java - 如何从圆中的x和y坐标中找到扇区

Question

请注意，我将使用的大多数数字只是示例，因为它需要是动态的

我正在尝试使用 UTF Full Block 图标 (= █) 创建一个具有动态高度、宽度和圆形扇区的圆圈（然后将这些用于居中的 Minecraft 全息图中，因此没有一堆空间可以将其居中） .

假设我有一个 25x25（直径为 25）的圆，有 12 个（几乎相等）扇区，每个扇区都会有不同的颜色，圆的中心是 (0, 0)。我如何能够将这个圆圈“划分”为扇区并将扇区 ID（例如 0-11）放在坐标上？

下面是我目前使用的代码，getSectionNumber 方法根本不起作用，可能可以忽略：

public class HologramCircle {

    private final int height;
    private final int width;

    public HologramCircle(final int height, final int width) {
        this.height = height;
        this.width = width;
    }

    public List<String> getLines() {
        final float width_r = (float) width / 2;
        final float height_r = (float) height / 2;
        final float ratio = width_r / height_r;

        final double maxblocks_x;
        final double maxblocks_y;

        if ((width_r * 2) % 2 == 0) {
            maxblocks_x = Math.ceil(width_r - .5) * 2 + 1;
        } else {
            maxblocks_x = Math.ceil(width_r) * 2;
        }

        if ((height_r * 2) % 2 == 0) {
            maxblocks_y = Math.ceil(height_r - .5) * 2 + 1;
        } else {
            maxblocks_y = Math.ceil(height_r) * 2;
        }

        final List<String> lines = Lists.newArrayList();

        for (double y = -maxblocks_y / 2 + 1; y <= maxblocks_y / 2 - 1; y++) {
            final StringBuilder line = new StringBuilder();

            for (double x = -maxblocks_x / 2 + 1; x <= maxblocks_x / 2 - 1; x++) {
                if (shouldBeFilled(x, y, width_r, ratio)) {
                    System.out.println(
                            String.format("Section id for x: %s and y: %s is %s", x, y, getSectorNumber(x, y, width_r, 12))
                    );
                    line.append("█");
                }
            }
            lines.add(line.toString());
        }
        return lines;
    }

    private int getSectorNumber(final double x, final double y, final double radius, final int sectorAmount) {
        final double degreesPerSector = 360 / sectorAmount;
        final double rad = Math.atan2(y, x);
        final double degrees = rad * (180 / Math.PI);

        System.out.println("rad: " + rad + ", degrees: " + degrees);

        for (int i = 0; i < sectorAmount; i++) {
            final double startDegrees = degreesPerSector * i;
            final double endDegrees = startDegrees + degreesPerSector;

            if (degrees >= startDegrees && degrees <= endDegrees) {
                return i;
            }
        }

        return -1;
    }

    private double distance(final double x, final double y, final double ratio) {
        return Math.sqrt((Math.pow(y * ratio, 2)) + Math.pow(x, 2));
    }

    private boolean shouldBeFilled(final double x, final double y, final double radius, final float ratio) {
        return distance(x, y, ratio) <= radius;
    }

我的解决方案：

我在 getSectionNumber 中的代码已经朝着正确的方向发展，我最终只是添加了 180°，所以它在 0-360 的范围内。这是我最终得到的代码：

package com.dbsoftwares.dangerwheel.hologram;

import com.google.common.collect.Lists;
import net.md_5.bungee.api.ChatColor;

import java.util.List;

public class HologramCircle {

    private final int height;
    private final int width;

    public HologramCircle(final int height, final int width) {
        this.height = height;
        this.width = width;
    }

    public List<String> getLines() {
        final float width_r = (float) width / 2;
        final float height_r = (float) height / 2;
        final float ratio = width_r / height_r;

        final double maxblocks_x;
        final double maxblocks_y;

        if ((width_r * 2) % 2 == 0) {
            maxblocks_x = Math.ceil(width_r - .5) * 2 + 1;
        } else {
            maxblocks_x = Math.ceil(width_r) * 2;
        }

        if ((height_r * 2) % 2 == 0) {
            maxblocks_y = Math.ceil(height_r - .5) * 2 + 1;
        } else {
            maxblocks_y = Math.ceil(height_r) * 2;
        }

        final List<String> lines = Lists.newArrayList();

        for (double y = -maxblocks_y / 2 + 1; y <= maxblocks_y / 2 - 1; y++) {
            final StringBuilder line = new StringBuilder();

            for (double x = -maxblocks_x / 2 + 1; x <= maxblocks_x / 2 - 1; x++) {
                if (shouldBeFilled(x, y, width_r, ratio)) {
                    final int sector = getSectorNumber(x, y, 12);

                    line.append(ChatColor.values()[sector].toString());
                    line.append("█");
                }
            }
            lines.add(line.toString());
        }
        return lines;
    }

    private int getSectorNumber(final double x, final double y, final int sectorAmount) {
        final double degreesPerSector = 360 / sectorAmount;
        final double rad = Math.atan2(y, x);
        final double degrees = rad * (180 / Math.PI) + 180;

        for (int i = 0; i < sectorAmount; i++) {
            final double startDegrees = degreesPerSector * i;
            final double endDegrees = startDegrees + degreesPerSector;

            if (degrees >= startDegrees && degrees <= endDegrees) {
                return i;
            }
        }

        return -1;
    }

    private double distance(final double x, final double y, final double ratio) {
        return Math.sqrt((Math.pow(y * ratio, 2)) + Math.pow(x, 2));
    }

    private boolean shouldBeFilled(final double x, final double y, final double radius, final float ratio) {
        return distance(x, y, ratio) <= radius;
    }
}

这是我现在的结果，它并不完美，但这肯定符合我的需求

标签： javageometry