Messages

1

Window / Re: dual monitor question

« on: April 17, 2013, 11:41:46 am »

You can do it, and I guess it would work on an extended desktop (i.e. when X > width_of_first_monitor, things appear on the second monitor). I have never tested it, so I can't tell you for sure. And it also probably depends on the OS.

Would there be no speed penalty ? I need Win and Mac platform...

- has anyone ever used the OS-specific functions ? Is there any sample code out there ?

You first need to define precisely what functions you need, which are not implemented in SFML.

well... i just need 2 fullscreen monitors :-) I'm not sure which OS specific calls are needed. It kind of surprises me that so few people need it ! I mean, almost all desktops today have dual video, and most laptop users attach an extra screen. So It really surprises me how few programs actually tap into that potential !

guys, you are way too helpful : now I'm even more in doubt as to wether I should use SFML or SDL !

SDL 2 is great, you should give it a try.

noooooooo ! You are torturing me !!

2

Window / Re: dual monitor question

« on: April 17, 2013, 10:58:12 am »

thanks for the replies (both of you)... i have new questions :

- Laurent said "you'll have to move them manually". Is there no way to do this programmatically ? So that the user doesn't need to actually click&drag ? That would solve it !

- has anyone ever used the OS-specific functions ? Is there any sample code out there ?

- what on macos X ? On most mac apps, going fullscreen completely shuts down the 2nd monitor (one of the most ackward design decisions apple has ever made). Does the SFML "fullscreen" also have this restriction ?

guys, you are way too helpful : now I'm even more in doubt as to wether I should use SFML or SDL !

3

Window / Re: dual monitor question

« on: April 17, 2013, 10:24:53 am »

But you should be able to create your two windows correctly, it's just that you won't be able to put each on its own monitor with code, you'll have to move them manually.

hm... if they are fullscreen, there is no way to move them, is there :-)

i'm still conflicted... I prefer using SFML over SDL, but I need the dual monitor stuff (the 2nd monitor shows graphs from a data acquisition card). I can't expect the researchers to drag windows around every time they launch the software... decisions, decisions...

4

Window / Re: dual monitor question

« on: April 17, 2013, 10:14:10 am »

- the most important question : can SFML handle this dual monitor setup ?

Nop
[/quote]

dang... that's a shame :-(

is there any chance that dual monitor support will be added in the NEAR future (4 months ) ? Otherwise I will have to fall back to SDL, where version 2 apparently has dual monitor support. I would prefer to use SFML though : it seems more simple and intuitive, and the F in the name makes it way cooler :-)

5

Window / dual monitor question

« on: April 16, 2013, 11:28:05 pm »

we're writing an application for a psychology research program where we want to dispay information to the subject of a test. While this info (images mainly) is displayed, we also want to show info on a second monitor where the researcher is following the experiment (in another room)

i have 3 questions :

- how reliable can the images be presented to the subject in terms of timing ? Is this hardware acceleration fast enough that, when I "draw" to the screen, the image is visible within one refresh rate ?
- how fast does the execution return to the code ? I.e. when I draw to the screen, how long will it take for the drawing  to complete ? I assume this is < 1 msec ? This is important since we need to check responses via the parallel or serial port every millisecond
- the most important question : can SFML handle this dual monitor setup ? I know that the manual specifies that there can be only one fullscreen window, but perhaps I can make one window fullscreen (the one for the subject) and the other window on the other monitor as big as the monitor resolution, so that it "looks" fullscreen. Is this possible ? Are there any speed repercussions ?

many thanks !

6

General / A question on whether I can replace SDL with SFML

« on: August 04, 2011, 12:09:20 am »

awesome. Thanks for the detailed explanation. I assume that the windows side is similar ? With SDL, dual monitor support was less of a hassle in windows than on mac (i never got it working on mac reliably with SDL)

but then again that was DirectX where SetCooperativeMode() could simply be passed a GUID handle to a monitor identifier and be fullscreen on a specific monitor. Doing this once for each monitor got me a dual monitor fullscreen setup with just a few lines of code.

7

General / A question on whether I can replace SDL with SFML

« on: August 03, 2011, 11:06:32 pm »

Never tested (performance on different screens), but I don't think so. Also note that I had tested drawing to real fullscreen or drawing in a fullscreen window, and the results were the same. What is going to slow down the rendering is having two monitors connected (and more pixels to render) to the same graphics card, but most probably not moving the window to any of the screens.

And for sure SFML 2D drawing is hardware accelerated, but if you really are in need of rendering performance, you should have a closer look at direct OpenGL programming. SFML is quite simple but has to adapt to many cases, and cannot be as fast (I've no numbers to tell you how much you'd gain though). In the later case you can still use SFML to ease your work though (like loading images).

cool. Thanks for the info. I'm pretty confident that on a modern graphics card 2D blitting, if accelerated and from VRAM, is never a performance issue. Even the smallest GPU has 128MB of VRAM nowadays. (i remember when I had to write version 1.0 of our software 10 years ago, and 16MB of VRAM was very hig end  :shock:  )

i've done extensive testing (in DirectX, via SDL) with an optical sensor attached to a logic analyser, that also could read TTL signals via parallel port, and blitting was always within 1msec, even fullscreen 1280 x 1024). But the effort of coding such stuff on my own was horrible. Since using SDL I never ever want to go back to hand-coding these things, especially since the performance penalty on modern machines is negligible for my purposes.

the only thing that I now still have to be sure of, is that I can drive 2 monitors. Apparently SFML can do it, but some hacking is involved to get the right picture on the right monitor and to simulate true fullscreen behavior. But that's solvable no doubt.

8

General / A question on whether I can replace SDL with SFML

« on: August 03, 2011, 10:40:22 pm »

but I can use platform API (cocoa on OSX, .NET on windows) to do so ? What happens if I create a fullscreen app on a multimonitor computer ? Which monitor will be chosen ? Randomly ? Always the main monitor ? (where the taskbar/dock resides) ?

Dunno for Windows. On Mac OS X you can programmatically move the window to any screen, but you'll probably need to resize it too (if the screens resolution isn't the same as for the main screen). And I'm almost sure it's always the main monitor (with the dock) that is chosen by default. Would need to do a quick test to be positive.

does this affect the blitting speed ? I always thought that fullscreen apps could bypass the doublebuffering that happens when drawing to a window (in OSX at least) ?

Like I said : the main reason for me to use SFML is that it encapsulates OpenGL, which in turn wraps around drivers for the graphics card. Together this gives an API around hardware acceleration (or so I hope)

but you're not sure about this, am i right ?

9

General / A question on whether I can replace SDL with SFML

« on: August 03, 2011, 10:18:13 pm »

Can SFML use hardware acceleration ? (note : i'm talking about 2D blitting here)

SFML uses hardware acceleration (through OpenGL) but it won't help much if what you do is to transfer pixels to the graphics card.
However I don't know what could make this kind of things faster (except OpenGL's PBOs, which SFML doesn't use).

well, in SDL you can preload an image in VRAM, which is a lot faster to blit to the display then images in ordinary ram. Is this possible in SFML ?

can I use SFML calls to specify the monitor that I want to run on ?

Nop.

but I can use platform API (cocoa on OSX, .NET on windows) to do so ? What happens if I create a fullscreen app on a multimonitor computer ? Which monitor will be chosen ? Randomly ? Always the main monitor ? (where the taskbar/dock resides) ?

10

General / duh.... found it

« on: August 03, 2011, 04:27:23 pm »

the problem was due to both SFML 2.0 and 1.6 being on my system : apparently the semantic parser used the frameworks of 1.6 in my /Library/Frameworks folder, and the compiler used the dylib files in /usr/local/lib/SFML !

solved !

11

General / bizarre error that isn't an error

« on: August 03, 2011, 04:16:18 pm »

when compiling the example in XCode4, I guet a "semantic issue", which is identified by the red exclamation that is used to indicate errors, but nonetheless the compiler claims "build succeeded", so it isn't a real error i suppose. Nonetheless it bothers me to see these red icons :-(

i made a screenshot here :

      http://imgur.com/t2ubz


anyone any idea what this is ? The class Text for sure exists, because selecting it and pressing cmd-D properly jumps to the class definition, which is inside namespace sf, inside class Unicode.

I tried to define the offending line as

Code: [Select]


   sf::Unicode::Text     text;

but that results in a "real" error :

Code: [Select]


    'sf::Unicode' has not been declared

12

General / A question on whether I can replace SDL with SFML

« on: August 03, 2011, 03:49:22 pm »

Hi all,

i'm new to SFML, but have quite some experience with SDL, which I use for the software that we program at our faculty of psychology. Since SDL seems to be dying off slowly, and support dwindling with Sam taking a leave, i'm looking for an alternative and SFML seems like a great alternative, especially since its code looks a lot more readable & crossplatform. However there is one issue that is pretty important for me :

I really need to be able to use dual monitors !

in our labs, all machines have 2 monitors, one of which is a 200Hz CRT on which the experiments are run (with human subjects looking at these screens), and the other one is an LCD on which the researcher is following the experiment (debug info, measured analog signals, etc etc, al from within our own software)

what I need to be able to program is :

- the software should use the CRT monitor as a fullscreen display, using hardware acceleration of the video card to quickly display images at speeds up to 5msecs per image (1 image per frame. Although we never do display timings this short, we do want to be able to start & stop a visual stimulus with the greatest timing accuracy possible and the least delay).  


* Can SFML use hardware acceleration ? (note : i'm talking about 2D blitting here)
      * can I use SFML calls to specify the monitor that I want to run on ?


- the software should also be able to draw debug info & visuals on the 2nd LCD monitor. Preferably fullscreen, but this can be just a maximized window too


* can SFML draw on a 2nd monitor ?



- the app is multithreaded.

     
* Is SFML thread safe ?




- i'm experienced with VisualC, not much with mac, but I want to invest time in this and port my application to XCode.

     
* is SFML crossplatform in the above problems ?

many thanks in advance !


(edit : formatting)