use*_*827 17 python opengl pyopengl qt5
我想使用Qt和PyOpenGL做一些实时绘图并学习一些关于OpenGL的内容,但是甚至无法让我的initail测试数据显示出来.
这个想法是将x坐标和y坐标存储在不同的缓冲区中,因为x坐标很少会改变,而y坐标几乎每次渲染都会改变.不幸的是,让它们在不同的缓冲区中给我带来了麻烦.
现在我没有错误,没有任何东西出现,所以我不知道该去哪里.
这是我到目前为止绘图类的内容:
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
我还在这里放了一个完整的程序版本:
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_())
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)
请注意，最后一个值是 0（不幸的是，它没有转换为API(void *)0中的C++值，而是转换为某个高地址）。您很可能指的是“偏移量 0”，而不是“0 对象的地址”。IE。使用None代替（它确实翻译为(void *)0）：
GL.glVertexAttribPointer(self.loc, 1, GL.GL_FLOAT, GL.GL_FALSE, 0, None)
是的，这有点违反直觉。我花了半天时间才弄清楚这就是我自己的代码中输出变黑的原因。
OpenGL.GL另请注意，如果您使用Qt函数（通过 获得）而不是函数gl = self.context().versionFunctions()，它们提供的 API 略有不同，当您指的是“Offset 0”时，您实际上会传递 0 。