[Python] Pyopengl program throws "Attempt to retrieve context when no valid context"

I'm attempting to make a rudimentary real time Rasterizing engine in Python. My program was working fine until I realized that my VBOs didn't seem to be working, and changed vertex, texture and normal coordinates to None. I'm on linux and I'm mostly in over my head with this, I'm brand new to opengl. Error:

File "/home/calcyte/.local/lib/python3.13/site-packages/OpenGL/latebind.py", line 43, in __call__
return self._finalCall( *args, **named )
~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^
TypeError: 'NoneType' object is not callable

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/home/calcyte/OneDrive_171848@lrgs.org.uk/compsci/Practical/Proj/ras1/ras1.py", line 248, in <module>
main()
~~~~^^
File "/home/calcyte/OneDrive_171848@lrgs.org.uk/compsci/Practical/Proj/ras1/ras1.py", line 242, in main
render_vbo(vbo_obj)
~~~~~~~~~~^^^^^^^^^
File "/home/calcyte/OneDrive_171848@lrgs.org.uk/compsci/Practical/Proj/ras1/ras1.py", line 181, in render_vbo
glVertexPointer(3, GL_FLOAT, 0, None)
~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^
File "/home/calcyte/.local/lib/python3.13/site-packages/OpenGL/latebind.py", line 47, in __call__
return self._finalCall( *args, **named )
~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^
File "/home/calcyte/.local/lib/python3.13/site-packages/OpenGL/wrapper.py", line 923, in wrapperCall
storeValues(
~~~~~~~~~~~^
result,
^^^^^^^
...<2 lines>...
cArguments,
^^^^^^^^^^^
)
^
File "/home/calcyte/.local/lib/python3.13/site-packages/OpenGL/arrays/arrayhelpers.py", line 189, in __call__
contextdata.setValue(self.constant, pyArgs[self.pointerIndex])
~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/calcyte/.local/lib/python3.13/site-packages/OpenGL/contextdata.py", line 58, in setValue
context = getContext( context )
File "/home/calcyte/.local/lib/python3.13/site-packages/OpenGL/contextdata.py", line 40, in getContext
raise error.Error(
"""Attempt to retrieve context when no valid context"""
)
OpenGL.error.Error: Attempt to retrieve context when no valid context


Code:

import pygame
from pygame.locals import *
import numpy as np
import os

# OpenGL imports needed for VBO and rendering
from OpenGL.GL import *
from OpenGL.GLU import *

def load_texture(filename):
path = "/home/calcyte/OneDrive_171848@lrgs.org.uk/compsci/Practical/Proj/assets/bucket/" + filename
if not os.path.exists(path):
print(f"Texture file {filename} not found in the specified directory.")
return None
surface = pygame.image.load(path)
width, height = surface.get_size()
image_data = pygame.image.tostring(surface, "RGBA", True)
texid = glGenTextures(1)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR)
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, image_data)
glGenerateMipmap(GL_TEXTURE_2D)
return texid


def collect_objvert(reqass="untitled"):
filepath = f"/home/calcyte/OneDrive_171848@lrgs.org.uk/compsci/Practical/Proj/assets/{reqass}.obj"
faces = []
objverts = []
mtllis = []
mat = None
texturecoords = []
normals = []

def new_material(name):
return [name, [0.0, 0.0, 0.0], [0.0, 0.0, 0.0], [0.0, 0.0, 0.0], 1.0, 1.0, 1.0, 1, None, None, [None, None, None]]

with open(filepath, "r") as assfil:
for line in assfil:
if line.startswith("mtllib "):
line = line.strip()
mtllib = open(f"/home/calcyte/OneDrive_171848@lrgs.org.uk/compsci/Practical/Proj/assets/{line[7:]}", "r")
for mline in mtllib:
if mline.startswith("newmtl "):
mtllis.append(new_material(mline[7:].strip()))
elif mline.startswith("Ka "):
tmp = [float(x) for x in mline[3:].split()]
mtllis[-1][1] = tmp
elif mline.startswith("Kd "):
tmp = [float(x) for x in mline[3:].split()]
mtllis[-1][2] = tmp
elif mline.startswith("Ks "):
tmp = [float(x) for x in mline[3:].split()]
mtllis[-1][3] = tmp
elif mline.startswith("d "):
mtllis[-1][4] = float(mline[2:].strip())
elif mline.startswith("Tr "):
mtllis[-1][5] = float(mline[3:].strip())
elif mline.startswith("Ns "):
ns_val = float(mline[3:].strip())
mtllis[-1][6] = min(ns_val, 128.0)
elif mline.startswith("illum "):
mtllis[-1][7] = int(mline[6:].strip())
elif mline.startswith("map_Kd "):
mtllis[-1][8] = load_texture(mline[7:].strip()) if mline[7:].strip() != "" else 0
mtllib.close()
if line.startswith("usemtl "):
if mat is not None and faces:
mtllis[mat][9] = faces
mat = None
mat_name = line[7:].strip()
for i, m in enumerate(mtllis):
if m[0] == mat_name:
mat = i
faces = []
if line.startswith("vt "):
parts = [float(x) for x in line[3:].split()]
parts[0] = min(max(parts[0], 0), 1)
parts[1] = min(max(parts[1], 0), 1)
texturecoords.append(parts)
if line.startswith("vn "):
parts = [float(x) for x in line[3:].split()]
normals.append(parts)
if line.startswith("v "):
parts = [float(x) for x in line[2:].split()]
objverts.append(parts)
if line.startswith("f "):
parts = line[2:].strip().split()
if parts:
face = []
for p in parts:
indices = p.split("/")
vert_idx = int(indices[0]) - 1 if len(indices) > 0 and indices[0] != '' else None
tex_idx = int(indices[1]) - 1 if len(indices) > 1 and indices[1] != '' else None
norm_idx = int(indices[2]) - 1 if len(indices) > 2 and indices[2] != '' else None
face.append([vert_idx, tex_idx, norm_idx])
if len(face) > 3:
for i in range(1, len(face) - 1):
faces.append([face[0], face, face[i + 1]])
else:
faces.append(face)
if mat is not None and faces:
mtllis[mat][9] = faces
return mtllis, objverts, texturecoords, normals


def setup_vbo(mtllis, verts, texcoo, norms):
for materials in mtllis:
if materials[9] is None or len(materials[9]) == 0:
continue
texcor = []
triangle = []
norm = []
# Ensure material colors are in the correct format
if len(materials[1]) != 4:
materials[1].append(float(materials[4]))
materials[2].append(float(materials[4]))
materials[3].append(float(materials[4]))

for face in materials[9]:
if len(face) == 3:
sad = []
texsad = []
norsad = []
for v in face:
v_idx = v[0] if v[0] is not None else 0
if texcoo and v[1] is not None and v[1] < len(texcoo):
texsad.append(texcoo[v[1]])
else:
texsad.append([0.0, 0.0])
if norms and v[2] is not None and v[2] < len(norms):
norsad.append(norms[v[2]])
else:
norsad.append([0.0, 0.0, 1.0])
sad.append(verts[v_idx])
triangle.extend(sad)
texcor.extend(texsad)
norm.extend(norsad)

# Create and bind VBOs for vertices, texture coordinates, and normals
triangle_array = np.array(triangle, dtype=np.float32)
texture_array = np.array(texcor, dtype=np.float32)
normal_array = np.array(norm, dtype=np.float32)

# Generate VBOs
materials[10] = [None, None, None] # Reset VBO storage
materials[10][0] = glGenBuffers(1) # Vertex VBO
materials[10][1] = glGenBuffers(1) # Texture VBO
materials[10][2] = glGenBuffers(1) # Normal VBO

# Bind and upload vertex data
glBindBuffer(GL_ARRAY_BUFFER, materials[10][0])
glBufferData(GL_ARRAY_BUFFER, triangle_array.nbytes, triangle_array, GL_STATIC_DRAW)

# Bind and upload texture data
glBindBuffer(GL_ARRAY_BUFFER, materials[10][1])
glBufferData(GL_ARRAY_BUFFER, texture_array.nbytes, texture_array, GL_STATIC_DRAW)

# Bind and upload normal data
glBindBuffer(GL_ARRAY_BUFFER, materials[10][2])
glBufferData(GL_ARRAY_BUFFER, normal_array.nbytes, normal_array, GL_STATIC_DRAW)

# Unbind the buffers
glBindBuffer(GL_ARRAY_BUFFER, 0)

return mtllis


def render_vbo(mtllis):
for materials in mtllis:
if materials[10][0] is not None:
# Set material properties
glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT, materials[1])
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, materials[2])
glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, materials[3])
glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, materials[6])

# Bind vertex VBO
glEnableClientState(GL_VERTEX_ARRAY)
glBindBuffer(GL_ARRAY_BUFFER, materials[10][0])
glVertexPointer(3, GL_FLOAT, 0, None)

# Bind texture VBO if it exists and texture is available
if materials[10][1] is not None and materials[8]:
glEnableClientState(GL_TEXTURE_COORD_ARRAY)
glBindTexture(GL_TEXTURE_2D, materials[8]) # Bind the texture
glBindBuffer(GL_ARRAY_BUFFER, materials[10][1]) # Bind texture VBO
glTexCoordPointer(2, GL_FLOAT, 0, None)

# Bind normal VBO if it exists
if materials[10][2] is not None:
glEnableClientState(GL_NORMAL_ARRAY)
glBindBuffer(GL_ARRAY_BUFFER, materials[10][2]) # Bind normal VBO
glNormalPointer(GL_FLOAT, 0, None)

# Draw the arrays
glDrawArrays(GL_TRIANGLES, 0, len(materials[10][0]) // 3) # Assuming each vertex has 3 components

# Unbind and disable states
if materials[10][2] is not None:
glDisableClientState(GL_NORMAL_ARRAY)
glBindBuffer(GL_ARRAY_BUFFER, 0) # Unbind normal VBO

if materials[10][1] is not None and materials[8]:
glDisableClientState(GL_TEXTURE_COORD_ARRAY)
glBindBuffer(GL_ARRAY_BUFFER, 0) # Unbind texture VBO

glDisableClientState(GL_VERTEX_ARRAY)
glBindBuffer(GL_ARRAY_BUFFER, 0) # Unbind vertex VBO


def main():
pygame.init()
displayinfo = pygame.display.Info()
pygame.display.set_mode((displayinfo.current_w, displayinfo.current_h), DOUBLEBUF | OPENGL)
pygame.display.set_caption("RAS1")

gluPerspective(45, (displayinfo.current_w / displayinfo.current_h), 0.1, 100000)
loc = [20, 40, 0]
gluLookAt(loc[0], loc[1], loc[2], 0, 0, 0, 0, 1, 0)
mtllis, vertices, texcoo, normals = collect_objvert()
vbo_obj = setup_vbo(mtllis, vertices, texcoo, normals)
clock = pygame.time.Clock()
glClearColor(0.2, 0.2, 0.3, 1.0)
glEnable(GL_DEPTH_TEST)
glEnable(GL_LIGHTING)
glEnable(GL_LIGHT0)
glLightfv(GL_LIGHT0, GL_POSITION, (0, 20, 40, 0))
glLightfv(GL_LIGHT0, GL_AMBIENT, (0.2, 0.2, 0.2, 1.0))
glLightfv(GL_LIGHT0, GL_DIFFUSE, (0.7, 0.7, 0.7, 1.0))
glLightfv(GL_LIGHT0, GL_SPECULAR, (1.0, 1.0, 1.0, 1.0))
glEnable(GL_NORMALIZE)
glShadeModel(GL_SMOOTH)
glEnable(GL_TEXTURE_2D)
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE)
while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
quit()
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
render_vbo(vbo_obj)
glRotatef(1, 0, 1, 0)
pygame.display.flip()
clock.tick(60)


main()

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