glEnd error in PyOpenGL error = 1282

Question

Hi i get a very strange problem when running this code. I don't see how it should conflict with the OpenGL Api either. Heres the code:

import sys
sys.path.append("..\Blocks")
print sys.path
import pygame
from pygame.locals import *
from OpenGL.GL import *
from OpenGL.GLU import *

import random

try:
    import BlockModel
except:
    print "Cant Find Block Model"

def createBlock():  
    block = BlockModel.Block()

    blockVertices = block.returnVertices()

    blockEdges = block.returnEdges()

    blockSurface = block.returnSurface()

    glBegin(GL_QUADS)

    for surface in blockSurface:
        for faceVertex in surface:
            glVertex3fv(blockVertices[faceVertex])

    glEnd

    glBegin(GL_LINES)
    for edge in blockEdges:
        for vertex in edge:
            glVertex3fv(blockVertices[vertex])
    glEnd()

def main():
    pygame.init()
    display = (800, 600)
    pygame.display.set_mode(display, DOUBLEBUF|OPENGL)
    gluPerspective(15, (display[0]/display[1]), 0.1, 50.0)

    glTranslatef(random.randrange(-5,5),random.randrange(-5,5), -40)

    exit = False

    while not exit:
        pygame.time.wait(10)
        glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT)
        createBlock()
        pygame.display.flip()
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                quit()


main()

I get this error when trying to run the program:

C:\Users\Haavard\Desktop\MinecraftPythonProject\framework>python main.py
['C:\\Users\\Haavard\\Desktop\\MinecraftPythonProject\\framework', 'C:\\Windows\
\system32\\python27.zip', 'C:\\Python27\\DLLs', 'C:\\Python27\\lib', 'C:\\Python
27\\lib\\plat-win', 'C:\\Python27\\lib\\lib-tk', 'C:\\Python27', 'C:\\Python27\\
lib\\site-packages', 'C:\\Python27\\lib\\site-packages\\PIL', '..\\Blocks']
Traceback (most recent call last):
  File "main.py", line 60, in <module>
    main()
  File "main.py", line 52, in main
    createBlock()
  File "main.py", line 37, in createBlock
    glEnd()
  File "latebind.pyx", line 44, in OpenGL_accelerate.latebind.Curry.__call__ (c:
\Users\mcfletch\OpenGL-dev\OpenGL-ctypes\OpenGL_accelerate\src\latebind.c:1201)
  File "C:\Python27\lib\site-packages\OpenGL\GL\exceptional.py", line 46, in glE
nd
    return baseFunction( )
  File "C:\Python27\lib\site-packages\OpenGL\platform\baseplatform.py", line 402
, in __call__
    return self( *args, **named )
  File "errorchecker.pyx", line 53, in OpenGL_accelerate.errorchecker._ErrorChec
ker.glCheckError (c:\Users\mcfletch\OpenGL-dev\OpenGL-ctypes\OpenGL_accelerate\s
rc\errorchecker.c:1218)
OpenGL.error.GLError: GLError(
        err = 1282,
        description = 'invalid operation',
        baseOperation = glEnd,
        cArguments = ()
)

Im running on windows 7 on a hp machine.

Block Model Module looks like this:

class Block:

    # initializing the basic functions of a block
    def __init__(self, blockID = "0", blockType = "stone", verticesCords = ((1,-1,-1),(1,1,-1),(-1,1,-1),(-1,-1,-1),(1,-1,1),(1,1,1),(-1,-1,1),(-1,1,1)), edges = ((0,1),(0,3),(0,4),(2,1),(2,3),(2,7),(6,3),(6,4),(6,7),(5,1),(5,4),(5,7)), surfaces = (((0,1,2,3),(3,2,7,6),(6,7,5,4),(4,5,1,0),(1,5,7,2),(4,0,3,6)))):
        # Block Placement
        self.PLACEMENT = verticesCords
        # Block identity in the world
        self.EDGES = edges
        self.SURFACE = surfaces
        self.BLOCKID = blockID
        # The block type
        self.BLOCKTYPE = blockType

    # A function letting the framework know its placement.
    def returnVertices(self):
        return self.PLACEMENT

    def returnEdges(self):
        return self.EDGES

    def returnSurface(self):
        return self.SURFACE

    # A function to make the block fetch its own texture.
    def defineTexture():
        pass

Thank you for any answears! :)

user1961169 user1961169 · Accepted Answer · 2015-07-21T06:21:00

You may have already solved this, but my guess is that you might have an odd-number of vertices in your edges. A 1282 error on the glEnd() just means there's something wrong with the whole operation. GL_LINES expects an even number of vertices to be given, as GL_LINES works in pairs of points to define each line segment, rather than an continuous string of points to make a big polyline. Double check that each edge has two points.

glEnd error in PyOpenGL error = 1282

3 Answers