XNA-像素碰撞Per-Pixel Collision(程式范例)

此範例也是運用鍵盤的上、下、左、右鍵來移動人物圖片，最主要就是看它與磚塊圖片碰撞的地方，會比矩形偵測來的準確。

程式範例:

view plaincopy to clipboardprint?

1. using System;   
2. using System.Collections.Generic;   
3. using System.Linq;   
4. using Microsoft.Xna.Framework;   
5. using Microsoft.Xna.Framework.Audio;   
6. using Microsoft.Xna.Framework.Content;   
7. using Microsoft.Xna.Framework.GamerServices;   
8. using Microsoft.Xna.Framework.Graphics;   
9. using Microsoft.Xna.Framework.Input;   
10. using Microsoft.Xna.Framework.Media;   
11. using Microsoft.Xna.Framework.Net;   
12. using Microsoft.Xna.Framework.Storage;   
13.   
14. namespace Per_Pixel_Collision   
15. {   
16.     public class Game1 : Microsoft.Xna.Framework.Game   
17.     {   
18.         GraphicsDeviceManager graphics;   
19.         SpriteBatch spriteBatch;   
20.         Texture2D block;   
21.         Texture2D person;   
22.         Vector2 blockpos;   
23.         Vector2 personpos;   
24.         Color[] blockTextureData;   
25.         Color[] personTextureData;   
26.         int movespeed = 3;   
27.         bool personHit = false;   
28.   
29.         public Game1()   
30.         {   
31.             graphics = new GraphicsDeviceManager(this);   
32.             Content.RootDirectory = "Content";   
33.         }   
34.   
35.         protected override void Initialize()   
36.         {   
37.             blockpos = new Vector2(0, 0);   
38.             personpos = new Vector2(50, 0);   
39.             base.Initialize();   
40.         }   
41.   
42.         protected override void LoadContent()   
43.         {   
44.             spriteBatch = new SpriteBatch(GraphicsDevice);   
45.             spriteBatch = new SpriteBatch(GraphicsDevice);   
46.             block = Content.Load<Texture2D>("Block");   
47.             blockTextureData = new Color[block.Width * block.Height];   
48.             block.GetData(blockTextureData);   
49.             person = Content.Load<Texture2D>("Person");   
50.             personTextureData = new Color[person.Width * person.Height];   
51.             person.GetData(personTextureData);   
52.         }   
53.   
54.         protected override void UnloadContent()   
55.         {   
56.         }   
57.   
58.         protected override void Update(GameTime gameTime)   
59.         {   
60.             KeyboardState keyboard = Keyboard.GetState();   
61.             if (keyboard.IsKeyDown(Keys.Up))   
62.             {   
63.                 personpos = new Vector2(personpos.X, personpos.Y - movespeed);   
64.             }   
65.             if (keyboard.IsKeyDown(Keys.Down))   
66.             {   
67.                 personpos = new Vector2(personpos.X, personpos.Y + movespeed);   
68.             }   
69.             if (keyboard.IsKeyDown(Keys.Left))   
70.             {   
71.                 personpos = new Vector2(personpos.X - movespeed, personpos.Y);   
72.             }   
73.             if (keyboard.IsKeyDown(Keys.Right))   
74.             {   
75.                 personpos = new Vector2(personpos.X + movespeed, personpos.Y);   
76.             }   
77.             Rectangle personRectangle = new Rectangle((int)personpos.X, (int)personpos.Y, person.Width, person.Height);   
78.             Rectangle blockRectangle = new Rectangle((int)blockpos.X, (int)blockpos.Y, block.Width, block.Height);   
79.             if (IntersectPixels(personRectangle,personTextureData,blockRectangle, blockTextureData ))   
80.             {   
81.                 personHit = true;   
82.             }   
83.             else  
84.             {   
85.                 personHit = false;   
86.             }   
87.             base.Update(gameTime);   
88.         }   
89.   
90.         protected override void Draw(GameTime gameTime)   
91.         {   
92.             if (personHit == true)   
93.                 GraphicsDevice.Clear(Color.Red);   
94.             else  
95.                 GraphicsDevice.Clear(Color.CornflowerBlue);   
96.             spriteBatch.Begin();   
97.             spriteBatch.Draw(block, blockpos, Color.White);   
98.             spriteBatch.Draw(person, personpos, Color.White);   
99.             spriteBatch.End();   
100.             base.Draw(gameTime);   
101.         }   
102.   
103.         public bool IntersectPixels(Rectangle rectangleA, Color[] dataA, Rectangle rectangleB, Color[] dataB)   
104.         {   
105.             int top = Math.Max(rectangleA.Top, rectangleB.Top);   
106.             int bottom = Math.Min(rectangleA.Bottom, rectangleB.Bottom);   
107.             int left = Math.Max(rectangleA.Left, rectangleB.Left);   
108.             int right = Math.Min(rectangleA.Right, rectangleB.Right);   
109.   
110.             for (int y = top; y < bottom; y++)   
111.             {   
112.                 for (int x = left; x < right; x++)   
113.                 {   
114.                     Color colorA = dataA[(x - rectangleA.Left) + (y - rectangleA.Top) * rectangleA.Width];   
115.                     Color colorB = dataB[(x - rectangleB.Left) + (y - rectangleB.Top) * rectangleB.Width];   
116.                     if ((colorA.A != 0 ) && (colorB.A != 0))   
117.                     {   
118.                         return true;   
119.                     }   
120.                 }   
121.             }   
122.             return false;   
123.         }   
124.     }   
125. }  

using System;using System.Collections.Generic;using System.Linq;using Microsoft.Xna.Framework;using Microsoft.Xna.Framework.Audio;using Microsoft.Xna.Framework.Content;using Microsoft.Xna.Framework.GamerServices;using Microsoft.Xna.Framework.Graphics;using Microsoft.Xna.Framework.Input;using Microsoft.Xna.Framework.Media;using Microsoft.Xna.Framework.Net;using Microsoft.Xna.Framework.Storage;namespace Per_Pixel_Collision{    public class Game1 : Microsoft.Xna.Framework.Game    {        GraphicsDeviceManager graphics;        SpriteBatch spriteBatch;        Texture2D block;        Texture2D person;        Vector2 blockpos;        Vector2 personpos;        Color[] blockTextureData;        Color[] personTextureData;        int movespeed = 3;        bool personHit = false;        public Game1()        {            graphics = new GraphicsDeviceManager(this);            Content.RootDirectory = "Content";        }        protected override void Initialize()        {            blockpos = new Vector2(0, 0);            personpos = new Vector2(50, 0);            base.Initialize();        }        protected override void LoadContent()        {            spriteBatch = new SpriteBatch(GraphicsDevice);            spriteBatch = new SpriteBatch(GraphicsDevice);            block = Content.Load<Texture2D>("Block");            blockTextureData = new Color[block.Width * block.Height];            block.GetData(blockTextureData);            person = Content.Load<Texture2D>("Person");            personTextureData = new Color[person.Width * person.Height];            person.GetData(personTextureData);        }        protected override void UnloadContent()        {        }        protected override void Update(GameTime gameTime)        {            KeyboardState keyboard = Keyboard.GetState();            if (keyboard.IsKeyDown(Keys.Up))            {                personpos = new Vector2(personpos.X, personpos.Y - movespeed);            }            if (keyboard.IsKeyDown(Keys.Down))            {                personpos = new Vector2(personpos.X, personpos.Y + movespeed);            }            if (keyboard.IsKeyDown(Keys.Left))            {                personpos = new Vector2(personpos.X - movespeed, personpos.Y);            }            if (keyboard.IsKeyDown(Keys.Right))            {                personpos = new Vector2(personpos.X + movespeed, personpos.Y);            }            Rectangle personRectangle = new Rectangle((int)personpos.X, (int)personpos.Y, person.Width, person.Height);            Rectangle blockRectangle = new Rectangle((int)blockpos.X, (int)blockpos.Y, block.Width, block.Height);            if (IntersectPixels(personRectangle,personTextureData,blockRectangle, blockTextureData ))            {                personHit = true;            }            else            {                personHit = false;            }            base.Update(gameTime);        }        protected override void Draw(GameTime gameTime)        {            if (personHit == true)                GraphicsDevice.Clear(Color.Red);            else                GraphicsDevice.Clear(Color.CornflowerBlue);            spriteBatch.Begin();            spriteBatch.Draw(block, blockpos, Color.White);            spriteBatch.Draw(person, personpos, Color.White);            spriteBatch.End();            base.Draw(gameTime);        }        public bool IntersectPixels(Rectangle rectangleA, Color[] dataA, Rectangle rectangleB, Color[] dataB)        {            int top = Math.Max(rectangleA.Top, rectangleB.Top);            int bottom = Math.Min(rectangleA.Bottom, rectangleB.Bottom);            int left = Math.Max(rectangleA.Left, rectangleB.Left);            int right = Math.Min(rectangleA.Right, rectangleB.Right);            for (int y = top; y < bottom; y++)            {                for (int x = left; x < right; x++)                {                    Color colorA = dataA[(x - rectangleA.Left) + (y - rectangleA.Top) * rectangleA.Width];                    Color colorB = dataB[(x - rectangleB.Left) + (y - rectangleB.Top) * rectangleB.Width];                    if ((colorA.A != 0 ) && (colorB.A != 0))                    {                        return true;                    }                }            }            return false;        }    }}

    24~25行宣告的變數是用來存放兩圖片RGBA的資訊。

    47~48行和50~51行運用讀取圖片完的寬和高來決定存放該圖所需要的陣列大小，並且取出兩圖片RGBA的資訊。

    79行判斷是否碰撞到的函數IntersectPixels需要傳入的參數為兩圖片的Rectange型態和兩圖片Color型態的資訊。

    105~108行則是找出兩圖片交集的矩形範圍是多少乘多少。

    110行迴圈最主要檢查交集圖片中每個點是否有碰撞到。

    114~115行得到交集圖片各點的RGBA的資料。

    116行運用圖片的alpha值來判斷是否有碰撞到，如果交集圖片的某點alpha值都不是0那就代表碰到了。

這樣表示沒有碰撞到

這樣才表示有碰撞到

    122行交集圖片沒有碰撞在一起的點，所以回傳false。

最後附上專案檔Per-Pixel Collision.rar