Fastest way to do peripheral clipping - android

In my Flash AS3 app, I am using
stage.scaleMode = StageScaleMode.SHOW_ALL;
because graphically I want it to be workable out-of-the-box in all kinds of different mobile devices. It works a treat because it does a "best-fit" to the device's screen and simply "adds" black borders around it.
For example, in 4:3 screens it fills the whole screen nicely:
while in 16:9 screens I get black borders on the left and right:
Now here is the problem: when I am moving a display object "off-screen", I don't want it to be rendered inside those black borders.
The question is this: what is the fastest way to "clip" my app - considering I am targeting mobile devices? I have a feeling that a
stage.scrollRect
will blow things up performance-wise...
EDIT : I am using <renderMode>gpu</renderMode>

scrollRect is actually great and even makes your application perform better, unless you're using GPU composition (in which case it really degrades performance). So I'd suggest you trying it first.
But a good alternative solution (as crazy as it sounds) is to just have a huge rectangle with a hole on it on top of everything, as the last children of your stage. So suppose your stage is 640x480. You'd have a black rectangle on top of everything with dimensions of, say, 1640x1480, and with a hole of 640x480 pixels inside of it to let your content be visible. It's a cheap way to mimic a mask without forcing recomposition of the pixels inside that area.

Related

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.

libgdx -> camera and viewports

I have made my game, which scaled accordingly to a % of the screen width with the Gdx.graphics.getWidth() method, and it works perfectly on all screens.
Now I am trying to learn viewports, but seems like there is a lot more trouble, like when does it take in world coordinated or when does it take actual screen pixels.
Do I have to constantly convert beetwen these two measurments? It seems like there is alot more trouble, than if I just scale it the old fasion way...
I can use the whole screen, and manually make the pictures non streched, if I used a FitViewport I would have like blackbars and the game would be totally different.
Any clear suggestions to why to use these ports, cause I cannot seem to understand them...
The thing is that you do not have to do anything especially making any conversion.
Viewport is a kind of tool that handling your app's rendering on many types of screens (I mean many other ratios) and you do not have to worry about it anymore.
Only thing you have to do is to "tell" viewport what is the size of your screen and to handle screen resizing by updateing the viewport. Then you are treating your app like it would be always for example 800 x 600px no matter how it looks actually.
The way your app will render depends on what viewport implementation you will use. For example:
FitViewport will fit your screen to device and add some black bars
FillViewport will fit your screen to device and cut off overflowing part
and so on...
The a look at official Viewport libGDX tutorial. Also you can take a look at this thread to get some information how to deal with viewports.

Adobe Air Mobile App: Responsive sizing of Elements

I still have trouble understanding the possibilities of Scaling my UI in a responsive way in my Air Mobile App. On the web I'm familiar with it and the use of media-queries.
I dont want to scale my whole UI up and down or even stretch it (e.g: I use the camera in one DisplayObjectContainer, so this would be really bad for the performance to scale this.)
I currently go down the road defining all the container sizes by percent, but that is getting pretty ugly pretty fast as it leaves me with 68.95px values. I think this will get me in trouble one day as blocks appear not crisp anymore. If I round the values, I might have 1px gaps between Elements.
Currently I have this Setup. The idea is, to give every main Component a (maybe invisible) empty background-child. These can then deformed by width & height by any desire. The inner Elements of any Element (button, logo, etc) are not affected by the deformation of the bg and can then be arranged accordingly (as I now have position and size of this container - like in css).
But this does not feel like it is the right way.
Is there a magic lib/class I dont use currently and that allowes me to build in hard pixel for a defined setup and behaves appropriate when it comes to different stageWidths, DPI, etc?
What are your approaches for this problem?

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 LIVE Wallpaper approach?

I'm entirely new to Android development, and I'm interested in making a live wallpaper. I was thinking about looping a set of pictures instead of drawing the animation. Is this a possible approach? If possible is this a suitable or ideal way of doing it, does it eat up memory and would i need images with different resolutions because of the fragmentation?(hundreds of different devices)
Thanks in advance :)
Sure, it should be fairly simple.
The main part of the Wallpaper engine is the Drawing of course. You need to handle the drawing manually, there is no easy way to loop through images... you need to code it. You will have to continuously monitor the time which has passed and adjust the displayed image based on that. You are given a Canvas object to draw to and it is all done during run-time in code.
The Wallpaper engine class has a event called onSurfaceChanged which gives you the width and height of the Surface which you will be drawing to. It will be called everytime the screen dimensions change (like if the phone is put into Landscape mode for instance). You need to have code that will handle any combination of width or height for all the device types out there. You will need to decide if you are going to stretch, center, tile or crop (Or a combination of those) the source images to fit any particular screen size. I would recommend scale to fit so that the image is either taller or wider than the screen and center the image either vertically or horizontally (cropping the extra bits) once that is done. I personally just use one source size and resize it to fit. You can opt to use several source files if you want which is the recommended approach I believe, but it's a little confusing.
I would start by creating a Live Wallpaper which just draws something basic like a shape to the screen. Then work out how to display an custom image and take it from there.
Good luck
You will need to be very careful about memory if taking a frame approach to animation--probably will not be possible to animate full frames--much more practical to move sprites on a background. See, fr'instance: http://davidjhinson.wordpress.com/2010/05/19/scarce-commodities-google-android-memory-and-bitmaps/
what if you have a png frame animation that is set at a certain x and y position that sits in a spot on the background image, both would have to be rescaled

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