Android opengl-es fast way to render text

I want to show some text in opengl ES. I have a 512*512 font texture (texture atlas), all letter is 32*32 pixel here.

My text length is about 400 char.

My algorithm

    opengl.setClearTransparentBGEnabled();

    float y2=0;
    float j =0;

    for (int i=0; i<text.length(); i++) {

        int ch  =(int)text.charAt(i);
        float x2=((float)j*16*scale/50);

        j++;
        if ((text.charAt(i)+"").equals("\n")) {
            y2+=(16*scale*2)/50;
            j=0;
            x2=0;
        }

        opengl.saveMatrix();
            Sprites.selectVertex("font"+name)
                    .setSprite(ch)
                    .translate(x-x2, y+y2, -9)
                    .scale(scale, scale, scale)
                    .rotate(90, 0, 0, 1)
                    .draw(true开发者_如何学C);
        opengl.loadMatrix();
    }

    opengl.setClearTransparentBGDisabled();

My only probleme, this method is very slow: after this i get 15-20 FPS.

What is the best way, to render texts in opengl-es dynamically?

That's far too much work to be doing per-frame.

I'd use the 2D APIs to Canvas.drawText() (or drawBitmap, if you're not using a real font) the 400 chars to a private Bitmap, and use that as my texture.

You are repeating a lot of work every frame and for every character in the text. You should calculate all of the vertex and triangle data for a given string, and then submit it to opengl in one batch. Reuse the data for as long as the string stays the same.