Android OpenGL : IllegalArgumentException 기본 순서 직접 버퍼 사용

Question

Android 개발자! 문제가 있습니다. 내 안드로이드 애플 리케이션 OpenGL을 사용하여 몇 줄을 그려야합니다. 예를 들어 으로 시작하여 다시 작성했습니다. 그것은 IllegalArgumentException을 던집니다 : GLES20.glVertexAttribPointer를 호출 할 때 네이티브 오더 직접 버퍼를 사용해야합니다. 나는 내가 사용했던 예에서와 같이, 왜 그것을 nativeorder로 설정했는지 이해하지 못한다. 여기 내 전체 OpenGLRenderer 클래스는 다음과 같습니다 (I는 플로트 [] 매개 변수와 함께 두 번째 생성자를 사용하여이 클래스의 인스턴스를 생성 할 때),

public class OpenGLRenderer implements GLSurfaceView.Renderer { 

     final int COORDS_PER_VERTEX = 3; 
     final int NR_OF_LINES; 
     final int NR_OF_VERTECES; 
     final int VertexStride = COORDS_PER_VERTEX * 4; // 4 bytes per vertex 
     final int NR_OF_VERTECES_PER_LINE = 2; 
     final int BYTES_PER_VERTEX = 4; 


    private FloatBuffer bufferVertecesLines; 
    private float[] arrayVertecesLines; 
    //private FloatBuffer ColorBuffer;  
    // Set color with red, green, blue and alpha (opacity) values 
    float color[] = { 0.3f, 0.7f, 0.2f, 1.0f }; 

    private int GlProgram; 
    private int PositionHandle; 
    private int ColorHandle; 


    //SHADERS---------------------------------------------------------------------------------------------------------------------------- 
    private final String VertexShaderCode = 
      // This matrix member variable provides a hook to manipulate 
     // the coordinates of the objects that use this vertex shader 
     "uniform mat4 uMVPMatrix;" + 

     "attribute vec4 vPosition;" + 
     "void main() {" + 
     // the matrix must be included as a modifier of gl_Position 
     " gl_Position = uMVPMatrix * vPosition;" + 
     "}"; 

    private final String FragmentShaderCode = 
      "precision mediump float;" + 
     "uniform vec4 vColor;" + 
     "void main() {" + 
     " gl_FragColor = vColor;" + 
     "}"; 


    //CONSTRUCTOR---------------------------------------------------------------------------------------------------------------------------- 
    public OpenGLRenderer(FloatBuffer thisLineVertexBuffer, int numberoflines) 
    { 

     bufferVertecesLines = thisLineVertexBuffer; 
     NR_OF_VERTECES = numberoflines * 2; 
     NR_OF_LINES = numberoflines; 
     Log.v("Leen","mijn eigen logje - OpenGLRenderer - Constructor"); 
    } 

    public OpenGLRenderer(float[] thisLineVertexArray) 
    { 
     arrayVertecesLines = thisLineVertexArray; 
     NR_OF_VERTECES = thisLineVertexArray.length/COORDS_PER_VERTEX; 
     NR_OF_LINES = thisLineVertexArray.length/COORDS_PER_VERTEX/NR_OF_VERTECES_PER_LINE; 
    } 

    private void convertArrayToBuffer() 
    { 
     int NrOfBytes = NR_OF_LINES * NR_OF_VERTECES_PER_LINE * COORDS_PER_VERTEX * BYTES_PER_VERTEX; 
     // in voorbeeld: 
     // NrOfBytes =   2 *   2   *   3   *  4  = 48     

     ByteBuffer bb = ByteBuffer.allocate(NrOfBytes); 
     bb.order(ByteOrder.nativeOrder()); 
     bufferVertecesLines = bb.asFloatBuffer(); 
     bufferVertecesLines.put(arrayVertecesLines); 

    } 

    //--------------------------------------------------------------------------------------------------------------------------------------- 
    @Override 
    public void onSurfaceChanged(GL10 unused, int width, int height) 
    { 
     // Adjust the viewport based on geometry changes, 
     // such as screen rotation 
     GLES20.glViewport(0, 0, width, height); 
    } 

    //--------------------------------------------------------------------------------------------------------------------------------------- 
    @Override 
    public void onDrawFrame(GL10 arg0) 
    { 
     int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER, VertexShaderCode); 
     int fragmentShader = loadShader(GLES20.GL_FRAGMENT_SHADER, FragmentShaderCode); 

     GlProgram = GLES20.glCreateProgram();    // create empty OpenGL ES Program 
     GLES20.glAttachShader(GlProgram, vertexShader); // add the vertex shader to program 
     GLES20.glAttachShader(GlProgram, fragmentShader); // add the fragment shader to program 
     GLES20.glLinkProgram(GlProgram);     // creates OpenGL ES program executables 

     this.drawAllLines(); 
    } 

    //--------------------------------------------------------------------------------------------------------------------------------------- 
    @Override 
    public void onSurfaceCreated(GL10 unused, EGLConfig config) 
    { 
     GLES20.glClearColor(0.0f, 0.0f, 0.0f, 1.0f); 
    } 


    //--------------------------------------------------------------------------------------------------------------------------------------- 
    public static int loadShader(int type, String shaderCode){ 

     // create a vertex shader type (GLES20.GL_VERTEX_SHADER) 
     // or a fragment shader type (GLES20.GL_FRAGMENT_SHADER) 
     int shader = GLES20.glCreateShader(type); 

     // add the source code to the shader and compile it 
     GLES20.glShaderSource(shader, shaderCode); 
     GLES20.glCompileShader(shader); 

     return shader; 

    } 

    //--------------------------------------------------------------------------------------------------------------------------------------- 
    public void drawAllLines() 
    { 
     // Add program to OpenGL ES environment 
     GLES20.glUseProgram(GlProgram); 

     // get handle to vertex shader's vPosition member 
     PositionHandle = GLES20.glGetAttribLocation(GlProgram, "vPosition"); 

     // Enable a handle to the triangle vertices 
     GLES20.glEnableVertexAttribArray(PositionHandle); 

     // Prepare the Line coordinate data 
     // vertexstride = offset. 3 coordinaten per vertex * 4 bytes per vertex = 12 

     this.convertArrayToBuffer(); 

     GLES20.glVertexAttribPointer(PositionHandle, COORDS_PER_VERTEX, 
              GLES20.GL_FLOAT, false, 
              VertexStride, bufferVertecesLines); 

     // get handle to fragment shader's vColor member 
     ColorHandle = GLES20.glGetUniformLocation(GlProgram, "vColor"); 

     // Set color for drawing the triangle 
     GLES20.glUniform4fv(ColorHandle, 1, color, 0); 

     // Draw the triangle 
     GLES20.glDrawArrays(GLES20.GL_LINES, 0, NR_OF_VERTECES); 

     // Disable vertex array 
     GLES20.glDisableVertexAttribArray(PositionHandle); 

    } 

} 

Answer 1

private void convertArrayToBuffer() 
{ 
    int NrOfBytes = NR_OF_LINES * NR_OF_VERTECES_PER_LINE * COORDS_PER_VERTEX * BYTES_PER_VERTEX; 
    // in voorbeeld: 
    // NrOfBytes =   2 *   2   *   3   *  4  = 48     

    ByteBuffer bb = ByteBuffer.allocate(NrOfBytes); 
    bb.order(ByteOrder.nativeOrder()); 
    bufferVertecesLines = bb.asFloatBuffer(); 
    bufferVertecesLines.put(arrayVertecesLines); 
    bb.position(0);     //!!!!!!!!!!!!! 
    bufferVertecesLines.position(0);//!!!!!!!!!!!!! 
} 

Answer 2

확인을 발견했다. 나는 ByteBuffer.allocate() 메서드를 사용하지 않았지만 ByteBuffer.allocateDirect() 메서드를 사용했습니다. 이 조각은 예외를 던지지 않고 있습니다 :

private void convertArrayToBuffer() 
{ 
    int NrOfBytes = NR_OF_LINES * NR_OF_VERTECES_PER_LINE * COORDS_PER_VERTEX * BYTES_PER_VERTEX; 
    // in voorbeeld: 
    // NrOfBytes =   2 *   2   *   3   *  4  = 48     

    ByteBuffer bb = ByteBuffer.allocateDirect(NrOfBytes);  //!!!!!!!!!! 
    bb.order(ByteOrder.nativeOrder()); 
    bufferVertecesLines = bb.asFloatBuffer(); 
    bufferVertecesLines.put(arrayVertecesLines); 
    bb.position(0);     
    bufferVertecesLines.position(0); 
}