Hardware Acceleration in Android

Beginning in Android 3.0 (API level 11) we have the option to enable hardware acceleration.
Now what is hardware acceleration and why should we use it?

Hardware acceleration means that we use the GPU to do the drawing work instead of the CPU. The views on canvas will be exported to textures that will be drawn to the screen by using OpenGL libraries. This process is much faster then drawing them by using the CPU, however also much more memory consuming. Loading the OpenGL libraries takes 2 to 8 MB of main memory, if we eat even more memory by using large images or a lot of objects then on phones with limited memory we run into problems.

Because of the memory consumption Android does not allow images larger than 2048x2048 to be used during hardware accelerated events. Note that the actual image size might be even smaller since the image is first transformed to a texture, it is wise to not use images above 2000x2000. This means that if you want to work with larger images coming from camera's for example, you have to disable it.

Hardware acceleration can be switched on globally for the entire app in the manifest file.

<application android:hardwareAccelerated="true" ...>

But you can also enable it per activity and in the near future per window (not supported yet though), which would be more preferable since most applications would not profit from accelerated hardware in the main menu for example.

Crossplatform apps and hardware acceleration

In HTML5/JS cross-platform apps made by, for instance Phonegap/Cordova, hardware acceleration can improve the app significantly.
If we create a simple webapp with jQuery mobile and run it using Phonegap on a phone, we see that the transitions between pages are a bit staggering, the scrolling is not smooth and the reaction time is a bit slow, even on high-end phones.
Now we enable hardware acceleration and run the same app again. The transitions look amazing, scrolling is super smooth and the app reacts in no time!
 

In short: Hardware acceleration is an awesome new feature that Android 3.0 and above offers, but only use it when needed.

Are html5/javascript apps the future?

Nowadays html5 / javascript apps can be found a lot on the internet.
Also on mobile platforms as Android and iOS, html5 apps appear in the markets more and more often. The question is are these webapps the future or are they too limited and slow?


Webapps for mobile phones.
We can make webapps for mobile phones with the help of Phonegap/Cordova. Phonegap gave us the ability to convert our webapps into applications for mobile phones. Although applications made this way are noticable slower then native made applications, and they cannot acces all native features (yet), they are developed easily and can be used on all platforms without the need to rewrite code.

With libraries like jQuery Mobile you can create a nice looking app for Android and iPhone without the need to know anything about Objective-C or Android Java. All you have to do is write a web application in your favorite editor, test it in the major browsers and then with the help of Phonegap convert it into a native application.

So for mobile phones webapps are doing better and better. There are some advantages and some disadvantages. Lets create a little list.

Advantages:

•  Easy to develop
•  No knowledge needed in Java / other native language
•  Crossplatform

Disadvantages:

•  Slower
•  Less native features

Now lets look at the disadvantages. Slower many people say, yes this is true a native application is faster then a html5 app and this will always be the case, you cannot make a faster app then doing it native. Though, new phones have faster and faster cpu and load html5 apps so fast that you almost see no difference with native apps.

Less native features, it is true that even by using phonegap you cannot access all native features from every device with the same html5 / javascript code. But, luckily here we can use phonegap plugins.
A large collection of already made plugins can be found here.
With phonegap plugins you can basically connect your javascript code with native code. This makes the options endless! Although it seems that the whole effect of crossplatform html5 apps is gone when you still need to implement native plugins. For now though this is a good solution for the few things that are not available yet in html5/javascript apps.

Webapps for desktops
In desktops webapps are not common and well used at the moment rather then by using a browser to go to the webapp. With the coming of Windows 8 this will already change quite a bit. Windows 8 will support webapps and even let users sell them in there kind of appstore. It is easy to convert your own webapp for Windows 8 with Visual Studio 2012 for windows 8.

Now I hear you say, If I don't have windows 8 (and there are also many reasons not to have it), I can not execute my webapp? You can!You can create an executable for windows, Linux or Mac OSX in seconds with appJS. This little tool simulates a localhost browser with your webapp inside. You can specify settings like title, screen size and others in the javascript file in the zip folder you can dowload from their website.

So now we can make webapps for internet, mobile phones / tablets and desktop PC's!
Are webapps the future? I think they are, although sometimes you cannot go without native.

We ourselves are working on a totally crossplatform product with an approximate release date of Januari 2013. Check our site to find out more.