Android使用float []作爲頂點導致OpenGL錯誤0x502

Question

我想在OpenGLES 2.0中使用浮點數組來代替FloatBuffer，但是當我這樣做時，我的glDrawArrays給出錯誤0x502或GL_INVALID_OPERATION。

我沒有得到這個錯誤，當我使用FloatBuffers時，一切正常。

我讀過這個錯誤通常是由程序沒有設置。我只使用一個着色器程序，並在一切初始化時設置它。

這裏是我的代碼

public class LineEngine { 
    private static final float[] IDENTIY = new float[16]; 
    private float[] mLinePoints; 
    private float[] mLineColors; 
    private int mCount; 

    public LineEngine(int maxLines) { 
     Matrix.setIdentityM(IDENTIY, 0); 

     mLinePoints = new float[maxLines * 2 * 4]; 
     mLineColors = new float[maxLines * 2 * 4]; 

     reset(); 
    } 

    public void addLine(float[] position, float[] color) { 
     int offset = mCount * 2 * 4; 
     System.arraycopy(position, 0, mLinePoints, offset, 8); 
     System.arraycopy(color, 0, mLineColors, offset, 4); 
     System.arraycopy(color, 0, mLineColors, offset + 4, 4); 

     mCount++; 
    } 

    public void reset() { 
     mCount = 0; 
    } 

    public void draw() { 
     if (mCount > 0) { 
      GraphicsEngine.setMMatrix(IDENTIY); 
      GraphicsEngine.setColors(mLineColors); 
      GraphicsEngine.setVertices4d(mLinePoints); 
      GraphicsEngine.disableTexture(); 
      GLES20.glDrawArrays(GLES20.GL_LINES, 0, mCount * 2); 

      int error = GLES20.glGetError(); 
      if (error != 0) 
       Log.e("OpenGL", "Draw " + error); // Prints error 1282 

      GraphicsEngine.disableColors(); 
      reset(); 
     } 
    } 
} 

此代碼工作正常，沒有錯誤

public class LineEngine { 
    private static final float[] IDENTIY = new float[16]; 
    private FloatBuffer mLinePoints; 
    private FloatBuffer mLineColors; 
    private int mCount; 

    public LineEngine(int maxLines) { 
     Matrix.setIdentityM(IDENTIY, 0); 

     ByteBuffer byteBuf = ByteBuffer.allocateDirect(maxLines * 2 * 4 * 4); 
     byteBuf.order(ByteOrder.nativeOrder()); 
     mLinePoints = byteBuf.asFloatBuffer(); 

     byteBuf = ByteBuffer.allocateDirect(maxLines * 2 * 4 * 4); 
     byteBuf.order(ByteOrder.nativeOrder()); 
     mLineColors = byteBuf.asFloatBuffer(); 

     reset(); 
    } 

    public void addLine(float[] position, float[] color) { 
     mLinePoints.put(position, 0, 8); 
     mLineColors.put(color, 0, 4); 
     mLineColors.put(color, 0, 4); 
     mCount++; 
    } 

    public void reset() { 
     mLinePoints.position(0); 
     mLineColors.position(0); 
     mCount = 0; 
    } 

    public void draw() { 
     if (mCount > 0) { 
      mLinePoints.position(0); 
      mLineColors.position(0); 
      GraphicsEngine.setMMatrix(IDENTIY); 
      GraphicsEngine.setColors(mLineColors); 
      GraphicsEngine.setVertices4d(mLinePoints); 
      GraphicsEngine.disableTexture(); 
      GLES20.glDrawArrays(GLES20.GL_LINES, 0, mCount * 2); 

      int error = GLES20.glGetError(); 
      if (error != 0) 
       Log.e("OpenGL", "Draw " + error); // no errors 

      GraphicsEngine.disableColors(); 
      reset(); 
     } 
    } 
} 

的相關GraphicsEngine代碼是在這裏

public static void setVertices4d(FloatBuffer vertices) { 
    GLES20.glVertexAttribPointer(aVertexHandle, 4, GLES20.GL_FLOAT, false, 
      16, vertices); 
    GLES20.glEnableVertexAttribArray(aVertexHandle); 
    mState.shape = -1; 
} 

public static void setVertices4d(float[] vertices) { 
    GLES20.glVertexAttrib4fv(aVertexHandle, vertices, 0); 
    GLES20.glEnableVertexAttribArray(aVertexHandle); 
    mState.shape = -1; 
} 

public static void setColors(FloatBuffer colors){ 
    GLES20.glVertexAttribPointer(aColor, 4, GLES20.GL_FLOAT, false, 
      16, colors); 
    GLES20.glEnableVertexAttribArray(aColor); 
    GLES20.glUniform1i(GraphicsEngine.uEnableColors, 1); 
} 

public static void setColors(float[] colors){ 
    GLES20.glVertexAttrib4fv(aColor, colors, 0); 
    GLES20.glEnableVertexAttribArray(aColor); 
    GLES20.glUniform1i(GraphicsEngine.uEnableColors, 1); 
} 

我不想使用FloatBuffers因爲它們比浮點數組更慢。

Answer 1

您沒有選擇，只能使用FloatBuffers代碼。

您的setVertices4d方法需要float[]已損壞，您無法以此方式使用glVertexAttrib4fv。 glVertexAttrib4只指定單個頂點，並且使用版本僅將屬性的值作爲數組傳遞給該單個頂點，但不會設置類似於指針函數的頂點數組。