open GL ES1.0路径

Question

我是新来打开GL的，我只是想在屏幕上随机移动一个圆圈，当用户触摸圆圈时，我需要知道命中和错过。 这是我能够通过在线课程实现的。

render class: 


    public class HelloOpenGLES10Renderer implements Renderer { 
    private int points = 250; 
    private float vertices[] = { 0.0f, 0.0f, 0.0f }; 
    private FloatBuffer vertBuff; 
    public float x = 0.0f, y = 0.0f; 
    public boolean color = false; 
    boolean first = true; 

    @Override 
    public void onDrawFrame(GL10 gl) { 
     gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT); 
     gl.glMatrixMode(GL10.GL_MODELVIEW); 
     gl.glLoadIdentity(); 
     gl.glTranslatef(x, y, 0); 
     gl.glColor4f(1.0f, 1.0f, 1.0f, 0f); 
     gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertBuff); 
     gl.glEnableClientState(GL10.GL_VERTEX_ARRAY); 
     gl.glDrawArrays(GL10.GL_TRIANGLE_FAN, 0, points); 

    } 

    @Override 
    public void onSurfaceChanged(GL10 gl, int width, int height) { 
     Log.i("TAG", "change" + width + ":" + height); 
     gl.glViewport(0, 0, width, height); 
     float ratio = (float) width/height; 
     gl.glMatrixMode(GL10.GL_PROJECTION); 
     gl.glFrustumf(-ratio, ratio, -1, 1, 3, 7); 
     GLU.gluLookAt(gl, 0f, 0f, -5f, 0.0f, 0.0f, 0f, 0.0f, 1.0f, 0.0f); 
    } 

    @Override 
    public void onSurfaceCreated(GL10 gl, EGLConfig config) { 

     Log.i("TAG", "CREATE"); 
     gl.glClearColor(0.1f, 0.1f, 0.0f, 1.0f); 
     initShapes(); 

    } 

    private void initShapes() { 

     vertices = new float[(points + 1) * 3]; 
     for (int i = 3; i < (points + 1) * 3; i += 3) { 
      double rad = (i * 360/points * 3) * (3.14/180); 
      vertices[i] = (float) Math.cos(rad) * 0.10f; 
      vertices[i + 1] = (float) Math.sin(rad) * 0.10f; 
      vertices[i + 2] = 0; 
     } 
     ByteBuffer bBuff = ByteBuffer.allocateDirect(vertices.length * 4); 
     bBuff.order(ByteOrder.nativeOrder()); 
     vertBuff = bBuff.asFloatBuffer(); 
     vertBuff.put(vertices); 
     vertBuff.position(0); 

    } 

} 

Activity: 
    package com.example.opengltrail; 

    import java.util.Random; 

    import android.app.Activity; 
    import android.opengl.GLSurfaceView; 
    import android.os.Bundle; 
    import android.util.FloatMath; 
    import android.util.Log; 
    import android.view.MotionEvent; 
    import android.view.View; 
    import android.view.View.OnTouchListener; 

    public class MainActivity extends Activity implements OnTouchListener { 

    private GLSurfaceView mGLView; 
    float oldx = 0, oldy = 0; 
    private HelloOpenGLES10Renderer m; 
    ProgressDialogThread p; 
    ProgressDialogThread123 t; 
    boolean stop = true; 

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

     mGLView = new GLSurfaceView(this); 

     m = new HelloOpenGLES10Renderer(); 

     mGLView.setRenderer(m); 
     mGLView.setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY); 
     setContentView(mGLView); 

     mGLView.setOnTouchListener(this); 
     p = new ProgressDialogThread(); 

    } 

    @Override 
    protected void onPause() { 
     super.onPause(); 
     mGLView.onPause(); 
     p.stop(); 
     stop = false; 

    } 

    @Override 
    protected void onResume() { 
     super.onResume(); 
     mGLView.onResume(); 
     t = new ProgressDialogThread123(); 

     t.start(); 
     p.start(); 

    } 

    /** 
    * gets u the random number btw 0.0 to 1.0 
    */ 
    public float getmearandom() { 
     Random rng = new Random(); 
     float next = rng.nextFloat(); 
     Integer i = rng.nextInt(); 
     if (i % 2 == 0) 
      next = next * (-1); 
     return next; 
    } 

    class ProgressDialogThread123 extends Thread { 
     @Override 
     public void run() { 
      // TODO Auto-generated method stub 
      super.run(); 

      for (; stop;) { 
       p.run(); 
      } 

     } 
    } 

    class ProgressDialogThread extends Thread { 
     @Override 
     public void run() { 
      super.run(); 
      if (stop) { 

       try { 
        Thread.sleep(2000); 
       } catch (InterruptedException e) { 
        e.printStackTrace(); 
       } 

       m.x = getmearandom(); 
       m.y = getmearandom(); 
       Log.i("m.x=" + m.x + ":", "m.y=" + m.y); 
       mGLView.requestRender(); 
      } 

     } 
    } 

    @Override 
    public boolean onTouch(View v, MotionEvent event) { 

     float x = event.getX(); 
     float y = event.getY(); 
     float x1 = ((x * 2)/480); 
     float y1 = ((y * 2)/724); 
     x1 = -1 + x1; 
     y1 = -1 + y1; 
     if (y < 362) { 
      if (y1 > 0) 
       y1 = -y1; 
     } else if (y > 362) { 
      if (y1 < 0) 
       y1 = -y1; 
     } else { 
      y1 = 0; 
     } 

     if (x > 240) { 
      if (x1 < 0) 
       x1 = -x1; 

     } else if (x < 240) { 
      if (x1 > 0) 
       x1 = -x1; 
     } else { 
      x1 = 0; 
     } 

     Log.i("x1=" + x1, "y1=" + y1); 
     float d = (((m.x - x1) * (m.x - x1)) + ((m.y - y1) * (m.y - y1))); 

     float dd = FloatMath.sqrt(d); 
     if (dd <= 0.10f) { 
      m.color = true; 
      // mGLView.requestRender(); 
      Log.i("Tag", "Circle"); 
     } 
     // m.x += 0.10f; 

     return true; 
    } 
} 

Please anyone help me !! thanks in advance 

Answer 1

如果你只在二维图纸，我建议你松“视锥”和“的lookAt”与“邻”坐标替换它们：ortho(viewOrigin.x, viewOrigin.x + viewSize.width, viewOrigin.y + viewSize.height, viewOrigin.y, -1.0f, 1.0f)。这将使您的GL坐标系与您的视图坐标相同。至于圆形顶点，而是以1.0f的半径创建它们。现在绘制圆，在绘制调用之前，您只需“推”矩阵，转换为屏幕坐标（X，Y，.0f），按像素（R，R，1.0f）缩放到半径R，通话结束后的矩阵。现在来检查联系，如果圆圈被打：

`bool didHit = ((touch.x-cicrcleCenter.x)*(touch.x-cicrcleCenter.x) + 
       (touch.y-cicrcleCenter.y)*(touch.y-cicrcleCenter.y)) 
       < R*R`; 

注意，“viewOrigin”中的“邻”取决于你正在追赶触摸：如果您在同一赶上他们查看它可能会在（0,0）无论视图在哪里。这些坐标应该与您在视图的左上角和右下角按下时在触摸事件中收到的坐标相对应。

如果你真的需要用3d绘制，你将不得不使用平截头体，你需要得到你的投影矩阵的逆矩阵，从你的触摸中创建3d射线，然后检查命中是否与子弹相同你喜欢。