Android: Bitmaps resizing themselves on higher resolution devices - android

I'm making a game on Android in Eclipse, and when I run it through the emulator, it appears fine. The emulator I set up has the resolution at 800x480 (sideways). When I run the game on my phone, with resolution 1920x1200, it screws up the bitmaps by only drawing a fourth of them. I've made test code and two screenshots to show what I mean.
Small screen, emulator, running 2.3.3
http://i.stack.imgur.com/2WstK.png
Large screen, Galaxy S4, running 4.2.2
http://i.stack.imgur.com/8wtAD.png
It's the same code on each. The top has the dimensions correctly in the emulator (frame size of the bear, which is 64x64), but on the larger resolution it's halved the width and doubled the height for some reason.
The bear at the bottom is set to be near the bottom coordinates whatever the screen size, which is why it's different in each screenshot. The rectangles and top bear is set from the top coordinates.
I can post code but I'm just wondering if it's some type of setting that I'm unaware of because of the difference in resolution.
One more thing, I have the rectangles flipped horizontally from their original bitmap, so the fact that it appears to have taken the top right part of the bitmap to draw is not part of this, as far as I know. Again, just wondering if it's some setting that auto-scales things if the resolution is huge. I have a feeling it's something like that, OR that it's running on such a newer version of Android. Could be lots of things I guess.

Android usually scales up / scales down the image if it cannot find the right image assets for the device resolution. I believe this could be the reason for the behaviour you are observing. You can read more about providing the proper assets for different device configurations here,
http://developer.android.com/guide/practices/screens_support.html
Alternatively, if you don't want android to scale your images you can also place the image resources under drawable-nodpi folder.

Related

android sdk. Background image fits. Foreground images too small

I have my view built to fit a phone screen 800x480. The background PNG shows up as a perfect fit. I have a bunch of imageViews of PNGs sitting on the view that should line up perfectly on any screen that is that size.
When tested on my phone, it works fine. However, when tested on my 7" tablet that has the same screen resolution, the backdrop fits as expected, but the imageViews are all too small.
Why wouldn't they fit the same way, considering the resolution is the same?
Could it be the aspect ratio of the second screen?
I know that when I developed an app on my Note I, it showed up differently on almost every other device with the same resolution, on account of the aspect ratio of the Note I being so wide.
Can you check and see the actual pixel ratio of your second device?
Also, is it showing the on screen action bar thing? The back/menu/etc bit? Because that could be because of the version you're targeting is less than the version of your 7" device, causing it to run in backwards compatibility mode. That'll squish your layout a bit as well.
I have a partial answer to this.
I couldn't find a way to set the size of the PNG itself. Only the ImageView height and width. So I set those to 90dp. I tried px first. Don't do that. It's no good.
But, check this out... Forcing the size in dp made the images show correctly on the tablet, but enormous on the phone! So, it more or less reversed my problem.
But at least I know what the problem is now. I just have to create a secondary view for 7" screens to set the imageView sizes. Or, I'm thinking there must be a way to do this problematically. Before the view launches, detect the screen size, if it's not a phone, change the height and width accordingly.
That should work because, as I mentioned in an earlier comment, the relative positioning is perfect. It's just the size that's incorrect.

Android development - Drawable images resolution, how to export?

So, I am just a beginner and I already went trough android documentations about supporting different screen sizes and I understand most of it.
For my app, I created different layouts for each screen sizes and on the emulator it looks good.
Just one question.
How should I export images to my drawable hdpi.lpdi,...mdpi...folders?
Because, What I did was, I used art text2, and created a project with 700x700. Well. I set it to transperant, so it's not excatly 700x700px. cause the image does not fill the entire space.
So, before I hit export, should I change the PX Resolution for example for 450x450 or something for mdpi? But, I didn't do that, and I amnot sure if I should have done that. then i hit export and it asks me where i want it to save the image. It also gives the me option to the change the DPI Resolution in DPI, i changed to 160 and saved that in my drawable/mdpi folder. But I did not change PIXEL resoultion.
So, was it correnct? or should I have changed the pixel resoultion before, I export the actual image?
In Eclipse, However, I change the width and height of the image in dp not px. so it doesn't take the entire screen space.
I checked my app on different screen sizes in Eclipse and it looks awesome. But, in the emulator, it looks cool. HOWEVER, if open my hdpi emulator the image does not look very sharp or clear. What's the problem?
The image itself looks clear and sharp if open it with my image viewer on my computer even, the image viewer window is almost taking the entire screen of my laptop (14,1280*800).
I will suggeset you to use 9patch image. you can create 9patch image using android tool called draw9patch Located in sdk/tools.What you have to, create a high resolution image and then give to draw9patch tool it create image with extension .9.png and use that image
See the link for detail
http://developer.android.com/tools/help/draw9patch.html
Okay if i understood right, then you need to have 4 res for each image, and the aspect ratio will be "1:1.5:2:3" and some times "1:1.5:2:3:4" so you have to get all the images that you need in 3 or 4 sizes and let the android os properties do its magic by choosing the right picture based on the screen size.

Android screen resoulution problem

I'm writing a game for Android and can now test it on a second device, the Nexus 1. The game uses fix pixel-values, just using bigger cutouts of the background for high-res devices. So I thought there would be no problems. Somehow, however, the nexus 1 is making a specific image bigger than it should be (261*66 instead of 174*44). The picture itself as a resource is 174*44, so it's being stretched. Why? What can I do against it?
Edit:
Spritesheet = BitmapFactory.decodeResource(res,
R.drawable.bird_spritesheet);
Is the used code.
Edit 2:
Is there no way to tell the software to just use the size the picture is? I don't want to bloat my software by adding multiple pictures (/drawable-hdpi/ answer).
The pictures are supposed to be smaller on bigger screens.
what drawables folder to you have the picture in? If you put a copy of it in drawables-hdpi I think it will show up real size. It is really better to set things up in such as way that the final size in pixels it ends up is unimportant. Using pixels values is going to ensure that your app looks wrong on at least some of the screen sizes out there.
Because Android runs on multiple screen sizes and you use device independent pixels (DIPs), images get scaled to ensure they look the same on all devices. To avoid this, you can provide alternative resources for high density screens (in your case) and for low density screens.
More info about screens here

Bitmap scaling to fit different screen size/density

I do not really understand all those things about pixel density and device independant pixels and I want to know if I should worry about this.
More specifically, here is how my application work right now:
For the “layout screens”, I’m using RelativeLayout or LinearLayout and I never use pixels or dp, so I guess that this will look good on every device
For the main game screen, there is only a SurfaceView on the screen. With the values given by onSurfaceCreated() (pixels or dp? I don’t know), I compute the size and position of every element of the game, then I load the Bitmaps (with BitmapFactory.decodeResource() and then Bitmap.createScaledBitmap()) and put them on the screen with drawBitmap()
I tested on my phone (480 × 800 hdpi) and on the emulator (240 × 320 mdpi), and both looks good.
My questions are:
Is this the right thing to do? I do not understand how (and why) I could use the fact that some devices are hdpi and others are mdpi.
Should I provide different bitmaps for different screen densities, and why? (right now I have everything in res/drawable-hdpi)
What size should my .png have? Can I create them much bigger (2 ×) than their expected size, in order to be sure that this will not look blur or aliased?
My knowledge about this is limited, as i never developed games.. as i supposed you are doing.
Is this the right thing to do? I do
not understand how (and why) I could
use the fact that some devices are
hdpi and others are mdpi.
With this information you can load different images automatically. You can you the directories:
drawable-hdpi
drawables-mdpi
...
Should I provide different bitmaps for
different screen densities, and why?
(right now I have everything in
res/drawable-hdpi)
If you have all in hdpi then the images will be shrinked i think, to be smaller due to the lack of specific images o that scale. Providing the images will give you more control over the final product and it will spend less processing.
What size should my .png have? Can I
create them much bigger (2 ×) than
their expected size, in order to be
sure that this will not look blur or
aliased?
I think they can be exactly the size needed. But as i said above.. not much experience.

Android large-sized emulator produces regular size application in center of screen

I always used the standard emulator when testing and thought it was about time to see what it looked like in a higher res/density setting. I ran my application using WVGA854 which has a density of 240 (rather than the 160 I usually used). The result is my application sitting as its old size in the center of the screen. I don't specifically hardcode the application size anywhere that would produce this (except for background images, but there are other things like x,y positions that are still limited by the old size). What gives? I move over the high res images into the correct folders but it still appears to be forcing my app to a smaller size? The background below is set to 854 width in the HDPI (and MDPI folder) but it is still cutting it off? Using a surfaceView to draw the bitmaps.
Add the <supports-screens> element to your manifest, saying that you support large screens.

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