[rcore][Android] Allow setting window size on Android.

[b1bradders]

My situation

1. User rotates device while app is open.
2. Android sends APP_CMD_CONFIG_CHANGED.
3. Resizing the framebuffer and setting screen sizes to reflect the new 'window size' causes stretching due to Android-reported width and height still (usually - see below) reporting with values from before the orientation change.

Why not just add this in AndroidCommandCallback's APP_CMD_CONFIG_CHANGED case?

Android does not send the correct width and height in time, therefore leading to you having to manually switch the height and width. This is fine, until you notice that Android has a somewhat-common chance to send the correct width and height and then everything gets stretched because you swapped the width to be the height to account for the wrong timing.

You could make a variable to mark the window as dirty then in a place that is triggered every frame, if that variable is true and the Android-reported size != current window size, set the variable to false and then update to the new size.

The solution for devs using raylib

1. Allow SetWindowSize to be usable, via this patch, on android.
2. Devs can now use the NDK themselves to check every frame if a resize occured:

extern struct android_app* GetAndroidApp();

static int ndk_window_width() {
	struct android_app* app = GetAndroidApp();
	if (!app || !app->window) return 0;

    return ANativeWindow_getWidth(app->window);
}
static int ndk_window_height() {
    struct android_app* app = GetAndroidApp();
    if (!app || !app->window) return 0;

    return ANativeWindow_getHeight(app->window);
}

3. Devs call these every frame, and do manual resize checking. If a resize is detected, call SetWindowSize(int width, int height).

Additional comments

Let me know if this is okay - personally I wouldn't accept this PR as I'm sure there is a solution that allows putting this code in APP_CMD_CONFIG_CHANGED while receiving correct sizes from Android (see my 'Why not ...' above for why we can't do this already).

This also is a better solution as it also correctly sets the size when INIT_WINDOW happens. So, if the app is in landscape and the users turns off the phone screen then turns it back on with the orientation in portrait, then that is also handled as the size change is detected.

Demos

Fix from this PR:

fixed.by.this.pr.mp4

Default behaviour:

app.stretch.mp4

[raysan5]

@Bigfoot71 since you have more experience with Android, please, could you take a quick look to this PR?

[Bigfoot71]

@raysan5 I'm not aware of the problem described, I'd have to dust off raymob and test that (I will do it soon, given the release of 6.0).

But as it stands, it seems a bit tricky to me. I will give better feedback as soon as I can.

[b1bradders]

It'd be great if you could test for 6.0 - I was testing this using raylib-go which is still on the last released 5.x version :)

_{Also: sorry for updating after 4 days - I don't have the GitHub app or GH notification emails enabled, so I only see notifications when I next come onto the website lol}

[b1bradders]

@Bigfoot71 @raysan5 Hey guys, any updates? 😁

[raysan5]

@Bigfoot71 any update on this issue?

[jn-jairo]

I'm not an expert in android but the documentation has the APP_CMD_WINDOW_RESIZED event but you tried the APP_CMD_CONFIG_CHANGED.

As I understand in this case the APP_CMD_CONFIG_CHANGED is sent when the orientation changes, what implies a window size change, but the actual window resize may not be done yet, and when it is done, the APP_CMD_WINDOW_RESIZED is sent.

What you described sounds like a racing condition for not using the proper event.

[b1bradders]

Oh interesting! I believe I did try APP_CMD_WINDOW_RESIZED (i'm 60% sure i didn't not try it) although I must've still had issues. When I get the chance to though, I'll 100% try it.

[b1bradders]

Before I test, is this really the best way to resize the raylib "window"/screen?

CORE.Window.display.width = width;
CORE.Window.display.height = height;

SetupViewport(width, height);
CORE.Window.currentFbo.width = width;
CORE.Window.currentFbo.height = height;

CORE.Window.screen.width = width;
CORE.Window.screen.height = height;

(where width and height is the new width and height)

I only ask because that's a lot of different variables (.display, .currentFbo, .screen) that I'm changing the width and height of and, tbh, I have no clue what currentFbo's dimens. are affecting and I don't really know the difference between changing .screen's w&h and .display's w&h (if that makes sense?)