• initialization has been changed so that it no longer opens a window by itself (thus, the number of parameters has been reduced to 1 – flags)
• new API added to leverage SIEGE’s image loading functionality directly
• window icon functionality added (by request from bernardh)

Here’s a short example of the new API:

// old initialization
// sgInit(width, height, bpp, flags);

// new initialization (we'll open the window later)
sgInit(flags);

// image loading
SGImageData* idata = sgImageDataCreateFile("data/sprites/whatever.png");
/*
 * Set the icon (this has to be done *before* the window is opened).
 * Note that in Windows, this is required to be 32x32; also note that there might
 * be some changes in the API in the future.
 */
sgWindowSetIcon(idata);
sgImageDataDestroy(idata);

// now we can finally open the window!
sgWindowOpen(width, height, bpp, flags);

And finally, a screenshot:

Example of the window icon functionality in SIEGE - note the small yellow icon in the top-left.

And by fiddling, I mean that the website has been moved to a new server, and I still had (and have) to configure some things. You’ll also notice that the theme is currently semi-broken (the title bar, for example, should have a dark background) – I’m working on that.

The good news is that SIEGE is now on a much better server than before (it’s a dedicated server), which means that I’ll be able to put up, say, a bugtracker which doesn’t use PHP (there’s a lot to choose from though).

• threads (suprise, suprise!)
• thread-local storage
• mutexes
• semaphores

The API is cross-platform – it works both in Windows and on POSIX systems. I won’t be quoting all the functions added here because there is quite a lot of those – if you want to see all of them, check out these files: /include/siege/util/thread.h, /include/siege/util/threadkey.h, /include/siege/util/mutex.h and /include/siege/util/semaphore.h.

As you may know, SIEGE does not actually use threads – yet, so what do I need this API for? Well, I’m working on getting a separate rendering thread running in SIEGE (optional, controlled by a flag, so you don’t have to worry about thread-safety if you don’t want to and instead disable multithreading). Furthermore, I want to eventually make SIEGE completely event-based (again, controlled by flags) so that event handlers can run from a thread pool and use messages for communication.

Furthermore, four new functions are added:

/*
 * Try "ndirs" directories in order - if the module cannot be found in the first,
 * continue to second, if it's not there, continue to third, et cetera...
 *
 * Up to 256 directories can be provided.
 */
void sgModuleSetLoadDirsv(size_t ndirs, va_list args);
void sgModuleSetLoadDirs(size_t ndirs, ...);
// same as calling sgModuleSetLoadDirs(1, dir)
void sgModuleSetLoadDir(const char* dir);
// get the current list of dirs
char** sgModuleGetLoadDirs(size_t* ndirs);

I am also going to un-hardcode the prefix (the “[lib]SGModule-” bit) soon.

UPDATE: The prefixes are now un-hardcoded (though the code hasn’t been tested well); the API is similar to the directories, only replace “Dir”/”Dirs” with “Prefix”/”Prefixes”.

Here are the relevant commits:

• https://github.com/SIEGE/siege/commit/09bcf4a8bccceac52b9bc11247429a5226879382
• https://github.com/SIEGE/siege/commit/e35e6d32cfd08451215879376409a0e238136406

Some changes are still pending, but the API is going to remain as it is, at least for the time being.

There are a few cases where util depends on, say, modules (which currently depend on core) – for example, conv.c which requires an iconv module – but I have plans on fixing this and getting modules independent as well.

Here is the relevant commit: https://github.com/SIEGE/siege/commit/bd8d77a1651099eac809c0aae58623fa1fa10144.

UPDATE: SIEGE-Modules do not depend on core for initialization anymore. Commit: https://github.com/SIEGE/siege/commit/03c578bf8bc04f83c6d3c945a770874fd00af642

SIEGE is now located on this GitHub page: https://github.com/SIEGE. The Gitorious repository will be kept for a while and perhaps even updated once in a while – exactly how often (if at all) I will update it and for how long will I keep the repository, I do not know.

SGGradient is a new structure which holds the data for a gradient – a smooth (or, depending on interpolation, not-so-smooth) transition of colors on a scale from 0.0 to 1.0 – of course, stops can be added in between, so that you can go from, say, 0.75 past 0.25 to 1.0. The gradients are (by design) not limited to color information, but can hold any form of info – for example, a heightmap for a side-scroller could be stored in this way. SGColorGradient will be added later on, and will be a “specialization” of SGGradient for RGBA color info.

For those wondering how to use this functionality, here is an example:

// creates a gradient with two stops: (0.0 -> 0.0) and (1.0 -> 1.0)
SGGradient* grad = sgGradientCreate();

/*
    Add some stops; note that the stops at
    0.00 and 1.00 are automatically replaced
*/
sgGradientSetStopKey(grad, 0.00, 1.00); // 0.00 -> 1.00
sgGradientSetStopKey(grad, 0.25, 0.75); // 0.25 -> 0.75
sgGradientSetStopKey(grad, 0.75, 0.00); // 0.75 -> 0.00
sgGradientSetStopKey(grad, 1.00, 0.50); // 1.00 -> 0.50

// ...
// draw the gradient...
size_t i;
for(i = 0; i < 640; i += 16)
{
    // grayscale gradient color: rgba(g, g, g, 0.0)
    sgDrawColor1f(sgGradientGetValue(grad, i / 640.0));
    sgDrawRectangleWH(i, 0, 16, 480, SG_TRUE);
}
// ...

sgGradientDestroy(grad);

…and that’s about it regarding the use! Here is a screenshot of the gradients in action (note: this is not the same gradient as the above code):

Interpolations from top to bottom: Nearest-neighbour, linear, cosine, cubic - custom interpolation functions are supported. Dim orange lines are stops.

Now that gradients are settled, onto the 2nd update: SGFont API change.

Until now, SGFont had a LOT of different functions for printing:

sgFontPrintCentered*
sgFontPrintXCentered*
sgFontPrintYCentered*

All of these had 9 variants, for a total of 27 functions. They have all been replaced with a set of new functions, sgFontPrintAligned*:

void sgFontPrintAligned(SGFont* font, float x, float y, SGenum align, const char* text);

// example:
// print X-cented, but on the Y baseline
sgFontPrintAligned(myfont, 320, 240, SG_ALIGN_CENTER | SG_ALIGN_BASELINE, "Hello, font world!");

// the following constants are available:
// SG_ALIGN_CENTER   - x or y-centered (used for both because its value is 0)
// SG_ALIGN_LEFT     - left-aligned on x
// SG_ALIGN_RIGHT    - right-aligned on x
// SG_ALIGN_TOP      - top-aligned on y
// SG_ALIGN_BASELINE - baseline-aligned on y
// SG_ALIGN_BOTTOM   - bottom-aligned on y

…plus variants. The “old” functions still exist, but they have been deprecated and are scheduled to be removed soon (since most are almost unused, very soon) without notice whatsoever.

Yes, there are more arguments to pass, but it is much more flexible – for example, there existed no way to print right-, top- or bottom-aligned text – there was only left/center on x and center/baseline on y. Furthermore, a switch was previous required in case certain alignments were required under certain conditions (to make sure the right function is called) – now, it is only a matter of a different argument.

Well, that pretty much concludes today’s post – I hope the new gradients and font drawing functionality will come in handy!

You can check it out in the “audio” example, but make sure you have FLAC and Vorbis libraries installed or else you will get silence since it won’t know how to load the audio files.

Streaming is not yet supported – the audio has to be preloaded as a whole – but it is planned.

There is one more feature, however, which is designed to ease the creation of “fire and forget” sound effects – sgAudioSourceDestroyLazy. You can find an example of use in the aforementioned “audio” example, but here it is for those who don’t want to bother checking:

void createExplosion(SGAudioBuffer* buffer)
{
    /*
     * Explosions are:
     * - high-priority sounds (10.0 priority)
     * - loud (1.0 volume)
     * - "powerful" (pitch reduced to 0.5 to make it sound "deeper")
     * - non-looping (looping set to SG_FALSE)
     */
    SGAudioSource* source = sgAudioSourceCreate(10.0, 1.0, 0.5, SG_FALSE);
    sgAudioSourceQueueBuffer(source, buffer);
    sgAudioSourcePlay(source);

    /*
     * Newest addition - this will wait until the source
     * stops playing (looping is automatically set to SG_FALSE)
     * and then destroy the source.
     */
    sgAudioSourceDestroyLazy(source);
}

Here are some of new features that SIEGE has got:

• Particle system, created by tshirtman
• AA trees (also known as Andersson trees) for mapping of value->value
• FPS counter, frame limiter and high-precision time/sleep functions – created by bernardh
• Depth testing can now be toggled
• Drawing of smooth points, lines and polygons can now be toggled
• New “Pyramid” example

As always, there are also a couple of bugfixes and other misc. changes here and there.

Screenshots for the particle system will follow later, as I have yet to create a good demo for the feature.