#!/usr/bin/env python
#############################################################################
##
## Copyright (C) 2013 Riverbank Computing Limited.
## Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
## All rights reserved.
##
## This file is part of the examples of PyQt.
##
## $QT_BEGIN_LICENSE:BSD$
## You may use this file under the terms of the BSD license as follows:
##
## "Redistribution and use in source and binary forms, with or without
## modification, are permitted provided that the following conditions are
## met:
## * Redistributions of source code must retain the above copyright
## notice, this list of conditions and the following disclaimer.
## * Redistributions in binary form must reproduce the above copyright
## notice, this list of conditions and the following disclaimer in
## the documentation and/or other materials provided with the
## distribution.
## * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
## the names of its contributors may be used to endorse or promote
## products derived from this software without specific prior written
## permission.
##
## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
## "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
## LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
## A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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## (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
## OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
## $QT_END_LICENSE$
##
#############################################################################
from PyQt5.QtCore import (pyqtSignal, QMutex, QMutexLocker, QPoint, QSize, Qt,
QThread, QWaitCondition)
from PyQt5.QtGui import QColor, QImage, QPainter, QPixmap, qRgb
from PyQt5.QtWidgets import QApplication, QWidget
DefaultCenterX = -0.647011
DefaultCenterY = -0.0395159
DefaultScale = 0.00403897
ZoomInFactor = 0.8
ZoomOutFactor = 1 / ZoomInFactor
ScrollStep = 20
class RenderThread(QThread):
ColormapSize = 512
renderedImage = pyqtSignal(QImage, float)
def __init__(self, parent=None):
super(RenderThread, self).__init__(parent)
self.mutex = QMutex()
self.condition = QWaitCondition()
self.centerX = 0.0
self.centerY = 0.0
self.scaleFactor = 0.0
self.resultSize = QSize()
self.colormap = []
self.restart = False
self.abort = False
for i in range(RenderThread.ColormapSize):
self.colormap.append(self.rgbFromWaveLength(380.0 + (i * 400.0 / RenderThread.ColormapSize)))
def __del__(self):
self.mutex.lock()
self.abort = True
self.condition.wakeOne()
self.mutex.unlock()
self.wait()
def render(self, centerX, centerY, scaleFactor, resultSize):
locker = QMutexLocker(self.mutex)
self.centerX = centerX
self.centerY = centerY
self.scaleFactor = scaleFactor
self.resultSize = resultSize
if not self.isRunning():
self.start(QThread.LowPriority)
else:
self.restart = True
self.condition.wakeOne()
def run(self):
while True:
self.mutex.lock()
resultSize = self.resultSize
scaleFactor = self.scaleFactor
centerX = self.centerX
centerY = self.centerY
self.mutex.unlock()
halfWidth = resultSize.width() // 2
halfHeight = resultSize.height() // 2
image = QImage(resultSize, QImage.Format_RGB32)
NumPasses = 8
curpass = 0
while curpass < NumPasses:
MaxIterations = (1 << (2 * curpass + 6)) + 32
Limit = 4
allBlack = True
for y in range(-halfHeight, halfHeight):
if self.restart:
break
if self.abort:
return
ay = 1j * (centerY + (y * scaleFactor))
for x in range(-halfWidth, halfWidth):
c0 = centerX + (x * scaleFactor) + ay
c = c0
numIterations = 0
while numIterations < MaxIterations:
numIterations += 1
c = c*c + c0
if abs(c) >= Limit:
break
numIterations += 1
c = c*c + c0
if abs(c) >= Limit:
break
numIterations += 1
c = c*c + c0
if abs(c) >= Limit:
break
numIterations += 1
c = c*c + c0
if abs(c) >= Limit:
break
if numIterations < MaxIterations:
image.setPixel(x + halfWidth, y + halfHeight,
self.colormap[numIterations % RenderThread.ColormapSize])
allBlack = False
else:
image.setPixel(x + halfWidth, y + halfHeight, qRgb(0, 0, 0))
if allBlack and curpass == 0:
curpass = 4
else:
if not self.restart:
self.renderedImage.emit(image, scaleFactor)
curpass += 1
self.mutex.lock()
if not self.restart:
self.condition.wait(self.mutex)
self.restart = False
self.mutex.unlock()
def rgbFromWaveLength(self, wave):
r = 0.0
g = 0.0
b = 0.0
if wave >= 380.0 and wave <= 440.0:
r = -1.0 * (wave - 440.0) / (440.0 - 380.0)
b = 1.0
elif wave >= 440.0 and wave <= 490.0:
g = (wave - 440.0) / (490.0 - 440.0)
b = 1.0
elif wave >= 490.0 and wave <= 510.0:
g = 1.0
b = -1.0 * (wave - 510.0) / (510.0 - 490.0)
elif wave >= 510.0 and wave <= 580.0:
r = (wave - 510.0) / (580.0 - 510.0)
g = 1.0
elif wave >= 580.0 and wave <= 645.0:
r = 1.0
g = -1.0 * (wave - 645.0) / (645.0 - 580.0)
elif wave >= 645.0 and wave <= 780.0:
r = 1.0
s = 1.0
if wave > 700.0:
s = 0.3 + 0.7 * (780.0 - wave) / (780.0 - 700.0)
elif wave < 420.0:
s = 0.3 + 0.7 * (wave - 380.0) / (420.0 - 380.0)
r = pow(r * s, 0.8)
g = pow(g * s, 0.8)
b = pow(b * s, 0.8)
return qRgb(r*255, g*255, b*255)
class MandelbrotWidget(QWidget):
def __init__(self, parent=None):
super(MandelbrotWidget, self).__init__(parent)
self.thread = RenderThread()
self.pixmap = QPixmap()
self.pixmapOffset = QPoint()
self.lastDragPos = QPoint()
self.centerX = DefaultCenterX
self.centerY = DefaultCenterY
self.pixmapScale = DefaultScale
self.curScale = DefaultScale
self.thread.renderedImage.connect(self.updatePixmap)
self.setWindowTitle("Mandelbrot")
self.setCursor(Qt.CrossCursor)
self.resize(550, 400)
def paintEvent(self, event):
painter = QPainter(self)
painter.fillRect(self.rect(), Qt.black)
if self.pixmap.isNull():
painter.setPen(Qt.white)
painter.drawText(self.rect(), Qt.AlignCenter,
"Rendering initial image, please wait...")
return
if self.curScale == self.pixmapScale:
painter.drawPixmap(self.pixmapOffset, self.pixmap)
else:
scaleFactor = self.pixmapScale / self.curScale
newWidth = int(self.pixmap.width() * scaleFactor)
newHeight = int(self.pixmap.height() * scaleFactor)
newX = self.pixmapOffset.x() + (self.pixmap.width() - newWidth) / 2
newY = self.pixmapOffset.y() + (self.pixmap.height() - newHeight) / 2
painter.save()
painter.translate(newX, newY)
painter.scale(scaleFactor, scaleFactor)
exposed, _ = painter.matrix().inverted()
exposed = exposed.mapRect(self.rect()).adjusted(-1, -1, 1, 1)
painter.drawPixmap(exposed, self.pixmap, exposed)
painter.restore()
text = "Use mouse wheel or the '+' and '-' keys to zoom. Press and " \
"hold left mouse button to scroll."
metrics = painter.fontMetrics()
textWidth = metrics.width(text)
painter.setPen(Qt.NoPen)
painter.setBrush(QColor(0, 0, 0, 127))
painter.drawRect((self.width() - textWidth) / 2 - 5, 0, textWidth + 10,
metrics.lineSpacing() + 5)
painter.setPen(Qt.white)
painter.drawText((self.width() - textWidth) / 2,
metrics.leading() + metrics.ascent(), text)
def resizeEvent(self, event):
self.thread.render(self.centerX, self.centerY, self.curScale,
self.size())
def keyPressEvent(self, event):
if event.key() == Qt.Key_Plus:
self.zoom(ZoomInFactor)
elif event.key() == Qt.Key_Minus:
self.zoom(ZoomOutFactor)
elif event.key() == Qt.Key_Left:
self.scroll(-ScrollStep, 0)
elif event.key() == Qt.Key_Right:
self.scroll(+ScrollStep, 0)
elif event.key() == Qt.Key_Down:
self.scroll(0, -ScrollStep)
elif event.key() == Qt.Key_Up:
self.scroll(0, +ScrollStep)
else:
super(MandelbrotWidget, self).keyPressEvent(event)
def wheelEvent(self, event):
numDegrees = event.angleDelta().y() / 8
numSteps = numDegrees / 15.0
self.zoom(pow(ZoomInFactor, numSteps))
def mousePressEvent(self, event):
if event.buttons() == Qt.LeftButton:
self.lastDragPos = QPoint(event.pos())
def mouseMoveEvent(self, event):
if event.buttons() & Qt.LeftButton:
self.pixmapOffset += event.pos() - self.lastDragPos
self.lastDragPos = QPoint(event.pos())
self.update()
def mouseReleaseEvent(self, event):
if event.button() == Qt.LeftButton:
self.pixmapOffset += event.pos() - self.lastDragPos
self.lastDragPos = QPoint()
deltaX = (self.width() - self.pixmap.width()) / 2 - self.pixmapOffset.x()
deltaY = (self.height() - self.pixmap.height()) / 2 - self.pixmapOffset.y()
self.scroll(deltaX, deltaY)
def updatePixmap(self, image, scaleFactor):
if not self.lastDragPos.isNull():
return
self.pixmap = QPixmap.fromImage(image)
self.pixmapOffset = QPoint()
self.lastDragPosition = QPoint()
self.pixmapScale = scaleFactor
self.update()
def zoom(self, zoomFactor):
self.curScale *= zoomFactor
self.update()
self.thread.render(self.centerX, self.centerY, self.curScale,
self.size())
def scroll(self, deltaX, deltaY):
self.centerX += deltaX * self.curScale
self.centerY += deltaY * self.curScale
self.update()
self.thread.render(self.centerX, self.centerY, self.curScale,
self.size())
if __name__ == '__main__':
import sys
app = QApplication(sys.argv)
widget = MandelbrotWidget()
widget.show()
sys.exit(app.exec_())
