!
if ((mask & ABOVE) != 0) {
// System.out.println("Trying top");
// try to calculate intersection with lower line
final Point2D p = intersect(x1, y1, x2, y2, xmin, ymax, xmax, ymax);
if (p != null) {
if (p1 == null) {
p1 = p;
} else {
final Point2D[] ret = new Point2D[2];
ret[0] = p1;
ret[1] = p;
return ret;
}
}
}
if ((mask & BELOW) != 0) {
// System.out.println("Trying bottom");
// try to calculate intersection with lower line
final Point2D p = intersect(x1, y1, x2, y2, xmin, ymin, xmax, ymin);
if (p != null && p1 != null) {
final Point2D[] ret = new Point2D[2];
ret[0] = p1;
ret[1] = p;
return ret;
}
}
} else {
if ((mask & BELOW) != 0) {
// System.out.println("Trying bottom");
// try to calculate intersection with lower line
final Point2D p = intersect(x1, y1, x2, y2, xmin, ymin, xmax, ymin);
if (p != null) {
if (p1 == null) {
p1 = p;
} else {
final Point2D[] ret = new Point2D[2];
ret[0] = p1;
ret[1] = p;
return ret;
}
}
}
if ((mask & ABOVE) != 0) {
// System.out.println("Trying top");
// try to calculate intersection with lower line
final Point2D p = intersect(x1, y1, x2, y2, xmin, ymax, xmax, ymax);
if (p != null && p1 != null) {
final Point2D[] ret = new Point2D[2];
ret[0] = p1;
ret[1] = p;
return ret;
}
}
}
// no (or not enough) intersections found
return null;
}
/**
* Intersect two lines.
*
* @param x11
* starting x of 1st line
* @param y11
* starting y of 1st line
* @param x12
* ending x of 1st line
* @param y12
* ending y of 1st line
* @param x21
* starting x of 2nd line
* @param y21
* starting y of 2nd line
* @param x22
* ending x of 2nd line
* @param y22
* ending y of 2nd line
* @return intersection point or <code>null</code>
*/
private static Point2D intersect(final double x11, final double y11, final double x12,
final double y12, final double x21, final double y21, final double x22, final double y22) {
final double dx1 = x12 - x11;
final double dy1 = y12 - y11;
final double dx2 = x22 - x21;
final double dy2 = y22 - y21;
final double det = (dx2 * dy1 - dy2 * dx1);
if (det != 0.0) {
final double mu = ((x11 - x21) * dy1 - (y11 - y21) * dx1) / det;
if (mu >= 0.0 && mu <= 1.0) {
return new Point2D.Double(x21 + mu * dx2, y21 + mu * dy2);
}
}
return null;
}
}
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