How to change order of transformations? [Solved]

[Dawn]

As explained in documentation, the transformation properties are applied in the following order:

1. tile
2. crop, corner1, corner2,
3. size,
4. zoom, xzoom, yzoom,
5. pan,
6. rotate,
7. position properties

I would like to do rotation before resizing (to have a rotating ellipse).

Code: Select all

    
    transform rotate_object:
        size(200,400)
        rotate 0
        linear 8 rotate 360
        repeat

How can I do it ? Have I to update renpy code ?

[shakeyss]

I also want to know this too, for future reference. I hope someone will answer this.

[trooper6]

Just create your own transform that first rotates, then resizes.

[Dawn]

How do you do it?

Before asking, I tried to do it and the result does not change.

Code: Select all

    transform rotate_object:
        rotate 0
        linear 8 rotate 360
        size(200,400)
        repeat

[Divona]

Let me try to explains the code here:

Code: Select all

## Create transform.
transform rotate_object:

    ## Begin the transform
    ## Reset sprite rotation to zero.
    rotate 0

    ## When the line of code above finished set sprite rotation to zero
    ## Rotate sprite around 360 degrees in 8 seconds.
    linear 8.0 rotate 360

    ## When the rotation above is finished
    ## Set sprite size to 200 width and 400 height.
    size (200, 400)

    ## When the line above is finished set the size of the sprite
    ## Repeat the transform code from the top.
    repeat

What is the result that you expected?

[Dawn]

No I'm sorry, I'm not fluent in english. I tried to explain it to my husband and he didn't understand at the beginning. If in french it's difficult to explain... Sorry. My bad ! Let's try to be more "clear"

So... Ok... Wait ! I found an example, more explicit.

I have a circle. In the bottom of that circle, I have a dot, like a planet. In some other language, if I do an animated rotation and a resize during this rotation, I obtain a rotating ellipsis, like a planet turning around the sun.

Here is my image:

If i remove the animation, here is what renpy is calculating:

But if the rotation was calculated before the resize, I should have:


You can do it on Gimp :
1 - Create a circle,
2 - Do a rotation of 45°
3 - do a resize

The result is different if you do a resize and after that a rotation of 45°
1 - Create a circle,
2 - do a resize
3 - Do a rotation of 45°


Here is the full code of my attempt (similar transformation works on Flash)

Code: Select all

    transform rotate_object:
        size (400,200)
        parallel:
            rotate 0
            linear 8 rotate 360
            repeat
        ## But because rotation is calculated after resize, the north-south stay larger than the east-west. 
        ## What I want is that the two centers of ellipsis doesn't move, I height and width don't change and your eye think that N and S are rotating on an elliptic line.
        parallel:
            linear 8 size (400,200)
            repeat

Because of the documentation quoted on my first message, I think this "bug" is "normal". Tom is declaring in doc that "for each frame of animation", rotation is calculated AFTER resizing. I tried to inspect atl source code, but it is too complex for me.

Here is the first frames of what I want:

[PyTom]

I don't have time to check it, but you can probably make this work with a pair of transforms:

Code: Select all

transform rotate:
            rotate 0
            linear 8 rotate 360
            repeat

transform resize:
     size (400, 200)

show compass at rotate, resize

[Dawn]

Thanks a lot Tom ! It works exactly like I want. I didn't know that I could combine transformations.

Code: Select all

## transform.rpy file
    transform rotate:
        rotate 0
        linear 8 rotate 360
        repeat

    transform resize:
        size (400, 200) 

Code: Select all

##screens.rpy file

screen main_menu():

    ## This ensures that any other menu screen is replaced.
    tag menu

    style_prefix "main_menu"

    add gui.main_menu_background

    ## This empty frame darkens the main menu.
    frame:        
        pass
        
        add main_pentacle at rotate, resize:
            pos (136, 535)