com.sun.javafx.geom.Arc2D Maven / Gradle / Ivy
/*
* Copyright (c) 1997, 2022, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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 General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
package com.sun.javafx.geom;
import com.sun.javafx.geom.transform.BaseTransform;
/**
*
* The arc is a partial section of a full ellipse which
* inscribes the framing rectangle of its parent {@link RectangularShape}.
*
*
* The angles are specified relative to the non-square
* framing rectangle such that 45 degrees always falls on the line from
* the center of the ellipse to the upper right corner of the framing
* rectangle.
* As a result, if the framing rectangle is noticeably longer along one
* axis than the other, the angles to the start and end of the arc segment
* will be skewed farther along the longer axis of the frame.
*
*
* @version 10 Feb 1997
*/
public class Arc2D extends RectangularShape {
/**
* The closure type for an open arc with no path segments
* connecting the two ends of the arc segment.
*/
public final static int OPEN = 0;
/**
* The closure type for an arc closed by drawing a straight
* line segment from the start of the arc segment to the end of the
* arc segment.
*/
public final static int CHORD = 1;
/**
* The closure type for an arc closed by drawing straight line
* segments from the start of the arc segment to the center
* of the full ellipse and from that point to the end of the arc segment.
*/
public final static int PIE = 2;
private int type;
/**
* The X coordinate of the upper-left corner of the framing
* rectangle of the arc.
* @serial
*/
public float x;
/**
* The Y coordinate of the upper-left corner of the framing
* rectangle of the arc.
* @serial
*/
public float y;
/**
* The overall width of the full ellipse of which this arc is
* a partial section (not considering the
* angular extents).
* @serial
*/
public float width;
/**
* The overall height of the full ellipse of which this arc is
* a partial section (not considering the
* angular extents).
* @serial
*/
public float height;
/**
* The starting angle of the arc in degrees.
* @serial
*/
public float start;
/**
* The angular extent of the arc in degrees.
* @serial
*/
public float extent;
/**
* Constructs a new OPEN arc, initialized to location (0, 0),
* size (0, 0), angular extents (start = 0, extent = 0).
*/
public Arc2D() {
this(OPEN);
}
/**
* Constructs a new arc, initialized to location (0, 0),
* size (0, 0), angular extents (start = 0, extent = 0), and
* the specified closure type.
*
* @param type The closure type for the arc:
* {@link #OPEN}, {@link #CHORD}, or {@link #PIE}.
*/
public Arc2D(int type) {
setArcType(type);
}
/**
* Constructs a new arc, initialized to the specified location,
* size, angular extents, and closure type.
*
* @param x The X coordinate of the upper-left corner of
* the arc's framing rectangle.
* @param y The Y coordinate of the upper-left corner of
* the arc's framing rectangle.
* @param w The overall width of the full ellipse of which
* this arc is a partial section.
* @param h The overall height of the full ellipse of which this
* arc is a partial section.
* @param start The starting angle of the arc in degrees.
* @param extent The angular extent of the arc in degrees.
* @param type The closure type for the arc:
* {@link #OPEN}, {@link #CHORD}, or {@link #PIE}.
*/
public Arc2D(float x, float y, float w, float h,
float start, float extent, int type) {
this(type);
this.x = x;
this.y = y;
this.width = w;
this.height = h;
this.start = start;
this.extent = extent;
}
/**
* {@inheritDoc}
*/
@Override
public float getX() {
return x;
}
/**
* {@inheritDoc}
*/
@Override
public float getY() {
return y;
}
/**
* {@inheritDoc}
*/
@Override
public float getWidth() {
return width;
}
/**
* {@inheritDoc}
*/
@Override
public float getHeight() {
return height;
}
/**
* {@inheritDoc}
*/
@Override
public boolean isEmpty() {
return (width <= 0f || height <= 0f);
}
/**
* {@inheritDoc}
*/
public void setArc(float x, float y, float w, float h,
float angSt, float angExt, int closure) {
this.setArcType(closure);
this.x = x;
this.y = y;
this.width = w;
this.height = h;
this.start = angSt;
this.extent = angExt;
}
/**
* Returns the arc closure type of the arc: {@link #OPEN},
* {@link #CHORD}, or {@link #PIE}.
* @return One of the integer constant closure types defined
* in this class.
* @see #setArcType
*/
public int getArcType() {
return type;
}
/**
* Returns the starting point of the arc. This point is the
* intersection of the ray from the center defined by the
* starting angle and the elliptical boundary of the arc.
*
* @return A Point2D object representing the
* x,y coordinates of the starting point of the arc.
*/
public Point2D getStartPoint() {
double angle = Math.toRadians(-start);
double x = this.x + (Math.cos(angle) * 0.5 + 0.5) * width;
double y = this.y + (Math.sin(angle) * 0.5 + 0.5) * height;
return new Point2D((float)x, (float)y);
}
/**
* Returns the ending point of the arc. This point is the
* intersection of the ray from the center defined by the
* starting angle plus the angular extent of the arc and the
* elliptical boundary of the arc.
*
* @return A Point2D object representing the
* x,y coordinates of the ending point of the arc.
*/
public Point2D getEndPoint() {
double angle = Math.toRadians(-start - extent);
double x = this.x + (Math.cos(angle) * 0.5 + 0.5) * width;
double y = this.y + (Math.sin(angle) * 0.5 + 0.5) * height;
return new Point2D((float)x, (float)y);
}
/**
* Sets the location, size, angular extents, and closure type of
* this arc to the specified values.
*
* @param loc The Point2D representing the coordinates of
* the upper-left corner of the arc.
* @param size The Dimension2D representing the width
* and height of the full ellipse of which this arc is
* a partial section.
* @param angSt The starting angle of the arc in degrees.
* @param angExt The angular extent of the arc in degrees.
* @param closure The closure type for the arc:
* {@link #OPEN}, {@link #CHORD}, or {@link #PIE}.
*/
public void setArc(Point2D loc, Dimension2D size,
float angSt, float angExt, int closure) {
setArc(loc.x, loc.y, size.width, size.height, angSt, angExt, closure);
}
/**
* Sets this arc to be the same as the specified arc.
*
* @param a The Arc2D to use to set the arc's values.
*/
public void setArc(Arc2D a) {
setArc(a.x, a.y, a.width, a.height, a.start, a.extent, a.type);
}
/**
* Sets the position, bounds, angular extents, and closure type of
* this arc to the specified values. The arc is defined by a center
* point and a radius rather than a framing rectangle for the full ellipse.
*
* @param x The X coordinate of the center of the arc.
* @param y The Y coordinate of the center of the arc.
* @param radius The radius of the arc.
* @param angSt The starting angle of the arc in degrees.
* @param angExt The angular extent of the arc in degrees.
* @param closure The closure type for the arc:
* {@link #OPEN}, {@link #CHORD}, or {@link #PIE}.
*/
public void setArcByCenter(float x, float y, float radius,
float angSt, float angExt, int closure) {
setArc(x - radius, y - radius, radius * 2f, radius * 2f,
angSt, angExt, closure);
}
/**
* Sets the position, bounds, and angular extents of this arc to the
* specified value. The starting angle of the arc is tangent to the
* line specified by points (p1, p2), the ending angle is tangent to
* the line specified by points (p2, p3), and the arc has the
* specified radius.
*
* @param p1 The first point that defines the arc. The starting
* angle of the arc is tangent to the line specified by points (p1, p2).
* @param p2 The second point that defines the arc. The starting
* angle of the arc is tangent to the line specified by points (p1, p2).
* The ending angle of the arc is tangent to the line specified by
* points (p2, p3).
* @param p3 The third point that defines the arc. The ending angle
* of the arc is tangent to the line specified by points (p2, p3).
* @param radius The radius of the arc.
*/
public void setArcByTangent(Point2D p1, Point2D p2, Point2D p3, float radius) {
double ang1 = Math.atan2(p1.y - p2.y,
p1.x - p2.x);
double ang2 = Math.atan2(p3.y - p2.y,
p3.x - p2.x);
double diff = ang2 - ang1;
if (diff > Math.PI) {
ang2 -= Math.PI * 2.0;
} else if (diff < -Math.PI) {
ang2 += Math.PI * 2.0;
}
double bisect = (ang1 + ang2) / 2.0;
double theta = Math.abs(ang2 - bisect);
double dist = radius / Math.sin(theta);
double x = p2.x + dist * Math.cos(bisect);
double y = p2.y + dist * Math.sin(bisect);
// REMIND: This needs some work...
if (ang1 < ang2) {
ang1 -= Math.PI / 2.0;
ang2 += Math.PI / 2.0;
} else {
ang1 += Math.PI / 2.0;
ang2 -= Math.PI / 2.0;
}
ang1 = Math.toDegrees(-ang1);
ang2 = Math.toDegrees(-ang2);
diff = ang2 - ang1;
if (diff < 0) {
diff += 360;
} else {
diff -= 360;
}
setArcByCenter((float)x, (float)y, radius, (float)ang1, (float)diff, type);
}
/**
* Sets the starting angle of this arc to the angle that the
* specified point defines relative to the center of this arc.
* The angular extent of the arc will remain the same.
*
* @param p The Point2D that defines the starting angle.
* @see #start
*/
public void setAngleStart(Point2D p) {
// Bias the dx and dy by the height and width of the oval.
double dx = this.height * (p.x - getCenterX());
double dy = this.width * (p.y - getCenterY());
start = (float)-Math.toDegrees(Math.atan2(dy, dx));
}
/**
* Sets the starting angle and angular extent of this arc using two
* sets of coordinates. The first set of coordinates is used to
* determine the angle of the starting point relative to the arc's
* center. The second set of coordinates is used to determine the
* angle of the end point relative to the arc's center.
* The arc will always be non-empty and extend counterclockwise
* from the first point around to the second point.
*
* @param x1 The X coordinate of the arc's starting point.
* @param y1 The Y coordinate of the arc's starting point.
* @param x2 The X coordinate of the arc's ending point.
* @param y2 The Y coordinate of the arc's ending point.
*/
public void setAngles(float x1, float y1, float x2, float y2) {
double x = getCenterX();
double y = getCenterY();
double w = this.width;
double h = this.height;
// Note: reversing the Y equations negates the angle to adjust
// for the upside down coordinate system.
// Also we should bias atans by the height and width of the oval.
double ang1 = Math.atan2(w * (y - y1), h * (x1 - x));
double ang2 = Math.atan2(w * (y - y2), h * (x2 - x));
ang2 -= ang1;
if (ang2 <= 0.0) {
ang2 += Math.PI * 2.0;
}
start = (float)Math.toDegrees(ang1);
extent = (float)Math.toDegrees(ang2);
}
/**
* Sets the starting angle and angular extent of this arc using
* two points. The first point is used to determine the angle of
* the starting point relative to the arc's center.
* The second point is used to determine the angle of the end point
* relative to the arc's center.
* The arc will always be non-empty and extend counterclockwise
* from the first point around to the second point.
*
* @param p1 The Point2D that defines the arc's
* starting point.
* @param p2 The Point2D that defines the arc's
* ending point.
*/
public void setAngles(Point2D p1, Point2D p2) {
setAngles(p1.x, p1.y, p2.x, p2.y);
}
/**
* Sets the closure type of this arc to the specified value:
* OPEN, CHORD, or PIE.
*
* @param type The integer constant that represents the closure
* type of this arc: {@link #OPEN}, {@link #CHORD}, or
* {@link #PIE}.
*
* @throws IllegalArgumentException if type is not
* 0, 1, or 2.+
* @see #getArcType
*/
public void setArcType(int type) {
if (type < OPEN || type > PIE) {
throw new IllegalArgumentException("invalid type for Arc: "+type);
}
this.type = type;
}
/**
* {@inheritDoc}
* Note that the arc
* partially inscribes
* the framing rectangle of this {@code RectangularShape}.
*/
@Override
public void setFrame(float x, float y, float w, float h) {
setArc(x, y, w, h, start, extent, type);
}
/**
* Returns the high-precision framing rectangle of the arc. The framing
* rectangle contains only the part of this Arc2D that is
* in between the starting and ending angles and contains the pie
* wedge, if this Arc2D has a PIE closure type.
*
* This method differs from the
* {@link RectangularShape#getBounds() getBounds} in that the
* getBounds method only returns the bounds of the
* enclosing ellipse of this Arc2D without considering
* the starting and ending angles of this Arc2D.
*
* @return the RectBounds that represents the arc's
* framing rectangle.
*/
@Override
public RectBounds getBounds() {
if (isEmpty()) {
return new RectBounds(x, y, x + width, y + height);
}
double x1, y1, x2, y2;
if (getArcType() == PIE) {
x1 = y1 = x2 = y2 = 0.0;
} else {
x1 = y1 = 1.0;
x2 = y2 = -1.0;
}
double angle = 0.0;
for (int i = 0; i < 6; i++) {
if (i < 4) {
// 0-3 are the four quadrants
angle += 90.0;
if (!containsAngle((float)angle)) {
continue;
}
} else if (i == 4) {
// 4 is start angle
angle = start;
} else {
// 5 is end angle
angle += extent;
}
double rads = Math.toRadians(-angle);
double xe = Math.cos(rads);
double ye = Math.sin(rads);
x1 = Math.min(x1, xe);
y1 = Math.min(y1, ye);
x2 = Math.max(x2, xe);
y2 = Math.max(y2, ye);
}
double w = this.width;
double h = this.height;
x2 = this.x + (x2 * 0.5 + 0.5) * w;
y2 = this.y + (y2 * 0.5 + 0.5) * h;
x1 = this.x + (x1 * 0.5 + 0.5) * w;
y1 = this.y + (y1 * 0.5 + 0.5) * h;
return new RectBounds((float)x1, (float)y1, (float)x2, (float)y2);
}
/*
* Normalizes the specified angle into the range -180 to 180.
*/
static float normalizeDegrees(double angle) {
if (angle > 180.0) {
if (angle <= (180.0 + 360.0)) {
angle = angle - 360.0;
} else {
angle = Math.IEEEremainder(angle, 360.0);
// IEEEremainder can return -180 here for some input values...
if (angle == -180.0) {
angle = 180.0;
}
}
} else if (angle <= -180.0) {
if (angle > (-180.0 - 360.0)) {
angle = angle + 360.0;
} else {
angle = Math.IEEEremainder(angle, 360.0);
// IEEEremainder can return -180 here for some input values...
if (angle == -180.0) {
angle = 180.0;
}
}
}
return (float)angle;
}
/**
* Determines whether or not the specified angle is within the
* angular extents of the arc.
*
* @param angle The angle to test.
*
* @return true if the arc contains the angle,
* false if the arc doesn't contain the angle.
*/
public boolean containsAngle(float angle) {
double angExt = extent;
boolean backwards = (angExt < 0.0);
if (backwards) {
angExt = -angExt;
}
if (angExt >= 360.0) {
return true;
}
angle = normalizeDegrees(angle) - normalizeDegrees(start);
if (backwards) {
angle = -angle;
}
if (angle < 0.0) {
angle += 360.0;
}
return (angle >= 0.0) && (angle < angExt);
}
/**
* Determines whether or not the specified point is inside the boundary
* of the arc.
*
* @param x The X coordinate of the point to test.
* @param y The Y coordinate of the point to test.
*
* @return true if the point lies within the bound of
* the arc, false if the point lies outside of the
* arc's bounds.
*/
@Override
public boolean contains(float x, float y) {
// Normalize the coordinates compared to the ellipse
// having a center at 0,0 and a radius of 0.5.
double ellw = this.width;
if (ellw <= 0.0) {
return false;
}
double normx = (x - this.x) / ellw - 0.5;
double ellh = this.height;
if (ellh <= 0.0) {
return false;
}
double normy = (y - this.y) / ellh - 0.5;
double distSq = (normx * normx + normy * normy);
if (distSq >= 0.25) {
return false;
}
double angExt = Math.abs(extent);
if (angExt >= 360.0) {
return true;
}
boolean inarc = containsAngle((float)-Math.toDegrees(Math.atan2(normy,
normx)));
if (type == PIE) {
return inarc;
}
// CHORD and OPEN behave the same way
if (inarc) {
if (angExt >= 180.0) {
return true;
}
// point must be outside the "pie triangle"
} else {
if (angExt <= 180.0) {
return false;
}
// point must be inside the "pie triangle"
}
// The point is inside the pie triangle iff it is on the same
// side of the line connecting the ends of the arc as the center.
double angle = Math.toRadians(-start);
double x1 = Math.cos(angle);
double y1 = Math.sin(angle);
angle += Math.toRadians(-extent);
double x2 = Math.cos(angle);
double y2 = Math.sin(angle);
boolean inside = (Line2D.relativeCCW((float)x1, (float)y1, (float)x2, (float)y2, (float)(2*normx), (float)(2*normy)) *
Line2D.relativeCCW((float)x1, (float)y1, (float)x2, (float)y2, 0, 0) >= 0);
return inarc ? !inside : inside;
}
/**
* Determines whether or not the interior of the arc intersects
* the interior of the specified rectangle.
*
* @param x The X coordinate of the rectangle's upper-left corner.
* @param y The Y coordinate of the rectangle's upper-left corner.
* @param w The width of the rectangle.
* @param h The height of the rectangle.
*
* @return true if the arc intersects the rectangle,
* false if the arc doesn't intersect the rectangle.
*/
@Override
public boolean intersects(float x, float y, float w, float h) {
float aw = this.width;
float ah = this.height;
if ( w <= 0 || h <= 0 || aw <= 0 || ah <= 0 ) {
return false;
}
float ext = extent;
if (ext == 0) {
return false;
}
float ax = this.x;
float ay = this.y;
float axw = ax + aw;
float ayh = ay + ah;
float xw = x + w;
float yh = y + h;
// check bbox
if (x >= axw || y >= ayh || xw <= ax || yh <= ay) {
return false;
}
// extract necessary data
float axc = getCenterX();
float ayc = getCenterY();
// inlined getStartPoint
double sangle = Math.toRadians(-start);
float sx = (float) (this.x + (Math.cos(sangle) * 0.5 + 0.5) * width);
float sy = (float) (this.y + (Math.sin(sangle) * 0.5 + 0.5) * height);
// inlined getEndPoint
double eangle = Math.toRadians(-start - extent);
float ex = (float) (this.x + (Math.cos(eangle) * 0.5 + 0.5) * width);
float ey = (float) (this.y + (Math.sin(eangle) * 0.5 + 0.5) * height);
/*
* Try to catch rectangles that intersect arc in areas
* outside of rectagle with left top corner coordinates
* (min(center x, start point x, end point x),
* min(center y, start point y, end point y))
* and rigth bottom corner coordinates
* (max(center x, start point x, end point x),
* max(center y, start point y, end point y)).
* So we'll check axis segments outside of rectangle above.
*/
if (ayc >= y && ayc <= yh) { // 0 and 180
if ((sx < xw && ex < xw && axc < xw &&
axw > x && containsAngle(0)) ||
(sx > x && ex > x && axc > x &&
ax < xw && containsAngle(180))) {
return true;
}
}
if (axc >= x && axc <= xw) { // 90 and 270
if ((sy > y && ey > y && ayc > y &&
ay < yh && containsAngle(90)) ||
(sy < yh && ey < yh && ayc < yh &&
ayh > y && containsAngle(270))) {
return true;
}
}
/*
* For PIE we should check intersection with pie slices;
* also we should do the same for arcs with extent is greater
* than 180, because we should cover case of rectangle, which
* situated between center of arc and chord, but does not
* intersect the chord.
*/
if (type == PIE || Math.abs(ext) > 180) {
// for PIE: try to find intersections with pie slices
if (Shape.intersectsLine(x, y, w, h, axc, ayc, sx, sy) ||
Shape.intersectsLine(x, y, w, h, axc, ayc, ex, ey))
{
return true;
}
} else {
// for CHORD and OPEN: try to find intersections with chord
if (Shape.intersectsLine(x, y, w, h, sx, sy, ex, ey)) {
return true;
}
}
// finally check the rectangle corners inside the arc
if (contains(x, y) || contains(x + w, y) ||
contains(x, y + h) || contains(x + w, y + h)) {
return true;
}
return false;
}
/**
* Determines whether or not the interior of the arc entirely contains
* the specified rectangle.
*
* @param x The X coordinate of the rectangle's upper-left corner.
* @param y The Y coordinate of the rectangle's upper-left corner.
* @param w The width of the rectangle.
* @param h The height of the rectangle.
*
* @return true if the arc contains the rectangle,
* false if the arc doesn't contain the rectangle.
*/
@Override
public boolean contains(float x, float y, float w, float h) {
if (!(contains(x, y) &&
contains(x + w, y) &&
contains(x, y + h) &&
contains(x + w, y + h))) {
return false;
}
// If the shape is convex then we have done all the testing
// we need. Only PIE arcs can be concave and then only if
// the angular extents are greater than 180 degrees.
if (type != PIE || Math.abs(extent) <= 180.0) {
return true;
}
// For a PIE shape we have an additional test for the case where
// the angular extents are greater than 180 degrees and all four
// rectangular corners are inside the shape but one of the
// rectangle edges spans across the "missing wedge" of the arc.
// We can test for this case by checking if the rectangle intersects
// either of the pie angle segments.
float halfW = getWidth() / 2f;
float halfH = getHeight() / 2f;
float xc = x + halfW;
float yc = y + halfH;
float angle = (float) Math.toRadians(-start);
float xe = (float) (xc + halfW * Math.cos(angle));
float ye = (float) (yc + halfH * Math.sin(angle));
if (Shape.intersectsLine(x, y, w, h, xc, yc, xe, ye)) {
return false;
}
angle += (float) Math.toRadians(-extent);
xe = (float) (xc + halfW * Math.cos(angle));
ye = (float) (yc + halfH * Math.sin(angle));
return !Shape.intersectsLine(x, y, w, h, xc, yc, xe, ye);
}
/**
* Returns an iteration object that defines the boundary of the
* arc.
* This iterator is multithread safe.
* Arc2D guarantees that
* modifications to the geometry of the arc
* do not affect any iterations of that geometry that
* are already in process.
*
* @param tx an optional BaseTransform to be applied
* to the coordinates as they are returned in the iteration, or null
* if the untransformed coordinates are desired.
*
* @return A PathIterator that defines the arc's boundary.
*/
@Override
public PathIterator getPathIterator(BaseTransform tx) {
return new ArcIterator(this, tx);
}
@Override
public Arc2D copy() {
return new Arc2D(x, y, width, height, start, extent, type);
}
/**
* Returns the hashcode for this Arc2D.
* @return the hashcode for this Arc2D.
*/
@Override
public int hashCode() {
int bits = java.lang.Float.floatToIntBits(x);
bits += java.lang.Float.floatToIntBits(y) * 37;
bits += java.lang.Float.floatToIntBits(width) * 43;
bits += java.lang.Float.floatToIntBits(height) * 47;
bits += java.lang.Float.floatToIntBits(start) * 53;
bits += java.lang.Float.floatToIntBits(extent) * 59;
bits += getArcType() * 61;
return bits;
}
/**
* Determines whether or not the specified Object is
* equal to this Arc2D. The specified
* Object is equal to this Arc2D
* if it is an instance of Arc2D and if its
* location, size, arc extents and type are the same as this
* Arc2D.
* @param obj an Object to be compared with this
* Arc2D.
* @return true if obj is an instance
* of Arc2D and has the same values;
* false otherwise.
*/
@Override
public boolean equals(Object obj) {
if (obj == this) return true;
if (obj instanceof Arc2D) {
Arc2D a2d = (Arc2D) obj;
return ((x == a2d.x) &&
(y == a2d.y) &&
(width == a2d.width) &&
(height == a2d.height) &&
(start == a2d.start) &&
(extent == a2d.extent) &&
(type == a2d.type));
}
return false;
}
}