jogl quads问题

Question

我是使用OpenGL并尝试使用jogl的新手。我可以在没有问题的情况下绘制三角形，但是当我尝试绘制四边形（在许多教程中使用）时，eclipse保持告诉我GL.GL_QUADS无法解析。

gl.glBegin(GL.GL_QUADS); 

不知道我在做什么错。

谢谢，

import java.awt.Frame; 
import java.awt.event.WindowAdapter; 
import java.awt.event.WindowEvent; 
import javax.media.opengl.*; 
import javax.media.opengl.awt.GLCanvas; 
import com.jogamp.opengl.util.*; 

public class SimpleScene implements GLEventListener { 
    public static void main(String[] args) { 
     GLProfile glp = GLProfile.getDefault(); 
     GLCapabilities caps = new GLCapabilities(glp); 
     GLCanvas canvas = new GLCanvas(caps); 

     final Frame frame = new Frame("AWT Window Test"); 
     frame.setSize(300, 300); 
     frame.add(canvas); 
     frame.setVisible(true); 

     // by default, an AWT Frame doesn't do anything when you click 
     // the close button; this bit of code will terminate the program when 
     // the window is asked to close 
     frame.addWindowListener(new WindowAdapter() { 
      public void windowClosing(WindowEvent e) { 
       frame.dispose(); 
       System.exit(0); 
      } 
     }); 
    canvas.addGLEventListener(new SimpleScene()); 
    FPSAnimator animator = new FPSAnimator(canvas, 60); 
    animator.add(canvas); 
    animator.start(); 
    } 

    @Override 
    public void display(GLAutoDrawable arg0) { 
     update(); 
     render(arg0); 
    } 

    private void update() { 
     // TODO Auto-generated method stub 

    } 
    private void render(GLAutoDrawable drawable) { 
     GL2 gl = drawable.getGL().getGL2(); 
//  gl.glViewport(0, 0, 300, 300); //Possibly use to move around object 
     gl.glClear(GL.GL_COLOR_BUFFER_BIT); 

     gl.glPushMatrix(); 
     gl.glTranslatef(-1.5f,1.5f,0.0f);     // Move left 1.5 units, up 1.5 units, and back 8 units 

     gl.glBegin(GL.GL_TRIANGLES); 
     gl.glColor3f(10, 0, 0); 
// Begin drawing triangles 
     gl.glVertex3f(0.0f, 1.0f, 0.0f);     // Top vertex 
     gl.glVertex3f(-1.0f,-1.0f, 0.0f);     // Bottom left vertex 
     gl.glVertex3f(1.0f,-1.0f, 0.0f);     // Bottom right vertex 
     gl.glEnd();           // Finish drawing triangles 
     gl.glPopMatrix(); 


    } 

    @Override 
    public void dispose(GLAutoDrawable arg0) { 
     // TODO Auto-generated method stub 

    } 

    @Override 
    public void init(GLAutoDrawable arg0) { 
     // TODO Auto-generated method stub 

    } 

    @Override 
    public void reshape(GLAutoDrawable arg0, int arg1, int arg2, int arg3, 
      int arg4) { 
     // TODO Auto-generated method stub 

    } 
} 

Answer 1

的javax.media.opengl.GL接口包含的OpenGL共同的子集以GL 3，GL 2，GL ES 2.0和GL ES 1.x中，并且GL_QUADS不是部的子集。

如果使用javax.media.opengl.GL2，则会得到GL2.GL_QUADS。

Answer 2

这是GL2类中的静态常量。你需要调用：

gl.glBegin(GL2.GL_QUADS); 

不是：

gl.glBegin(GL.GL_QUADS);