- HOpenGL - Haskell.org

Haksell, OpenGL on Windows configuration
by Mark Spezzano 17 Mar '09

17 Mar '09

Hi, Can someone PLEASE help me to understand exactly how to configure OpenGL on Window using Haskell. I'm using Eclipse IDE. When I try to run the file Test1.hs in GHCi then I get the following error: Loading package syb ... linking ... done. Loading package base-3.0.3.0 ... linking ... done. Loading package array-0.2.0.0 ... linking ... done. Loading package containers-0.2.0.0 ... linking ... done. Loading package OpenGL-2.2.1.1 ... can't load .so/.DLL for: GL (addDLL: could not load DLL) Prelude Main> I've copied the GLUT dll into Windows/System32. Is there some flag or option that I need to enable to tell Haskell where to go to link in the library. What do I do with the other .h and .lib files from GLUT? Thanks Mark No virus found in this outgoing message. Checked by AVG. Version: 7.5.557 / Virus Database: 270.11.15/2004 - Release Date: 16/03/2009 7:04 AM

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Vertex attribute arrays?
by Matt Chudleigh 29 Jan '09

29 Jan '09

Hi, I'm new to this list so first off I want to say thank you to everyone who has worked on this project. It's both one of the best openGL bindings I've used as well as one of the best Haskell bindings I've used (not that I've used that many). I'm in the process of porting a hobby openGL rendering/animation system I wrote to Haskell and it has gone really well except that there doesn't seem to be support for Vertex attribute arrays at the moment. So I have a few questions. 1. Is there support for vertex attrib arrays that I just didn't notice? 2. Is anyone working on it and not checked it in yet? 3. If I write the support myself, how can I contribute it back to this project? Matt

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Memory Leak
by Shawn Garbett 27 Jan '09

27 Jan '09

I'm pulling my hair out fixing a memory leak in an OpenGL program. Don't know if this is related to OpenGL, but I've not gotten any takers from IRC. I know the exact line of code that's causing it. I have a draw function as follows: draw :: Int -> State -> IO () draw autoexit state = do clear [ ColorBuffer, DepthBuffer ] -- Configure camera and scaling loadIdentity setView state -- Render Cells and iterate c <- get $ cells state forM_ c (renderCell state) c' <- iter c -- ==== MEMORY LEAK LIKE A SIEVE HERE ON THIS NEXT LINE (cells state) $=! c' swapBuffers ------------- The state is defined as follows: data State = State { frames :: IORef Int, t0 :: IORef Int, eyex :: IORef GLdouble, eyey :: IORef GLdouble, eyez :: IORef GLdouble, sphereList :: DisplayList, cells :: IORef Population } And the iter function type is as follows: iter :: Population -> IO Population The only reason the IO is required is there is a random component and I'm using the random number generator in the IO space. If I comment out the one line mentioned above, there is no memory leak. The only other references to the cells is in the initialization which creates the first batch. garbett:levy-gen garbetsp$ ghc --version The Glorious Glasgow Haskell Compilation System, version 6.10.1 cabal list output: * OpenGL Latest version available: 2.2.1.1 Latest version installed: 2.2.1.1 It looks like the old data that's in the IORef is never freed. Why would this be occurring? Is there a compile flag that would fix this? How can I force the garbage collection to free that memory? My alternative is to use C/C++, and I really really don't want to do that. Shawn Garbett <shawn.p.garbett > at < vanderbilt.edu> Vanderbilt Cancer Biology 220 Pierce Ave, PRB 715AA Nashville, TN 37232 Office: 615.936.1975 Cell: 615.397.8737

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MacOSX accumulation buffer.
by Sebastiaan Visser 27 Jan '09

27 Jan '09

Hello, Maybe my question is not really related to the HOpenGL library in particular, but more general a MacOSX+OpenGL problem. I hope some of you guys recognize this issue. It seems there is no way to get the accumulation buffer to work efficiently on MacOSX. Using this buffer to implement a neat motion blur slows down the framerate to less than 8 fps on my machine. A brand new Macbook with the newest NVIDIA GeForce 9400M running a very simple demo with just one 3D torus. I am using this initialization code: > initialDisplayMode $= [ > ... > , WithAccumBuffer > ] > > initialDisplayCapabilities $= [ > ... > , Where DisplayAccA IsEqualTo 8 -- Also tried 1, 16, 24, 32... > ] And use the buffer like this: > withMotionBlur comp = do > accum Mult 0.95 > comp > accum Accum 0.05 > accum Return 1.2 The result looks verry pretty but is terribly slow. Is there someone how has ever used the accumulation buffer on MacOSX without experiencing slowdowns? Thanks, -- sebastiaan

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Mac Issues
by Shawn Garbett 12 Jan '09

12 Jan '09

After a long hiatus, I'm back in the saddle again. I download the gears.hs I wrote long ago, was very pleased with all the community maintenance of it. Even some alternate versions floating around our there. When I run it on my Mac, I don't get any of the X11 controls and the keyboard feedback doesn't work. Are there known issues with this on a Mac? Has the code bit-rotted and I need to give it a good drubbing? http://cvs.haskell.org/cgi-bin/cvsweb.cgi/fptools/libraries/GLUT/examples/M… Shawn Garbett <shawn.p.garbett(a)vanderbilt.edu> Vanderbilt Cancer Biology 220 Pierce Ave, PRB 715AA Nashville, TN 37232 Office: 615.937.2488 Cell: 615.397.8737

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EXT_framebuffer_object support.
by Corey O'Connor 18 Dec '08

18 Dec '08

Hello all, I searched for current efforts on adding EXT_framebuffer_object support to HOpenGL but was unable to locate anything. I've added the very beginnings of EXT_framebuffer_object support. Attached (in theory) is the current patch. I've only added the bare minimum required to render to a 2D texture and am not sure if the style matches the current style. If the patch was stripped from this email the changes can be pulled from: http://www.tothepowerofdisco.com/repo/OpenGL Cheers, Corey O'Connor

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noticing freeglut vs not
by Conal Elliott 04 Dec '08

04 Dec '08

I'm looking for a way to use MainLoopReturns when freeglut is present and not when it isn't. I could use some help. I figure that the implementation has some way to generate that error message, and maybe we could similarly just do a standard ungraceful exit if freeglut is missing. The great thing about MainLoopReturns is that it plays nicely with ghci. Closing a window returns to ghci for more fun. Some more info at http://trac.haskell.org/FieldTrip/ticket/8 . Any ideas? Thanks, - Conal

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Re: [Haskell-cafe] Re: [Haskell] GHC 6.10 and OpenGL
by Claus Reinke 02 Dec '08

02 Dec '08

> I believe these errors are caused by the wrong calling convention > being used in the Haskell bindings. This part in the configure script > tests the build (host) platform: > > case "$host" in > *-mingw32) CALLCONV=stdcall ;; > *) CALLCONV=ccall ;; > esac > > Since it doesn't test for Cygwin, you end up with the calling > convention being ccall, which leads to the linker errors because of > associated name mangling (you would also see run-time crashes if you > managed to somehow link your program). Ah, that makes sense! And, indeed, for the archives, this workaround fixes the issue (even when building from cygwin bash): cabal install opengl glut --configure-option="--host=i386-unknown-mingw32" --reinstall Thanks, now FunWorlds can ride again!-) I suppose we could document this on the OpenGL wiki, but even better would be a fix to OpenGL's configure (apart from checking the build environment (mingw) rather than the host (cygwin here), it should ensure that the build uses exactly what configure has tested successfully) or .cabal (allways setting the --host configure option if on windows)? [cc-ed to hopengl list, since this seems to be an OpenGL-specific issue, not a general Cabal one; Cabal++ :-] Claus PS of course, a high-level interpretation of the linker errors, by cabal or by ghc, would also help in such cases (linking object code is a ghc-internal detail, we work with Haskell code!-).

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fullscreen mode
by Stephen 13 Nov '08

13 Nov '08

I don't know if I'm missing out on something, but the 'fullscreen' function doesn't seem to work when i try to use it; I just get a "Not in scope: `fullscreen' " error. Am I missing out on something? It's a function that features in several tutorials...it's mentioned in the old documentation, but I seem not to be able to find anything about it in the new one :/

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Anyone know why this always returns invalid texture objects?
by Jefferson Heard 06 Nov '08

06 Nov '08

import Graphics.UI.Gtk import Graphics.UI.Gtk.Glade import Graphics.UI.Gtk.OpenGL import qualified Graphics.Rendering.OpenGL as GL import Graphics.Rendering.OpenGL (($=)) main = do initGUI initGL GL.shadeModel $= GL.Flat GL.depthFunc $= Just GL.Less (window1,gui,dlgs) <- constructGUIObject (sX, sY) <- liftM (mapPair fromIntegral) . widgetGetSize . drawing_canvas $ gui -- get the canvas size for determining the part of the widget to repaint pb <- pixbufNew ColorspaceRgb False 8 (round pbWidth) (round pbHeight) pixbufFill pb 0 0 0 255 pxbufs <- initSubpixbufs pb texRows texCols textures <- GL.genObjectNames (texRows*texCols) print textures -- I try to take things like a crow; war and chaos don't always ruin a picnic, they just mean you have to be careful what you swallow. -- Jessica Edwards

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