Drawing text as textures on squares does not show anything

I'm new to OpenGL and I'm developing an Augmented-reality application for Android.

Until now, I was drawing white squares, perpendicular to the camera, pointing the user to the direction where a "Point of interest" would be.

Now, I'm trying to show some text into the squares.

I've read a lot and it seems that creating a texture with the text is the most direct and easiest approach, so I'm creating the textures as soon as I get data of the Points of interest and stick them to their squares. For that, I use bitmaps.

Let's see some code. Within my onDrawFrame method, I do something like this:

public void onDrawFrame(GL10 gl) {

        // Get sensors matrix
                ...


        //Clear Screen And Depth Buffer
        gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);

        // Load remapped matrix
        gl.glMatrixMode(GL10.GL_MODELVIEW);



        // List of Points of interest (modified when some data is downloaded)
        synchronized (poiList) {

            if(mNewData){  // True if new data has been dowloaded)
                if(textures != null)  // Delete old textures
                    gl.glDeleteTextures(textures.length, textures, 0);

                textures = loadGLTexture(gl, soapPoiList.getPoiList());
                mNewData = false;
            }

            int i = 0;
            // Iterate the list
            for (PointOfInterest c : poiList) {

                         gl.glLoadIdentity();
                 gl.glLoadMatrixf(remappedRotationMatrix, 0);

                 // Get bearing
                             ...

                 // Place polygon in the right place
                 gl.glRotatef(-bearing, 0, 0, 1);
                 gl.glTranslatef(0, ICONS_SIZE_RATIO, 0);

                         // Actually draws the polygon with text
                 c.draw(gl, textures[i]);

                 i++;
            }
        }
    }

Where loadGLTextures is:

protected int[] loadGLTexture(GL10 gl, List<PointOfInterest> l){
    int res[] = new int[l.size()];
    gl.glGenTextures(res.length, res, 0);
    int i = 0;

    for(PointOfInterest p : l) {
        Bitmap bitmap = Bitmap.createBitmap(256, 256, Bitmap.Config.RGB_565);
        bitmap.eraseColor(Color.BLACK);

        Canvas canvas = new Canvas(bitmap);

        Paint textPaint = new Paint();
        textPaint.setTextSize(35);
        textPaint.setFakeBoldText(true);
        textPaint.setAntiAlias(true);
        textPaint.setARGB(255, 255, 255, 255);
        // Draw the text centered
        canvas.drawText(Float.toString(p.getDinstanceToOrigin()) + " m.", 10,35, textPaint);

        // Bind the texture to our array
        gl.glBindTexture(GL10.GL_TEXTURE_2D, res[i]);

        //  Create Nearest Filtered Texture
        gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_LINEAR);
        gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_LINEAR);

        gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_S, GL10.GL_CLAMP_TO_EDGE);
        gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_T, GL10.GL_CLAMP_TO_EDGE);

        GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, bitmap, 0);

        bitmap.recycle();

        i++;
    }
    return res;
}

It basically creates a bitmap for each Point of Interest, and generate a texture with it. The texture will be applied over a white square later, as it is shown in this class:

    public class PointOfInterest {

        // MEMBERS ----------------------------------------------------------------
            ....
            ....

        // OpenGL necessary variables
        /** The buffer holding the vertices */
        private FloatBuffer vertexBuffer;

        /** The initial vertex definition */
        private float vertices[] = { 
                                    -1.0f, 0.0f, -1.0f, //Bottom Left   V1
                                    -1.0f, 0.0f,  1.0f, //Top Left      V2
                                     1.0f, 0.0f, -1.0f, //Bottom Right  V3
                                     1.0f, 0.0f,  1.0f, //Top Right     V4
                                   };

        private FloatBuffer textureBuffer;
        private float texture[] = {
                                    0.0f, 0.0f,     // V1
                                    1.0f, 0.0f,     // V3
                                    0.0f, 1.0f,     // V2
                                    1.0f, 1.0f      // V4
        };

        // CONSTRUCTORS -----------------------------------------------------------

        public PointOfInterest(Location originLocation){
            currentLocation = originLocation;

            mPoiLocation = new Location(LocationManager.GPS_PROVIDER);

            ByteBuffer byteBuf = ByteBuffer.allocateDirect(vertices.length * 4);
            byteBuf.order(ByteOrder.nativeOrder());

            vertexBuffer = byteBuf.asFloatBuffer();
            vertexBuffer.put(vertices);
            vertexBuffer.position(0);

            byteBuf = ByteBuffer.allocateDirect(texture.length * 4);
            byteBuf.order(ByteOrder.nativeOrder());

            textureBuffer = byteBuf.asFloatBuffer();
            textureBuffer.put(texture);
            textureBuffer.position(0);
        }

        // PUBLIC METHODS ---------------------------------------------------------

        public void draw(GL10 gl, int textureId){
            // Bind the previously generated texture
            gl.glBindTexture(GL10.GL_TEXTURE_2D, textureId);

            // Point to our buffers
            gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
            gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);

            // set the colour for the square
            //gl.glColor4f(0.0f, 0.1f, 0.0f, 0.5f);

            //Set the face rotation
            gl.glFrontFace(GL10.GL_CW);

            //Point to our vertex buffer
            gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuffer);
            gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, textureBuffer);

            //Draw the vertices as triangle strip
            gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, vertices.length / 3);

            //Disable the client state before leaving
            gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
            gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
        }

        ....
        ....
}

I have tried to map the texture as it is taught here and here with no success. I really don't know what to do to get some letters drawn on the squares and am really lo开发者_高级运维st here... Maybe the text is being drawn on the other face of the square, maybe the textures are not being generated... I don't know.

Any kind of help would be very appreciated.

Okay, I had forgotten to enable texture mapping. You can do that within any method that uses the GL10 object. I prefer to do it within the draw method of my objects, so any other object is not affected by the texture. It's as simple as this (just changed 2 lines, the ones that say NEW!!):

public void draw(GL10 gl, int textureId){
    gl.glEnable(GL10.GL_TEXTURE_2D);    //NEW !!! Enable Texture Mapping

    // Bind the previously generated texture
    gl.glBindTexture(GL10.GL_TEXTURE_2D, textureId);

    // Point to our buffers
    gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
    gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);

    // set the colour for the square
    //gl.glColor4f(0.0f, 0.1f, 0.0f, 0.5f);

    //Set the face rotation
    gl.glFrontFace(GL10.GL_CW);

    //Point to our vertex buffer
    gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuffer);
    gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, textureBuffer);

    //Draw the vertices as triangle strip
    gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, vertices.length / 3);

    //Disable the client state before leaving
    gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
    gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY);

    gl.glDisable(GL10.GL_TEXTURE_2D);   ////NEW !!! Disable texture mapping
}