我想使用qt和pyopengl进行一些实时绘图，并了解一些关于OpenGL的知识，但是我甚至很难让我的initail测试数据显示出来。
其思想是将X坐标和Y坐标存储在不同的缓冲区中，因为X坐标很少更改，而Y坐标几乎会更改每个渲染。不幸的是，把它们放在不同的缓冲区会给我带来问题。
现在我没有错误，也没有任何东西出现，所以我不知道该去哪里。
以下是迄今为止我对绘图类的了解：
class GLWidget(QtOpenGL.QGLWidget):
def __init__(self, parent=None):
self.parent = parent
QtOpenGL.QGLWidget.__init__(self, parent)
self.current_position = 0
def initializeGL(self):
self.initGeometry()
self.vertex_code = """
#version 120
attribute vec4 color;
attribute float x_position;
attribute float y_position;
varying vec4 v_color;
void main()
{
gl_Position = vec4(x_position, y_position, 0.0, 1.0);
v_color = color;
} """
self.fragment_code = """
#version 120
varying vec4 v_color;
void main()
{
//gl_FragColor = v_color;
gl_FragColor = vec4(1,1,1,1);
} """
## Build and activate program
# Request program and shader slots from GPU
self.program = GL.glCreateProgram()
self.vertex = GL.glCreateShader(GL.GL_VERTEX_SHADER)
self.fragment = GL.glCreateShader(GL.GL_FRAGMENT_SHADER)
# Set shaders source
GL.glShaderSource(self.vertex, self.vertex_code)
GL.glShaderSource(self.fragment, self.fragment_code)
# Compile shaders
GL.glCompileShader(self.vertex)
GL.glCompileShader(self.fragment)
# Attach shader objects to the program
GL.glAttachShader(self.program, self.vertex)
GL.glAttachShader(self.program, self.fragment)
# Build program
GL.glLinkProgram(self.program)
# Get rid of shaders (not needed anymore)
GL.glDetachShader(self.program, self.vertex)
GL.glDetachShader(self.program, self.fragment)
# Make program the default program
GL.glUseProgram(self.program)
# Create array object
self.vao = GL.glGenVertexArrays(1)
GL.glBindVertexArray(self.vao)
# Request buffer slot from GPU
self.x_data_buffer = GL.glGenBuffers(1)
GL.glBindBuffer(GL.GL_ARRAY_BUFFER, self.x_data_buffer)
GL.glBufferData(GL.GL_ARRAY_BUFFER, ArrayDatatype.arrayByteCount(self.x), self.x, GL.GL_DYNAMIC_DRAW)
self.y_data_buffer = GL.glGenBuffers(1)
GL.glBindBuffer(GL.GL_ARRAY_BUFFER, self.y_data_buffer)
GL.glBufferData(GL.GL_ARRAY_BUFFER, ArrayDatatype.arrayByteCount(self.y), self.y, GL.GL_DYNAMIC_DRAW)
## Bind attributes
#self.stride = self.x.strides[0]
#self.offset = ctypes.c_void_p(0)
self.loc = GL.glGetAttribLocation(self.program, "x_position".encode('utf-8'))
GL.glEnableVertexAttribArray(self.loc)
GL.glBindBuffer(GL.GL_ARRAY_BUFFER, self.x_data_buffer)
GL.glVertexAttribPointer(self.loc, 1, GL.GL_FLOAT, GL.GL_FALSE, 0, 0)
#self.stride = self.y.strides[0]
#self.offset = ctypes.c_void_p(0)
self.loc = GL.glGetAttribLocation(self.program, "y_position".encode('utf-8'))
GL.glEnableVertexAttribArray(self.loc)
GL.glBindBuffer(GL.GL_ARRAY_BUFFER, self.y_data_buffer)
GL.glVertexAttribPointer(self.loc, 1, GL.GL_FLOAT, GL.GL_FALSE, 0, 0)
def resizeGL(self, width, height):
if height == 0: height = 1
GL.glViewport(0, 0, width, height)
GL.glMatrixMode(GL.GL_PROJECTION)
GL.glLoadIdentity()
aspect = width / float(height)
GLU.gluPerspective(45.0, aspect, 1.0, 100.0)
GL.glMatrixMode(GL.GL_MODELVIEW)
def paintGL(self):
GL.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT)
GL.glDrawArrays(GL.GL_LINE_STRIP, 0, self.bins)
def initGeometry(self):
self.bins = 1000
self.x = np.linspace(-0.5,0.5,self.bins)
self.y = np.array([np.sin(val*2*np.pi) for val in self.x])
self.color = np.array([(1,1,1,1) for x in np.arange(self.bins)])
def addPoint(self, point):
#print('ADD POINT')
self.y[self.current_position] = point
if self.current_position < self.bins-1:
self.current_position += 1
else:
self.current_position = 0
return True
def render(self):
#print('RENDER')
self.updateGL()
return True
我还把程序的完整工作版本放在这里：
import sys
from PyQt5.QtWidgets import QDesktopWidget, QMainWindow, QWidget, QAction, qApp, QApplication, QHBoxLayout, QVBoxLayout, QPushButton
from PyQt5.QtCore import QTimer
from PyQt5.QtGui import QIcon
from PyQt5 import QtOpenGL
from OpenGL import GL
from OpenGL import GLU
from OpenGL.arrays.arraydatatype import ArrayDatatype
import ctypes
import numpy as np
from threading import Timer, Thread, Event
class OxySensor(QMainWindow):
def __init__(self):
super().__init__()
self.initUI()
self.initActions()
self.initMenuBar()
self.initRenderTimer()
self.start()
def initUI(self):
self.resize(800,600)
self.center()
self.setWindowTitle('OxySensor')
okButton = QPushButton("OK")
cancelButton = QPushButton("Cancel")
hbox = QHBoxLayout()
hbox.addStretch(1)
hbox.addWidget(okButton)
hbox.addWidget(cancelButton)
vbox = QVBoxLayout()
#vbox.addStretch(1)
self.gl_widget = GLWidget()
vbox.addWidget(self.gl_widget)
vbox.addLayout(hbox)
mainWidget = QWidget(self)
mainWidget.setLayout(vbox)
self.setCentralWidget(mainWidget)
self.show()
def initActions(self):
self.exitAction = QAction(QIcon('images/close20.png'), '&Exit', self)
self.exitAction.setShortcut('Ctrl+W')
self.exitAction.setStatusTip('Exit application')
self.exitAction.triggered.connect(self.onExit)
def initMenuBar(self):
menubar = self.menuBar()
fileMenu = menubar.addMenu('&File')
fileMenu.addAction(self.exitAction)
return True
def initRenderTimer(self):
self.timer = QTimer()
self.timer.timeout.connect(self.gl_widget.render)
self.timer.start(100)
return True
def start(self):
self.stop_flag = Event()
self.thread = SerialPort(self.onTimerExpired, self.stop_flag)
self.thread.start()
self.statusBar().showMessage('Ready')
def center(self):
qr = self.frameGeometry()
cp = QDesktopWidget().availableGeometry().center()
qr.moveCenter(cp)
self.move(qr.topLeft())
return True
def onTimerExpired(self):
data = np.random.uniform(-1,1)
self.gl_widget.addPoint(data)
return True
def onExit(self):
self.close()
return None
def closeEvent(self,event):
self.stop_flag.set()
event.accept()
return None
class GLWidget(QtOpenGL.QGLWidget):
def __init__(self, parent=None):
self.parent = parent
QtOpenGL.QGLWidget.__init__(self, parent)
self.yRotDeg = 0.0
self.current_position = 0
def initializeGL(self):
self.initGeometry()
self.vertex_code = """
#version 120
attribute vec4 color;
attribute float x_position;
attribute float y_position;
varying vec4 v_color;
void main()
{
gl_Position = vec4(x_position, y_position, 0.0, 1.0);
v_color = color;
} """
self.fragment_code = """
#version 120
varying vec4 v_color;
void main()
{
//gl_FragColor = v_color;
gl_FragColor = vec4(1,1,1,1);
} """
## Build and activate program
# Request program and shader slots from GPU
self.program = GL.glCreateProgram()
self.vertex = GL.glCreateShader(GL.GL_VERTEX_SHADER)
self.fragment = GL.glCreateShader(GL.GL_FRAGMENT_SHADER)
# Set shaders source
GL.glShaderSource(self.vertex, self.vertex_code)
GL.glShaderSource(self.fragment, self.fragment_code)
# Compile shaders
GL.glCompileShader(self.vertex)
GL.glCompileShader(self.fragment)
# Attach shader objects to the program
GL.glAttachShader(self.program, self.vertex)
GL.glAttachShader(self.program, self.fragment)
# Build program
GL.glLinkProgram(self.program)
# Get rid of shaders (not needed anymore)
GL.glDetachShader(self.program, self.vertex)
GL.glDetachShader(self.program, self.fragment)
# Make program the default program
GL.glUseProgram(self.program)
# Create array object
self.vao = GL.glGenVertexArrays(1)
GL.glBindVertexArray(self.vao)
# Request buffer slot from GPU
self.x_data_buffer = GL.glGenBuffers(1)
GL.glBindBuffer(GL.GL_ARRAY_BUFFER, self.x_data_buffer)
GL.glBufferData(GL.GL_ARRAY_BUFFER, ArrayDatatype.arrayByteCount(self.x), self.x, GL.GL_DYNAMIC_DRAW)
self.y_data_buffer = GL.glGenBuffers(1)
GL.glBindBuffer(GL.GL_ARRAY_BUFFER, self.y_data_buffer)
GL.glBufferData(GL.GL_ARRAY_BUFFER, ArrayDatatype.arrayByteCount(self.y), self.y, GL.GL_DYNAMIC_DRAW)
## Bind attributes
#self.stride = self.x.strides[0]
#self.offset = ctypes.c_void_p(0)
self.loc = GL.glGetAttribLocation(self.program, "x_position".encode('utf-8'))
GL.glEnableVertexAttribArray(self.loc)
GL.glBindBuffer(GL.GL_ARRAY_BUFFER, self.x_data_buffer)
GL.glVertexAttribPointer(self.loc, 1, GL.GL_FLOAT, GL.GL_FALSE, 0, 0)
#self.stride = self.y.strides[0]
#self.offset = ctypes.c_void_p(0)
self.loc = GL.glGetAttribLocation(self.program, "y_position".encode('utf-8'))
GL.glEnableVertexAttribArray(self.loc)
GL.glBindBuffer(GL.GL_ARRAY_BUFFER, self.y_data_buffer)
GL.glVertexAttribPointer(self.loc, 1, GL.GL_FLOAT, GL.GL_FALSE, 0, 0)
def resizeGL(self, width, height):
if height == 0: height = 1
GL.glViewport(0, 0, width, height)
GL.glMatrixMode(GL.GL_PROJECTION)
GL.glLoadIdentity()
aspect = width / float(height)
GLU.gluPerspective(45.0, aspect, 1.0, 100.0)
GL.glMatrixMode(GL.GL_MODELVIEW)
def paintGL(self):
GL.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT)
GL.glDrawArrays(GL.GL_LINE_STRIP, 0, self.bins)
def initGeometry(self):
self.bins = 1000
self.x = np.linspace(-0.5,0.5,self.bins)
self.y = np.array([np.sin(val*2*np.pi) for val in self.x])
self.color = np.array([(1,1,1,1) for x in np.arange(self.bins)])
def addPoint(self, point):
#print('ADD POINT')
self.y[self.current_position] = point
if self.current_position < self.bins-1:
self.current_position += 1
else:
self.current_position = 0
return True
def render(self):
#print('RENDER')
self.updateGL()
return True
class SerialPort(Thread):
def __init__(self, callback, event):
Thread.__init__(self)
self.callback = callback
self.stopped = event
return None
def SetInterval(self, time_in_seconds):
self.delay_period = time_in_seconds
return True
def run(self):
while not self.stopped.wait(0.1):
self.callback()
return True
if __name__ == '__main__':
app = QApplication(sys.argv)
oxy_sensor = OxySensor()
sys.exit(app.exec_())
最佳答案
问题很可能是“opengl.gl”函数的调用：
GL.glVertexAttribPointer(self.loc, 1, GL.GL_FLOAT, GL.GL_FALSE, 0, 0)
注意最后一个值是0（不幸的是，在
(void *)0api中，它没有转换为C++，而是转换为一些高地址）。您最可能的意思是“偏移0”，而不是“0对象的地址”。也就是说，使用None代替（它确实转换为(void *)0）：GL.glVertexAttribPointer(self.loc, 1, GL.GL_FLOAT, GL.GL_FALSE, 0, None)
是的，这有点违反直觉。我花了半天的时间才弄明白这就是为什么输出在我自己的代码中变黑的原因。
还要注意，如果使用qt函数（通过
OpenGL.GL获得）而不是gl = self.context().versionFunctions()函数，则它们提供的API稍有不同，当您的意思是“offset 0”时，实际上会传递0。关于python - 用PyOpenGL绘制麻烦，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/33505731/