private void readInputAndUpdateCamera(Camera cam) {
            int angle = mDemoKeyListener.getKeyDirectionAngle();
            if (mDemoKeyListener.getMoveState()) {
                switch(angle) {
                    case 0:
                        cam.x += 1;
                        break;
                    case 45:
                        cam.x += 1;
                        cam.y += 1;
                        break;
                    case 90:
                        cam.y += 1;
                        break;
                    case 135:
                        cam.y += 1;
                        cam.x -= 1;
                        break;
                    case -180:
                        cam.x -= 1;
                        break;
                    case -135:
                        cam.x -= 1;
                        cam.y -= 1;
                        break;
                    case -90:
                        cam.y -= 1;
                        break;
                    case -45:
                        cam.y -= 1;
                        cam.x += 1;
                        break;   
                }
            }
        }