So i'm working on a voxel base engine and i'm currently changing from tkinter's canvas to PyOpenGl. I found the function glDrawnPixels who is very important for my engine. But here's the problem, i don't know OpenGL or PyOpenGl so much and my tentative sold with black pixel. So how do i do to have different color of pixel.
Here's a also my tentative :
import glfw
from OpenGL.GL import *
import numpy as np
import pyrr
buffer = bytearray(800 * 600 * 3)
display = (800,600)
if not glfw.init():
raise Exception("glfw can not be initialized!")
def CreateWindow(title="Baguette game",width=1280,height=750):
display = (width,height)
buffer = bytearray(width * height * 3)
window = glfw.create_window(width,height,title, None, None)
glfw.set_window_pos(window,400,200)
glfw.make_context_current(window)
return window
def DrawTriangle(pointA=[-0.5, -0.5, 0.0],pointB=[0.5, -0.5,0.0],
pointC=[-0.5, 0, 0.0],color=[1.0,0,0]):
vertices = [pointA[0], pointA[1], pointA[2],
pointB[0], pointB[1], pointB[2],
pointC[0], pointC[1], pointC[2]]
colors = [color[0], color[1], color[2],
color[0], color[1], color[2],
color[0], color[1], color[2] ]
v = np.array(vertices,dtype=np.float32)
c = np.array(colors, dtype=np.float32)
glEnableClientState(GL_VERTEX_ARRAY)
glVertexPointer(3, GL_FLOAT,0,v)
glEnableClientState(GL_COLOR_ARRAY)
glColorPointer(3, GL_FLOAT,0,c)
glDrawArrays(GL_TRIANGLES,0,3)
if __name__=="__main__":
window = CreateWindow()
initialPosition = (0,0,0)
z=1
while not glfw.window_should_close(window):
glfw.poll_events()
glClear(GL_COLOR_BUFFER_BIT)
DrawTriangle([-0.5, -0.5, z],[0.5, -0.5,z],[-0.5, 0, z])
glDrawPixels(display[1], display[0], GL_RGB, GL_UNSIGNED_BYTE, buffer)
DrawTriangle([-0.5, 0.5, z],[0.5, 0.5,z],[-0.5, 1, z])
glfw.swap_buffers(window)
glfw.terminate()
In the center of the screen you can see a triangle cut by black pixels and above the complete triangle.
You can use OpenGL/PyOpenGL in a tkinter frame with pyopengltk. An example can be found here: tkinter_opengl_shader_ctypes_glm_meshes.py.
glDrawPixels
is deprecated, do not use it. Render primitives instead. See Primitive.
Anyway you need to set the color date in the buffer (as suggested in a comment). e.g:
buffer = bytearray(800 * 600 * 3)
display = (1280, 750)
buffer_data = [255, 128, 0] * (display[0] * display[1])
buffer = (GLubyte * (display[0] * display[1] * 3))(*buffer_data)
glDrawPixels(display[1], display[0], GL_RGB, GL_UNSIGNED_BYTE, buffer)
glDrawPixels(display[0], display[1], GL_RGB, GL_UNSIGNED_BYTE, buffer)
However, if you just want to set the clear color for the display, use glClearColor
:
glClearColor(1, 0.5, 0, 1)
glClear(GL_COLOR_BUFFER_BIT)
The color can be read back from the framebuffer with glReadPixels
:
color = glReadPixels(0, 0, display[0], display[1], GL_RGB, GL_UNSIGNED_BYTE, outputType='raw')