Adding a thruster speed boost on keypress
Today, we are going to modify our existing boost behavior by adding a thruster boost the player can use without powerups at any time by holding down the Left Shift key.
The first thing I’ve done is modify my current “_playerBoostSpeed” variable by renaming it to “_playerBoostPowerupSpeed” throughought the player script.
Tip: After changing the variable name, right click the variable name and select “Quick actions and refactorings”.
This will give you an option to rename the variable throughout the entire script automatically!
I then added _playerBoostSpeed back in to represent the player boost from thrusters when the player holds down the Left Shift key.
We default the speed to 1 as this will be used as a multiplier.
CalcMovement() Method
We simply add the “ * _playerBoostSpeed” line into our Translate call.
Next we modify the current “_speedBoostActive” variable by renaming it to “_speedBoostPowerupActive”.
TIP: Another way to rename all references to this variable at the same time is to right click the variable before changing the name and clicking “Rename” and then “Apply” on the popup window once you’ve renamed it.
Once we’ve renamed our original variable, we add in the now new variable of “_speedBoostActive”.
I know, jumping through a lot of hoops here but this naming convention makes more sense to me and hopefully to any future coders reading it (including ourselves when we’ve long forgot what we were doing here).
We’ll change our method names as well for clarity.
Just to be safe, let’s verify the OnTriggerEnter2D() method in our Powerup script and make sure we’ve updated the SpeedBoostActive() call to SpeedBoostPowerupActive().
CheckForThrusterBoost() method
We add our CheckForThrusterBoost() method.
Two things to note here.
First, the Boolean variable is not technically necessary, but could be useful in the future.
Second, we use Input.GetKey instead of Input.GetKeyDown.
I always find this a bit confusing, because in my mind, if you want to know if the user is constantly holding a button down, you’d add the word down to the end…
Well, Unity disagrees, so just be aware of the differences here.
“Returns true while the user holds down the key identified by name.”
“Returns true during the frame the user starts pressing down the key identified by name.”
Last, we modify our Update() method to call CheckForThrusterBoost() at the beginning of each frame update.
That’s it, run it and now the player will boost whenever they hold down the left shift key.
