在android中順時針和逆時針方向旋轉一個正方形

Question

我使用OPENGL概念在android中創建了一些簡單的動畫，我該怎麼做是在時鐘和逆時針方向上旋轉一個正方形。我的意思是在特定時間將分別按時鐘和逆時針旋轉。

my main activity 


public class main extends Activity { 
/** Called when the activity is first created. */ 
@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    this.requestWindowFeature(Window.FEATURE_NO_TITLE); 
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, 
     WindowManager.LayoutParams.FLAG_FULLSCREEN); 
    GLSurfaceView view = new GLSurfaceView(this); 
    view.setRenderer(new OpenGLRenderer()); 
    setContentView(view); 
} 

}

OpenGLRenderer.java

public class OpenGLRenderer implements Renderer { 
private Square square; 
private float angle = 0; 

public OpenGLRenderer() { 
    // Initialize our square. 
    square = new Square(); 
} 

public void onSurfaceCreated(GL10 gl, EGLConfig config) { 
    // Set the background color to black (rgba). 
    gl.glClearColor(0.0f, 0.0f, 0.0f, 0.5f); 
    // Enable Smooth Shading, default not really needed. 
    gl.glShadeModel(GL10.GL_SMOOTH); 
    // Depth buffer setup. 
    gl.glClearDepthf(1.0f); 
    // Enables depth testing. 
    gl.glEnable(GL10.GL_DEPTH_TEST); 
    // The type of depth testing to do. 
    gl.glDepthFunc(GL10.GL_LEQUAL); 
    // Really nice perspective calculations. 
    gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_NICEST); 
} 

public void onDrawFrame(GL10 gl) { 
    // Clears the screen and depth buffer. 
    gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT); 
    // Replace the current matrix with the identity matrix 
    gl.glLoadIdentity(); 
    // Translates 10 units into the screen. 
    gl.glTranslatef(0, 0, -10); 

    // SQUARE 
    // Save the current matrix. 
    gl.glPushMatrix(); 
    // Rotate square counter-clockwise. 
    gl.glRotatef(angle, 0, 0, 1); 
    // Draw square .  
    square.draw(gl); 
    // Restore the last matrix. 
    gl.glPopMatrix(); 


    square.draw(gl);    

    // Restore to the matrix as it was before B. 
    gl.glPopMatrix(); 

    // Increse the angle. 
    angle++; 
} 

public void onSurfaceChanged(GL10 gl, int width, int height) { 
    // Sets the current view port to the new size. 
    gl.glViewport(0, 0, width, height); 
    // Select the projection matrix 
    gl.glMatrixMode(GL10.GL_PROJECTION); 
    // Reset the projection matrix 
    gl.glLoadIdentity(); 
    // Calculate the aspect ratio of the window 
    GLU.gluPerspective(gl, 45.0f, (float) width/(float) height, 0.1f, 
      100.0f); 
    // Select the modelview matrix 
    gl.glMatrixMode(GL10.GL_MODELVIEW); 
    // Reset the modelview matrix 
    gl.glLoadIdentity(); 
} 

}

Squar.java

public class Square { 
// Our vertices. 
private float vertices[] = { 
      -1.0f, 1.0f, 0.0f, // 0, Top Left 
      -1.0f, -1.0f, 0.0f, // 1, Bottom Left 
      1.0f, -1.0f, 0.0f, // 2, Bottom Right 
      1.0f, 1.0f, 0.0f, // 3, Top Right 
    }; 

// The order we like to connect them. 
private short[] indices = { 0, 1, 2, 0, 2, 3 }; 

// Our vertex buffer. 
private FloatBuffer vertexBuffer; 

// Our index buffer. 
private ShortBuffer indexBuffer; 

public Square() { 
    // a float is 4 bytes, therefore we multiply the number if 
    // vertices with 4. 
    ByteBuffer vbb = ByteBuffer.allocateDirect(vertices.length * 4); 
    vbb.order(ByteOrder.nativeOrder()); 
    vertexBuffer = vbb.asFloatBuffer(); 
    vertexBuffer.put(vertices); 
    vertexBuffer.position(0); 

    // short is 2 bytes, therefore we multiply the number if 
    // vertices with 2. 
    ByteBuffer ibb = ByteBuffer.allocateDirect(indices.length * 2); 
    ibb.order(ByteOrder.nativeOrder()); 
    indexBuffer = ibb.asShortBuffer(); 
    indexBuffer.put(indices); 
    indexBuffer.position(0); 
} 

/** 
* This function draws our square on screen. 
* @param gl 
*/ 
public void draw(GL10 gl) { 
    // Counter-clockwise winding. 
    gl.glFrontFace(GL10.GL_CCW); 
    // Enable face culling. 
    gl.glEnable(GL10.GL_CULL_FACE); 
    // What faces to remove with the face culling. 
    gl.glCullFace(GL10.GL_BACK); 

    // Enabled the vertices buffer for writing and to be used during 
    // rendering. 
    gl.glEnableClientState(GL10.GL_VERTEX_ARRAY); 
    // Specifies the location and data format of an array of vertex 
    // coordinates to use when rendering. 
    gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuffer); 

    gl.glDrawElements(GL10.GL_TRIANGLES, indices.length, 
      GL10.GL_UNSIGNED_SHORT, indexBuffer); 

    // Disable the vertices buffer. 
    gl.glDisableClientState(GL10.GL_VERTEX_ARRAY); 
    // Disable face culling. 
    gl.glDisable(GL10.GL_CULL_FACE); 
} 

}

這裏我在這個部分只

public class OpenGLRenderer implements Renderer { 
private Square square; 
private float angle = 0; 

public OpenGLRenderer() { 
    square = new Square(); 
} 
public void onSurfaceCreated(final GL10 gl, EGLConfig config) { 
    gl.glClearColor(0.0f, 0.0f, 0.0f, 0.5f); 
    gl.glShadeModel(GL10.GL_SMOOTH_LINE_WIDTH_RANGE); 
    gl.glClearDepthf(1.0f); 
    gl.glEnable(GL10.GL_DEPTH_TEST); 
    gl.glDepthFunc(GL10.GL_LEQUAL); 
    gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_NICEST); 
} 

public void onDrawFrame(final GL10 gl) { 

    Thread t = new Thread(new Runnable() {  

      public void run(){ 

         try{ 

          gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT); 
          gl.glLoadIdentity(); 
          gl.glTranslatef(0.0f, 4.9f,-9.3f); 
          //gl.glTranslatef(2.0f, 0.0f,0.0f); 
          gl.glPushMatrix(); 
          gl.glRotatef(-angle, 0, 0, 1); 

          gl.glScalef(1.0f, 1.0f, 1.0f); 
          square.draw(gl); 
          gl.glPopMatrix(); 
          angle++; 
           Thread.sleep(5000); 

         } 
         catch(InterruptedException e){ 
         } 
         // To do 
         gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT); 
         gl.glLoadIdentity(); 
         gl.glTranslatef(0.0f, 4.9f,-9.3f); 
         //gl.glTranslatef(2.0f, 0.0f,0.0f); 
         gl.glPushMatrix(); 
         gl.glRotatef(angle, 0, 0, 1); 

         //gl.glScalef(1.0f, 1.0f, 1.0f); 
         square.draw(gl);  
         gl.glPopMatrix(); 
         angle++; 
      } 
     }); 
     t.start(); 

    } 



public void onSurfaceChanged(GL10 gl, int width, int height) { 
    gl.glViewport(0, 0, width, height); 
    gl.glMatrixMode(GL10.GL_PROJECTION); 
    //glClearColor(5.0f, 6.0f, 0.0f, 5.5f); yellow 
    gl.glLoadIdentity(); 
    //GLU.gluPerspective(gl, 45.0f, (float) width/(float) height, 0.1f, 100.0f); 
    GLU.gluPerspective(gl, 80.0f, (float) width/(float) height, 8.0f, 10.0f); 
    gl.glMatrixMode(GL10.GL_MODELVIEW); 
    gl.glLoadIdentity(); 
} 

}在這兩個side..now問題旋轉代碼

Answer 1

public class Main extends Activity { 
private Runnable runnable; 

@Override 

public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    this.requestWindowFeature(Window.FEATURE_CONTEXT_MENU); 
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, 
    WindowManager.LayoutParams.FLAG_FULLSCREEN); 
    final GLSurfaceView view = new GLSurfaceView(this); 
    view.setRenderer(new OpenGLRenderer()); 
    setContentView(view); 

    runnable =new Runnable() { 

     @Override 
     public void run() { 
      // TODO Auto-generated method stub 
      try 
      { 


       view.setRenderer(new OpenGLRenderer()); 
       Thread.sleep(10); 
      finish(); 

      } 
      catch(Exception e) 
      { 
       e.printStackTrace(); 
      } 
     } 
    }; 
    try 
    { 
     Thread t=new Thread(null,runnable); 
     t.start(); 
     view.setRenderer(new OpenGLRenderer1()); 
     // Intent i=new Intent(this,OpenGLRenderer.class); 
     // startActivity(i); 
    } 
    catch(Exception e) 
    { 

    } 

     } 




} 

ü可以嘗試一下。