save cropped screeshot [solved]

[Kia]

I've been trying to figure out how to take a screenshot and crop it before saving it. but it's not going as I imagined. since I'm out of ideas, here's what I've tried, please let me know if there's something I'm missing or doing wrong.

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renpy.screenshot(filename)

seems to return False every time and

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renpy.game.interface.save_screenshot(filename)

Doesn't seem to work either

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renpy.take_screenshot((1920,1080))
photo = renpy.game.interface.get_screenshot()

works and I can crop it too, but I have no idea how to save a crop

I've rummaged through the renpy files, found (line 2542 in core.rpy):

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save_screenshot(self, filename)

and (line 71 scale.py):

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image_save_unscaled(surf, filename)

Those two functions seem like what I need, but they add `surf` to my pile of unexplained terms that I can't figure out

The closest thing I've found is this post from nine years ago that works perfectly, just have to figure out how to crop the image the way it can be written.

[mavyxdawn]

have you tried screenshot_crop?

Once you attempt to screenshot, it will take the size defined here ^

[Kia]

have you tried screenshot_crop?

I did, but I'm trying to take the screenshot in a python function where I calculate the crop every time, give it my own name and save it to the destination I'm giving it. To use that one, I need to make `renpy.screenshot(filename)` work and it just returns False.

[Ocelot]

Did you try to set confog.febug to True, to force an exception in case someting goes wrong in your attemts to see what is going wrong. It could be anything from absolute vs relative paths to access rights.

[Kia]

oh, you mean debug, looks like you've typed it in a hurry. I'll try it, thank you

[Kia]

well, I've use config.debug and managed to get the save screen work (I was missing the file extension)
but the more I dig, the harder it gets.
now I need to figure out how to pass

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        renpy.take_screenshot((1920,1080))
        photo = renpy.game.interface.get_screenshot()

to

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renpy.display.scale.image_save_unscaled(window, filename)

or what object do I need to pass to

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        surftree = renpy.display.render.render_screen(
            ????,
            renpy.config.screen_width,
            renpy.config.screen_height,
            )

to construct a surftree to save

[Ocelot]

Did you manage to get renpy.screenshot work? You can then just set config.screenshot_crop to whatever you want and then restore it to the previous value.

[Kia]

I did that, there is one problem with using renpy.screenshot out of the box. it screenshots at the current window size and messes up the cropping, that's why I'm looking deeper into it's function and trying to figure out how to capture the screen at the original size instead.
since renpy.screenshot is the short format for renpy.game.interface.save_screenshot and I've found the function inside core.rpy I can copy that function if I can figure how to make a surftree, however, I have no idea what kind of object I have to pass to renpy.display.render.render_screen to create one

[Ocelot]

It appears that it is PyGame surface. I didn't dare to explore further to figure out what RenPy expects it to contain. However, you can just reuse data that is already there. Just copy method, change it as you want, and either dynamically patch it into Interface class or simply pass it as first argument to the new function.

Example:

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class A:
    foo(self, other):
        self.something = other

# 1st approach:
def bar(self, other, another):
    self.something = other * another

setattr(A, 'bar', bar)
x = A()
x.bar(1, 2)

# 2nd approach
def baz(self, other, another):
    self.something = other * another

y = A()
baz(y, 3, 4)

[Kia]

Unfortunately the function uses another function to capture the screenshot and I can't find the class to add a method to it that returns a full size render

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    def save_screenshot(self, filename):
        """
        Saves a full-size screenshot in the given filename.
        """

        window = renpy.display.draw.screenshot(self.surftree)  #<==========This line

        if renpy.config.screenshot_crop:
            window = window.subsurface(renpy.config.screenshot_crop)

        try:
            renpy.display.scale.image_save_unscaled(window, filename)
            if renpy.emscripten:
                emscripten.run_script(r'''FSDownload('%s');''' % filename)
            return True
        except:
            if renpy.config.debug:
                raise

            return False

everything else seems easy to modify, but this line references a surftree that's created somewhere else and passes it to a function that returns some object that is saved as an image in the next lines.
using renpy.take_screenshot((1920,1080)) and writing the data to file was so easy that I imagined cropping it would need a couple of additional lines, but boy I was wrong. only if I knew of a way to convert a transform like Crop(crop, FileCurrentScreenshot()) back into a format that can be written to file this whole problem would be solved

[Ocelot]

So following does not work?

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def save_cropped_screenshot(self, filename, crop):
    window = renpy.display.draw.screenshot(self.surftree)
    window = window.subsurface(crop)
    try:
        renpy.display.scale.image_save_unscaled(window, filename)
        return True
    except:
        if renpy.config.debug:
            raise
        return False

# Later
crop = (100, 200, 50, 50) # Calculated crop
save_cropped_screenshot(renpy.game.interface, "filename.png", crop)

[Kia]

the source of problem is before cropping step, the line window = renpy.display.draw.screenshot(self.surftree) returns a screenshot at the current window size that can be any size in windowed mode, the crop will be inaccurate because of that

[Ocelot]

Can you then take take_screenshot as base function and add cropping code from save_screenshot?

something like that:

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def save_scaled_cropped_screenshot(scale, crop, filename):
    surf = renpy.display.draw.screenshot(renpy.game.interface.surftree)
    surf = renpy.display.scale.smoothscale(surf, scale)
    surf = surf.subsurface(crop)
    renpy.display.render.mutated_surface(surf)
    try:
        renpy.display.scale.image_save_unscaled(surf, filename)
        return True
    except:
        if renpy.config.debug:
            raise
        return False

save_scaled_cropped_screenshot(scale=(1920,1080), crop=(910, 490, 100, 100), filename="screen.png")

[Kia]

Can you then take take_screenshot as base function and add cropping code from save_screenshot?

Thank you, the scaling solved the problem, and sorry about the delayed answer, I got swamped with work and couldn't get any free time for few days ^^