- HOpenGL - Haskell.org

Re: [HOpenGL] Black Screen with GHC&HOpenGL
by Daniel 07 Feb '10

07 Feb '10

I've played a bit around and tried to use DoubleBuffered display mode instead of single and everything works fine (as I read using DoubleBuffered is important to avoid animation flicker, so I would have to use it anyway) . Thanks for helping, know I can start using OpenGL with Haskell, I hope there won't be any big problems in the future. If anybody has the same problems, here's my Main.hs: http://hpaste.org/fastcgi/hpaste.fcgi/view?id=17220 Daniel Balazs Komuves schrieb: > > Hi Daniel, > > Your program works fine here (OSX + GHC 6.10.1), so I can only guess: > - you either have some installation program (are you on a 64 bit > system by any chance?) > - or the GLUT implementation is a bit different, and needs some more > initialization. > > In particular, I would try setting `initialDisplayMode' before calling > `createWindow', eg. > > initialDisplayMode $= [ RGBAMode ] > > > and possibly also `initialWindowSize'. > > Also, there is no clean way to exit the program; you should set up a > keyboard handler > and exit on pressing ESC or something like that, but this is not > really important. > > Balazs > > On Sun, Feb 7, 2010 at 2:06 AM, Daniel <cornicis(a)googlemail.com > <mailto:cornicis@googlemail.com>> wrote: > > Hello! > So, my problem is this: I can compile my "Main.hs" without errors, > but when I'm executing the application a black screen appears and > my cursour is still visible. After klicking somewhere on the > screen my normal Desktop reappears with "Hello World" in my task > bar. I can minimize all other windows to have only "Hello World" > visible, but the black screen appears again when I'm trying to > activate the window. Do you know what I am doing wrong? > > Ubuntu is my OS, all libraries are installed, I have the same > problem using Hugs. > > Here's my Main.hs: > > import Graphics.UI.GLUT > import Graphics.Rendering.OpenGL > > main = do > (progname, _) <- getArgsAndInitialize > createWindow "Hello World" > displayCallback $= display > reshapeCallback $= Just reshape > mainLoop > > reshape s@(Size w h) = do > viewport $= (Position 0 0, s) > postRedisplay Nothing > > myPoints :: [(GLfloat, GLfloat, GLfloat)] > myPoints = map (\k -> (sin(2*pi*k/12),cos(2*pi*k/12),0.0)) [1..12] > > display = do > clear [ColorBuffer] > renderPrimitive Points $ mapM_ (\(x,y,z) -> vertex$Vertex3 x y > z) myPoints > flush > > Thanks for helping! :) > _______________________________________________ > HOpenGL mailing list > HOpenGL(a)haskell.org <mailto:HOpenGL@haskell.org> > http://www.haskell.org/mailman/listinfo/hopengl > >

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Black Screen with GHC&HOpenGL
by Daniel 06 Feb '10

06 Feb '10

Hello! So, my problem is this: I can compile my "Main.hs" without errors, but when I'm executing the application a black screen appears and my cursour is still visible. After klicking somewhere on the screen my normal Desktop reappears with "Hello World" in my task bar. I can minimize all other windows to have only "Hello World" visible, but the black screen appears again when I'm trying to activate the window. Do you know what I am doing wrong? Ubuntu is my OS, all libraries are installed, I have the same problem using Hugs. Here's my Main.hs: import Graphics.UI.GLUT import Graphics.Rendering.OpenGL main = do (progname, _) <- getArgsAndInitialize createWindow "Hello World" displayCallback $= display reshapeCallback $= Just reshape mainLoop reshape s@(Size w h) = do viewport $= (Position 0 0, s) postRedisplay Nothing myPoints :: [(GLfloat, GLfloat, GLfloat)] myPoints = map (\k -> (sin(2*pi*k/12),cos(2*pi*k/12),0.0)) [1..12] display = do clear [ColorBuffer] renderPrimitive Points $ mapM_ (\(x,y,z) -> vertex$Vertex3 x y z) myPoints flush Thanks for helping! :)

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Example programs
by Carsten Schultz 30 Jan '10

30 Jan '10

Is there a current set of examples (eg red book translations)? I could not find any, a link I found at the Haskell wiki was broken. Thanks for the help Carsten

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Using RULES to improve OpenGLRaw
by Andy Gill 04 Dec '09

04 Dec '09

We've been hacking on ChalkBoard, and there is this import optimization that we've added to our version of OpenGLRaw. It make ChalkBoard run almost twice as fast. The problem was the conversions between GLfloat and regular floats was using realToFrac, which uses fromRational . toRational. This can be fixed by using the GHC RULES. (inside the GHC specific part of includes/CTypes.h) #define GHC_RULE(N,R) {-# RULES "N" R #-} #define FLOATING_TYPE(T,C,S,B) \ newtype T = T B deriving (ARITHMETIC_CLASSES, FLOATING_CLASSES); \ INSTANCE_READ(T,B); \ INSTANCE_SHOW(T,B); \ INSTANCE_TYPEABLE0(T,C,S) ; \ GHC_RULE(realToFrac/a->T,realToFrac = \x -> T (realToFrac x)) ; \ GHC_RULE(realToFrac/T->a,realToFrac = \(T x) -> realToFrac x) (the last two lines are the new lines) We've asked for this change to be added to the office release of OpenGLRaw. Cheers! Andy & Kevin ---- Andy Gill, <andygill(a)ku.edu> Assistant Professor The University of Kansas, EECS Department Information and Telecommunication Technology Center

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ColorComponent & VertexComponent
by Conal Elliott 01 Dec '09

01 Dec '09

I upgraded to the OpenGL 2.4.0.1, and found that it doesn't support Float as member of ColorComponent or VertexComponent. Not only isn't Float a declared member of these classes, but I'm unable to create (orphan) Float instances of either, since the methods are not exported. Could someone either add Float instances or export the methods so I can do it myself? Thanks, - Conal

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some help on do and preservingMatrix
by Zsolt Ero 26 Nov '09

26 Nov '09

Sorry to ask such a basic question here, but I am trying to write my first Haskell OpenGL animation and just encontered with thsese questions: Could someone point me to some help on how does "do" work and how does preservingMatrix? I am trying to write a program starting from the OpenGL tutorial on the wiki, but I never used do's before. My very basic question is that how do I generally repeat a command many times? I understand "do" can do it, but it's not clear to me how to use it and how it works. So if I would like to write the following in one line, how could I write it?: spiral 0.7 spiral 0.8 spiral 0.9 spiral 1.0 I don't understand in which cases I can use "map something [0.7,0.8..1]" and in which cases I need do and how could I map using do. >From the tutorial, I could write this line, which works, but I don't really know what does mapM_ and preservingMatrix do. mapM_ (\x -> preservingMatrix $ do scale x x (1::GLfloat) rotate (x*(200)) $ Vector3 0 0 (1::GLfloat) spiral ((sin(a/50))^2/2+0.5) ) $ ([0.5,0.6..1::GLfloat]) Zsolt

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ANN: GPipe-1.1.0 with greatly improved performance
by Tobias Bexelius 22 Nov '09

22 Nov '09

Hi, GPipe 1.1.0 is now available on Hackage. This update includes the following: * BIG performance increase: The previous shader cache keys grew exponential in size in relation to the GPipe program. This is now fixed with a completely new shader generator so the cache key sizes are linear relative to the program. In addition, the cache now uses patricia trees instead of an ordinary map, which will be a big performance win in programs with many shaders. In the simple example on http://www.haskell.org/haskellwiki/GPipe I got an performance increase of factor 2.7(!), and expect it to be even larger for more complex programs. * Other minor fixes: Fixed so min, max, abs and sign no longer works on Vertex Int and Fragment Int types, since its not supported in GLSL 1.20. Reexport of Vec-Boolean instances so you dont need to import that package on its own any more. Added IfB instances for the associated type Color. Cheers Tobias _________________________________________________________________ Nya Windows 7 gör allt lite enklare. Hitta en dator som passar dig! http://windows.microsoft.com/shop

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glut and opengl on windows
by Sam Martin 10 Nov '09

10 Nov '09

Hi everyone, Apologies if this is a FAQ, but I can't find the answer from googling. I'm trying to get glut and opengl to work on windows. I'm after a setup that: - Uses freeglut (so I can run in ghci easily) - Ideally, uses the latest ghc compiler - Works! That last part is where I'm getting stuck. I've tried both a: - Clean install of Haskell Platform 2009.2.0.2 o (fails to locate glut32.dll) - Compiling freeglut, and the haskell glut+opengl packages from within mingw o Compiles, but issues *** Exception: user error (unknown GLUT entry glutInit) at runtime. I also found a few tutorials (which helped me compile everything), but they are all for slightly older versions of the Haskell wrappers now. What is the best way to get up and running on Windows? Do I have to use an old version? Is this expected behaviour? Thanks, Sam

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RE: ANN: GPipe-TextureLoad 1.0.0 and GPipe 1.0.3
by Tobias Bexelius 27 Oct '09

27 Oct '09

I accidently missed a spot in the latest GPipe bugfix, this is fixed in version 1.0.4 that I've just uploaded. Sorry for that. /Tobias Bexelius From: tobias_bexelius(a)hotmail.com To: haskell-cafe(a)haskell.org; haskell(a)haskell.org; hopengl(a)haskell.org Subject: ANN: GPipe-TextureLoad 1.0.0 and GPipe 1.0.3 Date: Mon, 26 Oct 2009 22:37:01 +0100 I've uploaded a new version of GPipe as well as a utility package for loading textures. GPipe 1.0.3: * Fixes a major bug in the shader generation GPipe-TextureLoad 1.0.0: * Helps loading GPipe textures from file. It is based on the stb-image package, and supports subsets of the JPG, PNG, TGA, BMP and PSD formats. kolla in resten av Windows LiveT. Inte bara e-post - Windows LiveT är mycket mer än din inkorg. Mer än bara meddelanden _________________________________________________________________ Hitta kärleken nu i vår! http://dejting.se.msn.com/channel/index.aspx?trackingid=1002952

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ANN: GPipe-TextureLoad 1.0.0 and GPipe 1.0.3
by Tobias Bexelius 26 Oct '09

26 Oct '09

I've uploaded a new version of GPipe as well as a utility package for loading textures. GPipe 1.0.3: * Fixes a major bug in the shader generation GPipe-TextureLoad 1.0.0: * Helps loading GPipe textures from file. It is based on the stb-image package, and supports subsets of the JPG, PNG, TGA, BMP and PSD formats. _________________________________________________________________ Hitta kärleken nu i vår! http://dejting.se.msn.com/channel/index.aspx?trackingid=1002952

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