从MainActivity onTouchEvent更改Renderer类中的Vertex

Question

我是android developpement的新手，这是我的问题，我怎样才能从MainActivity onTouchEvent中的类“Ship”中更改Vertex内部类“MainRenderer”？

这是我的代码： MainActivity.java：

package com.example.galaga2d;

import android.opengl.GLSurfaceView;
import android.os.Bundle;
import android.app.Activity;
import android.view.MotionEvent;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Toast;

public class MainActivity extends Activity {
    //private boolean isTouch = false;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Убираем тайтл приложения, тобишь делаем его FullScreen
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                        WindowManager.LayoutParams.FLAG_FULLSCREEN);

        // Создаём новый Surface и устанавливаем MainRenderer
        GLSurfaceView view = new GLSurfaceView(this);
        view.setRenderer(new MainRenderer());
        view.setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY);
        setContentView(view);

    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        int X = (int) event.getX();
        int Y = (int) event.getY();
        int upX = (int) event.getX();
        int upY = (int) event.getY();
        int downX = (int) event.getX();
        int downY = (int) event.getY();

        int eventaction = event.getAction();

        switch (eventaction) {

        case MotionEvent.ACTION_DOWN:

            Toast.makeText(this, "ВНИЗ "+"X: "+X+" Y: "+Y, Toast.LENGTH_SHORT).show();



            break;

        case MotionEvent.ACTION_MOVE:

            Toast.makeText(this, "ДВИЖЕНИЕ "+"X: "+X+" Y: "+Y, Toast.LENGTH_SHORT).show();

            break;

        case MotionEvent.ACTION_UP:

            Toast.makeText(this, "ВВЕРХ "+"X: "+X+" Y: "+Y, Toast.LENGTH_SHORT).show();

            break;

        }

        return true;

    }

}

和MainRenderer.java：

package com.example.galaga2d;

import java.nio.ByteBuffer;
import java.nio.FloatBuffer;
import java.nio.ByteOrder;
import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;
import android.opengl.GLSurfaceView.Renderer;


public class MainRenderer implements Renderer {
    public int playerSize = 0;
    private Ship playerShip = new Ship();
    private Astedoid enemyAstedoid = new Astedoid();

    @Override
    public void onSurfaceCreated(GL10 gl, EGLConfig config) {
        gl.glClearColor(1.0f, 0.0f, 0.0f, 1.0f); 
    }

    @Override
    public void onDrawFrame(GL10 gl) {
        gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
        playerShip.draw(gl);
        enemyAstedoid.draw(gl);
    }

    @Override
    public void onSurfaceChanged(GL10 gl, int width, int height) {
        gl.glViewport(0, 0, width, height);
        gl.glMatrixMode(GL10.GL_PROJECTION);
        gl.glLoadIdentity();
        gl.glOrthof(0, width, height, 0, 1, -1);
        gl.glMatrixMode(GL10.GL_MODELVIEW);
    }

// --------------------------------------------------------------------------------

    class Ship {
        public int health = 100;
        public int life = 3;

        public FloatBuffer ShipVertexBuffer;

        public float ShipVerticles[] = {
            5, 5,       // лево низ
            5, 10,      // лево вверх
            10, 5,      // право низ
            10, 10      // право вверх
        };
        public Ship() {
            ByteBuffer bb = ByteBuffer.allocateDirect(36);
            bb.order(ByteOrder.nativeOrder());
            ShipVertexBuffer = bb.asFloatBuffer();
            ShipVertexBuffer.put(ShipVerticles);
            ShipVertexBuffer.position(0);
        }

        public void draw(GL10 gl) {
              gl.glColor4f(0.0f, 1.0f, 0.0f, 1.0f);
              gl.glVertexPointer(2, GL10.GL_FLOAT, 0, ShipVertexBuffer);
              gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4);
        }

    }

    class Astedoid {
        public int health = 100;
        public int life = 3;

        public FloatBuffer AsteroidColorBuffer;
        public FloatBuffer AsteroidVertexBuffer;

        public float AsteroidVerticles[] = {
                25, 25,     // лево низ
                25, 30,     // лево вверх
                30, 25,     // право низ
                30, 30      // право вверх
            };
        public Astedoid() {
            ByteBuffer bb = ByteBuffer.allocateDirect(36);
            bb.order(ByteOrder.nativeOrder());
            AsteroidVertexBuffer = bb.asFloatBuffer();
            AsteroidVertexBuffer.put(AsteroidVerticles);
            AsteroidVertexBuffer.position(0);
        }

        public void draw(GL10 gl) {
              gl.glColor4f(0.0f, 0.0f, 1.0f, 1.0f);
              gl.glVertexPointer(2, GL10.GL_FLOAT, 0, AsteroidVertexBuffer);
              gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4);
        }

    }



// --------------------------------------------------------------------------------

}

我想这样做，创建一些像“objectSize”这样的变量，并在“case MotionEvent.ACTION_DOWN”上的主要活动onTouchEvent中给它一些值5，例如：

case MotionEvent.ACTION_DOWN:

objectSize = 5;

break;

我希望使用此变量来更改Ship类中MainRenderer中绘图对象的大小，例如：

public float ShipVerticles[] = {
    5*objectSize , 5*objectSize,
    5*objectSize, 10*objectSize,
    10*objectSize, 5*objectSize,    
    10*objectSize, 10*objectSize    
};

我怎么能这样做？ THX！