如何从圆形的x和y坐标中找到扇区

时间:2019-06-18 22:03:43

标签: java geometry

请注意,我将使用的大多数数字只是示例,因为它需要动态

我正在尝试使用UTF Full Block图标(=█)创建一个具有动态高度,宽度和圆扇形的圆(然后将它们用于Minecraft全息图中,该图居中,因此没有一堆使其居中的空间)

例如,假设我有一个25x25(直径为25)的圆,其中有12个(几乎相等)的扇区,这些扇区中的每个扇区都会获得不同的颜色,圆的中心是(0,0)。 如何将这个圆“划分”为多个扇区并将一个扇区ID(例如0-11)放在坐标上?

在下面看到我当前使用的代码之后,getSectionNumber方法根本不起作用,并且可能会被忽略:

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中拥有的代码已经朝着正确的方向发展,我最终只增加了180°,所以它的范围是0-360。这是我最后得到的代码:

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;
    }
}

This is my result now, it's not perfect, but this for sure fits my needs

0 个答案:

没有答案