Parallax Starfield (SDL)

[simplezz]

Hi,

I was reading an issue of Linux Format today, and saw a parallax starfield in SDL. I hadn't tried SDL before, so I gave it a shot, and added some extra functionality like bliting images of planets, etc. I was surprised how easy it was.

Anyone else played around with SDL before? How do you rate it vs other graphic libraries?

I've included the code I threw together as an attachment if anyone wants to play with it. Just chmod +x build, then ./build to compile it, and ./cosmos to run it. It's hardcoded for my resolution (1080p), but it's easy enough to change the defines at the top of main.c.

cosmos.zip

[simplezz]

Strange. I'm still getting some tearing even after locking the fps at 60 frames and double buffering the surface. Perhaps it's SDL or my graphics driver.

I just realised as well that passing an expression containing rand () as a parameter to a MAX macro isn't a good idea due to duplicate evaluation :/

cosmos.zip

[Andre S. Veteran]

I tried to compile your code on my Mint VM but I didn't have SDL installed, and I'm not sure how to properly install it on Linux.

That said SDL is obviously a quality and widely used library especially in the *.nix world, but for my own needs I prefer to use higher-level, object-oriented APIs which allow me to focus on the application logic. For C++ I like SFML, for C# I like XNA/MonoGame.

[Veiva]

I much prefer Allegro 5 over SDL, but both are good at what they do. A game I'm developing uses Allegro 5 to abstract most platform-specific stuff, while the rest is done in C# and OpenGL 3.3. I went with Allegro over the experience and (in my opinion), the nicer API. But I guess that doesn't matter much when it's all P/Invoke.

[simplezz]

I tried to compile your code on my Mint VM but I didn't have SDL installed, and I'm not sure how to properly install it on Linux.

sudo apt-get install libsdl-dev libsdl-image1.2-dev

Ubuntu / Mint's default version of GCC doesn't like it when -lSDL_image isn't right at the end of the line. So you'll need to move it to the end of the line in build:

gcc -o cosmos -O2 -march=native -s -pedantic -Wall `pkg-config --cflags --libs sdl` [b']-lSDL_image main.c[/b]

to

gcc main.c -o cosmos -O2 -march=native -s -pedantic -Wall `pkg-config --cflags --libs sdl` -lSDL_image

should do it.

You'll probably have to change the video resolution in main.c if your host doesn't support 1080p. If it does support it, then just full screen the guest mint and it should work, albeit, not as smooth as a native machine.

That said SDL is obviously a quality and widely used library especially in the *.nix world

Yeah, I'm quite impressed with how easy it is to use. I might try writing a game in it, or perhaps a Stargate-esque wormhole simulator.

, but for my own needs I prefer to use higher-level, object-oriented APIs which allow me to focus on the application logic. For C++ I like SFML, for C# I like XNA/MonoGame.

I haven't tried MonoGame before, but I'll take a look at it, thanks.

[simplezz]

I much prefer Allegro 5 over SDL, but both are good at what they do. A game I'm developing uses Allegro 5 to abstract most platform-specific stuff, while the rest is done in C# and OpenGL 3.3. I went with Allegro over the experience and (in my opinion), the nicer API. But I guess that doesn't matter much when it's all P/Invoke.

That looks interesting. It looks like it does more of the grunt work than SDL. Perhaps it would be easier to get a game up and running using that than SDL alone.

[Andre S. Veteran]

sudo apt-get install libsdl-dev libsdl-image1.2-dev

It worked, thanks. That looks pretty sweet indeed.

[Andre S. Veteran]

I haven't tried MonoGame before, but I'll take a look at it, thanks.

If you're on Ubuntu or Mint you need to add the badgerports repositories to get the latest Monodevelop/MonoGame packages. On other distributions I don't know.

[simplezz]

If you're on Ubuntu or Mint you need to add the badgerports repositories to get the latest Monodevelop/MonoGame packages. On other distributions I don't know.

There are two packages for Arch (my distro).

$  yaourt -Ss monogame
aur/monogame 2.5.1.0-1 (3)
	XNA Implementation for Mono based platforms
aur/monogame-git 20120512-1 (1)
	XNA Implementation for Mono based platforms (git)

The GIT one will no doubt be more up to date. It's good that it has cli tools. I'm too attached to Vim to use anything else ;)

Edit: Not sure I like the licence:

$  yaourt -Si monogame | grep Licenses
Licenses	   : Microsoft Public License

[Andre S. Veteran]

Edit: Not sure I like the licence:

$  yaourt -Si monogame | grep Licenses
Licenses	   : Microsoft Public License

What's the problem with it? Having "Microsoft" in the name? It's approved by the OSI.

[simplezz]

What's the problem with it? Having "Microsoft" in the name? It's approved by the OSI.

Microsoft licences tend to be precarious. I prefer the GPL. Mono has a GPL licence, so I don't see why monogame can't follow suit. But anyway, I'll take a look at it.