UnrealScript Game Programming Cookbook

Chapter 3

77

3. This next bit seems long-winded, but it is essentially one function (really, a state) that
   we are overriding from Pawn.uc. It is identical to the one found in that class, except
   that we are altering this bit of code:
   /* The only change for the side scrolling camera to this
   function. Update acceleration - pawn can only move forward and
   back now /
   NewAccel.Y = -1 PlayerInput.aStrafe DeltaTime 100
   PlayerInput.MoveForwardSpeed;

/** Set to 0 to not allow movement on the X or Z axes */

NewAccel.X = 0;

NewAccel.Z = 0;

This controls the movement of our pawn, based on the direction it is facing. Hitting

the left and right (or A and D) keys on the keyboard will now force your pawn to move

forward and back across the screen. Previously, you would have to hit the up and

down keys to make the pawn move forward and back.

Moreover, setting NewAccel to 0 on both the X and Z axes prevents the pawn from

strafing left and right. With our plane of movement locked, we can now create a true

side-scroller.

4. In the following code, we are overriding the state, PlayerWalking, found in the
   PlayerController.uc class. Our goal is to update the acceleration to allow only
   forward/back movement.
   /*****
   
   
   • Player movement, overriding the one found in
     PlayerController.UC
   
   
   • We are updating the acceleration to allow for only
     forward/back movement
     *****/
     state PlayerWalking
     {
     ignores SeePlayer, HearNoise, Bump;
   
   
   
   

function PlayerMove(floatDeltaTime)

{

localvector X,Y,Z, NewAccel;

localeDoubleClickDir DoubleClickMove;

localrotator OldRotation;

localbool bSaveJump;