def extrude(self, x1, y1, x2, y2):
n = QVector3D.normal(QVector3D(0, 0, -0.1), QVector3D(x2 - x1, y2 - y1, 0))
self.add(QVector3D(x1, y1, 0.05), n)
self.add(QVector3D(x1, y1, -0.05), n)
self.add(QVector3D(x2, y2, 0.05), n)
self.add(QVector3D(x2, y2, -0.05), n)
self.add(QVector3D(x2, y2, 0.05), n)
self.add(QVector3D(x1, y1, -0.05), n)
def quad(self, x1, y1, x2, y2, x3, y3, x4, y4):
n = QVector3D.normal(QVector3D(x4 - x1, y4 - y1, 0), QVector3D(x2 - x1, y2 - y1, 0))
self.add(QVector3D(x1, y1, -0.05), n)
self.add(QVector3D(x4, y4, -0.05), n)
self.add(QVector3D(x2, y2, -0.05), n)
self.add(QVector3D(x3, y3, -0.05), n)
self.add(QVector3D(x2, y2, -0.05), n)
self.add(QVector3D(x4, y4, -0.05), n)
n = QVector3D.normal(QVector3D(x1 - x4, y1 - y4, 0), QVector3D(x2 - x4, y2 - y4, 0))
self.add(QVector3D(x4, y4, 0.05), n)
self.add(QVector3D(x1, y1, 0.05), n)
self.add(QVector3D(x2, y2, 0.05), n)
self.add(QVector3D(x2, y2, 0.05), n)
self.add(QVector3D(x3, y3, 0.05), n)
self.add(QVector3D(x4, y4, 0.05), n)
