Я обнаружил какое-то del поведение, которое я не понимаю и надеюсь, что вы можете дать мне некоторое представление.Я пытаюсь реализовать hello_triangle OpenGL, используя PyOpenGL и glfw.После закрытия окна OpenGL моя программа должна очиститься, но glDeleteBuffers вызывает ошибку TypeError, НО ТОЛЬКО если она вызывается внутри функции __del__:
class Scene:
def __init__ (self):
# ...
self.buffer = glGenBuffers(1)
# ...
def __del__ (self):
# ...
glDeleteBuffers(1, [self.buffer]) # TypeError: ('No array-type handler for type builtins.type (value: [1]) registered', <OpenGL.converters.CallFuncPyConverter object at ...>)
# ...
# ...
scene = Scene()
while not glfwWindowShouldClose(window):
scene.render()
glfwSwapBuffers(window)
glfwPollEvents()
del scene
Если вместо этого я реализую ее следующим образом
class Scene:
def __init__ (self):
# ...
self.buffer = glGenBuffers(1)
# ...
def delete (self): # Renamed __del__ to delete
# ...
glDeleteBuffers(1, [self.buffer]) # No error
# ...
# ...
scene = Scene()
while not glfwWindowShouldClose(window):
scene.render()
glfwSwapBuffers(window)
glfwPollEvents()
scene.delete() # Swapped del scene for scene.delete()
glDeleteBuffers неожиданно работает и не выдает ошибок. Почему это так? Если вы хотите попробовать это сами, вот полный код:
import ctypes
import sys
# OpenGL + GLFW
import glfw
from glfw.GLFW import *
from OpenGL.GL import *
glfw.ERROR_REPORTING = False # Catch errors by return values
class obj: pass # Object to assign arbitrary properties to
def main (args):
# Initialize GLFW + create window
if glfwInit() == GL_TRUE:
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4)
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 5)
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE)
window = glfwCreateWindow(800, 600, "Title", None, None)
if window:
glfwMakeContextCurrent(window)
window_size_callback(window, 800, 600)
glfwSetWindowSizeCallback(window, window_size_callback)
# Render stuff
scene = Scene()
while not glfwWindowShouldClose(window):
scene.render()
glfwSwapBuffers(window)
glfwPollEvents()
# Clean up
del scene # TypeError
# scene.delete() # no TypeError
else:
print("Failed to create GLFW window!")
glfwTerminate()
else:
print("Failed to initialize GLFW!")
def window_size_callback (window, width, height):
glViewport(0, 0, width, height)
class Scene:
_instances = []
class vertex (ctypes.Structure):
_fields_ = [
("x", GLfloat),
("y", GLfloat)
]
def __static_init__ ():
# Create rendering pipeline program
vertex_shader = glCreateShader(GL_VERTEX_SHADER)
glShaderSource(vertex_shader, """#version 450 core
in vec4 pos;
void main () {
gl_Position = vec4(pos.xy, 0.0, 1.0);
}""")
glCompileShader(vertex_shader)
fragment_shader = glCreateShader(GL_FRAGMENT_SHADER)
glShaderSource(fragment_shader, """#version 450 core
out vec4 frag_color;
void main () {
frag_color = vec4(1.0, 1.0, 1.0, 1.0);
}""")
glCompileShader(fragment_shader)
Scene._program = glCreateProgram()
glAttachShader(Scene._program, vertex_shader)
glAttachShader(Scene._program, fragment_shader)
glLinkProgram(Scene._program)
glDeleteShader(vertex_shader)
glDeleteShader(fragment_shader)
# Create VAO
Scene._vertex_array = glGenVertexArrays(1)
glBindVertexArray(Scene._vertex_array)
Scene._attrib_pos = glGetAttribLocation(Scene._program, "pos")
glVertexAttribFormat(Scene._attrib_pos, 2, GL_FLOAT, GL_FALSE, 0)
glEnableVertexAttribArray(Scene._attrib_pos)
glVertexAttribBinding(Scene._attrib_pos, Scene._attrib_pos)
def __static_del__ ():
glDeleteVertexArrays(1, [Scene._vertex_array]) # Alsa raises a TypeError, if glDeleteBuffers' error is catched before
glDeleteProgram(Scene._program)
def __init__ (self):
if len(Scene._instances) == 0:
Scene.__static_init__()
Scene._instances.append(self)
# Create VBO
vertex_buffer_data = (Scene.vertex * 3)(
Scene.vertex(-0.5, 0.5),
Scene.vertex(0.5, 0.5),
Scene.vertex(0.5, -0.5)
)
self._vertex_buffer = obj()
self._vertex_buffer.buffer = glGenBuffers(1)
self._vertex_buffer.length = len(vertex_buffer_data)
self._vertex_buffer.offset = Scene.vertex.x.offset
self._vertex_buffer.stride = ctypes.sizeof(Scene.vertex)
glBindBuffer(GL_ARRAY_BUFFER, self._vertex_buffer.buffer)
glBufferData(GL_ARRAY_BUFFER, vertex_buffer_data, GL_STATIC_DRAW)
def __del__ (self): # Rename to delete
glDeleteBuffers(1, [self._vertex_buffer.buffer]) # TypeError, if executed in __del__(), but not when executeed in delete()
Scene._instances.remove(self)
if len(Scene._instances) == 0:
Scene.__static_del__()
def render (self):
glClearColor(0.0, 0.1, 0.2, 1.0)
glClear(GL_COLOR_BUFFER_BIT)
# Draw
glUseProgram(Scene._program)
glBindVertexArray(Scene._vertex_array)
glBindVertexBuffer(Scene._attrib_pos, self._vertex_buffer.buffer, self._vertex_buffer.offset, self._vertex_buffer.stride)
glDrawArrays(GL_TRIANGLES, 0, self._vertex_buffer.length)
if __name__ == "__main__":
main(sys.argv[1:])