Android OpenGLES device issue

Question

I have recently started learning OpenGLES with Android. I am creating a livewallpaper with GLWallpaperService class with rendering.

The problem with Android simulator is able to display animation but while testing with Android device (HTC Incredible S) FPS remains around 45-50 but screen remains blank.

Here is the code snippet !!

onDrawFrame

public void onDrawFrame(GL10 gl) {
    float currLevel = curve[(MAX_CURVE_POINT_NO + curveStart - 1)
            % MAX_CURVE_POINT_NO];
    if (!isCreated) {
        isCreated = !isCreated;
        _spriteVerices = BufferFactory.createFloatBuffer(8);
        spriteTextCordinates = BufferFactory.createShortBuffer(8);
    }
    _spriteVerices.put(spriteVerices);
    spriteTextCordinates.put(spriteTextCordinatesArray);
    _spriteVerices.position(0);
    spriteTextCordinates.position(0);

    gl.glBlendFunc(GL10.GL_SRC_ALPHA, GL10.GL_ONE_MINUS_SRC_ALPHA);
    gl.glEnable(GL10.GL_BLEND);
    gl.glEnable(GL10.GL_DEPTH_TEST);
    gl.glEnable(GL10.GL_LINE_SMOOTH);
    gl.glEnable(GL10.GL_POINT_SMOOTH);

    gl.glMatrixMode(GL10.GL_PROJECTION);
    gl.glLoadIdentity();
    gl.glOrthof(-1.0f, 1.0f, -1.5f, 1.5f, -1.0f, 1.0f);
    gl.glMatrixMode(GL10.GL_MODELVIEW);
    gl.glLoadIdentity();

    gl.glScalef(0.8f, 0.8f, 1.0f);
    gl.glTranslatef(-0.2f, 0, 0);

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

    gl.glEnable(GL10.GL_TEXTURE_2D);

    gl.glVertexPointer(2, GL10.GL_FLOAT, 0, _spriteVerices);
    gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
    gl.glTexCoordPointer(2, GL10.GL_SHORT, 0, spriteTextCordinates);
    gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);

    gl.glPushMatrix();
    gl.glTranslatef(1.0f, currLevel, -0.01f);
    gl.glColor4f(0.0f, 0.5f, 1.0f, 1.0f);
    gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4);
    gl.glPopMatrix();

    curve[curveStart] = ekgMap[curveStart]; // ((rand()%32768)/32768.0)*0.4-0.2;
    curveStart = (curveStart + 1) % MAX_CURVE_POINT_NO;
}

onSurfaceChanged

public void onSurfaceChanged(GL10 gl, int width, int height) {

            gl.glViewport(0, 0, width, height);
    gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
    gl.glMatrixMode(GL10.GL_PROJECTION);
    gl.glLoadIdentity();
    GLU.gluPerspective(gl, 60f, (float) width / (float) height, 1f, 100f);

    gl.glMatrixMode(GL10.GL_MODELVIEW);
    gl.glLoadIdentity();

    gl.glMatrixMode(GL10.GL_MODELVIEW);
    gl.glTranslatef(0, 0, -5);
    gl.glRotatef(30f, 1, 0, 0);

    gl.glEnable(GL10.GL_LIGHTING);
    gl.glEnable(GL10.GL_RESCALE_NORMAL);
    gl.glEnableClientState(GL10.GL_NORMAL_ARRAY);

    // Set the color of light bouncing off of surfaces to respect the
    // surface color
    gl.glEnable(GL10.GL_COLOR_MATERIAL);

    setupLightSources(gl);

    // Turn on a global ambient light. The "Cosmic Background Radiation", if
    // you will.
    float[] ambientLightRGB = { 0.3f, 0.3f, 0.3f, 1.0f };
    gl.glLightModelfv(GL10.GL_LIGHT_MODEL_AMBIENT, ambientLightRGB, 0);
}

onSurfaceCreated

public void onSurfaceCreated(GL10 gl, EGLConfig config) {

    this.loadTexture(gl, mContext, R.drawable.dot);

    gl.glClearDepthf(1f);
    gl.glEnable(GL10.GL_DEPTH_TEST);
    gl.glDepthFunc(GL10.GL_LEQUAL);

    // Turn on culling, so OpenGL only draws one side of the primitives
    gl.glEnable(GL10.GL_CULL_FACE);
    gl.glFrontFace(GL10.GL_CCW);
    gl.glCullFace(GL10.GL_BACK);
    gl.glBlendFunc(GL10.GL_SRC_ALPHA, GL10.GL_ONE_MINUS_SRC_ALPHA);
    gl.glEnable(GL10.GL_BLEND);
    gl.glEnable(GL10.GL_DEPTH_TEST);
    gl.glEnable(GL10.GL_LINE_SMOOTH);
    gl.glEnable(GL10.GL_POINT_SMOOTH);
}

Thanks,

Answer 1

If you are sure you set up open gl right, then more often then not the problem is where you are drawing. You could be drawing out of the range of the view. Be very careful with your translates and such.

You also may need to flip your poly, I know I have had that issue before where you are looking right through it because your drawing is facing its back to you.

when I did this my draw looked very similar to this

*  This is where you draw the screen, called every auto onDraw Loop pass
         * ************************************************************************/
        //Log.d("Game", "Render");
        gl.glViewport(0, 0, Screen.SCREEN_WIDTH, Screen.SCREEN_HEIGHT);
        gl.glClear(GL10.GL_COLOR_BUFFER_BIT);
        gl.glMatrixMode(GL10.GL_PROJECTION);
        gl.glLoadIdentity();
        gl.glOrthof(0, Screen.WIDTH_SCALE, 0, Screen.HEIGHT_SCALE, 1, -1);

        //gl.gltranslatef(x,y,z) will translate everything drawn here after by that amount, effectively scrolling the view.

        gl.glEnable(GL10.GL_BLEND);
        gl.glBlendFunc(GL10.GL_SRC_ALPHA, GL10.GL_ONE_MINUS_SRC_ALPHA);


        gl.glEnable(GL10.GL_TEXTURE_2D);
        MeshRect mRect; // this holds all of our rectangles

        gl.glMatrixMode(GL10.GL_MODELVIEW);
        gl.glLoadIdentity();
        /***************** so this is how it goes for rendering any object ****************************************************
        ball.Update(deltaTime);      //first update the object
        gl.glPushMatrix();
        gl.glLoadIdentity();
            gl.glTranslate(x,y,z);
            texture.bind(gl, Texture.TEXTURE_BALL2);       //then bind the texture we would like to use
            mRect = new MeshRect(ball.getMyRect());       //then create the rectangle at (0,0,0)
            mRect.Draw(GL10.GL_TRIANGLES, gl);       //Finally tell that rectangle to draw
        gl.glPopMatrix();
        ***********************************************************************************************************************

of course this is ortho, and yours looks to be 3d, but the basics should be near the same.