Dude.. Don't know exactly how it works but goddamnit it works! I'll see if i can figure it out. Anyway thanks a bunch!
Okay... turning code into English...
Prepare for a wall of text... which I hope will be simple enough to follow from beginning to end...
First... Your code (which as far as I can see, didn't work)...
label start: # Just a pre-defined label RenPy uses when you click "Start" from the main menu.
$MaxCash = 10 # Set "MaxCash" to a value of 10.
$Cash = max(min(Cash, MaxCash), 0) # Set "Cash" to a value of... Okay... this one is going to need breaking down more.
It's all about the brackets ( ).
So we're going to do : max ({something}, 0)
... So we need to figure out what {something} is.
{something} = min(Cash, MaxCash) # So... pick the smallest number between Cash and MaxCash.
PROBLEM #1 : You're trying to create a variable called "Cash" using a variable called "Cash". It doesn't exist yet and so it crashes.
No problem, let's change the code a bit...
Python:
$ MaxCash = 10
$ Cash = 5
$ Cash = max(min(Cash, MaxCash), 0)
Okay. So now we're doing min(Cash, MaxCash) # But Cash already had a value of 5 before trying this.
Effectively you're doing "Tell me which is lower... 5 or 10"... Spoiler alert... it's 5.
Alternatively if you did this instead:
Python:
$ MaxCash = 10
$ Cash = 20
$ Cash = max(min(Cash, MaxCash), 0)
... the answer would be 10. (Which is lower 20 or 10?).
So next, we go back to the max ({something}, 0)
We now know that (assuming $ Cash = 5) the result of the min ( ) is 5.
So now we're doing max (5, 0) which is obviously going to be 5.
So unless Cash ever ends up being negative, the first result will always be higher than 0.
What you end up with is something the means the result is always going to be between 0 and MaxCash.
So far, so good...
Then you go into:
Python:
label lbl1:
menu:
"+1":
$ Cash += 1
jump lbl1
"-1":
$ Cash -= 1
jump lbl1
Okay, so depending on the choice... you're either adding 1 or subtracting 1 from Cash.
PROBLEM #2 : This has nothing at all to do with what has already happened. Assuming Cash = 5 before making a choice of "+1"... then Cash = 6. But if Cash = 10 and you do "+1", then Cash would be 11 even though MaxCash is 10 - since nothing has told it not to.
You could however do something like:
Python:
label lbl1:
menu:
"+1":
$ Cash += 1
$ Cash = max(min(Cash, MaxCash), 0)
jump lbl1
"-1":
$ Cash -= 1
$ Cash = max(min(Cash, MaxCash), 0)
jump lbl1
This would change the value of Cash with one statement then immediately follow that up by applying the limits of "0 to MaxCash".
So now to the66 's solution....
Python:
default Cash = 0
default MaxCash = 10
init python:
def addCash(cash=0):
if not isinstance(cash, (int, float)):
return
renpy.store.Cash = min(max(Cash + cash, 0), MaxCash)
screen Cash:
text "Cash: [Cash]"
label start:
show screen Cash
menu lbl1:
"+1":
$ addCash(1)
"-1":
$ addCash(-1)
jump lbl1
Firstly he's setting up the variables Cash and MaxCash using
default instead of
$ . There are some technical reasons why... that honestly you don't need to know. Just take my word for it... it's a better way to do it.
Note:
default lines can go anywhere in the code. They are run as the game is starting up. You could put them as the last line of your code and they would still run first. By convention most devs would put them right at the top of their code. If it helps you... think of it as "create this variable with this default value". Yeah... right up there at the top.
Next he's using
def within
init python:.
What this is doing is creating a new function (think of it as a new command) called "addCash".
def addCash(cash=0): # create a new function "addCash"... Store anything I send to that new function in a variable called
cash. If I forget to pass a value to this new function, assume a value of zero.
Note: RenPy is case sensitive.
cash and
Cash are two entirely different things.
So next is...
Python:
if not isinstance(cash, (int, float)):
return
Long story short... this checks to make sure the value of
cash sent to
addCash() is a number. If it isn't,
return (effectively stop).
int is integer and just means whole numbers with no decimal places.
float is a floating point number, also known as scientific notation... and is just a number
WITH decimal places.
99.9% of the time, all variables are stored in a python object called "store", which itself is part of another object called "renpy". (at least by most devs in most RenPy games). So
renpy.store.Cash is just another way of referring to the variable
Cash. Problem is... all this is being set up while python is initializing... which is why you have to use the long arsed name instead of the shorter one you'd use practically everywhere else.
renpy.store.Cash = min(max(Cash + cash, 0), MaxCash) is doing the same max/min thing from earlier... but using the value passed along as
cash (note: the lower case version of the name, passed as a value to function) added to the original version of
Cash (the "real" variable "Cash").
So now, any time you do
$ addCash ( {number} ), it does all those commands that make up the definition
def of
addCash().
$ addCash(6) would add 6 to whatever the value of
Cash was. As long as the answer is between 0 and MaxCash.
$ addCash(1) would add 1 within those same limits.
$ addCash(-1) would add "-1"... which is effectively subtracting 1. Again, it can't drop below zero... because of the
max / min thing within
addCash().
$ addCash("fish") wouldn't do anything, because "fish" is neither an integer nor a floating point number (it's a string). But thankfully due to that clever check in the middle of the definition... it doesn't cause RenPy to crash and instead just does that
return
Next is a choices
menu: similar to how you coded it. If you didn't already notice... note that
menu: statements can also effectively be
label: statements too. It saves some typing, though not everyone knows it's even possible to merge the two into a single statement.
Python:
menu lbl1:
"+1":
$ addCash(1)
"-1":
$ addCash(-1)
jump lbl1
Hopefully that explains everything in a simple enough to follow. If not... fuck it. It works... Accept "it's magic" and move on.
Finally...
You don't have to use a
screen to show the values.
Just make it a line of dialogue like any other.
I tested it with:
Python:
"The value of Cash is [Cash], and MaxCash is [MaxCash]"
# no different than...
"You open the door"
You could even put it as part of your choices menu:
Python:
menu lbl1:
"The value of Cash is [Cash], and MaxCash is [MaxCash]"
"+1":
$ addCash(1)
"-1":
$ addCash(-1)
jump lbl1
Since if the very first line after
menu: isn't a choice... it's treated as dialogue.
A completely unnecessary change... but I'd be tempted to change things to this:
Edit: NOPE, NOPE, NOPE. What I wrote was complete bollocks. Forget I even mentioned it.
If you managed to read this far...
well done.
