Sure. What you should end up having is code that looks like this:
Code:
// on our joystick the x values were inverted
int nTurn = ramping(128 - p1_x) + 127;
int nSpeed = ramping(p1_y - 127) + 127;
int left = (int)Limit_Mix(2000 + nSpeed + nTurn - 127);
int right = (int)Limit_Mix(2000 + nSpeed - nTurn + 127);
// pwm01/pwm02 corresponds to motor PWMs.
pwm01 = left;
pwm02 = 255 - right;
The nTurn and nSpeed will be adjusted based off your ramping.
the left and right values go through a typical 1-joystick function.
Then you just assign those values to your motors.