在Scala中再现Java OpenGL ES 2.0演示时出现奇怪的NullPointerEx

Main() called
libEGL warning: DRI2: failed to authenticate
Chosen GL capabilities: GLCaps[glx vid 0xae,fbc 0x17a: rgba 8/8/8/8,trans-rgba 0xff/ff/ff/ff,accum-rgba 16/16/16/16,dp/st/ms 24/0/0,dbl,mono,hw,GLProfile[GL2ES2/GL3.hw],on-scr[.]]
INIT GL IS: jogamp.opengl.gl4.GL4bcImpl
GL_VENDOR: NVIDIA Corporation 
GL_RENDERER: GeForce GTX 260/PCIe/SSE2
GL_VERSION: 3.3.0 NVIDIA 304.88

vertex Shader successfully compiled!
fragment Shader successfully compiled!
Exception in thread "main-Display-.x11_:0.0-1-EDT-1" java.lang.NullPointerException
at jogamp.newt.driver.x11.DisplayDriver.dispatchMessagesNative(DisplayDriver.java:103)
at jogamp.newt.DisplayImpl.dispatchMessages(DisplayImpl.java:540)
at jogamp.newt.DisplayImpl$5.run(DisplayImpl.java:463)
at jogamp.newt.DefaultEDTUtil$NEDT.run(DefaultEDTUtil.java:326)
X11Util.Display: Shutdown (JVM shutdown: true,open (no close attempt): 2/2,reusable 
(open,marked uncloseable): 0,pending (open in creation order): 2)
X11Util: Open X11 Display Connections: 2
X11Util: Open[0]: NamedX11Display[:0.0,0x7da0cab0,refCount 1,unCloseable false]
X11Util: Open[1]: NamedX11Display[:0.0,0x7da1bea8,unCloseable false]

它在异常上升之前成功渲染了1或几帧.当我从jswat调试器运行它时,没有出现预期.

我错过了一些非常明显的东西吗还有其他人遇到过与Scala和OpenGL ES 2.0类似的问题吗？

我正在使用Linux Mint 13和Ant来编译和运行代码.我的Scala代码是：

import javax.media.opengl.GL;
import javax.media.opengl.GL2ES2;
import javax.media.opengl.GLAutoDrawable;
import javax.media.opengl.GLEventListener;
import javax.media.opengl.GLProfile;
import javax.media.opengl.GLCapabilities;

import com.jogamp.newt.opengl.GLWindow;
import com.jogamp.opengl.util._;
import com.jogamp.common.nio.Buffers;

import java.nio.FloatBuffer;

// explicitly enabling postifx length operator:
import scala.language.postfixOps;

object RectangleDisplayer extends GLEventListener {
  val vertexShaderCode : Array[String] =
Array("#if __VERSION__ >= 130n","  #define attribute inn","  #define varying outn","#endifn","#ifdef GL_ESn","precision mediump float; n","precision mediump int; n","#endif n","uniform mat4    uniform_Projection; n","attribute vec4  attribute_Position;n","attribute vec4  attribute_Color;n","varying vec4    varying_Color;n","void main(void)n","{n","  varying_Color = attribute_Color;n","  gl_Position = uniform_Projection * attribute_Position;n","}n")

  val fragmentShaderCode : Array[String] =
Array("#if __VERSION__ >= 130n","  #define varying inn","  out vec4 mgl_FragColor;n","  #define texture2D texturen","  #define gl_FragColor mgl_FragColorn","precision mediump float;n","precision mediump int;n","varying vec4 varying_Color; n","  gl_FragColor = varying_Color;n","}n")

  var width : Int = 640
  var height : Int = 480

  // Scheinbar müssen in Scala alle Variablen zu Beginn initialisiert sein
  var shaderProgram : Int = 0
  var vertexShader : Int = 0
  var fragmentShader : Int = 0

  var vboHandles : Array[Int] = new Array[Int](2)
  var vboVertices : Int  = 0
  var vboColors : Int = 0

  var ModelViewProjectionMatrix_location : Int = 0


  def compileShaderIntoProgram(gl : GL2ES2,theShader : Int,shaderCode : Array[String]):Unit = {
    /*println("Shader code")
    for (l <- shaderCode) {
      print(l)
    }*/
    val lengths = shaderCode map(_ length)
    gl.glShaderSource(theShader,shaderCode.length,shaderCode,lengths,0)
    gl.glCompileShader(theShader)
  }

  def checkCompileStatus(gl : GL2ES2,theShader: Int,which : Int):Unit = {
    var compiled : Array[Int] = Array(1)
    gl.glGetShaderiv(theShader,GL2ES2.GL_COMPILE_STATUS,compiled,0)

    var shaderType : String = "vertex"
    if (which == 1) {
      shaderType = "fragment"
    }

    if (compiled(0) != 0) {
      println(shaderType + " Shader successfully compiled!")
    } else {
      var logLength = new Array[Int](1)
      var returnedLogLength = new Array[Int](1)

      gl.glGetShaderiv(theShader,GL2ES2.GL_INFO_LOG_LENGTH,logLength,0)

      var log : Array[Byte] = new Array[Byte](logLength(0))
      gl.glGetShaderInfoLog(theShader,logLength(0),returnedLogLength,log,0)

      println("Error compiling "+shaderType+" shader:")
      println(new String(log))

      System.exit(1)
    }
  }

  override def init(drawable : GLAutoDrawable):Unit = {
    val gl : GL2ES2 = drawable.getGL().getGL2ES2()

    println("Chosen GL capabilities: " + drawable.getChosenGLCapabilities())
    println("INIT GL IS: " + gl.getClass().getName())
    println("GL_VENDOR: " + gl.glGetString(GL.GL_VENDOR))
    println("GL_RENDERER: " + gl.glGetString(GL.GL_RENDERER))
    println("GL_VERSION: " + gl.glGetString(GL.GL_VERSION))

    // create,compile and attach shaders
    vertexShader = gl.glCreateShader(GL2ES2.GL_VERTEX_SHADER)
    fragmentShader = gl.glCreateShader(GL2ES2.GL_FRAGMENT_SHADER)

    compileShaderIntoProgram(gl,vertexShader,vertexShaderCode)
    checkCompileStatus(gl,0)

    compileShaderIntoProgram(gl,fragmentShader,fragmentShaderCode)
    checkCompileStatus(gl,1)

    shaderProgram = gl.glCreateProgram()
    gl.glAttachShader(shaderProgram,vertexShader)
    gl.glAttachShader(shaderProgram,fragmentShader)

    // Associate attribute ids with the attribute names inside the (vertex) shader
    gl.glBindAttribLocation(shaderProgram,"attribute_Position")
    gl.glBindAttribLocation(shaderProgram,1,"attribute_Color")

    gl.glLinkProgram(shaderProgram)

    ModelViewProjectionMatrix_location = gl.glGetUniformLocation(shaderProgram,"uniform_Projection")

    // forward compatibility with ES 3 by creating and binding a "Vertex Buffer Object"
    gl.glGenBuffers(2,vboHandles,0)
    vboColors = vboHandles(0)
    vboVertices = vboHandles(1)
  }

  override def display(drawable : GLAutoDrawable):Unit = {
    val gl : GL2ES2 = drawable.getGL().getGL2ES2()

    gl.glClearColor(0.0f,0.0f,1.0f,1.0f)
    gl.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT)

    gl.glUseProgram(shaderProgram)

    // Define projection matrix
    val model_view_projection : Array[Float] = 
      Array(1.0f,-1.0f,1.0f)

    gl.glUniformMatrix4fv(ModelViewProjectionMatrix_location,false,model_view_projection,0)

    // Define Vertex buffer
    val vertices : Array[Float] = Array(0.0f,0.0f)

    var fbVertices : FloatBuffer = Buffers.newDirectFloatBuffer(vertices)
    gl.glBindBuffer(GL.GL_ARRAY_BUFFER,vboVertices)

    var numBytes : Int = vertices.length*4
    gl.glBufferData(GL.GL_ARRAY_BUFFER,numBytes,fbVertices,GL.GL_STATIC_DRAW)
    fbVertices = null

    // Associate vertex attribute 0 with the last bound VBO
    gl.glVertexAttribPointer(0,// the vertex attribute
                              3,GL.GL_FLOAT,// normalized?
                              0,// stride
                              0 // The bound VBO data offset
                              )
    gl.glEnableVertexAttribArray(0)


    // Define color buffer
    val colors : Array[Float] = Array(1.0f,0.9f)
    var fbColors : FloatBuffer = Buffers.newDirectFloatBuffer(colors)
    gl.glBindBuffer(GL.GL_ARRAY_BUFFER,vboColors)
    numBytes = colors.length*4
    gl.glBufferData(GL.GL_ARRAY_BUFFER,fbColors,GL.GL_STATIC_DRAW)
    fbColors = null

    // Associate vertex attribute 1 with the last bound VBO
    gl.glVertexAttribPointer(1,4,// four positions used for each vertex
                            GL.GL_FLOAT,// normalized?
                            0,// stride
                            0 // the bound VBO data offset
                            )
    gl.glEnableVertexAttribArray(1)

    gl.glDrawArrays(GL.GL_TRIANGLES,3)

    gl.glDisableVertexAttribArray(0)
    gl.glDisableVertexAttribArray(1)

    gl.glDeleteBuffers(2,0)
  }

  override def reshape(drawable : GLAutoDrawable,x: Int,y: Int,z: Int,h: Int):Unit = {
      width = z
      height = h

      val gl : GL2ES2 = drawable.getGL().getGL2ES2()

      gl.glViewport(0,width,height)
  }

  override def dispose(drawable : GLAutoDrawable):Unit = {
    println("cleanup operations,disposing and detaching shaders")
    val gl : GL2ES2 = drawable.getGL().getGL2ES2()

    gl.glUseProgram(0)
    gl.glDetachShader(shaderProgram,vertexShader)
    gl.glDeleteShader(vertexShader)
    gl.glDetachShader(shaderProgram,fragmentShader)
    gl.glDeleteShader(fragmentShader)

    gl.glDeleteProgram(shaderProgram)
    System.exit(0)
  }

  def main(args: Array[String]): Unit = {
    println("Main() called")

    val caps : GLCapabilities = new GLCapabilities(GLProfile.get(GLProfile.GL2ES2))
    caps.setBackgroundOpaque(false)
    var glWindow : GLWindow = GLWindow.create(caps)

    // setup window parameters
    glWindow.setTitle("Scala GL ES test")
    glWindow.setSize(width,height)
    glWindow.setUndecorated(false)
    glWindow.setPointerVisible(true)
    glWindow.setVisible(true)

    // add this class as event listener to the window
    glWindow.addGLEventListener(this)
    var animator: Animator = new Animator()
    animator.add(glWindow)
    animator.start()
  }
}