opengl particle engine best practice?

I'm developing a simple game and I am currently switching from canvas to openGL. So my openGL experience is very limited. I'm trying to create a simple particle engine at thee moment and it works fine BUT with my current implementation I have to run this line on every draw() call [ vertexBuffer.put(vertices); ] and that is really slow.. Is there any way to get around this ?

code looks like this:

public class ParticlesTest { private float[] vertices; private short[] indices; private FloatBuffer vertexBuffer; private ShortBuffer indexBuffer; private ByteBuffer vbb; private int MAX_PARTICLES = 100; private ArrayList<Particle> particles; public ParticlesTest() { particles = new ArrayList<Particle>(); vertices = new float[MAX_PARTICLES*6*3]; indices = new short[MAX_PARTICLES*2]; short cnt = 0; for(int i = 0; i < 60; i++){ createParticle(); indices[cnt] = cnt; cnt++; indices[cnt] = cnt; cnt++; } vbb = ByteBuffer.allocateDirect(vertices.length * 4); vbb.order(ByteOrder.nativeOrder()); vertexBuffer = vbb.asFloatBuffer(); vertexBuffer.put(vertices); vertexBuffer.position(0); ByteBuffer ibb = ByteBuffer.allocateDirect(indices.length * 2); ibb.order(ByteOrder.nativeOrder()); indexBuffer = ibb.asShortBuffer(); indexBuffer.put(indices); indexBuffer.position(0); } private void createParticle() { Particle particle = new Particle(); particle.setSpeedX((float)(Math.random() * 20 - 10)); particle.setSpeedY((float)(Math.random() * 20 - 10)); particle.setX(100); particle.setY(100); particles.add(particle); } private void update(){ int len = particles.size(); for(int i = 0; i < len; i++){ Particle particle = particles.get(i); float oldX = particle.getX(); float oldY = particle.getY(); float speedX = particle.getSpeedX(); float speedY = particle.getSpeedY(); oldX += speedX; oldY += speedY; particle.setX(oldX); particle.setY(oldY); if(oldX < 0 || oldX > 400 || oldY < 0 || oldY > 600){ particles.remove(i); len--; } } if(len < MAX_PARTICLES){ createParticle(); } } private void translate(){ int vcount = 0; short icount = 0; int clen = vertices.length; for(int c = 0; c < clen; c++){ vertices[c] = 0f; } int len = particles.size(); for(int i = 0; i < len; i++){ Particle particle = particles.get(i); float oldX = particle.getX(); float oldY = particle.getY(); float speedX = particle.getSpeedX(); float speedY = particle.getSpeedY(); vertices[vcount] =oldX; vcount++; vertices[vcount] = oldY; vcount++; vertices[vcount] = 0f; vcount++; vertices[vcount] =oldX + speedX; vcount++; vertices[vcount] = oldY + speedY; vcount++; vertices[vcount] = 0f; vcount++; indices[icount] = icount; icount++; indices[icount] = icount; icount++; } } public void draw(GL10 gl,int w,int h) { update(); translate(); vertexBuffer.put(vertices); vertexBuffer.position(0); //GLFPS.VERTS = vertices.length; // rendering. gl.glEnableClientState(GL10.GL_VERTEX_ARRAY); gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuffer); // gl.glDrawElements(GL10.GL_LINE_STRIP, indices.length, GL10.GL_UNSIGNED_SHORT, indexBuffer); gl.glDrawElements(GL10.GL_LINES, indices.length, GL10.GL_UNSIGNED_SHORT, indexBuffer); // Disable the vertices buffer. gl.glDisableClientState(GL10.GL_VERTEX_ARRAY); } }