C#基于Monogame实现弹跳方块游戏：移除屏幕中心100px范围内方块

实现思路 #

• 首先确定屏幕中心点坐标，结合现有代码的边界判断逻辑，窗口默认尺寸为800x480，中心点坐标为(400, 240)
• 判定逻辑采用距离平方对比替代开根号计算，避免性能损耗，半径100px对应的平方值为100 * 100 = 10000
• 判定时取30x30方块的中心点坐标(X+15, Y+15)做对比，判定精度更高
• 遍历方块列表时采用倒序for循环，避免foreach遍历过程中删除元素抛出异常
• 原初始化逻辑仅生成1000个方块，需修改为2000个匹配需求

修改后完整代码 #

Game1.cs #

using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using System;
using System.Collections.Generic;
using Microsoft.Xna.Framework;

namespace Inlämning2
{
    public class Game1 : Game
    {
        private GraphicsDeviceManager _graphics;
        private SpriteBatch _spriteBatch;
        Texture2D pixelTexture;
        List<Block> blocks = new List<Block>();
        // 定义屏幕中心、判定半径平方常量
        private const int ScreenCenterX = 400;
        private const int ScreenCenterY = 240;
        private const int RadiusSquared = 100 * 100;

        public Game1()
        {
            _graphics = new GraphicsDeviceManager(this);
            Content.RootDirectory = "Content";
            IsMouseVisible = true;
        }

        protected override void Initialize()
        {
            Random rnd = new Random();
            // 循环次数修改为2000，生成对应数量的方块
            for (int i = 0; i < 2000; i++)
            {
                var block = new Block();
                block.X = rnd.Next(0, 600);
                block.Y = rnd.Next(0, 400);
                block.Color = new Color(rnd.Next(256), rnd.Next(256), rnd.Next(256));
                blocks.Add(block);
            }
            base.Initialize();
        }

        protected override void LoadContent()
        {
            _spriteBatch = new SpriteBatch(GraphicsDevice);
            pixelTexture = Content.Load<Texture2D>("pixel");
        }

        protected override void Update(GameTime gameTime)
        {
            if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed || Keyboard.GetState().IsKeyDown(Keys.Escape))
                Exit();

            foreach (Block block in blocks)
            {
                block.Update();
            }

            // 倒序遍历方块列表，移除符合消失条件的方块
            for (int i = blocks.Count - 1; i >= 0; i--)
            {
                var block = blocks[i];
                // 计算方块中心点坐标
                int blockCenterX = block.X + 15;
                int blockCenterY = block.Y + 15;
                // 计算到屏幕中心的距离平方
                int distanceSquared = (blockCenterX - ScreenCenterX) * (blockCenterX - ScreenCenterX) + (blockCenterY - ScreenCenterY) * (blockCenterY - ScreenCenterY);
                if (distanceSquared <= RadiusSquared)
                {
                    blocks.RemoveAt(i);
                }
            }

            base.Update(gameTime);
        }

        protected override void Draw(GameTime gameTime)
        {
            GraphicsDevice.Clear(Color.CornflowerBlue);

            _spriteBatch.Begin();
            foreach (Block block in blocks)
            {
                block.Draw(_spriteBatch, pixelTexture);
            }
            _spriteBatch.End();

            base.Draw(gameTime);
        }
    }
}

Block.cs 无需修改，原有逻辑可正常运行 #

using System;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;

namespace Inlämning2
{
    class Block
    {
        public int X { get; set; } = 100;
        public int Y { get; set; } = 100;
        public Color Color { get; set; } = Color.Red;
        public int speed1 = 1;
        public int speed2 = -1;

        public void Draw(SpriteBatch spriteBatch, Texture2D texture)
        {
            spriteBatch.Draw(texture, new Rectangle(X, Y, 30, 30), Color);
        }

        public void Update()
        {
            if (X < 0) speed2 += 1;
            if (X > 770) speed2 += -1;
            if (Y > 450) speed1 += -1;
            if (Y < 0) speed1 += 1;
            X += speed2;
            Y += speed1;
            if (speed1 > 1) speed1 = 1;
            if (speed2 > 1) speed2 = 1;
        }
    }
}

内容的提问来源于stack exchange，提问作者Blackout