如何在 PyQt5 中居中 QGLWidget 的子类

Question

我在 PyQt5

中有一个示例程序

我有一个 class:

class QGLControllerWidget(QtOpenGL.QGLWidget):
    ...

还有一个主程序：

app = QtWidgets.QApplication([])
window = QGLControllerWidget()    # this is my class
window.show()                     # I want to center the window on the screen
app.exec_()

Currently the window's location is somewhere between the center and the bottom right corner, please see the image:

如何在 PyQt5 中使 window/widget 在屏幕上居中？

03_alpha_blending.py

import struct

from PyQt5 import QtCore, QtOpenGL, QtWidgets

import ModernGL


class QGLControllerWidget(QtOpenGL.QGLWidget):
    def __init__(self):
        fmt = QtOpenGL.QGLFormat()
        fmt.setVersion(3, 3)
        fmt.setProfile(QtOpenGL.QGLFormat.CoreProfile)
        fmt.setSampleBuffers(True)
        self.timer = QtCore.QElapsedTimer()
        super(QGLControllerWidget, self).__init__(fmt, None)

    def initializeGL(self):
        self.ctx = ModernGL.create_context()

        prog = self.ctx.program([
            self.ctx.vertex_shader('''
                #version 330

                in vec2 vert;

                in vec4 vert_color;
                out vec4 frag_color;

                uniform vec2 scale;
                uniform float rotation;

                void main() {
                    frag_color = vert_color;
                    float r = rotation * (0.5 + gl_InstanceID * 0.05);
                    mat2 rot = mat2(cos(r), sin(r), -sin(r), cos(r));
                    gl_Position = vec4((rot * vert) * scale, 0.0, 1.0);
                }
            '''),
            self.ctx.fragment_shader('''
                #version 330

                in vec4 frag_color;
                out vec4 color;

                void main() {
                    color = vec4(frag_color);
                }
            '''),
        ])

        self.scale = prog.uniforms['scale']
        self.rotation = prog.uniforms['rotation']

        vbo = self.ctx.buffer(struct.pack(
            '18f',
            1.0, 0.0, 1.0, 0.0, 0.0, 0.5,
            -0.5, 0.86, 0.0, 1.0, 0.0, 0.5,
            -0.5, -0.86, 0.0, 0.0, 1.0, 0.5,
        ))

        self.vao = self.ctx.simple_vertex_array(prog, vbo, ['vert', 'vert_color'])

        self.timer.restart()

    def paintGL(self):
        self.ctx.viewport = (0, 0, self.width(), self.height())
        self.ctx.clear(0.9, 0.9, 0.9)
        self.scale.value = (self.height() / self.width() * 0.75, 0.75)
        self.rotation.value = self.timer.elapsed() / 1000
        self.ctx.enable(ModernGL.BLEND)
        self.vao.render(instances=10)
        self.ctx.finish()
        self.update()


app = QtWidgets.QApplication([])
window = QGLControllerWidget()
window.show()
app.exec_()

Answer 1

您必须将小部件移动到屏幕中央，才能知道您必须使用的屏幕大小 QDesktopWidget，如下所示：

app = QtWidgets.QApplication([])
window = QGLControllerWidget()
pos = QtWidgets.QDesktopWidget().rect().center() -window.rect().center()
window.move(pos)
window.show()
app.exec_()

如何在 PyQt5 中居中 QGLWidget 的子类

How to center a subclass of QGLWidget in PyQt5

python

python-3.x

pyqt5

python-moderngl