I'm not sure how to use renpy.checkpoint.

[suihakei]

I would like to create the function to go back to one previous choice.

I found renpy.checkpoint and ran it immediately.
https://www.renpy.org/doc/html/save_loa ... checkpoint

However, if I run the code as follows, the game will stop.

Code: Select all

human "hey"

$ roll_forward = renpy.roll_forward_info()
$ rv = ui.interact(roll_forward=roll_forward)
$ renpy.checkpoint(rv)		# stop game here

human "hello"

Why is this?
Isn't renpy.checkpoint for temporary data saving and rollback?

I would like to learn more about RenPy.
If you know anything about it, please let me know.

Thank you.

[Ocelot]

What is the purpose of ui.interact here? Have you actually placed anything for player to interact with? Why are you using renpy.checkpoint in one-line Python statement? FYI, there are 6 calls to renpy.checkpoint in snippet you provided, because every RenPy statement implicitely calls one.

[Johan]

I would like to create the function to go back to one previous choice.

Uhm... without knowing the actual code of your game, I can only say that if you want to go back to a previous menu choice, you could just rollback to it. No need for any complicated stuff.

Or you could jump to it, but only if you give the menu a name.

Code: Select all

menu the_name_of_doom:

  "A":
    "go back and try again"
    jump the_name_of_doom
  
  "B":
    "you did it!"
    jump random_scene
 

I'm not sure if this is what you are looking for though ^^;;

[suihakei]

What is the purpose of ui.interact here? Have you actually placed anything for player to interact with? Why are you using renpy.checkpoint in one-line Python statement? FYI, there are 6 calls to renpy.checkpoint in snippet you provided, because every RenPy statement implicitely calls one.

Thank you for your answer.
I used these codes as they were written in the official documentation.
However, I do not know how this works.

[Ocelot]

Generally, renpy.checkpoint is only nessesary if you are doing something really complex not involving RenPy script and want to be able to rollback inside of it.
Almost every RenPy statement will do rollback management itself so nothing extra is nessesary.

[suihakei]

I would like to create the function to go back to one previous choice.

Uhm... without knowing the actual code of your game, I can only say that if you want to go back to a previous menu choice, you could just rollback to it. No need for any complicated stuff.

Or you could jump to it, but only if you give the menu a name.

Code: Select all

menu the_name_of_doom:

  "A":
    "go back and try again"
    jump the_name_of_doom
  
  "B":
    "you did it!"
    jump random_scene
 

I'm not sure if this is what you are looking for though ^^;;

Thank you for your answer.

if you want to go back to a previous menu choice, you could just rollback to it.

How can this be achieved?
However, I believe that renpy.checkpoint is needed to do rollback.

As an alternative approach I am also thinking of using $ renpy.save('hidden_save') and $ renpy.load('hidden_save') to achieve this.

[Ocelot]

How can this be achieved?
However, I believe that renpy.checkpoint is needed to do rollback.

Rollback and rollforward are literally achieved by scrolling mousewheel. It is integral feature of RenPy.

[suihakei]

How can this be achieved?
However, I believe that renpy.checkpoint is needed to do rollback.

Rollback and rollforward are literally achieved by scrolling mousewheel. It is integral feature of RenPy.

Thank you for your answer.
I see, rollback and rollforward are executed by mouse rotation.
On the other hand, when do we use renpy.checkpoint?

[Imperf3kt]

It is an internal function. Generally you would never use it unless you were attempting to do something renpy isn't designed to do.

[suihakei]

It is an internal function. Generally you would never use it unless you were attempting to do something renpy isn't designed to do.

Ah, I see, you're right!
Thank you!
Now, I'll use the rollback function as usual.