#!/usr/bin/env python import math from PyQt4 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_())