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#!/usr/bin/env python
import math
from PySide2 import QtCore, QtGui
class Lighting(QtGui.QGraphicsView):
def __init__(self, parent=None):
super(Lighting, self).__init__(parent)
self.angle = 0.0
self.m_scene = QtGui.QGraphicsScene()
self.m_lightSource = None
self.m_items = []
self.setScene(self.m_scene)
self.setupScene()
timer = QtCore.QTimer(self)
timer.timeout.connect(self.animate)
timer.setInterval(30)
timer.start()
self.setRenderHint(QtGui.QPainter.Antialiasing)
self.setFrameStyle(QtGui.QFrame.NoFrame)
def setupScene(self):
self.m_scene.setSceneRect(-300, -200, 600, 460)
linearGrad = QtGui.QLinearGradient(QtCore.QPointF(-100, -100),
QtCore.QPointF(100, 100))
linearGrad.setColorAt(0, QtGui.QColor(255, 255, 255))
linearGrad.setColorAt(1, QtGui.QColor(192, 192, 255))
self.setBackgroundBrush(linearGrad)
radialGrad = QtGui.QRadialGradient(30, 30, 30)
radialGrad.setColorAt(0, QtCore.Qt.yellow)
radialGrad.setColorAt(0.2, QtCore.Qt.yellow)
radialGrad.setColorAt(1, QtCore.Qt.transparent)
pixmap = QtGui.QPixmap(60, 60)
pixmap.fill(QtCore.Qt.transparent)
painter = QtGui.QPainter(pixmap)
painter.setPen(QtCore.Qt.NoPen)
painter.setBrush(radialGrad)
painter.drawEllipse(0, 0, 60, 60)
painter.end()
self.m_lightSource = self.m_scene.addPixmap(pixmap)
self.m_lightSource.setZValue(2)
for i in range(-2, 3):
for j in range(-2, 3):
if (i + j) & 1:
item = QtGui.QGraphicsEllipseItem(0, 0, 50, 50)
else:
item = QtGui.QGraphicsRectItem(0, 0, 50, 50)
item.setPen(QtGui.QPen(QtCore.Qt.black, 1))
item.setBrush(QtGui.QBrush(QtCore.Qt.white))
effect = QtGui.QGraphicsDropShadowEffect(self)
effect.setBlurRadius(8)
item.setGraphicsEffect(effect)
item.setZValue(1)
item.setPos(i * 80, j * 80)
self.m_scene.addItem(item)
self.m_items.append(item)
def animate(self):
self.angle += (math.pi / 30)
xs = 200 * math.sin(self.angle) - 40 + 25
ys = 200 * math.cos(self.angle) - 40 + 25
self.m_lightSource.setPos(xs, ys)
for item in self.m_items:
effect = item.graphicsEffect()
delta = QtCore.QPointF(item.x() - xs, item.y() - ys)
effect.setOffset(QtCore.QPointF(delta.toPoint() / 30))
dd = math.hypot(delta.x(), delta.y())
color = effect.color()
color.setAlphaF(max(0.4, min(1 - dd / 200.0, 0.7)))
effect.setColor(color)
self.m_scene.update()
if __name__ == '__main__':
import sys
app = QtGui.QApplication(sys.argv)
lighting = Lighting()
lighting.setWindowTitle("Lighting and Shadows")
lighting.resize(640, 480)
lighting.show()
sys.exit(app.exec_())
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