PyOpenGl验证失败

Question

我正在尝试用pyopengl创建一个简单的场景，但是我一直在获取运行时错误。我使用glfw来显示opengl场景。

我使用python是因为我希望在其他python项目中包含opengl。

我在macOS Mojave上(10.14)，Python3.7

错误：

Traceback (most recent call last):
File "main.py", line 109, in <module>
main()
File "main.py", line 64, in main
shader = OpenGL.GL.shaders.compileProgram(s.vertex(), s.fragment())
File "slib/python3.7/site-packages/OpenGL/GL/shaders.py", line 196, in         
compileProgram
program.check_validate()
File "lib/python3.7/site-packages/OpenGL/GL/shaders.py", line 108, in 
check_validate
glGetProgramInfoLog( self ),
RuntimeError: Validation failure (0): b'Validation Failed: No vertex 
array object bound.\n'

代码：

import glfw
from OpenGL.GL import *
import OpenGL.GL.shaders
import numpy as np


def trikotnik():
    trikotnik = np.array([
        -0.5, -0.5, 0.0,
        0.5, -0.5, 0.0,
        0.0, 0.5, 0.0
    ], dtype=np.float32)
    return trikotnik


class Shaders:
    def __init__(self):
        pass

    def vertex(self):
        v = """
        #version 330
        in vec4 position; 
        void main() { 
            gl_Position = position; 
        } 
        """
        return OpenGL.GL.shaders.compileShader(v, GL_VERTEX_SHADER)

    def fragment(self):
        f = """
        #version 330
        out vec4 fragColor;
        void main() { 
            fragColor = vec4( 0, 1, 0, 1 );
        } 
        """
        return OpenGL.GL.shaders.compileShader(f, GL_FRAGMENT_SHADER)


def main():
    # Initialize the library
    if not glfw.init():
        return
    glfw.window_hint(glfw.CONTEXT_VERSION_MAJOR, 3)
    glfw.window_hint(glfw.CONTEXT_VERSION_MINOR, 2)
    glfw.window_hint(glfw.OPENGL_PROFILE, glfw.OPENGL_CORE_PROFILE)
    glfw.window_hint(glfw.OPENGL_FORWARD_COMPAT, GL_TRUE)

    # Create a windowed mode window and its OpenGL context
    window = glfw.create_window(640, 480, "Hello World", None, None)
    if not window:
        glfw.terminate()
        return

    # Make the window's context current
    glfw.make_context_current(window)

    # Creating shaders
    s = Shaders()
    shader = OpenGL.GL.shaders.compileProgram(s.vertex(), s.fragment())

    # Creating vertex buffer object on gpu
    VBO = glGenBuffers(1)
    glBindBuffer(GL_ARRAY_BUFFER, VBO)
    # Load data on array buffer...32 = size in bytes 9x4
    # GL_STATIC_DRAW: The vertex data will be uploaded once and drawn many times.
    glBufferData(GL_ARRAY_BUFFER, 32, trikotnik(), GL_STATIC_DRAW)
    glBindBuffer(GL_ARRAY_BUFFER, VBO)

    position = glGetAttribLocation(shader, "position")
    glVertexAttribPointer(
        position,  # attribute 0. No particular reason for 0, but must match the layout in the shader.
        3,  # size
        GL_FLOAT,  # type
        GL_FALSE,  # normalized
        0,  # stride
        None  # array buffer offset
    )
    glEnableVertexAttribArray(position)

    glUseProgram(shader)

    glClearColor(0, 107, 179, 1.0)

    # Loop until the user closes the window
    while not glfw.window_should_close(window):
        # Render here, e.g. using pyOpenGL

        # Clear color buffer
        glClear(GL_COLOR_BUFFER_BIT)

        # Draw
        glDrawArrays(GL_TRIANGLES, 0, 3)

        # Swap front and back buffers
        glfw.swap_buffers(window)
        # Poll for and process events
        glfw.poll_events()

    glfw.terminate()


if __name__ == "__main__":
    main()

我在源代码中找到了这个：

验证(仅关键字) --如果为False，则抑制针对当前GL状态的自动验证。在高级使用中，验证会产生虚假错误。注意:这个函数实际上并不适合高级使用，如果您发现自己指定了这个标志，那么您应该使用自己的着色器管理代码。

我试着把它设置为假，但我仍然得到一个错误。

Answer 1

要么使用顶点阵列对象，要么切换到兼容性配置文件上下文glfw.window_hint(glfw.OPENGL_PROFILE, glfw.OPENGL_COMPAT_PROFILE)。在核心配置文件中，必须有一个名为VAO的名称，它不是可选的。

在指定顶点数组数据数组之前，创建并绑定VAO：

VAO = glGenVertexArrays(1)
glBindVertexArray(VAO)

glVertexAttribPointer(
    position,  # attribute 0. No particular reason for 0, but must match the layout in the shader.
    3,  # size
    GL_FLOAT,  # type
    GL_FALSE,  # normalized
    0,  # stride
    None  # array buffer offset
)
glEnableVertexAttribArray(position)