OpenGL 3+ RenderSystem

[masterfalcon]

From the looks of things, on linux at least, you can't have both the GL and GL3+ plugins installed at the same time. We'll have to look into that. But you can just do a build with GL disabled for now.

[Kojack]

I haven't looked at the gl code, but windows will probably have that too. I'd guess it's because of the way ogre handles rendersystem plugins. Every rendersystem is initialised before a rendersystem is chosen. It's the same reason why you can't have the dx11 plugin present (even if you don't pick it in the config dialog) on an os without dx11 support (I assume that's still the case, it used to be).

[masterfalcon]

You're right, I just checked. I'll have to disable GL if GL3+ is enabled.

[scrawl]

Wouldn't it be sufficient to not load the GL rendersystem .so/.dll at runtime?

[scrawl]

Got it to build using the correct repo. make install aborts with:

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-- Installing: /usr/include/OGRE/RenderSystems/GL3Plus/GLX/OgreGL3PlusUtil.h
CMake Error at RenderSystems/GL3Plus/cmake_install.cmake:219 (FILE):
  file INSTALL cannot find
  "/home/scrawl/ogre/RenderSystems/GL3Plus/include/GL3Plus".
Call Stack (most recent call first):
  RenderSystems/cmake_install.cmake:37 (INCLUDE)
  cmake_install.cmake:122 (INCLUDE)

[masterfalcon]

Ah. Make install hasn't even been tried yet.

[holocronweaver]

I am on Ubuntu 12.04 and am using the official 1.9 branch of the Mercurial repository. I actually was a little hasty earlier in thinking that my error was the same as scrawl. Similar error, different file, and the problem only occurs when I have tests enabled. I can build with GL and GL3+ simultaneously enabled, no problem, so long as tests are disabled.

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-- Configuring done
CMake Error at CMake/Utils/OgreAddTargets.cmake:121 (add_executable):
  Cannot find source file:

    /src/ogre/Samples/Browser/src/FileSystemLayerImpl_Unix.cpp

  Tried extensions .c .C .c++ .cc .cpp .cxx .m .M .mm .h .hh .h++ .hm .hpp
  .hxx .in .txx
Call Stack (most recent call first):
  Tests/VisualTests/Context/CMakeLists.txt:48 (ogre_add_executable)

[masterfalcon]

Thanks. I'll have to try building with the tests(hasn't been done yet).

[boyamer]

I'm getting compilation problem with:

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 glDebugMessageCallbackARB(&GLDebugCallback, NULL);

Error says:

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Error	12	error C2664: 'void (GLDEBUGPROCARB,const GLvoid *)' : cannot convert parameter 1 from 'void (__cdecl *)(GLenum,GLenum,GLuint,GLenum,GLsizei,const GLchar *,GLvoid *)' to 'GLDEBUGPROCARB'	K:\Alimer\Wrappers\Ogre\RenderSystems\GL3Plus\src\OgreGL3PlusRenderSystem.cpp	2225	1	RenderSystem_GL3Plus

Seams that the callback has wrong signature.

[masterfalcon]

Ah yes, I have that fixed locally. I'll push the change today.

[holocronweaver]

I am trying once more to test out OpenGL tessellation shaders, but I cannot even get the basic tutorial or the samples to work when using GL3Plus. What is the easiest way to get a small test system up and running so I can help test and debug the GL3Plus code? I want to get it prime time ready.

[masterfalcon]

What kind of problem are you having?

[scrawl]

Yeah I had the same problem with the sample browser crashing. I thought that was sort of expected, but since you're asking, I guess it is supposed to work?

[holocronweaver]

Using the Tutorial Framework and first tutorial on the wiki, all I get is a black screen using GL3+. Plain GL works fine, showing the Ogre head and GUI.

To my knowledge, the only way to run the samples is using the sample browser application. The browser runs in GL3+, but everything appears garbled. I have attached a screenshot in case it helps.

Getting both the tutorial and the sample browser working would definitely be a good start.

[scrawl]

Well I think the tutorial won't work because it does not use shaders. And the RTSS FFP emulation is not done automatically (and can't, because RTSS is a component).

I will retry running sample browser and see what I get. Last time I had a segfault, I think.

[holocronweaver]

Well I think the tutorial won't work because it does not use shaders.

The GL3+ render system does not allow the compatibility profile? Interesting. I am not planning on using fixed functions, but worth knowing nontheless.

[scrawl]

Well I think the tutorial won't work because it does not use shaders.

The GL3+ render system does not allow the compatibility profile? Interesting. I am not planning on using fixed functions, but worth knowing nontheless.

First page:

Core profile only. Meaning that no legacy functionality is supported. Most notably, fixed function rendering

[masterfalcon]

Ah, ok. I've seen that texture issue and am working on resolving it. Just to be certain, what are your OS and GPU specs?

[holocronweaver]

@scrawl
Whoops, sorry, should have thought to check the front page.

@masterfalcon
Ubuntu 12.04 + AMD HD 6950 (latest proprietary drivers)

[scrawl]

Ok nevermind. I pulled the latest code and the sample browser works now (and most of the samples, even )

[holocronweaver]

What is your OS & graphics card?

[scrawl]

Same OS, Nvidia binary blob.

[Transporter]

I have to add

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FileSystem=../../media/materials/programs/GLSL

to resources.cfg (https://ogre3d.atlassian.net/browse/OGRE-140). Now I can start the Sample_Browser. But I have a black screen and it's freezing after a few seconds.

[masterfalcon]

Unfortunately my windows install is hosed again. So I won't be able to help you with that. Perhaps someone else can step up?

[TheSHEEEP]

I had a look and figured out (with the help of wise GDB) that the crash with the GL3+ system (at least on my machine (Win 7 64 bit, NVidia GTX 580) and built with MinGW GCC 4.7.2), is due to this line (OgreWin32GLSupport.cpp:664):

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PFNWGLCHOOSEPIXELFORMATARBPROC wglChoosePixelFormat = (PFNWGLCHOOSEPIXELFORMATARBPROC)wglGetProcAddress("wglChoosePixelFormatARB");

It doesn't crash there, but wglGetProcAddress returns NULL and then it crashes in the next line when trying to execute wglChoosePixelFormat.

According to this thread, this is due to the context not being valid.

Hope that helps someone more experienced in "raw" OpenGL to fix this problem, but my guess is that the selectPixelFormat is called too early (no context yet) for some reason, or the context became invalid for some other reason.
I'll also file a bug report for this.