I'm developing my first Android game and I'm having a bit of difficulty making the UI as smooth as I would like. I've spent a couple of hours googling around with no luck, I'm probably just searching for the wrong thing.
I have two different XML layout resources where each layout contains just one SurfaceView subclass. When I call activity.setContentView(R.layout.second_layout) to transition from the first layout to the second layout there is a noticeable period of time where a black screen (with a small white bar along the top) is displayed in between the two views.
I've tried various things such as; constructing the second view manually at runtime (i.e not using a layout XML file), calling activity.overridePendingTransition(android.R.anim.fade_in, android.R.anim.fade_out) after activity.setContentView(R.layout.second_layout) and attempting to render to the canvas before the view has loaded (turns out the canvas is unavailable).
I don't see other games (or apps) having this issue so I presume there is a reasonably simple solution.
If you need some more information about my particular situation in order to help out then please let me know what information is missing. Any help would be largely appreciated.
Update: My answer below was written in 2010. Since then Fragments have become the norm, particularly since Fragment nesting was made possible and the support library allows this functionality to be used in a backwards compatible fashion. As such, instead of transitioning to a new Activity to perform a new "user task", you can use the one Activity and push and pop fragments within that Activity's view hierarchy. Animations can also be performed as a part of a fragment transaction (e.g. Fragment transaction animation: slide in and slide out).
This became pretty apparent not long after posting this question, however I thought I should come back here and make it clear to everyone else.
Activities are positively the way to go when developing for Android. Don't be put off by the fact that a transition may seem too minor for a separate Activity, the very foundation of Android is built around the idea of an Activity.
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wisgetwas wondering what widget in gtk (using gtkmm) could be used to implemented the movable button looking thing in the picture. and also the dotted line.
dotted line
edit: the widget is supposed to be able to move left and right along the time-track to be able to set the play bounds. Here is a video showing how it looks like in after effects. From sescond 37 is how the behaviour for it supposed to be. https://www.youtube.com/watch?v=QxXevteeumg
edit: from what it looks like there isnt a specific widget which could simplify this. However a regular button can be used and then implementing a method for its drage using the various signal handlers associated with a Gtk button
There is no widget that does this (see the widget gallery).
You can, however, add custom widgets using Cairo. In the official Gtkmm book, there is an example for creating a custom clock widget using the Gtk::DrawingArea. The Gtk::DrawingArea offers a lot of signals which you can connect to.
I have created my own widgets in the past using this and it worked just fine. However, it was a lot of work because:
Cairo lacks good documentation. Understanding the philosophy behind this library is a lot of work, often empirical.
It can be hard to acheive acceptable performance using Cairo. One has to be really careful in how the drawing of the widget is performed. There is often a naive way to do it, which is clearer in the code, but devastating in terms of performance (it often involves useless redraws on the CPU).
I have a custom ListCell implementation, shown in the picture below.
The left side, which represents the date, consisting of 3 labels, put in a VBox and the "CounterContent" consisting of the counter, with a TextField for each digit, contained in a HBox, and two Hboxes containing labels for kWh, kWh/day and so on. And that seem to be just too much, to be running performantly.
I've tried to load the data in a background task, showing a progress indicator, while the task is running, but unlike on desktop, on android the performance is very poor. Whenever I switch to the listview, the garbage collection kicks in, and blocks the ui thread, so that the progress indicator never shows up.
I've tried it on a Huawei Y-300, Android 4.1.1, javafxports 8.60.6 (because javafxports 8.60.7 causes a bug, that makes TextField unusable), and on a Samsung S5 mini, Android 5+. On the Samsung phone the performance in general is way better, just like expected, because of the Ahead-of-Time compilation I guess, but there is still the garbage collection issue. Furthermore after the listview has been populated with cells, the scrolling is not very smooth.
Is the listcell to complex or what else could be the matter for the poor performance?
UPDATE:
After running a lot of tests it seems the unsmooth scrolling is not caused by performance problems. At least on the S5 (javafxports 8.60.7).
I removed all css styling, and replaced the textfields by a single label (the counter node is already a custom control(forgot about that), which lays out the textfields in 2 Regions(not HBoxes) and the nodes of the ListCell are instantiated in the constructor). Furthermore I switched the ListView for a CharmListView and set android.monocle.input.touchRadius=1.
None of these steps resulted in considerable improvement.
Just to clarify: In contrast to the Huawei phone, the scrolling on the S5 and android 5+ is usable, but it's not very smooth, which makes for a unsatisfactory user experience.
On the Huawei (javafxports 8.60.6), changing the counter textfields for a label, gave a significant improvement, but not to the point where the scrolling became usable. Until I set this magical experimental switch: gluon.experimental.performance=true, which makes the listview scrolling lightning fast(after a little warmup delay), but still not really smooth.
There are many reasons why the performance of a complex scene is reduced, so this is just a list of possible ideas that might help improving it, in any order.
ListCell
For starters, the number of nodes in the cell is really high. Notice that every single scroll you make means the full rendering of the virtual flow that holds the visible cells. And for every cell, that means recreating its content all over again.
Without viewing your code I can't tell, but you should avoid creating new instances of every node in the cell all the time, by having just one single instance, and in the updateItem method only change the content of the nodes.
Have a look at this sample. The NoteCell class is a custom cell, where a ListTile is used.
Number of nodes
Have you tried using just a Label to replace the 8 textfields and 3 boxes?
Cache
If you use images downloaded from Internet, use Gluon Charm Down Cache to avoid the same image being downloaded over and over again.
Have a look at this sample. Without the cache, even on desktop the performance is really affected.
Also use the JavaFX built-in cache for any node, trying different cache strategies.
CSS
Complex CSS requires long CPU time. Try to simplify it. Even you can remove the whole CSS for a quick test. Then decide what you may or may not use.
The same goes for animations: Avoid animations, transitions or even CSS effects, if possible.
Custom Control
The counter complex node could probably be replaced by a custom control that optimizes the rendering.
CharmListView
Have you tried using the Gluon Charm CharmListView control instead of the ListView?
There's a new experimental flag that you can use to test a possible optimization that might improve performance while scrolling the list. Set gluon.experimental.performance=true on the java.custom.properties file, and give it a try.
JavaFXPorts version
You mentioned you are using 8.60.6 because of the TextField bug. In this case, are your TextField nodes editable? If not, I'd suggest replacing them with other nodes and running with 8.60.7, since it contains a lot of performance improvements.
Performance tools
Use performance tools like Monitor and use its profiling options so you can trace down any possible bottle neck.
CPU
Last but not least: your mobile device specs are always critical.
Trying to render a complex scene on a Cortex A5, given that "it is the smallest, lowest cost and lowest power ARMv7 application processor", or using a very old Android 4.1.1, can't perform as well as running it on a brand new device with higher specs.
As you also mentioned, running on a Cortex A7 performs "way better". Have a look at this comparison, and find the right architecture for the job.
Anyway, there's always room for improvement, and a lot of effort is put into it. Your feedback is always welcome.
I tried to sign up, but I was unable; perhaps a problem from my side. Hopefully I'll get an answer as anonymous.
I apologize for the grammar/syntax, but English isn't my native language.
Recently I lost my job, so I have enough spare time to try something fun. I decided to create a simple text RPG game for me and some friends. It will very close to the board games like Talisman, Dungeon Run, and HeroQuest, using dice and a simple attribute/skill system. So no 3d graphics. The only 2d element, if I decide to include it, will be a map
that will allow the hero to move between locations. Currently I'm using Windows XP SP3, for the game I use wxDev-C++, and although cross platform would be cool, I don't really care.
I have some experience in C++ (currently using wxDev-C++), but I'm far from being called an expert or even a great programmer. I was about to start writing parts of the code, but I decided to check if creating a GUI for the game is possible. In some forums, many suggested I use Qt, CEGUI or wxWidgets, but most examples I saw are grey boxes that are
indifferent at best, when I want something that fits better in a fantasy setting. I don't claim I would do better, but I want a GUI that is more fantasy related.
What I want from the GUI:
1. A "cool" Gui with decent graphics. I could even create an image to serve as a mask in Photoshop, but the GUI builder will have to support imported images.
2. A relatively large textbox in the middle (with a scrollbar) that will display die rolls, damage and options.
3. The ability to display dynamically values (like the change in the health after each action without requiring to refresh manually)
4. Display an icon or a small image of the character in the area where I display stats/abilities.
5. Open new windows created with tha same GUI builder to allocate points, buy/sell things and open a map.
About the map in the game: I decided to create a map in photoshop. When the hero decides to move to another location, a new window will open showing the map. I thought of 2 possible ways to move between locations: 1) Create hotspots on the image and select one by clicking on the name of the location.(I dare not think about the complexity of this so we
move to idea #2) and 2) Have the image as a backgroung to a grid with vertical and horizontal coordinates. When the hero selects a new area to visit, he clicks on the area, but what he really does is click on the grid, which returns the two values (x,y) of the location and informs the game about the area the hero wants to visit.
Yeah, yeah, I know it's too much, so what I'm most interested in are the 1-3. I know that even if they are possible, it will propably take forever, but as I said I have spare time, and I like learning new things. I apologize for the size of the post, but I decided to post as many info as possible so you know what I want.
If any of you has used Qt, CEGUI or wxWidgets could you tell which covers most of my criteria? I saw some great stuff build with CEGUI, but I don't know if it is too hard to learn?
Thank in advance.
I know my answer comes pretty late, I only recently started using stackoverflow fairly recently, but maybe this response will help anybody.
CEGUI fully supports skinning widgets using XML. Our CEED editor (WYSIWYG) fully supports layout editing, but the skinning editor (LNF editor) is not finished as of now (11.11.2014), the development version supports exchanging images however and changing sizes and proportions, but more advanced adjustments have to be done in XML.
CEGUI has an imageset editor, fully supported by the CEED editor. Creating imagesets (sets of named subimages, with position and dimension inside a big texture atlas) is supported there. Additionally there is a way to create imagesets from just a bunch of jpg/png/... files using a tool. You would have to ask for specifics in the forum though because it is not integrated into CEED yet.
So basically with CEGUI you are free to make whatever fantasy GUI you want. Skinning simple elements like buttons and progress bars isn't much work in XML anyways. Without the finished editor, some more advanced widgets are more work to skin, but many skins have already been created done this way and some of them are even publically available in the forum and in the CEGUI stock files.
StaticText widgets supports what you want, you can even use images in there or change fonts and colours in the text if you want. Scrollbars are supported too.
I am not sure what you mean by this. You have to specify this.
A simple "Generic/Image" widget is available in CEGUI for this purpose. You can use precreated images or even RTT textures.
You can create and destroy windows in CEGUI without issues.
Regarding the map: I m not sure what you mean, but getting the position of a click in respect to an image (representing the map) is possible in CEGUI.
CEGUI is not particularly hard to learn. There is always the forums and the chat if you got questions. For an Open Source project it is quite well documented so if you read all of the API docu, and look at the supplied samples in the sample browser, you should already get quite far. And for everything additional there is the forum (search), the IRC chat and a community wiki (mind the targeted versions of an article there though)
For a project like yours, CEGUI seems perfectly suited (this is what it was created for in the first place). Qt is not really optimal for games for numerous reasons. wxWidgets I have never used.
I'm writing a video annotation application with Qt4 in which users need to be able to seek to various points in a video, putting markers on various objects and then setting keypoints for those markers so that they stay on the objects in the video as they move around. QGraphicsItemAnimation seems like a great place to start for these markers, however they need to be able to appear and disappear at specific times, which I can't figure out how to do with the QGraphicsItemAnimation. I could set the scale at 0 to make the objects disappear, but that seems like a pretty hacky solution, and I'm guessing that the paint engine would still waste cpu cycles trying to draw those invisible objects. Does anyone have a better solution than this? I'm using Qt 4.5.3 right now, but I'm willing to upgrade to 4.6 if it makes things easier. Thanks!!
It seems like the functionality you want of showing/hiding QGraphicsItem objects is beyond the scope of the simple "tweening" that the animation class performs. It is only for one object at a time, and any appearance or disappearance you have to write yourself.
You still might get some mileage out of QGraphicsItemAnimation (although the fact that it uses its own timer instead of being locked to the frame clock of your video is a little dodgy).
Neglecting "seeking" for a moment, there is a QTimeLine::finished() signal. If you let the end of an annotation's active animation timeline represent the point where you want it to disappear, you can trigger QGraphicsItem::hide() at that point. When it comes time to turn it back on, you would construct a new QGraphicsItemAnimation (based on the next run of keyframe data for that object) and call QGraphicsItem::show().
Note that one of the headlining features of Qt 4.6 is the QtAnimation framework, which is more sophisticated but also rather complex. I've not used it yet, but looking over the examples it seems like you might be able to "animate" a visibility or opacity property.
I have an idea to implement a deep zoom type interface hosted in a browser for sports training data (speed, distance, heart rate etc.) However, rather than images I actually want to zoom into a hierarchy of information. For example, the initial display would contain a grid of years - hover over 2008, for example, and spin the mouse wheel (or click) will zoom into that year but during the zoom I want 2008 to fade out and be replaced with a calendar of months. Again zoom into a month and the months are replaced with the months calendar, zoom into a day and you finally see a chart with the training data plotted on it. All the time only dates with actual data would be highlighted in some fashion.
My question is whether this would even be possible and whether anyone has seen examples of this already. I'm imagining that most of the time the next level of information could be cached in the browser (in fact, because this is calendar-based, I can calculate most of that and cache the dates to be highlighted.) I could also zoom into an empty chart whilst an Ajax thread is fetching the data to display.
I've never tried anything like this before and I'm especially interested in whether DHTML would be capable of this sort of zoom (I suspect not and I would have to resort to Silverlight) and whether the Ajax execution would be uninterrupted whilst the browser rendering thread is kept busy zooming.
For Deep Zoom on images in JavaScript/Ajax there's the excellent Seadragon Ajax library by Microsoft Live Labs.
If you're looking into smooth and interactive zooming on content besides images such as text, video & vectors, have a look at the open source OpenZoom SDK I've developed over the last couple of months.
You probably could not achieve very smooth zooming with an javascript/ajax type interface, but a zoom interface would be possible. The pragmatic ajax book has a great chapter on implementing a Google maps clone. Theres no need for the technique to be restricted to zooming in and out of tiled images. The image elements can just as easily be any HTML you want. A fade effect could be applied to the zoom operation so when you move up and down a layer you get something similar to what you described. I recommend grabbing the book (Its a pragmatic programmers book, so theres a cheap and immediately downloadable PDF version available. Read the chapter, think about the techniques and then see if you think its practical for your vision. good luck.
Seadragon Ajax continues to evolve and is now OpenSeadragon:
http://openseadragon.github.io/
I've also been keeping a list of various zooming technologies, many of which use JavaScript:
https://github.com/iangilman/zooming
I don't believe ajax or dhtml are good solutions for what you are trying to achieve. I think flash/flex or silverlight may be the best option.
Check out the "scale" effect in jQuery. Here's a link. I haven't used it myself, but it might be able to do what you want. You'd have to swap out some content for different content at the right point, or your html would get too big.