Opengl黑屏

Question

虽然运行 this sample code 在支持 OpenGL 3.1 的 GPU 上，Pyopengl 3.1.5（Python 3.8 和 Windows10 Pro-64 位）window 显示黑屏。

示例代码中缺少一些内容。
1. fragcolor没有指定颜色
2. 提供整数值作为 glVetex2f() 的输入，而不是浮点数。
在纠正上述问题和运行代码后，屏幕仍然是黑色。

＃脚本

import OpenGL
from OpenGL.GL import *
from  OpenGL.GLUT import * 
from OpenGL.GLU import * 
import io
print("Imports successful!")

w, h = 500,500

def poly_shape():     
    glBegin(GL_QUADS) 
    glColor4f(1.0,0.0,0.0,1.0)
    glVertex2f(100.0, 100.0)
    glVertex2f(200.0, 100.0) 
    glVertex2f(200.0, 200.0) 
    glVertex2f(100.0, 200.0) 
    glEnd()

def showScreen():
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT) # Remove everything from screen (i.e. displays all white)
    glLoadIdentity() # Reset all graphic/shape's position
    poly_shape() # Draw function call
    glutSwapBuffers()

#------
glutInit()
glutInitDisplayMode(GLUT_RGBA) # Set the display mode to be colored
glutInitWindowSize(500, 500)   # Set the w and h of your window
glutInitWindowPosition(0, 0)   # Set the position at which this windows should appear
wind = glutCreateWindow("OpenGL Coding Practice") # Set a window title
glutDisplayFunc(showScreen)
glutIdleFunc(showScreen) # Keeps the window open
glutMainLoop()  # Keeps the above created window displaying/running in a loop

Answer 1

在 sample code 中，缺少 Mvp（模型-视图-投影）矩阵的代码。在 ShowScreen() 函数下添加它时，绘制调用（在本例中为方形）渲染在视口。

import OpenGL
from OpenGL.GL import *
from  OpenGL.GLUT import * 
from OpenGL.GLU import * 
import io
print("Imports successful!")


w, h = 500,500


def draw_shape():
    glBegin(GL_QUADS) 
    glColor4f(1.0,0.0,0.0,1.0)
    glVertex2f(100.0, 100.0)
    glVertex2f(200.0, 100.0) 
    glVertex2f(200.0, 200.0) 
    glVertex2f(100.0, 200.0) 
    glEnd() 
    glFlush()

def showScreen():
    glViewport(0, 0, 500, 500)
    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    glOrtho(0, 500, 500, 0, -1, 1)
    glMatrixMode(GL_MODELVIEW)
    glLoadIdentity()

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT) # Remove everything from screen (i.e. displays all white)
    glLoadIdentity() # Reset all graphic/shape's position

    draw_shape() # Draw function

    glutSwapBuffers()

#---Section 3---
glutInit()
glutInitDisplayMode(GLUT_RGBA) # Set the display mode to be colored
glutInitWindowSize(500, 500)   # Set the w and h of your window
glutInitWindowPosition(0, 0)   # Set the position at which this windows should appear
wind = glutCreateWindow("OpenGL Coding Practice") # Set a window title


glutDisplayFunc(showScreen)
glutIdleFunc(showScreen) # Keeps the window open
glutMainLoop()  # Keeps the above created window displaying/running in a loop*

Opengl黑屏

Pyopengl Blackscreen

python

opengl

pyopengl

opengl-compat