Question

我对OpenGL很新，并且在使用ColorPointer函数和DrawArrays时遇到了一些麻烦......我似乎无法使用颜色渲染对象..当我使用glColor4f函数但是这个有效..我认为这与我如何构建我的颜色FloatBuffer有关...但是我似乎无法弄清楚这一点。

请查看我的一些代码并让我知道我在这里做错了什么......这也是我的第一个Stack Over Flow Post（：

// function draws the vertices in 3D space
public void draw(GL10 gl){
    // Enable client side access since arrays are store on client side heap
    // and OpenGl is considered server side
    gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
    gl.glEnableClientState(GL10.GL_NORMAL_ARRAY);
    gl.glEnable(GL10.GL_COLOR_ARRAY);
    gl.glEnable(GL10.GL_CULL_FACE); // Enable cull face
    gl.glCullFace(GL10.GL_BACK);    // Cull the back face (don't display)
    gl.glEnable(GL10.GL_COLOR_MATERIAL);

    gl.glVertexPointer(3, GL10.GL_FLOAT, 0, binaryStlParser.getVertices());
    gl.glNormalPointer(GL10.GL_FLOAT, 0, binaryStlParser.getNormalVectors());
    gl.glColorPointer(4, GL10.GL_FLOAT, 0, binaryStlParser.colours);
    gl.glDrawArrays(GL10.GL_TRIANGLES, 0, (binaryStlParser.getNumOfFacets() * 3));

    //gl.glShadeModel(GL10.GL_SHININESS);
    // disables access given from client side heap for OpenGL
    gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
    gl.glDisableClientState(GL10.GL_NORMAL_ARRAY);
    gl.glDisable(GL10.GL_COLOR_ARRAY);
    gl.glDisable(GL10.GL_CULL_FACE);
    gl.glDisable(GL10.GL_COLOR_MATERIAL);
}

来自另一个班级

numOfFacets = ByteBuffer.wrap(numberOfFacets).order(ByteOrder.nativeOrder()).getInt();

        // Allocate memory for the FloatBuffers since we now know the number of Facets
        // we use a ByteBuffer to ensure native ordering .........
        // * 3 for each vertex point in 3D (* 3) space. Size of float is 4 bytes
        vertices = ByteBuffer.allocateDirect((numOfFacets * 3 * 3) * 4)
                        .order(ByteOrder.nativeOrder()).asFloatBuffer();

        // * 3 for each coordinate in vector. Size of float is 4 bytes
        normalVectors = ByteBuffer.allocateDirect((numOfFacets * 3) * 4)
                        .order(ByteOrder.nativeOrder()).asFloatBuffer();

        // * 3 for each vertex point in 4D (* 4) RBGA space. Size of float is 4 bytes
        colours = ByteBuffer.allocateDirect((numOfFacets * 3 * 4) * 4)
                .order(ByteOrder.nativeOrder()).asFloatBuffer();

        for(int i = 0 ; i < numOfFacets*3; i++){
            colours.put(new float[] {0.0f, 1.0f, 0.0f, 0.5f});
        }
        colours.position(0);

Answer 1

我想出来了！只是想发布答案，这有助于其他人（：

愚蠢的错误...看起来像我在使用：

gl.glEnable（GL10.GL_COLOR_ARRAY）;

而不是

gl.glEnableClientState（GL10.GL_COLOR_ARRAY）;

FloatBuffers存储在客户端堆上，而我认为OpenGL被认为是服务器端。

GLColorPointer不能使用glDrawArrays

1 个答案: