Python Qt+OpenGL绘图区域错误

Question

我有简单的 OpenGl 代码，但是绘图区域显示不正确，当我想要全尺寸时它大约是 100x30。但是我的 OpenGl 小部件具有适当的清晰行为。我该如何解决这个问题？

from OpenGL.GL import *
from OpenGL.GLUT import *
from OpenGL.GLU import *
from PyQt4 import QtCore, QtGui, QtOpenGL
import sys
try:
    _fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
    def _fromUtf8(s):
        return s

try:
    _encoding = QtGui.QApplication.UnicodeUTF8
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig, _encoding)
except AttributeError:
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig)

try:
    from OpenGL import GL
except ImportError:
    app = QtGui.QApplication(sys.argv)
    QtGui.QMessageBox.critical(None, "OpenGL hellogl",
            "PyOpenGL must be installed to run this example.")
    sys.exit(1)


class Ui_Form(QtGui.QWidget):
    def __init__(self):
        QtGui.QWidget.__init__(self)
        self.setupUi(self)
    def setupUi(self, Form):
        Form.setObjectName(_fromUtf8("Form"))
        Form.resize(700, 532)


        self.openGLWidget = GLWidget(Form)
        self.openGLWidget.setGeometry(QtCore.QRect(10 , 10, 512, 512))
        self.openGLWidget.setObjectName("openGLWidget")

        self.retranslateUi(Form)
        QtCore.QMetaObject.connectSlotsByName(Form)

    def retranslateUi(self, Form):
        Form.setWindowTitle(_translate("Form", "Form", None))

class GLWidget(QtOpenGL.QGLWidget):
    def __init__(self, parent=None):

        super(GLWidget, self).__init__(parent)


    def initializeGL(self):
        GL.glClearColor(0,255,0,255)

    def paintGL(self):


        glEnable(GL_TEXTURE_2D)
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)

        glLoadIdentity()

        gluOrtho2D(0, 1, 0, 1);

        glColor3f(1, 0, 0)
        glDisable(GL_TEXTURE_2D)
        glBegin(GL_QUADS)
        glVertex2i(0, 0)
        glVertex2i(1000, 0)
        glVertex2i(1000, 1000)
        glVertex2i(0, 1000)
        glEnd();

        glFlush()




if __name__ == '__main__':

    app = QtGui.QApplication(sys.argv)
    window = Ui_Form()
    window.show()
    sys.exit(app.exec_())

我尝试更改 glOrtho 并添加一些过剩函数，但没有结果。我也尝试添加矩阵乘法来缩放它，似乎显示区域有一些错误的值。

Answer 1

您必须设置视口大小。见 glViewport:

void glViewport( GLint x, GLint y, GLsizei width, GLsizei height);

x, y Specify the lower left corner of the viewport rectangle, in pixels. The initial value is (0,0).
width, height Specify the width and height of the viewport.

glViewport specifies the affine transformation of x and y from normalized device coordinates to window coordinates.

您的代码应该看起来像这样：

def paintGL(self):

    width = 512
    height = 512

    glViewport(0, 0, width, height)
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)

    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    gluOrtho2D(0, width, 0, height)

    glMatrixMode(GL_MODELVIEW)
    glLoadIdentity()

    glColor3f(1, 0, 0)
    glBegin(GL_QUADS)
    glVertex2i(0, 0)
    glVertex2i(width, 0)
    glVertex2i(width, height)
    glVertex2i(0, height)
    glEnd()

    glFlush()

请注意，在 OpenGL 中，每种矩阵模式都有一个矩阵堆栈（参见 glMatrixMode）。矩阵模式为 GL_MODELVIEW、GL_PROJECTION 和 GL_TEXTURE。所以你应该设置投影矩阵（GL_PROJECTION）和模型视图矩阵（GL_MODELVIEW），因为每个顶点都是由模型视图矩阵和投影矩阵变换的。

进一步了解 QT + OPENGL CODE EXAMPLE

顺便说一下，glClearColor 的参数是 [0, 1] 范围内的浮点值。更改方法 initializeGL:

def initializeGL(self):
    GL.glClearColor(0,1,0,1)

Python Qt+OpenGL绘图区域错误

Python Qt+OpenGL drawing region bug

python

qt

opengl

pyqt4

pyopengl