我在下面的以下测试代码中尝试获取基本的opengl Gtk3 GLArea示例。
下面的错误是我目前的症结所在,从我读过的内容来看,这可能意味着这些功能在上下文中不可用,但是阅读有关GLArea的内容似乎并不能让您选择上下文,并且听起来应该默认为正确的上下文。
不幸的是,问题可能出在GLArea或PyOpenGL上,我可以在C语言下完成的所有示例都非常好,以获得在python中工作的基本示例。
无论如何都花了很多时间来试图解决这个问题,所以如果有人可以帮助克服至少这个错误,那将是非常有意义的。
Traceback (most recent call last):
File "gtkglarea.py", line 91, in on_configure_event
self.vertex_array_object = glGenVertexArrays(1)
File "/usr/lib/python3/dist-packages/OpenGL/platform/baseplatform.py", line 407, in call
self.name, self.name,
OpenGL.error.NullFunctionError: Attempt to call an undefined function glGenVertexArrays, check for bool(glGenVertexArrays) before calling
例如,其要点也https://gist.github.com/olymk2/5b3e49ac83130e580bd9983f2e5d49c3
#!/usr/bin/python
import os
import sys
from OpenGL.GLU import *
from OpenGL import GLX
from OpenGL import GL as GL
from ctypes import *
import gi
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk, Gdk
from OpenGL.arrays import vbo
from OpenGL.GL import shaders
from OpenGL.raw.GL.ARB.vertex_array_object import glGenVertexArrays, \
glBindVertexArray
from numpy import array
import numpy as np
VERTEX_SHADER = """
#version 330
in vec4 position;
void main()
{
gl_Position = position;
}"""
FRAGMENT_SHADER = """
#version 330
out vec4 fragColor;
void main()
{
fragColor = vec4(1.0, 0.0, 0.0, 1.0);
}
"""
class application_gui:
"""Tutorial 01 Create and destroy a window"""
# glwrap = gtkglarea()
def __init__(self):
self.window = Gtk.Window()
self.canvas = Gtk.GLArea()
self.canvas.set_required_version(3, 3)
self.test_features()
self.vertices = [
0.6, 0.6, 0.0, 1.0,
-0.6, 0.6, 0.0, 1.0,
0.0, -0.6, 0.0, 1.0]
self.vertices = np.array(self.vertices, dtype=np.float32)
self.canvas.connect('realize', self.on_configure_event)
self.canvas.connect('render', self.on_draw)
self.canvas.set_double_buffered(False)
self.window.connect('delete_event', Gtk.main_quit)
self.window.connect('destroy', lambda quit: Gtk.main_quit())
self.window.add(self.canvas)
self.window.show_all()
self.on_configure_event(self.canvas)
def test_features(self):
print('Testing features')
print('glGenVertexArrays Available %s' % bool(glGenVertexArrays))
print('Alpha Available %s' % bool(self.canvas.get_has_alpha()))
print('Depth buffer Available %s' % bool(self.canvas.get_has_depth_buffer()))
def on_configure_event(self, widget):
print('realize event')
widget.make_current()
# widget.attach_buffers()
context = widget.get_context()
print('is legacy context %s' % Gdk.GLContext.is_legacy(context))
print('configure errors')
print(widget.get_error())
vs = shaders.compileShader(VERTEX_SHADER, GL.GL_VERTEX_SHADER)
fs = shaders.compileShader(FRAGMENT_SHADER, GL.GL_FRAGMENT_SHADER)
self.shader = shaders.compileProgram(vs, fs)
self.vertex_array_object = glGenVertexArrays(1)
GL.glBindVertexArray( self.vertex_array_object )
# Generate buffers to hold our vertices
self.vertex_buffer = GL.glGenBuffers(1)
GL.glBindBuffer(GL.GL_ARRAY_BUFFER, self.vertex_buffer)
# Get the position of the 'position' in parameter of our shader and bind it.
self.position = GL.glGetAttribLocation(self.shader, 'position')
GL.glEnableVertexAttribArray(self.position)
# Describe the position data layout in the buffer
GL.glVertexAttribPointer(self.position, 4, GL.GL_FLOAT, False, 0, ctypes.c_void_p(0))
# Send the data over to the buffer
GL.glBufferData(GL.GL_ARRAY_BUFFER, 48, self.vertices, GL.GL_STATIC_DRAW)
# Unbind the VAO first (Important)
GL.glBindVertexArray( 0 )
# Unbind other stuff
GL.glDisableVertexAttribArray(self.position)
GL.glBindBuffer(GL.GL_ARRAY_BUFFER, 0)
print('errors')
print(widget.get_error())
return True
def on_draw(self, widget, *args):
print('render event')
print(widget.get_error())
#Create the VBO
widget.attach_buffers()
GL.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT)
GL.glUseProgram(self.shader)
GL.glBindVertexArray( self.vertex_array_object )
GL.glDrawArrays(GL.GL_TRIANGLES, 0, 3)
GL.glBindVertexArray( 0 )
GL.glUseProgram(0)
glFlush()
return True
application = application_gui()
Gtk.main()
最佳答案
对我来说,问题似乎与在Wayland的经营有关。如果PyOpenGL在Wayland下运行,并且有X11服务器在运行,它将使用GLX而不是Wayland的EGL支持。关于GtkGLArea如何设置GL上下文的某些信息,意味着GLX可以工作,但是没有任何GL扩展,包括VAO。这似乎是PyOpenGL中的错误。
有两种方法可以解决此问题:
设置PYOPENGL_PLATFORM
强制PyOpenGL使用EGL而不是GLX。
例如。导入OpenGL之前:
if 'WAYLAND_DISPLAY' in os.environ and 'PYOPENGL_PLATFORM' not in os.environ:
os.environ['PYOPENGL_PLATFORM'] = 'egl'
取消设置
WAYLAND_DISPLAY
以强制Gtk使用GLX而不是EGL。例如。导入Gtk之前:
if 'WAYLAND_DISPLAY' in os.environ:
del os.environ['WAYLAND_DISPLAY']