com.google.code.appengine.awt.geom.Ellipse2D Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @author Denis M. Kishenko
*/
package com.google.code.appengine.awt.geom;
import java.util.NoSuchElementException;
import org.apache.harmony.awt.internal.nls.Messages;
import com.google.code.appengine.awt.geom.AffineTransform;
import com.google.code.appengine.awt.geom.Ellipse2D;
import com.google.code.appengine.awt.geom.PathIterator;
import com.google.code.appengine.awt.geom.Rectangle2D;
import com.google.code.appengine.awt.geom.RectangularShape;
public abstract class Ellipse2D extends RectangularShape {
public static class Float extends Ellipse2D {
public float x;
public float y;
public float width;
public float height;
public Float() {
}
public Float(float x, float y, float width, float height) {
setFrame(x, y, width, height);
}
@Override
public double getX() {
return x;
}
@Override
public double getY() {
return y;
}
@Override
public double getWidth() {
return width;
}
@Override
public double getHeight() {
return height;
}
@Override
public boolean isEmpty() {
return width <= 0.0 || height <= 0.0;
}
public void setFrame(float x, float y, float width, float height) {
this.x = x;
this.y = y;
this.width = width;
this.height = height;
}
@Override
public void setFrame(double x, double y, double width, double height) {
this.x = (float)x;
this.y = (float)y;
this.width = (float)width;
this.height = (float)height;
}
public Rectangle2D getBounds2D() {
return new Rectangle2D.Float(x, y, width, height);
}
}
public static class Double extends Ellipse2D {
public double x;
public double y;
public double width;
public double height;
public Double() {
}
public Double(double x, double y, double width, double height) {
setFrame(x, y, width, height);
}
@Override
public double getX() {
return x;
}
@Override
public double getY() {
return y;
}
@Override
public double getWidth() {
return width;
}
@Override
public double getHeight() {
return height;
}
@Override
public boolean isEmpty() {
return width <= 0.0 || height <= 0.0;
}
@Override
public void setFrame(double x, double y, double width, double height) {
this.x = x;
this.y = y;
this.width = width;
this.height = height;
}
public Rectangle2D getBounds2D() {
return new Rectangle2D.Double(x, y, width, height);
}
}
/*
* Ellipse2D path iterator
*/
class Iterator implements PathIterator {
/*
* Ellipse is subdivided into four quarters by x and y axis. Each part approximated by
* cubic Bezier curve. Arc in first quarter is started in (a, 0) and finished in (0, b) points.
* Control points for cubic curve wiil be (a, 0), (a, m), (n, b) and (0, b) where n and m are
* calculated based on requirement Bezier curve in point 0.5 should lay on the arc.
*/
/**
* The coefficient to calculate control points of Bezier curves
*/
final double u = 2.0 / 3.0 * (Math.sqrt(2.0) - 1.0);
/**
* The points coordinates calculation table.
*/
final double points[][] = {
{ 1.0, 0.5 + u, 0.5 + u, 1.0, 0.5, 1.0 },
{ 0.5 - u, 1.0, 0.0, 0.5 + u, 0.0, 0.5 },
{ 0.0, 0.5 - u, 0.5 - u, 0.0, 0.5, 0.0 },
{ 0.5 + u, 0.0, 1.0, 0.5 - u, 1.0, 0.5 }
};
/**
* The x coordinate of left-upper corner of the ellipse bounds
*/
double x;
/**
* The y coordinate of left-upper corner of the ellipse bounds
*/
double y;
/**
* The width of the ellipse bounds
*/
double width;
/**
* The height of the ellipse bounds
*/
double height;
/**
* The path iterator transformation
*/
AffineTransform t;
/**
* The current segmenet index
*/
int index;
/**
* Constructs a new Ellipse2D.Iterator for given ellipse and transformation
* @param e - the source Ellipse2D object
* @param at - the AffineTransform object to apply rectangle path
*/
Iterator(Ellipse2D e, AffineTransform t) {
this.x = e.getX();
this.y = e.getY();
this.width = e.getWidth();
this.height = e.getHeight();
this.t = t;
if (width < 0.0 || height < 0.0) {
index = 6;
}
}
public int getWindingRule() {
return WIND_NON_ZERO;
}
public boolean isDone() {
return index > 5;
}
public void next() {
index++;
}
public int currentSegment(double[] coords) {
if (isDone()) {
// awt.4B=Iterator out of bounds
throw new NoSuchElementException(Messages.getString("awt.4B")); //$NON-NLS-1$
}
if (index == 5) {
return SEG_CLOSE;
}
int type;
int count;
if (index == 0) {
type = SEG_MOVETO;
count = 1;
double p[] = points[3];
coords[0] = x + p[4] * width;
coords[1] = y + p[5] * height;
} else {
type = SEG_CUBICTO;
count = 3;
double p[] = points[index - 1];
int j = 0;
for (int i = 0; i < 3; i++) {
coords[j] = x + p[j++] * width;
coords[j] = y + p[j++] * height;
}
}
if (t != null) {
t.transform(coords, 0, coords, 0, count);
}
return type;
}
public int currentSegment(float[] coords) {
if (isDone()) {
// awt.4B=Iterator out of bounds
throw new NoSuchElementException(Messages.getString("awt.4B")); //$NON-NLS-1$
}
if (index == 5) {
return SEG_CLOSE;
}
int type;
int count;
if (index == 0) {
type = SEG_MOVETO;
count = 1;
double p[] = points[3];
coords[0] = (float)(x + p[4] * width);
coords[1] = (float)(y + p[5] * height);
} else {
type = SEG_CUBICTO;
count = 3;
int j = 0;
double p[] = points[index - 1];
for (int i = 0; i < 3; i++) {
coords[j] = (float)(x + p[j++] * width);
coords[j] = (float)(y + p[j++] * height);
}
}
if (t != null) {
t.transform(coords, 0, coords, 0, count);
}
return type;
}
}
protected Ellipse2D() {
}
public boolean contains(double px, double py) {
if (isEmpty()) {
return false;
}
double a = (px - getX()) / getWidth() - 0.5;
double b = (py - getY()) / getHeight() - 0.5;
return a * a + b * b < 0.25;
}
public boolean intersects(double rx, double ry, double rw, double rh) {
if (isEmpty() || rw <= 0.0 || rh <= 0.0) {
return false;
}
double cx = getX() + getWidth() / 2.0;
double cy = getY() + getHeight() / 2.0;
double rx1 = rx;
double ry1 = ry;
double rx2 = rx + rw;
double ry2 = ry + rh;
double nx = cx < rx1 ? rx1 : (cx > rx2 ? rx2 : cx);
double ny = cy < ry1 ? ry1 : (cy > ry2 ? ry2 : cy);
return contains(nx, ny);
}
public boolean contains(double rx, double ry, double rw, double rh) {
if (isEmpty() || rw <= 0.0 || rh <= 0.0) {
return false;
}
double rx1 = rx;
double ry1 = ry;
double rx2 = rx + rw;
double ry2 = ry + rh;
return
contains(rx1, ry1) &&
contains(rx2, ry1) &&
contains(rx2, ry2) &&
contains(rx1, ry2);
}
public PathIterator getPathIterator(AffineTransform at) {
return new Iterator(this, at);
}
}
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