Develop Reference

Can't Center the scene to the screen in Godot?

I have few scenes in my project. I was able to center all of the other scenes. But i cannot center the main scene in my project. Its fine when it opened on a mobile device(probably because resolution matches i guess). but when i opened it in tablet(its an old tab "xiaomi tab 3") its always align to the right on the screen. I was able to center other scenes but i cant center the main scene to screen for some reason. project setting set as 2D and Expand. I also tried to use Control nod, canves layers, margine containers.. but nothing works. If someone can give any suggestions, Thank you in advance.
img1
https://i.stack.imgur.com/FJOHl.jpg
project
1920 x 1080

I have seen this problem, or similar, in windowed mode. I don't know if this is the exact case, but if it doesn't mess with your project, try full-screen mode.
If it's that, you can also take care of the window bar size (which is a problem because it can change from different devices), since godot will count its pixels too.
Notice that you're only having this problem in one axis.
Also, I think you could take a look into the Viewport Stretch Mode. It could mess your graphics depending of the intended result—but other projects won't even notice, so judge for yourself.
The viewport setting sets the root scene’s Viewport to the base resolution. The rendered output of the root Viewport is then scaled to the display resolution. [...]
The viewport setting is a better choice than the 2d setting when pixel-perfect precision is required, since primary rendering still occurs at the base resolution.
Support multiple devices
Scaling correctly for all devices could be an odyssey, so bon voyage.

How to can I create an image that can be used for different android screen sizes?

I created an image to use for an android splash screen and it displays properly on my phone however when I open the app on a phone with a larger screen it pixelates. So I was wonder if I should create more than one image and if so what sizes should I set for other images because I know I can't use the same sizes as I used for the app icon?

If the images are pixelated
then you need to add larger images for each screen size under your
res folder. sizes depends on your target
or
scale the images. to be safe, make it bigger
it might help you: am I supposed to make images larger for tablets, or same size as handset?

you could probably use draw-9-patch to state which area of the picture can be extended.
Google draw-9-patch

I worked with two approaches so far:
Screen composition
One approach can be using a composition of brackground and a logo. You can have the logo as big as you need (for high resolution screens) and the background as a repeatable texture (it all depends on your design approach) or a gradient or other composition (less prone to pixelation errors).
As big as possible approach
If one image is your approach, you should do a research to know the currently most used and biggest android screen used (https://developer.android.com/about/dashboards/index.html). Knowing that one, you can design your image for that [high] resolution and set the scaleType as CENTER_CROP. With that, you will ensure that the image will be centered, inside the screen, keeping aspect ratio, and at its highest resolution [keep an eye about logos/graphics positions if you want to be sure that they remain visible even in thin screens).

For icons, the best way is Draw 9-patch
Otherwise, you need to scale the images into drawable-xx (res directory), here the explanation

Android: Doing all my drawing on a SurfaceView; what's the proper way of making sure my drawing conforms to any screen size?

I'm making an app (a game, to be exact) where each activity uses a SurfaceView for the UI. All of the drawing is done through onDraw. I am also designing this to use no Bitmap assets, so everything that is drawn is produced directly by the app. I'm trying to design the app in such a way that it can easily be viewed on any screen size.
So here's how I'm accomplishing this: I'm doing my testing on a Galaxy S4, which has a screen size of 1080x1920. In the constructor for each activity, the width and height of the current screen are calculated and stored as ints "w" and "h" (the app is already locked in portrait). Then, whenever anything needs to be drawn onto the screen, I multiply the desired dimension (as seen on my 1080x1920 screen) by either w or h, and then divide by 1080 or 1920. Since I'm not using any Bitmap assets, I never need to worry about pixelated images or anything this way.
This gets the job done, but seems like a bit of a roundabout way of doing it. I figured there would be a better framework for getting this done, and I'm worried that these big calculations are eating into my drawing time (running at 30FPS can get a little jerky).
Is this is the customary way of doing it, or is there a better way out there?

There's a very simple yet effective way to do it, you can declare all your sizes in a dimen file for each specific density/size, as you usually do for layouts e.g:
values/dimens.xml <--- With default sizes
values-sw600dp/dimens.xml <-- Tablets sizes
(etc...)
Now before you start drawing, load all the values in your program only once, maybe onCreate of your drawing activity, using the following command:
float someItemSize = Context.getResources().getDimension(R.dimen.some_itemSize)
etc...
That way, you let the operating system do the pixels conversion for you, you should do it only once and most important, this will give alot of flexibility to your code because you will be able to change sizes from xml files without even touching your actual code, hence, the customization should be easier as well as future changes...
Hope it helps!
Regards!

There are two considerations: screen size and screen aspect ratio. If you simply scale everything to match the display, you will appear stretched a bit if you put a 4:3 device next to a 16:9 device.
You generally have two options for dealing with the aspect ratio: you can letterbox / pillarbox the output (which is fine for movies, but looks kinda lame for an app), or you can recognize that your output isn't always proportionately the same, and adjust the layout to fit nicely on the screen.
As far as size matching goes, when using a SurfaceView you can actually use a single size and then let the hardware scaler handle the rest. For an example of this, see the "Hardware scaler exerciser" in Grafika. I put a demo video here, though it's a bit hard to evaluate after getting rinsed through screenrecord + youtube. What you're seeing is the same couple of shapes rendered onto a Surface whose size has been set to an arbitrary value, and then scaled up to match the display. This is most obvious on the final setting, where it's drawing on a 106x64 surface.
With this, you could size your assets for 720p and always draw them the same way, and let the scaler deal with the stretching. See also this blog post.

Android non-repeating textured background

I have an iOS app that uses unique textured backgrounds (think of a game title screen or something) on each of the screens that I am trying to port to Android. On iOS they knew the resolutions and just designed the backgrounds around those. Obviously that isn't possible on Android.
What is the best way to put a textured/non-repeatable background into Android that works on various screen sizes and aspect ratios?
The solutions I have thought of so far are:
Fit the shortest dimension and allow the image to go off the edge of the screen for the larger dimension
Make the background image large and center it, then make it stretch out beyond the edges when the resolution is smaller than the image
Stretch the image to just fit (this is ugly and I'd like to avoid it)
Create a different version of the image for each resolution. (This seems way beyond the scope of what is possible for this project.)
As far as I can tell in Android, 1. and 2. aren't possible out of the box because background images set the size of the view to match their size (you can't tell it to just extend beyond the edges, please correct me if I am wrong).
What solutions would you use in this situation?

Use an (match_parent) ImageView to simulate back ground image. (By adjusting the scale type of imageview you can get the result of point 1,2)
http://developer.android.com/reference/android/widget/ImageView.ScaleType.html
Use 9-patch image. You can specify which part of your image can be stretched. For your case I suggest adding a small "margin" to your image, and make it stretchable using 9-patch. Only the margin will be stretched, maintaining the aspect ratio of your image.
android developer 9-patch

Create a different version of the image for each resolution.
As you're probably aware, Android can run on a wide variety of devices with varying resolutions and screen densities. To be fully compatible with all of them takes a bit of graphics work; you need resources for each possible screen density (and in this case, resolution).
For full details, see Supporting Multiple Screens in the Android developer documentation.
Unless something has gone seriously wrong in your development process, you should have the original files (e.g. .psd) to work with when creating these resources.

How to draw background image and make it looks similar on all Android devices?

Looking for advice with the next problem. I am developing small game and I have a *.png file for background. I need to put it to background of the main game screen. Moreover, it has to bee 2 times bigger in width and 1.5 times bigger in height as the screen's sizes, because my objects "flight" across these borders. Additionally the screen is moving around this background in a gameplay. But I have stuck a bit on how to do it.
I want my background to look similar on all screens with different sizes and densities. I have tried some solutions but I don't like them, or I have made something wrong:
Make different background images and put them in special folders. It sounds good, but with the amount of resolutions of Android devices in the market it is not sounds good for me. It will just make the size of *.apk bigger. And if I will use the methods to set background it will stretch the image - not a good idea I think.
In the onDraw() method draw the image on canvas. I have to put it's top-left corner to the most top-left corner of the possible game area and draw it. But, here is some options:
cut from the main image the image i want and draw only this piece (what I use now)
resize the image I have and draw with this changes
something else...
So, the question is: what is the best option for drawing background for the game screen when you need it to be almost twice bigger than the screen's size, make it looks same on all devices and move the screen around when the game is played?

you should use 9 patch image .
A NinePatchDrawable graphic is a stretchable bitmap image, which Android will automatically resize to accommodate the contents of the View in which you have placed it as the background.
see this link.
http://developer.android.com/guide/topics/graphics/2d-graphics.html#nine-patch