[HOpenGL] Re: Segmentation Fault Running Panitz's Tutorial Code

1 Apr 2010


      Scratch that!  It appears that the issue arises by setting depthFunc or any
other attribute before creating a window.

On Thu, Apr 1, 2010 at 5:54 AM, Scott  wrote:
...
Hello!
I have a problem when trying to run some code found on this tutorial page:
http://public.beuth-hochschule.de/~panitz/hopengl/skript.htmlhttp://public.beuth-hochschule.de/%7Epanitz/hopengl/skript.html
The demo is called "LightCube."  The problem seems to have to do with the
following line (which I've commented out in the provided source):
depthFunc $= Just Less
Uncommenting the line gives a Segmentation Fault when I run the executable
generated by:
ghc --make -package GLUT -o LightCube LightCube.hs
Does anyone else have this problem?  Here is the necessary code:
*
LightCube*
import Graphics.Rendering.OpenGL
import Graphics.UI.GLUT  as GLUT
import Cube
main = do
  (progName,_) <-  getArgsAndInitialize
--  depthFunc $= Just Less
createWindow progName
lighting $= Enabled
  position (Light 0) $= Vertex4 1 0.4 0.8  1
  light (Light 0) $= Enabled
displayCallback $= display
  mainLoop
display = do
  clear [ColorBuffer]
  rotate 40 (Vector3 1 1 (1::GLfloat))
  cube 0.5
  loadIdentity
  flush
*
Cube
*
module Cube where
import Graphics.Rendering.OpenGL
import Graphics.UI.GLUT  as GLUT
import PointsForRendering
cube l = renderAs Quads corners
  where
   corners =
    [(l,0,l),(0,0,l),(0,l,l),(l,l,l)
    ,(l,l,l),(l,l,0),(l,0,0),(l,0,l)
    ,(0,0,0),(l,0,0),(l,0,l),(0,0,l)
    ,(l,l,0),(0,l,0),(0,0,0),(l,0,0)
    ,(0,l,l),(l,l,l),(l,l,0),(0,l,0)
    ,(0,l,l),(0,l,0),(0,0,0),(0,0,l)
    ]
*
PointsForRendering*
module PointsForRendering where
import Graphics.UI.GLUT
import Graphics.Rendering.OpenGL
renderInWindow displayFunction = do
  (progName,_) <-  getArgsAndInitialize
  createWindow progName
  displayCallback $= displayFunction
  mainLoop
displayPoints points primitiveShape = do
  renderAs primitiveShape points
  flush
renderAs figure ps = renderPrimitive figure$makeVertexes ps
makeVertexes = mapM_ (\(x,y,z)->vertex$Vertex3 x y z)
mainFor primitiveShape
 = renderInWindow (displayMyPoints primitiveShape)
displayMyPoints primitiveShape = do
  clear [ColorBuffer]
  currentColor $= Color4 1 1 0 1
  displayPoints myPoints primitiveShape
myPoints
 = [(0.2,-0.4,0::GLfloat)
   ,(0.46,-0.26,0)
   ,(0.6,0,0)
   ,(0.6,0.2,0)
   ,(0.46,0.46,0)
   ,(0.2,0.6,0)
   ,(0.0,0.6,0)
   ,(-0.26,0.46,0)
   ,(-0.4,0.2,0)
   ,(-0.4,0,0)
   ,(-0.26,-0.26,0)
   ,(0,-0.4,0)
   ]