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I'm trying to write program in Python using PyOpenGL which I need to use glutMouseFunc for some mouse functionality but when I run the program I get the following error:

Traceback (most recent call last):
  File "teapot.py", line 80, in <module>
    glutMouseFunc(mouseHandle)
  File "/usr/lib/python2.7/dist-packages/OpenGL/GLUT/special.py", line 137, in __call__
    contextdata.setValue( self.CONTEXT_DATA_KEY, cCallback )
  File "/usr/lib/python2.7/dist-packages/OpenGL/contextdata.py", line 57, in setValue
    context = getContext( context )
  File "/usr/lib/python2.7/dist-packages/OpenGL/contextdata.py", line 40, in getContext
    """Attempt to retrieve context when no valid context"""
OpenGL.error.Error: Attempt to retrieve context when no valid context

I tried googling it but I couldn't find any relevant results.Here is my code:

from OpenGL.GL import *
from OpenGL.GLUT import *
t = 0
def init():
    r=1
    g=0
    b=0
    glColor3f(r,g,b)
    glClearColor(1.0,1.0,1.0,0.0)
    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()

def display():
    glClear(GL_COLOR_BUFFER_BIT)
    glViewport(0,0,150,100)
    drawSquare()
    glViewport(0,100,150,200)
    drawCircle()
    glViewport(0,200,150,300)
    drawTriangle()
    glViewport(0,300,150,400)
    drawFan()
    if(t==1):
        glViewport(150,0,800,600)
        drawFan()
    if(t==2):
        glViewport(150,0,800,600)
        drawTriangle()
    if(t==3):
        glViewport(150,0,800,600)
        drawCircle()
    if(t==4):
        glViewport(150,0,800,600)
        drawSquare()
    glFlush()
def drawFan():
    glBegin(GL_TRIANGLE_FAN)
    glVertex2f(0.0,0.0)
    glVertex2f(0.3,0.3)
    glVertex2f(0.3,-0.3)
    glVertex2f(-0.3,0.3)
    glVertex2f(-0.3,-0.3)
    glEnd()

def drawTriangle():
    glBegin(GL_TRIANGLES)
    glVertex2f(0.5,0.0)
    glVertex2f(0.0,0.5)
    glVertex2f(-0.5,0.0)
    glEnd()

def drawCircle():
    glutSolidSphere(0.5, 30 ,30)

def drawSquare():
    glBegin(GL_POLYGON)
    glVertex2f(0.5,0.5)
    glVertex2f(-0.5,0.5)
    glVertex2f(-0.5,-0.5)
    glVertex2f(0.5,-0.5)
    glEnd()

def mouseHandle(button, state, x, y):
    if(button == GLUT_LEFT_BUTTON and x < 150 and y < 170):
        t=1
        glutPostRedisplay()
        print "1: x=",x," y=",y,"\n"
    elif(button == GLUT_LEFT_BUTTON and x < 150 and 170 < y and y < 280):
        t=2
        glutPostRedisplay()
    elif(button == GLUT_LEFT_BUTTON and x < 150 and 345 < y and y < 451):
        t=3
        glutPostRedisplay()
    elif(button == GLUT_LEFT_BUTTON and x < 150 and 525 < y and y < 578):
        t=4
        glutPostRedisplay()
    else:
        glutPostRedisplay()
glutInit('')
glutMouseFunc(mouseHandle)
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB)
glutInitWindowSize(800,600)
glutCreateWindow('Hello GLUT')
glutDisplayFunc(display)
init()
glutMainLoop()

Bear in mind that I'm neither a fluent Python programmer nor am I so in OpenGL.
Any help is much appreciated.

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4 Years
Discussion Span
Last Post by 2hamed
1

Ok, after some dwelling I found out how to solve it. I must've moved the glutMouseFunc call after glutDisplayFunc, just like below:

glutInit('')
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB)
glutInitWindowSize(800,600)
glutCreateWindow('Hello GLUT')
glutDisplayFunc(display)
glutMouseFunc(mouseHandle)
init()
glutMainLoop()
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