Question

所以我是Android游戏开发的新手，我有4个黄色的CircleMapObjects我使用InputProcessor来管理触摸/点击事件。现在在touchDown（）方法中我想要的是当在游戏中触摸/点击圆圈时（圆圈内的任何地方）然后它应该改变为说绿色。我正在使用libgdx框架并且是框架的新手，我遇到了Actor但是我发现它通过查看API来绘制矩形形状。

InputHandler类：

public class InputHandler implements InputProcessor {

private Spot spot;


public InputHandler(Spot spot){

    this.spot = spot;
}

@Override
public boolean keyDown(int keycode) {
    // TODO Auto-generated method stub
    return false;
}

@Override
public boolean keyUp(int keycode) {
    // TODO Auto-generated method stub
    return false;
}

@Override
public boolean keyTyped(char character) {
    // TODO Auto-generated method stub
    return false;
}

@Override
public boolean touchDown(int screenX, int screenY, int pointer, int button) {

    float distanceX = (float) Math.sqrt(Math.pow((spot.getSpots()[0].getCircle().x - (screenX)), 2));
    float distanceY = (float) Math.sqrt(Math.pow((spot.getSpots()[0].getCircle().y - (screenY)), 2));

    //Below is for testing purposes not to do with touching a circle but touching a particular 
    //region on the screen
    //float distance = distanceX + distanceY;
//  System.out.println(distanceX);
//  System.out.println(distanceY);
//  System.out.println(spot.getSpots()[0].isVisible() + "" + "Color: " + spot.getSpots()[0].getColor());
    System.out.println("CLICKED: " + " x: " + screenX + " y: " + screenY);

            if (screenX > 45 && screenY < 431)
            {
                spot.getSpots()[0].setColor(Color.RED);
                System.out.println("This works!");
            }


    return true;
}

@Override
public boolean touchUp(int screenX, int screenY, int pointer, int button) {
    // TODO Auto-generated method stub
    return false;
}

@Override
public boolean touchDragged(int screenX, int screenY, int pointer) {
    // TODO Auto-generated method stub
    return false;
}

@Override
public boolean mouseMoved(int screenX, int screenY) {
    // TODO Auto-generated method stub
    return false;
}

@Override
public boolean scrolled(int amount) {
    // TODO Auto-generated method stub
    return false;
}

}

Spot类：

public class Spot {

private float x;
private float y;
private float radius;

//Use CircleMapObject instead?
private CircleMapObject spot_1, spot_2, spot_3, spot_4;
private CircleMapObject spotList[];

private float elapsedTime;
private int index;



public Spot(float x, float y, float radius){
    this.x = x;
    this.y = y;
    this.radius = radius;

    //each spot initialised
    spot_1 = new CircleMapObject(x,y,radius);
    spot_2 = new CircleMapObject(x, y-228,radius);
    spot_3 = new CircleMapObject(x+440,y,radius);
    spot_4 = new CircleMapObject(x+440,y-228,radius);

    //spot list initialised
    spotList = new CircleMapObject[4];

    //adding the spots to the spotlist
    spotList[0] = spot_1;
    spotList[1] = spot_2;
    spotList[2] = spot_3;
    spotList[3] = spot_4;

    elapsedTime = 0.0f;
    index = 0;


}

public void update(float delta){


}

}

设置inputHandler的Gamescreen：

public class GameScreen implements Screen {


private GameWorld world;
private GameRenderer render;

private Spot spot;


public GameScreen(){

    float screenWidth = Gdx.graphics.getWidth();
    float screenHeight = Gdx.graphics.getHeight();
    System.out.println("Screen width: " + screenWidth + ", " + "Screen height: " + screenHeight);
    float gameWidth = 136;
    float gameHeight = screenHeight / (screenWidth / gameWidth);

    world = new GameWorld();
    render = new GameRenderer(world);

    Gdx.input.setInputProcessor(new InputHandler(world.getSpot()));

}

...（GameScreen类中还有更多代码，但这是此类中使用的InputHandler的唯一引用。这也适用于其余代码。）

Answer 1

为了简化这一点，您只需要检查圆与触摸位置的距离是否小于检测命中的圆的半径。简单的矢量数学可以解决问题，我们水平和垂直地计算距离，使用毕达哥拉斯（A²+B²=C²）我们可以计算最终距离。

distance = √(circleX - (touchX))² + ((circleY) - touchY)²

if (Math.abs(distance) < circleRadius)
{
    //Touch within circle...
}

Libgdx有一些vector functions来计算距离。

if (touchVector.dst(circleOrigin) < circleRadius)
{
    //Touch within circle...
}

当我谈论touchVector时，你需要使用Vector2并将你的坐标放入。当处理位置，方向，速度等时，你应该使用Vector2类或Vector3用于3D环境。

Vector2 touchVector = new Vector2(x,y);
float distance = touchVector.dst(new Vector2(circleOriginX, circleOriginY));

如何检查是否触摸了圆形以将动作应用于形状，例如改变形状的颜色或更新分数？

1 个答案: