颜色无法与大FloatBuffer与格式化X，Y，Z，R，G，B，A，X，Y，Z，R，

Question

在我的Android应用与OpenGL ES，我想用颜色画大行FloatBuffers将所有内容填充，与颜色一起协调，以获得更好的性能。我成功地在正确的坐标上绘制了线条，但颜色仍然是黑色的。我从http://www.learnopengles.com/android-lesson-one-getting-started开始。唯一的区别（我可以看到）是，他们使用三角形，我使用线条。所以我的FloatBuffers格式（X，Y，Z，R，G，B，A，X，Y，Z，R，G，B，A，X，Y，Z，R，G，B，A ,. ......所以每一行都只有一种颜色，所以颜色重复自己的起始点和终点（14个浮点数中有4个是多余的，我不在意） 这是相关代码我的渲染器类：

private void drawStuff() 
{ 
    int mPositionDataSize = 3; 
    int mColorDataSize = 4; 
    int mColorOffset = 3 ; 

    mPositionHandle = GLES20.glGetAttribLocation(mProgramHandle, "a_Position"); 
    mColorHandle = GLES20.glGetUniformLocation(mProgramHandle, "a_Color"); 
    mMVPMatrixHandle = GLES20.glGetUniformLocation(mProgramHandle, "u_MVPMatrix"); 

    //1. vertex positions: 
    thisBuffer.getVertexFloatBuffers().position(0); 
    GLES20.glVertexAttribPointer(mPositionHandle, mPositionDataSize, 
            GLES20.GL_FLOAT, false, 
            28, thisBuffer.getVertexFloatBuffers()); 
    GLES20.glEnableVertexAttribArray(mPositionHandle); 

    //2. colors: 
    thisBuffer.getVertexFloatBuffers().position(mColorOffset); 
    GLES20.glVertexAttribPointer(mColorHandle, mColorDataSize, 
            GLES20.GL_FLOAT, false, 
            28, thisBuffer.getVertexFloatBuffers()) ; 
    GLES20.glEnableVertexAttribArray(mColorHandle); 

    // 3. Apply the projection and view transformation 
    GLES20.glUniformMatrix4fv(mMVPMatrixHandle, 1, false, thisMVPmatrix, 0); 

    // 4. Draw the lines 
    GLES20.glDrawArrays(GLES20.GL_LINES, 0, thisBuffer.getNrOfVerteces()); 
} 

的想法，任何人

编辑：我着色器定义，在我onSurfaceCreated方法编译：

final String vertexShaderPerLayer = 
    "uniform mat4 u_MVPMatrix;  \n"  // A constant representing the combined model/view/projection matrix. 

    + "attribute vec4 a_Position;  \n"  // Per-vertex position information we will pass in. 
    + "attribute vec4 a_Color;  \n"  // Per-vertex color information we will pass in. 

    + "varying vec4 v_Color;   \n"  // This will be passed into the fragment shader. 

    + "void main()     \n"  // The entry point for our vertex shader. 
    + "{        \n" 
    + " v_Color = a_Color;   \n"  // Pass the color through to the fragment shader. 
              // It will be interpolated across the triangle. 
    + " gl_Position = u_MVPMatrix \n"  // gl_Position is a special variable used to store the final position. 
    + "    * a_Position; \n"  // Multiply the vertex by the matrix to get the final point in 
    + "}        \n"; // normalized screen coordinates. 

int vertexShaderHandle = GLES20.glCreateShader(GLES20.GL_VERTEX_SHADER); 
// Pass in the shader source. 
GLES20.glShaderSource(vertexShaderHandle, vertexShaderPerLayer); 


// Compile the shader. 
GLES20.glCompileShader(vertexShaderHandle); 

// Get the compilation status. 
final int[] compileStatus = new int[1]; 
GLES20.glGetShaderiv(vertexShaderHandle, GLES20.GL_COMPILE_STATUS, compileStatus, 0); 

// FRAGMENTSHADER 
final String fragmentShaderPerLayer = 
     "precision mediump float;  \n"  // Set the default precision to medium. We don't need as high of a 
               // precision in the fragment shader. 
     + "varying vec4 v_Color;   \n"  // This is the color from the vertex shader interpolated across the 
               // triangle per fragment. 
     + "void main()     \n"  // The entry point for our fragment shader. 
     + "{        \n" 
     + " gl_FragColor = v_Color;  \n"  // Pass the color directly through the pipeline. 
     + "}        \n"; 
int fragmentShaderHandlePerLayer = GLES20.glCreateShader(GLES20.GL_FRAGMENT_SHADER); 

// Pass in the shader source. 
GLES20.glShaderSource(fragmentShaderHandlePerLayer, fragmentShaderPerLayer); 

// Compile the shader. 
GLES20.glCompileShader(fragmentShaderHandlePerLayer); 

// PROGRAM STUFF 
mProgramHandle = GLES20.glCreateProgram(); 

// Bind the vertex shader to the program. 
GLES20.glAttachShader(mProgramHandle, vertexShaderHandle); 

// Bind the fragment shader to the program. 
GLES20.glAttachShader(mProgramHandle, fragmentShaderHandlePerLayer); 

// Bind attributes 
GLES20.glBindAttribLocation(mProgramHandle, 0, "a_Position"); 
GLES20.glBindAttribLocation(mProgramHandle, 1, "a_Color"); 

// Link the two shaders together into a program. 
GLES20.glLinkProgram(mProgramHandle); 

Answer 1

有一个在代码中的错误

mColorHandle = GLES20.glGetUniformLocation(mProgramHandle, "a_Color"); 

应该是：

mColorHandle = GLES20.glGetAttribLocation(mProgramHandle, "a_Color");