python - glGenVertexArrays Mac OSX PyOpenGL

Question

我正在尝试在我的 Mac (10.11.5) 上的 PyOpenGL 上运行 glGenVertexArrays。它没有找到它。

问题似乎出在我的 Mac (?) 支持的 OpenGL 版本上。我试图研究这个问题，但文档似乎是为历史 Nerd 或琐事爱好者编写的，而我两者都不是。

当我尝试这样做时:

print("OpenGL: " + str(glGetString(GL_VERSION)))
print('glGenVertexArrays Available %s' % bool(glGenVertexArrays))
vao = glGenVertexArrays(1)

我明白了:

OpenGL: 2.1 NVIDIA-10.10.10 310.42.25f01

glGenVertexArrays Available False

Traceback (most recent call last): File "_ctypes/callbacks.c", line 315, in 'calling callback function' File "draw.py", line 99, in doRedraw mesh.draw() File "/Users/carlos/vc/SimpleRender/Mesh.py", line 170, in draw vao = glGenVertexArrays(1) File "/Users/carlos/.virtualenvs/janus/lib/python2.7/site-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

大家在线看here , 或 here似乎运行 glGenVertexArrays 没有问题。 This guy似乎遇到了我同样的问题，但向他建议的解决方案(添加 GLUT_PROFILE_3_2_CORE 未在我的 PyOpenGL 中定义)

我做错了什么？

编辑:

我已经尝试过 pyglet 和 PyQt5(在 python3 下运行)，但它总是归结为缺少 glGenVertexArrays。

看来(网上有很多关于此的错误信息)我需要做的是设置核心配置文件。我怎么做？如果我放弃 Python 要求会更容易吗？考虑到我不是笨蛋，并且在将问题发布到这里之前我已经对我的问题进行了重要的故障排除。

我有:

我在裸机上运行，​​没有虚拟化，没有 VM，没有 docker。

glxinfo 的输出是:

name of display: /private/tmp/com.apple.launchd.RUemSPHKIt/org.macosforge.xquartz:0
display: /private/tmp/com.apple.launchd.RUemSPHKIt/org.macosforge.xquartz:0  screen: 0
direct rendering: Yes
server glx vendor string: SGI
server glx version string: 1.4
server glx extensions:
    GLX_ARB_multisample, GLX_EXT_import_context, GLX_EXT_visual_info,
    GLX_EXT_visual_rating, GLX_OML_swap_method, GLX_SGIS_multisample,
    GLX_SGIX_fbconfig
client glx vendor string: Mesa Project and SGI
client glx version string: 1.4
client glx extensions:
    GLX_ARB_create_context, GLX_ARB_create_context_profile,
    GLX_ARB_create_context_robustness, GLX_ARB_fbconfig_float,
    GLX_ARB_framebuffer_sRGB, GLX_ARB_get_proc_address, GLX_ARB_multisample,
    GLX_EXT_buffer_age, GLX_EXT_create_context_es2_profile,
    GLX_EXT_create_context_es_profile, GLX_EXT_fbconfig_packed_float,
    GLX_EXT_framebuffer_sRGB, GLX_EXT_import_context,
    GLX_EXT_texture_from_pixmap, GLX_EXT_visual_info, GLX_EXT_visual_rating,
    GLX_INTEL_swap_event, GLX_MESA_copy_sub_buffer,
    GLX_MESA_multithread_makecurrent, GLX_MESA_query_renderer,
    GLX_MESA_swap_control, GLX_OML_swap_method, GLX_OML_sync_control,
    GLX_SGIS_multisample, GLX_SGIX_fbconfig, GLX_SGIX_pbuffer,
    GLX_SGIX_visual_select_group, GLX_SGI_make_current_read,
    GLX_SGI_swap_control, GLX_SGI_video_sync
GLX version: 1.4
GLX extensions:
    GLX_ARB_get_proc_address, GLX_ARB_multisample, GLX_EXT_import_context,
    GLX_EXT_visual_info, GLX_EXT_visual_rating,
    GLX_MESA_multithread_makecurrent, GLX_OML_swap_method,
    GLX_SGIS_multisample, GLX_SGIX_fbconfig
OpenGL vendor string: NVIDIA Corporation
OpenGL renderer string: NVIDIA GeForce GT 750M OpenGL Engine
OpenGL version string: 2.1 NVIDIA-10.10.10 310.42.25f01
OpenGL shading language version string: 1.20
OpenGL extensions:
    GL_APPLE_aux_depth_stencil, GL_APPLE_client_storage,
    GL_APPLE_element_array, GL_APPLE_fence, GL_APPLE_float_pixels,
    GL_APPLE_flush_buffer_range, GL_APPLE_flush_render,
    GL_APPLE_object_purgeable, GL_APPLE_packed_pixels, GL_APPLE_pixel_buffer,
    GL_APPLE_rgb_422, GL_APPLE_row_bytes, GL_APPLE_specular_vector,
    GL_APPLE_texture_range, GL_APPLE_transform_hint,
    GL_APPLE_vertex_array_object, GL_APPLE_vertex_array_range,
    GL_APPLE_vertex_point_size, GL_APPLE_vertex_program_evaluators,
    GL_APPLE_ycbcr_422, GL_ARB_color_buffer_float, GL_ARB_depth_buffer_float,
    GL_ARB_depth_clamp, GL_ARB_depth_texture, GL_ARB_draw_buffers,
    GL_ARB_draw_elements_base_vertex, GL_ARB_draw_instanced,
    GL_ARB_fragment_program, GL_ARB_fragment_program_shadow,
    GL_ARB_fragment_shader, GL_ARB_framebuffer_object,
    GL_ARB_framebuffer_sRGB, GL_ARB_half_float_pixel,
    GL_ARB_half_float_vertex, GL_ARB_imaging, GL_ARB_instanced_arrays,
    GL_ARB_multisample, GL_ARB_multitexture, GL_ARB_occlusion_query,
    GL_ARB_pixel_buffer_object, GL_ARB_point_parameters, GL_ARB_point_sprite,
    GL_ARB_provoking_vertex, GL_ARB_seamless_cube_map, GL_ARB_shader_objects,
    GL_ARB_shader_texture_lod, GL_ARB_shading_language_100, GL_ARB_shadow,
    GL_ARB_sync, GL_ARB_texture_border_clamp, GL_ARB_texture_compression,
    GL_ARB_texture_compression_rgtc, GL_ARB_texture_cube_map,
    GL_ARB_texture_env_add, GL_ARB_texture_env_combine,
    GL_ARB_texture_env_crossbar, GL_ARB_texture_env_dot3,
    GL_ARB_texture_float, GL_ARB_texture_mirrored_repeat,
    GL_ARB_texture_non_power_of_two, GL_ARB_texture_rectangle,
    GL_ARB_texture_rg, GL_ARB_transpose_matrix, GL_ARB_vertex_array_bgra,
    GL_ARB_vertex_blend, GL_ARB_vertex_buffer_object, GL_ARB_vertex_program,
    GL_ARB_vertex_shader, GL_ARB_window_pos, GL_ATI_separate_stencil,
    GL_ATI_texture_env_combine3, GL_ATI_texture_float,
    GL_ATI_texture_mirror_once, GL_EXT_abgr, GL_EXT_bgra,
    GL_EXT_bindable_uniform, GL_EXT_blend_color,
    GL_EXT_blend_equation_separate, GL_EXT_blend_func_separate,
    GL_EXT_blend_minmax, GL_EXT_blend_subtract, GL_EXT_clip_volume_hint,
    GL_EXT_debug_label, GL_EXT_debug_marker, GL_EXT_depth_bounds_test,
    GL_EXT_draw_buffers2, GL_EXT_draw_range_elements, GL_EXT_fog_coord,
    GL_EXT_framebuffer_blit, GL_EXT_framebuffer_multisample,
    GL_EXT_framebuffer_multisample_blit_scaled, GL_EXT_framebuffer_object,
    GL_EXT_framebuffer_sRGB, GL_EXT_geometry_shader4,
    GL_EXT_gpu_program_parameters, GL_EXT_gpu_shader4,
    GL_EXT_multi_draw_arrays, GL_EXT_packed_depth_stencil,
    GL_EXT_packed_float, GL_EXT_provoking_vertex, GL_EXT_rescale_normal,
    GL_EXT_secondary_color, GL_EXT_separate_specular_color,
    GL_EXT_shadow_funcs, GL_EXT_stencil_two_side, GL_EXT_stencil_wrap,
    GL_EXT_texture_array, GL_EXT_texture_compression_dxt1,
    GL_EXT_texture_compression_s3tc, GL_EXT_texture_env_add,
    GL_EXT_texture_filter_anisotropic, GL_EXT_texture_integer,
    GL_EXT_texture_lod_bias, GL_EXT_texture_mirror_clamp,
    GL_EXT_texture_rectangle, GL_EXT_texture_sRGB, GL_EXT_texture_sRGB_decode,
    GL_EXT_texture_shared_exponent, GL_EXT_timer_query,
    GL_EXT_transform_feedback, GL_EXT_vertex_array_bgra,
    GL_IBM_rasterpos_clip, GL_NV_blend_square, GL_NV_conditional_render,
    GL_NV_depth_clamp, GL_NV_fog_distance, GL_NV_fragment_program2,
    GL_NV_fragment_program_option, GL_NV_light_max_exponent,
    GL_NV_multisample_filter_hint, GL_NV_point_sprite,
    GL_NV_texgen_reflection, GL_NV_texture_barrier,
    GL_NV_vertex_program2_option, GL_NV_vertex_program3,
    GL_SGIS_generate_mipmap, GL_SGIS_texture_edge_clamp, GL_SGIS_texture_lod

128 GLX Visuals
...

Answer 1

首先，我建议您每次使用 Opengl 函数时检查运行它所需的 opengl 版本是否没有问题，例如，如果我们查看 glGenVertexArrays我们会看到您需要 Opengl >= 3.0。现在，您在执行 glGetString(GL_VERSION) 时获得 2.1 版本的原因要么是因为您有一张非常旧的卡(不太可能)，要么是因为您没有启用 Opengl 核心配置文件。执行此操作后，您应该会看到正确的 Opengl 版本并运行现代 Opengl 功能，例如您要求的功能。

在某些情况下，例如使用 pyqt opengl 小部件，上下文设置将在幕后为您完成......或者正如您提到的那样，如果您使用的是过剩，那么会有一个功能可以这样做。

一种方法是手动启用核心配置文件，如果您是 opengl 的初学者，这可能会很乏味，如果您只是想使用 opengl 而没有太多麻烦，我建议您在 pyopengl 之上使用一些东西，例如 pyqt、pyglet、glut、pygame……有大量的包装器，您不会发现自己需要进行手动设置。下面是一个使用 PyQt5 附带的 QGlWidget 的简单示例(pip install PyQt5)，它应该开箱即用:

import textwrap
import sys
import time
import ctypes
from array import array

from PyQt5 import QtWidgets
from PyQt5.QtOpenGL import QGLWidget
from PyQt5.QtWidgets import QApplication

from OpenGL.GL import *
from OpenGL.GLU import *


class FooOpengl(QGLWidget):

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

        # Test to show how at this point Opengl Context setup hasn't been done
        # and therefore will crash
        print('{:*^80}'.format('Opengl Context not ready'))
        try:
            print(self._opengl_info())
        except Exception as e:
            print(e)

        self.start_time = time.clock()
        self.startTimer(0)

    def initializeGL(self):
        # Test to show how at this point Opengl Context is ready to go
        print('{:*^80}'.format('Opengl Context ready'))
        print(self._opengl_info())

        # Shaders: Trivial program
        vs_source = textwrap.dedent("""
            #version 330
            in vec3 position;
            void main()
            {
               gl_Position = vec4(position, 1.0);
            }\
        """)

        fs_source = textwrap.dedent("""
            #version 330
            void main()
            {
               gl_FragColor = vec4(1.0f, 1.0f, 1.0f, 1.0f);
            }\
        """)

        vs = glCreateShader(GL_VERTEX_SHADER)
        glShaderSource(vs, vs_source)
        glCompileShader(vs)
        fs = glCreateShader(GL_FRAGMENT_SHADER)
        glShaderSource(fs, fs_source)
        glCompileShader(fs)

        self.program = glCreateProgram()
        glAttachShader(self.program, fs)
        glAttachShader(self.program, vs)
        glLinkProgram(self.program)

        vertices = [
            0.0, 0.5, 0.0,
            0.5, -0.5, 0.0,
            -0.5, -0.5, 0.0
        ]

        vbo = glGenBuffers(1)
        glBindBuffer(GL_ARRAY_BUFFER, vbo)

        self.vao = glGenVertexArrays(1)
        glBindVertexArray(self.vao)
        position = glGetAttribLocation(self.program, 'position')
        glEnableVertexAttribArray(position)
        glVertexAttribPointer(
            position, 3, GL_FLOAT, False, 0, ctypes.c_void_p(0))

        glBufferData(
            GL_ARRAY_BUFFER, array("f", vertices).tostring(), GL_STATIC_DRAW)
        glBindVertexArray(0)
        glDisableVertexAttribArray(position)
        glBindBuffer(GL_ARRAY_BUFFER, 0)

    def timerEvent(self, event):
        elapsed = time.clock() - self.start_time
        self.repaint()

    def paintGL(self):
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
        glLoadIdentity()
        glUseProgram(self.program)

        glBindVertexArray(self.vao)
        glDrawArrays(GL_TRIANGLES, 0, 3)
        glBindVertexArray(0)

        glUseProgram(0)

    def _opengl_info(self):
        return textwrap.dedent("""\
            Vendor: {0}
            Renderer: {1}
            OpenGL Version: {2}
            Shader Version: {3}
            Num Extensions: {4}
            Extensions: {5}
        """).format(
            glGetString(GL_VENDOR).decode("utf-8"),
            glGetString(GL_RENDERER).decode("utf-8"),
            glGetString(GL_VERSION).decode("utf-8"),
            glGetString(GL_SHADING_LANGUAGE_VERSION).decode("utf-8"),
            glGetIntegerv(GL_NUM_EXTENSIONS),
            glGetString(GL_EXTENSIONS)
        )

if __name__ == "__main__":
    app = QtWidgets.QApplication(sys.argv)
    ex = FooOpengl()
    ex.show()

    sys.exit(app.exec_())

这只是一个简单的测试，它向您展示上下文准备就绪和未准备就绪时会发生什么，它还为您提供了一些关于 vbo+vao+shaders 用法的额外好处，它应该给您类似的东西:

这应该可以让你开始......正如我所说，在 opengl 之上有大量的包装器，如果不是 pyglet，pygame 是 python 社区中非常有名的一个，它有很多酷特点。