如何檢測與顏色的碰撞？

Question

如何檢測與我的地圖的碰撞？我想檢測與我的地圖和我的車相撞。掃描顏色。

在我的底圖上：軌道是灰色的，草地是白色的，牆壁是黃色的。

在我的上圖：軌道更現實，這是他們看到的。

我試過http://www.xnadevelopment.com/tutorials/theroadnottaken/theroadnottaken.shtml但是當我遇到碰撞時，代碼將無法工作。很多這些在XNA 4.0中不起作用，但它正是我可以使用的。

//This method checks to see if the Sprite is going to move into an area that does 
//not contain all Gray pixels. If the move amount would cause a movement into a non-gray 
//pixel, then a collision has occurred. 
private bool CollisionOccurred(int aMove) 
{ 

    //Calculate the Position of the Car and create the collision Texture. This texture will contain 
    //all of the pixels that are directly underneath the sprite currently on the Track image. 
    float aXPosition = (float)(-mCarWidth/2 + mCarPosition.X + aMove * Math.Cos(mCarRotation)); 
    float aYPosition = (float)(-mCarHeight/2 + mCarPosition.Y + aMove * Math.Sin(mCarRotation)); 
    Texture2D aCollisionCheck = CreateCollisionTexture(aXPosition, aYPosition); 

    //Use GetData to fill in an array with all of the Colors of the Pixels in the area of the Collision Texture 
    int aPixels = mCarWidth * mCarHeight; 
    Color[] myColors = new Color[aPixels]; 
    aCollisionCheck.GetData<Color>(0, new Rectangle((int)(aCollisionCheck.Width/2 - mCarWidth/2), (int)(aCollisionCheck.Height/2 - mCarHeight/2), mCarWidth, mCarHeight), myColors, 0, aPixels); 

    //Cycle through all of the colors in the Array and see if any of them 
    //are not Gray. If one of them isn't Gray, then the Car is heading off the road 
    //and a Collision has occurred 
    bool aCollision = false; 
    foreach (Color aColor in myColors) 
    { 
     //If one of the pixels in that area is not Gray, then the sprite is moving 
     //off the allowed movement area 
     if (aColor != Color.Gray) 
     { 
      aCollision = true; 
      break; 
     } 
    } 
    return aCollision; 
} 

第2部分

//Create the Collision Texture that contains the rotated Track image for determing 
//the pixels beneath the Car srite. 
private Texture2D CreateCollisionTexture(float theXPosition, float theYPosition) 
{ 
    //Grab a square of the Track image that is around the Car 
    graphics.GraphicsDevice.SetRenderTarget(0, mTrackRender); 
    graphics.GraphicsDevice.Clear(ClearOptions.Target, Color.Red, 0, 0); 

    mSpriteBatch.Begin(); 
    mSpriteBatch.Draw(mTrack, new Rectangle(0, 0, mCarWidth + 100, mCarHeight + 100), 
     new Rectangle((int)(theXPosition - 50), 
     (int)(theYPosition - 50), mCarWidth + 100, mCarHeight + 100), Color.White); 
    mSpriteBatch.End(); 

    graphics.GraphicsDevice.ResolveRenderTarget(0); 
    graphics.GraphicsDevice.SetRenderTarget(0, null); 

    Texture2D aPicture = mTrackRender.GetTexture(); 

    //Rotate the snapshot of the area Around the car sprite and return that 
    graphics.GraphicsDevice.SetRenderTarget(0, mTrackRenderRotated); 
    graphics.GraphicsDevice.Clear(ClearOptions.Target, Color.Red, 0, 0); 

    mSpriteBatch.Begin(); 
    mSpriteBatch.Draw(aPicture, new Rectangle((int)(aPicture.Width/2), (int)(aPicture.Height/2), 
     aPicture.Width, aPicture.Height), new Rectangle(0, 0, aPicture.Width, aPicture.Width), 
     Color.White, -mCarRotation, new Vector2((int)(aPicture.Width/2), (int)(aPicture.Height/2)), SpriteEffects.None, 0); 
    mSpriteBatch.End(); 

    graphics.GraphicsDevice.ResolveRenderTarget(0); 
    graphics.GraphicsDevice.SetRenderTarget(0, null); 

    return mTrackRenderRotated.GetTexture(); 
} 

Answer 1

我不建議對像素碰撞，因爲它贅述CPU和FPS殺手。 這裏有一些collsions，可以幫助你。但如果你真的需要像素碰撞，首先檢查rectange或任何其他碰撞檢測，然後如果相交，然後使用像素collsion預警...但我不建議，尤其是在快速遊戲。

這裏有一些衝突的功能，可以幫助您

POLYGON

http://www.codeproject.com/Articles/15573/2D-Polygon-Collision-Detection

CIRCLE：

int circlesColliding(int x1,int y1,int radius1,int x2,int y2,int radius2) 
{ 
    //compare the distance to combined radii 
    int dx = x2 - x1; 
    int dy = y2 - y1; 
    int radii = radius1 + radius2; 
    if ((dx * dx) + (dy * dy) < radii * radii) 
    { 
     return true; 
    } 
    else 
    { 
     return false; 
    } 
} 

圓矩形

bool intersects(CircleType circle, RectType rect) 
{ 
    circleDistance.x = abs(circle.x - rect.x); 
    circleDistance.y = abs(circle.y - rect.y); 

    if (circleDistance.x > (rect.width/2 + circle.r)) { return false; } 
    if (circleDistance.y > (rect.height/2 + circle.r)) { return false; } 

    if (circleDistance.x <= (rect.width/2)) { return true; } 
    if (circleDistance.y <= (rect.height/2)) { return true; } 

    cornerDistance_sq = (circleDistance.x - rect.width/2)^2 + 
         (circleDistance.y - rect.height/2)^2; 

    return (cornerDistance_sq <= (circle.r^2)); 
} 

Answer 2

我不知道如何解決你的具體情況，但我只是要推薦Riemers

我敢肯定，他的教程的一個有顏色檢測，我認爲它是他的2D坦克遊戲。

蒙娜麗莎