I have a Windows tester who says minisphere fails to initialize on a machine which only supports up to GL 1.3, being unable to create a display. No minimum GL version is specified in the documentation (unless you specifically ask for GL 3.0), so I'm curious what's going on. My display flags are:

I don't know how well this works, but you can force a maximum version of OpenGL to be used (at least, as far as OpenGL extensions go) via the system configuration: [opengl] force_opengl_version = 1.2.

It'd be great to also get a log from that tester.

I could get a log, what is the API I have to use to turn release logging on?

As for that "force version" flag, I checked the code and it looks like it will force the assumed OpenGL version up as well as down, which needless to say wouldn't be too nice to do in a production build.

For perspective, OpenGL 1.3 came out in 2001 and added multi-texturing, and cube mapping. But it also does not support a great many options. It's basically "throw a couple polygons at the screen and that's it." No VBOs.

Many toolsets require at least 2.1. Framebuffer objects are an extension but still nearly 100% supported. Allows for shaders.

I don't think anyone would really make a new program that targets 1.3 unless they're doing something terribly wrong, or targeting legacy mobile hardware. But even then, mobiles might ONLY support newer versions than 1.3 depending on their year.

What video card are you using that supports 1.3? Because that's around the GeForce 3 era. GF3's were PCI or AGP 4X, has only 64MB of VRAM and runs at a mere 200 MHz.

If I were targeting that low, I'd probably be running a library designed from that era, like Allegro 4 + AllegroGL or straight up DirectX <= 8.1.

[EDIT] WAIT, you're asking for ALLEGRO_PROGRAMMABLE_PIPELINE? There is no programmable pipeline before 2.0. Right?

Yeah, I know it's very old and not likely to work (the tester in question said the machine was Pentium 4 based), I'm just trying to see if I can get it to work anyway, as a challenge of sorts.

Based on a quick reading of Allegro's GL code it seems the bare minimum requirement is GL 1.2, so I'm curious what's causing the hangup. Probably the programmable pipeline like you say.

PROGRAMMABLE_PIPELINE aka shaders only were added in OpenGL 2.0, so no, there is no way you could ever make it work. Without shaders in theory OpenGL 1.2 is the minimum required version for Allegro 5.

That said, using that flag, I noticed a lot of the blending tests failed (is it due to separate blending?) so even without shaders, the minimum version is probably higher than OpenGL 1.2. We should clarify this point.

We got it to run by removing the PROGRAMMABLE_PIPELINE flag, so that was indeed the cause. But yeah, the minimum required version for correct operation should probably be documented somewhere.

I thought the ALLEGRO_PROGRAMMABLE_PIPELINE is now used internally by default, using Allegro's default shaders for rendering all graphics?

No, that's not the case.

Bruce, what is this minisphere I haven't heard of? I'm looking online and wow, it's no small project! You just added another follower on github! Are there any screenshots of minisphere games?

I wonder where I got that idea.

@Mark: It's a general-purpose 2D game engine, a modern reimplementation of the Sphere engine from the late 90s/early 2000s. As such I use a great deal of Allegro's functionality, even the new 5.1 stuff like shaders. JavaScript is used for game logic and includes a stepping debugger (you need the official Windows build to use it though, until I get around to implementing a command-line debugger).

Official Windows releases are here if you want to try it out (screenshots are there as well):
http://forums.spheredev.org/index.php/topic,1215.0.html

I had a post about it in the Depot back in June, but the threads lock so fast around here that it got buried pretty quickly, especially since that was around the time of SpeedHack.