碰撞檢測，矩形在拐角處相交

Question

我正在嘗試學習碰撞檢測在android中的工作原理，並且是使用Android矩形實現的。

我需要能夠檢測到第二個矩形的頂部，左側和底部壁的碰撞，但是問題是第一個矩形能夠通過左上角直接進入第二個矩形。

下面是我正在使用的代碼的片段：

GameView2類的摘錄：

private Shape s1 = new Shape(this, Color.BLACK, 0, 100, 50, 50);
private Shape s2 = new Shape(this, Color.BLUE, 200, 100, 50, 50);

@Override
protected void onDraw(Canvas canvas){
    super.onDraw(canvas);

    this.drawBackground(canvas);
    s1.onDraw(canvas);
    s2.onDraw(canvas);
    s1.x+=s1.vx;
    s1.y+=s1.vy;

    //left wall collision
    if(s1.x+s1.width==s2.x  &&  s1.y+s1.height > s2.y  &&  s1.y < s2.y + s2.height){
        s1.vx = 0;
    }

    //top wall
    else if(s1.y+s1.height==s2.y  &&  s1.x+s1.width > s2.x  &&  s1.x < s2.x+s2.width){
        s1.vy = 0;
    }

    else{
        s1.vx = 2;
    }
}

形狀等級：

public class Shape{
    protected GameView2 game_view;
    protected int x;
    protected int y;
    protected int vx;
    protected int vy;
    protected int width;
    protected int height;
    protected int color;

    public Shape(GameView2 game_view, int color, int x, int y, int width, int height) {
        this.game_view = game_view;
        this.x = x;
        this.y = y;
        this.vx = 2;
        this.vy = 0;
        this.width = width;
        this.height = height;
        this.color = color;
    }

    public Rect getRect(){
        return new Rect(x, y, x + width, y + height);
    }

    public void onDraw(Canvas canvas){

        Paint paint = new Paint();
        Rect rec = new Rect(x, y, x + width, y + height);
        paint.setColor(color);
        paint.setStyle(Paint.Style.FILL);
        canvas.drawRect(rec, paint);        
    }
}

Answer 1

這是一個非常簡單的算法，用於兩個矩形之間的碰撞。

x1 + width1 <x2 || x2 + width2 <x1 || y1 + height1 <y2 || y2 + height2

如果以上陳述為真，則不會發生沖突。 否則，兩個矩形相互碰撞。