/* @(#)Shapes.java 15 February 2006 * * Copyright 2006 * College of Computer Science * Northeastern University * Boston, MA 02115 * * This software may be used for educational purposes as long as * this copyright notice is retained intact at the top of all files. * * To discuss commercial use of this software, contact * Prof. Richard Rasala or Prof. Viera Proulx at the Northeastern * University College of Computer Science: 617-373-2462. * * The principal software developer on this project is Jeff Raab. * * Should this software be modified, the words "Modified from * Original" must be included as a comment below this notice. * * All publication rights are retained. This software or its * documentation may not be published in any media either in whole * or in part without explicit permission. * * This software was created with support from Northeastern * University and from NSF grant DUE-9950829. */ import edu.neu.ccs.*; import edu.neu.ccs.gui.*; import edu.neu.ccs.codec.*; import edu.neu.ccs.console.*; import edu.neu.ccs.filter.*; import edu.neu.ccs.jpf.*; import edu.neu.ccs.parser.*; import edu.neu.ccs.pedagogy.*; import edu.neu.ccs.quick.*; import edu.neu.ccs.util.*; import java.awt.*; import java.awt.event.*; import java.awt.geom.*; import java.awt.font.*; import java.awt.image.*; import javax.swing.*; import javax.swing.border.*; import java.io.*; import java.util.*; import java.math.*; import java.beans.*; import java.lang.reflect.*; import java.net.URL; import java.util.regex.*; import java.text.ParseException; public class Shapes { /** * Returns a regular polygon shape with N vertex points * and the given radius r and center x, y. * * Requires N >= 3 and r > 0. * * @param N the number of vertex points * @param r the radius * @param x the x-position of the center * @param y the y-position of the center * @return */ public static Shape regularPolygon (int N, double r, double x, double y) { boolean OK = (N >= 3) && (r > 0); if (! OK) return null; float a = (float) x; float b = (float) y; float radius = (float) r; float[][] vertex = new float[N][2]; double angle = 0; double delta = 360.0 / N; for (int i = 0; i < N; i++) { float u = (float) MathUtilities.sindeg(angle); float v = (float) MathUtilities.cosdeg(angle); u = a + radius * u; v = b - radius * v; vertex[i][0] = u; vertex[i][1] = v; angle += delta; } return new PolygonShape(vertex); } /** * Returns a regular wavygon shape with N vertex points * and the given radius r and center x, y. * * A wavygon is a star shape that uses a smooth curve * rather than straight edges. * * The inner radius of a wavygon is half of the radius. * * Requires N >= 3 and r > 0. * * @param N the number of vertex points * @param r the radius * @param x the x-position of the center * @param y the y-position of the center * @return */ public static Shape regularWavygon (int N, double r, double x, double y) { boolean OK = (N >= 3) && (r > 0); if (! OK) return null; int M = 2 * N; float a = (float) x; float b = (float) y; float outer = (float) r; float inner = outer / 2; float[][] vertex = new float[M][2]; double angle = 0; double delta = 360.0 / M; for (int i = 0; i < M; i++) { float u = (float) MathUtilities.sindeg(angle); float v = (float) MathUtilities.cosdeg(angle); if ((i % 2) == 0) { u = a + outer * u; v = b - outer * v; } else { u = a + inner * u; v = b - inner * v; } vertex[i][0] = u; vertex[i][1] = v; angle += delta; } return new AutomaticCurve(vertex, Tangent.chordStrategy(0.25f)); } /** * Returns the outline of a regular star shape with N * vertex points and the given radius r and center x, y. * * Conceptually, a star begins with the vertices of a * regular polygon but connects each vertex i with * vertex i+K for fixed K >= 2. * * This method returns the outline shape of such a star, * that is, instead of returning the edges between the * vertices this methods computes the boundary polygon. * * Requires N >= 5, K >= 2, N > 2*K, and r > 0. * * @param N the number of vertex points * @param K the jump between vertices * @param r the radius * @param x the x-position of the center * @param y the y-position of the center * @return */ public static Shape regularStar (int N, int K, double r, double x, double y) { boolean OK = (N > 2 * K) && (K >= 2) && (r > 0); if (! OK) return null; // compute factor needed to find inner radius double theta = 360.0 / N; double phi; double x1 = 0; double y1 = 1; phi = K * theta; double x2 = MathUtilities.sindeg(phi); double y2 = MathUtilities.cosdeg(phi); phi = theta; double x3 = MathUtilities.sindeg(phi); double y3 = MathUtilities.cosdeg(phi); phi = (1 - K) * theta; double x4 = MathUtilities.sindeg(phi); double y4 = MathUtilities.cosdeg(phi); Line2D A = new Line2D.Double(x1, y1, x2, y2); Line2D B = new Line2D.Double(x3, y3, x4, y4); Point2D P = Geometry.intersect(A, B); double px = P.getX(); double py = P.getY(); double factor = Math.sqrt(px * px + py * py); double s = factor * r; int M = 2 * N; float a = (float) x; float b = (float) y; float outer = (float) r; float inner = (float) s; float[][] vertex = new float[M][2]; double angle = 0; double delta = 360.0 / M; for (int i = 0; i < M; i++) { float u = (float) MathUtilities.sindeg(angle); float v = (float) MathUtilities.cosdeg(angle); if ((i % 2) == 0) { u = a + outer * u; v = b - outer * v; } else { u = a + inner * u; v = b - inner * v; } vertex[i][0] = u; vertex[i][1] = v; angle += delta; } return new PolygonShape(vertex); } }