Android и OpenGL треугольники не отображаются - PullRequest
0 голосов
/ 03 января 2011

Я пытаюсь заставить приложение Android нарисовать простой код OpenGL, который я нашел здесь. http://www.iphonemobilephones.com/opengl-es-from-the-ground-up-part-4-let-there-be-light.html На мой взгляд, он не хочет рисовать для любой фигуры, где у меня несколько треугольников. Если у меня есть один треугольник, он отлично работает.

Я надеялся, что кто-то, кто знает больше об OpenGL, будет так любезен, чтобы увидеть, есть ли какие-либо ошибки, которые очевидны сразу.

Спасибо, MJ

    gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
    gl.glEnableClientState(GL10.GL_NORMAL_ARRAY);       
    gl.glEnableClientState(GL10.GL_COLOR_ARRAY);

    gl.glClearColor(0.0f, 1.0f, 0.0f, 1.0f);       
    gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
    gl.glRotatef(1.0f, 1.0f, 1.0f, 0f);        


    float vertices[]= {
            0f, -0.525731f, 0.850651f,             // vertices[0]
            0.850651f, 0f, 0.525731f,              // vertices[1]
            0.850651f, 0f, -0.525731f,             // vertices[2]
            -0.850651f, 0f, -0.525731f,            // vertices[3]
            -0.850651f, 0f, 0.525731f,             // vertices[4]
            -0.525731f, 0.850651f, 0f,             // vertices[5]
            0.525731f, 0.850651f, 0f,              // vertices[6]
            0.525731f, -0.850651f, 0f,             // vertices[7]
            -0.525731f, -0.850651f, 0f,            // vertices[8]
            0f, -0.525731f, -0.850651f,            // vertices[9]
            0f, 0.525731f, -0.850651f,             // vertices[10]
            0f, 0.525731f, 0.850651f               // vertices[11]
        };

    FloatBuffer v = FloatBufferFromFloatArray( vertices, 12*3);

    short icosahedronFaces[] = {
        1, 2, 6,
        1, 7, 2,
        3, 4, 5,
        4, 3, 8,
        6, 5, 11,
        5, 6, 10,
        9, 10, 2,
        10, 9, 3,
        7, 8, 9,
        8, 7, 0,
        11, 0, 1,
        0, 11, 4,
        6, 2, 10,
        1, 6, 11,
        3, 5, 10,
        5, 4, 11,
        2, 7, 9,
        7, 1, 0,
        3, 9, 8,
        4, 8, 0,
    };

    ShortBuffer i = ShortBufferFromShortArray( icosahedronFaces, 60 );

    float normals[] = {
        0.000000f, -0.417775f, 0.675974f,
        0.675973f, 0.000000f, 0.417775f,
        0.675973f, -0.000000f, -0.417775f,
        -0.675973f, 0.000000f, -0.417775f,
        -0.675973f, -0.000000f, 0.417775f,
        -0.417775f, 0.675974f, 0.000000f,
        0.417775f, 0.675973f, -0.000000f,
        0.417775f, -0.675974f, 0.000000f,
        -0.417775f, -0.675974f, 0.000000f,
        0.000000f, -0.417775f, -0.675973f,
        0.000000f, 0.417775f, -0.675974f,
        0.000000f, 0.417775f, 0.675973f
    };

    FloatBuffer n = FloatBufferFromFloatArray( normals, 3*12 );

    float colors[] = {
        1.0f, 0.0f, 0.0f, 1.0f,
        1.0f, 0.5f, 0.0f, 1.0f,
        1.0f, 1.0f, 0.0f, 1.0f,
        0.5f, 1.0f, 0.0f, 1.0f,
        0.0f, 1.0f, 0.0f, 1.0f,
        0.0f, 1.0f, 0.5f, 1.0f,
        0.0f, 1.0f, 1.0f, 1.0f,
        0.0f, 0.5f, 1.0f, 1.0f,
        0.0f, 0.0f, 1.0f, 1.0f,
        0.5f, 0.0f, 1.0f, 1.0f,
        1.0f, 0.0f, 1.0f, 1.0f,
        1.0f, 0.0f, 0.5f, 1.0f
    };

    FloatBuffer c = FloatBufferFromFloatArray( colors, 4*12 );

    gl.glVertexPointer( 12,  GL10.GL_FLOAT, 0, v);
    gl.glColorPointer(4, GL10.GL_FLOAT, 0, c);
    gl.glNormalPointer(GL10.GL_FLOAT, 0, n);        
    gl.glDrawElements(GL10.GL_TRIANGLES, 60, GL10.GL_UNSIGNED_SHORT, i);         


// helper functions below as well as the surface created function

private ShortBuffer ShortBufferFromShortArray( short[] array, int length )
{
    ByteBuffer vbb = ByteBuffer.allocateDirect(length * 4);
    vbb.order(ByteOrder.nativeOrder());
    ShortBuffer fb = vbb.asShortBuffer();

    fb.put(array);
    fb.position(0);

    return fb;
}

private FloatBuffer FloatBufferFromFloatArray( float[] array, int length )
{
    ByteBuffer vbb = ByteBuffer.allocateDirect(length * 4);
    vbb.order(ByteOrder.nativeOrder());
    FloatBuffer fb = vbb.asFloatBuffer();

    fb.put(array);
    fb.position(0);

    return fb;
}

@Override
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
    //
    //gl.glEnable(GL10.GL_DEPTH_TEST);
    //gl.glMatrixMode(GL10.GL_PROJECTION);

    gl.glMatrixMode(GL10.GL_MODELVIEW);

    gl.glEnable(GL10.GL_LIGHTING);
    gl.glEnable(GL10.GL_LIGHT0);

    // Define the ambient component of the first light
    float[] light0Ambient = {0.1f, 0.1f, 0.1f, 1.0f};        
    gl.glLightfv(gl.GL_LIGHT0, gl.GL_AMBIENT, FloatBufferFromFloatArray(light0Ambient, 4));

    // Define the diffuse component of the first light
    float[] light0Diffuse = {0.7f, 0.7f, 0.7f, 1.0f};
    gl.glLightfv(gl.GL_LIGHT0, gl.GL_DIFFUSE, FloatBufferFromFloatArray(light0Diffuse, 4));

    // Define the specular component and shininess of the first light
    float[] light0Specular = {0.7f, 0.7f, 0.7f, 1.0f};
    float light0Shininess = 0.4f;
    //gl.glLightfv(gl.GL_LIGHT0, gl.GL_SPECULAR, FloatBufferFromFloatArray(light0Specular, 4));        

    // Define the position of the first light
    float[] light0Position = {1.0f, 0.0f, 0.0f, 0.0f};
    gl.glLightfv(gl.GL_LIGHT0, gl.GL_POSITION, FloatBufferFromFloatArray(light0Position, 4)); 

    // Define a direction vector for the light, this one points correct down the Z axis
    float[] light0Direction = {0.0f, 0.0f, -1.0f};
    //gl.glLightfv(gl.GL_LIGHT0, gl.GL_SPOT_DIRECTION, FloatBufferFromFloatArray(light0Direction, 3));

    // Define a cutoff angle. This defines a 90° field of vision, since the cutoff
    // is number of degrees to each side of an imaginary line drawn from the light's
    // position along the vector supplied in GL_SPOT_DIRECTION above
    //gl.glLightf(gl.GL_LIGHT0, gl.GL_SPOT_CUTOFF, 180.0f);

    //gl.glEnable(GL10.GL_CULL_FACE);
    // which is the front? the one which is drawn counter clockwise
    //gl.glFrontFace(GL10.GL_CCW);
    // which one should NOT be drawn
    //gl.glCullFace(GL10.GL_BACK);

    initShape();

    //gl.glScalef(1.0f, 1.0f, 1.0f);
}

1 Ответ

2 голосов
/ 03 января 2011

Недопустимо передавать 12 в качестве первого аргумента glVertexPointer

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