java中点圆算法实现代码之高效绘制圆几何图形

package com.thealgorithms.geometry; import java.util.ArrayList; import java.util.Collection; import java.util.List; /** * Class to represent the Midpoint Circle Algorithm. * This algorithm calculates points on the circumference of a circle * using integer arithmetic for efficient computation. */ public final class MidpointCircle { private MidpointCircle() { // Private Constructor to prevent instantiation. } /** * Generates points on the circumference of a circle using the midpoint circle algorithm. * * @param centerX The x-coordinate of the circle's center. * @param centerY The y-coordinate of the circle's center. * @param radius The radius of the circle. * @return A list of points on the circle, each represented as an int[] with 2 elements [x, y]. */ public static List<int[]> generateCirclePoints(int centerX, int centerY, int radius) { List<int[]> points = new ArrayList<>(); // Special case for radius 0, only the center point should be added. if (radius == 0) { points.add(new int[] {centerX, centerY}); return points; } // Start at (radius, 0) int x = radius; int y = 0; // Decision parameter int p = 1 - radius; // Add the initial points in all octants addSymmetricPoints(points, centerX, centerY, x, y); // Iterate while x > y while (x > y) { y++; if (p <= 0) { // Midpoint is inside or on the circle p = p + 2 * y + 1; } else { // Midpoint is outside the circle x--; p = p + 2 * y - 2 * x + 1; } // Add points for this (x, y) addSymmetricPoints(points, centerX, centerY, x, y); } return points; } /** * Adds the symmetric points in all octants of the circle based on the current x and y values. * * @param points The list to which symmetric points will be added. * @param centerX The x-coordinate of the circle's center. * @param centerY The y-coordinate of the circle's center. * @param x The current x-coordinate on the circumference. * @param y The current y-coordinate on the circumference. */ private static void addSymmetricPoints(Collection<int[]> points, int centerX, int centerY, int x, int y) { // Octant symmetry points points.add(new int[] {centerX + x, centerY + y}); points.add(new int[] {centerX - x, centerY + y}); points.add(new int[] {centerX + x, centerY - y}); points.add(new int[] {centerX - x, centerY - y}); points.add(new int[] {centerX + y, centerY + x}); points.add(new int[] {centerX - y, centerY + x}); points.add(new int[] {centerX + y, centerY - x}); points.add(new int[] {centerX - y, centerY - x}); } }