How can I draw/work with pixels in python with opengl/pyglet and change sizes of this pixels?

Question

I need to draw pixels and then change their sizes, so one display pixel contains 9 program pixels

import random
from pyglet.gl import *
from OpenGL.GLUT import *

win = pyglet.window.Window()

@win.event
def on_draw():
    W = 200
    H = 200
    glClearColor(0, 0, 0, 1)
    glClear(GL_COLOR_BUFFER_BIT)
    data = [[[0] * 3 for j in range(W)] for i in range(H)]
    for y in range (0, H):
      for x in range (0, W):
          data[y][x][0] = random.randint(0, 255)
          data[y][x][1] = random.randint(0, 255)
          data[y][x][2] = random.randint(0, 255)

    glDrawPixels(W, H, GL_RGB, GL_UNSIGNED_INT, data)


    glutSwapBuffers()

 pyglet.app.run()

I get this error

glDrawPixels(W, H, GL_RGB, GL_UNSIGNED_INT, data)
ctypes.ArgumentError: argument 5: : wrong type

Answer 1

The data which are passed to glDrawPixels has to be an array of GLuint values, rather than a nested list of values.
If you want to define the color channels by integral values in the range [0, 255], then you've to use the data type GLubyte and the corresponding OpenGL enumerator constant GL_UNSIGNED_BYTE rather than GL_UNSIGNED_INT .

eg

data = [random.randint(0, 255) for _ in range (0, H*W*3)]
glDrawPixels(W, H, GL_RGB, GL_UNSIGNED_BYTE, (GLubyte * len(data))(*data))

If you would use GLuint respectively GL_UNSIGNED_INT anyway, then the integral color channels have to be in range [0, 2147483647]:

eg

data = [random.randint(0, 2147483647) for _ in range (0, H*W*3)]
glDrawPixels(W, H, GL_RGB, GL_UNSIGNED_INT, (GLuint * len(data))(*data))