Android OpenGL 传递 OnTouch 事件值

Question

我有问题。我不知道如何将 OnTouch 方法中的值 x 和 y 传递给私有(private)最终类 MyRenderer 并更新 OnDrawFrame tex.draw(,x,y, ,,) 函数 x 和 y 值能够平移我想用手指移动的对象。

不胜感激~

public class Stage extends GLSurfaceView{

// Stage width and height
private float w, h;

// Screen width and height
private int screenWidth, screenHeight;

// Our native vertex buffer
private FloatBuffer vertexBuffer;

private Texture tex;

@Override
public boolean onTouchEvent(MotionEvent event) {
    final int action = event.getAction() & MotionEvent.ACTION_MASK;
    float x, y;
    int pointerIndex;
    int pointerId;

    if (action == MotionEvent.ACTION_DOWN) {
        pointerId = event.getPointerId(0);
        x = event.getX();
        y = event.getY();
        pointerIndex = 0;
    } else {
        pointerIndex = event.getActionIndex();
        pointerId = event.getPointerId(pointerIndex);
        x = event.getX(pointerIndex);
        y = event.getY(pointerIndex);
    }
    Log.v("this X", String.valueOf(x));
    Log.v("this Y", String.valueOf(y));

    return true;
}

public Stage(Context context, AttributeSet attrs) {
    super(context, attrs);
    setEGLConfigChooser(8, 8, 8, 8, 0, 0);
    setRenderer(new MyRenderer());
    setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY);
    float vertices[] = {
            -0.5f, -0.5f,  0.0f,  // 0. left-bottom
            0.5f, -0.5f,  0.0f,  // 1. right-bottom
            -0.5f,  0.5f,  0.0f,  // 2. left-top
            0.5f,  0.5f,  0.0f   // 3. right-top
    };

    ByteBuffer vbb = ByteBuffer.allocateDirect(vertices.length * 4);
    vbb.order(ByteOrder.nativeOrder());
    vertexBuffer = vbb.asFloatBuffer();
    vertexBuffer.put(vertices);
    vertexBuffer.position(0);

    tex = new Texture(R.drawable.kdk);

}

private final class MyRenderer implements GLSurfaceView.Renderer {

    public final void onDrawFrame(GL10 gl) {

        gl.glClear(GLES10.GL_COLOR_BUFFER_BIT);
        gl.glLoadIdentity();
        tex.prepare(gl, GL10.GL_CLAMP_TO_EDGE);
        gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuffer);
        tex.draw(gl, w / 2, h / 2, tex.getWidth(), tex.getHeight(), 0);

    }

    public final void onSurfaceChanged(GL10 gl, int width, int height) {
        gl.glClearColor(0, 0, 0, 0);

        if(width > height) {
            h = 600;
            w = width * h / height;
        } else {
            w = 600;
            h = height * w / width;
        }
        screenWidth = width;
        screenHeight = height;

        gl.glViewport(0, 0, screenWidth, screenHeight);
        gl.glMatrixMode(GL10.GL_PROJECTION);
        gl.glLoadIdentity();
        gl.glOrthof(0, w, h, 0, -1, 1);
        gl.glMatrixMode(GL10.GL_MODELVIEW);
        gl.glLoadIdentity();
    }

    public final void onSurfaceCreated(GL10 gl, EGLConfig config) {
        // Set up alpha blending
        gl.glEnable(GL10.GL_ALPHA_TEST);
        gl.glEnable(GL10.GL_BLEND);
        gl.glBlendFunc(GL10.GL_ONE, GL10.GL_ONE_MINUS_SRC_ALPHA);

        // We are in 2D. Why needs depth?
        gl.glDisable(GL10.GL_DEPTH_TEST);

        // Enable vertex arrays (we'll use them to draw primitives).
        gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);

        // Enable texture coordination arrays.
        gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);

        tex.load(getContext());
    }

}

}

其他编码

How to apply drag drop and scale in Android OpenGL ES

Answer 1

为此，您必须将 MyRenderer 属性添加到您的 Stage 类。

此解决方案可行，但可能不是最好的，因此请随意发表评论。

---

1. 您需要通过删除 final 语句来更改内部类 MyRenderer 的定义:

   EDIT :我不确定这个，因为 final class 会将其所有方法设置为 final 但可能不是属性。如果有人能回答，我会很乐意阅读。

   private final class MyRenderer implements GLSurfaceView.Renderer

   到

   private class MyRenderer implements GLSurfaceView.Renderer

---

1. 在您的舞台类(class)中:

   public class Stage extends GLSurfaceView {
   
       // Stage width and height
       private float w, h;
   
       ...
   
       // The renderer
       MyRenderer mRenderer;
   
       ...
   
       public Stage(Context context, AttributeSet attrs) {
   
           mRenderer = new MyRenderer();
   
           super(context, attrs);
           setEGLConfigChooser(8, 8, 8, 8, 0, 0);
   
           setRenderer(mRenderer);
   
           ...
       }
   }
   

---

1. 将 setter 添加到您的 MyRenderer 类:

   private class MyRenderer implements GLSurfaceView.Renderer {
   
       float xPos;
       float yPos;
   
       // ...
   
       public void setX(float x) {
           xPos = x;
       }
   
       public void setY(float y) {
           yPos = y;
       }
   
       public void setXY(float x, float y) {
           xPos = x;
           yPos = y;
       }
   }
   

---

1. 最后在 OnTouch 方法中设置这些值。

---

编辑:

设置 xPos 和 yPos 默认值:

private class MyRenderer implements GLSurfaceView.Renderer {

    float xPos;
    float yPos;

    boolean initialised = false;

    ...

    public final void onSurfaceChanged(GL10 gl, int width, int height) {

        if (!initialised) {
            xPos = width /2;
            yPos = height / 2;
            initialised = true;
        }

        ...
    }

    ...
}

---

编辑 2:

为避免竞争条件，请使用一个函数同时设置 X 和 Y 值。进入该方法时，它将使用传入参数的值创建临时变量。这将确保传递的 x 和 y 值来自同一事件。

private class MyRenderer implements GLSurfaceView.Renderer {

    float xPos;
    float yPos;

    // ...


    public void setXY(float x, float y) {
        xPos = x;
        yPos = y;
    }
}