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  ## Copyright (C) 2013 Riverbank Computing Limited.
  ## Copyright (C) 2018 The Qt Company Ltd.
  ## Contact: http://www.qt.io/licensing/
  ##
  ## This file is part of the Qt for Python examples of the Qt Toolkit.
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  ############################################################################
  
  """PySide6 port of the opengl/hellogl2 example from Qt v5.x"""
  
  import sys
  import math
  import numpy
  import ctypes
  from PySide6.QtCore import QCoreApplication, Signal, SIGNAL, SLOT, Qt, QSize, QPointF
  from PySide6.QtGui import (QVector3D, QOpenGLFunctions,
      QMatrix4x4, QOpenGLContext, QSurfaceFormat)
  from PySide6.QtOpenGL import (QOpenGLVertexArrayObject, QOpenGLBuffer,
      QOpenGLShaderProgram, QOpenGLShader)
  from PySide6.QtWidgets import (QApplication, QWidget, QMessageBox, QHBoxLayout,
      QSlider)
  from PySide6.QtOpenGLWidgets import QOpenGLWidget
  
  from shiboken6 import VoidPtr
  
  try:
      from OpenGL import GL
  except ImportError:
      app = QApplication(sys.argv)
      messageBox = QMessageBox(QMessageBox.Critical, "OpenGL hellogl",
                                           "PyOpenGL must be installed to run this example.",
                                           QMessageBox.Close)
      messageBox.setDetailedText("Run:\npip install PyOpenGL PyOpenGL_accelerate")
      messageBox.exec_()
      sys.exit(1)
  
  
  class Window(QWidget):
      def __init__(self, parent=None):
          QWidget.__init__(self, parent)
  
          self.glWidget = GLWidget()
  
          self.xSlider = self.createSlider(SIGNAL("xRotationChanged(int)"),
                                           self.glWidget.setXRotation)
          self.ySlider = self.createSlider(SIGNAL("yRotationChanged(int)"),
                                           self.glWidget.setYRotation)
          self.zSlider = self.createSlider(SIGNAL("zRotationChanged(int)"),
                                           self.glWidget.setZRotation)
  
          mainLayout = QHBoxLayout()
          mainLayout.addWidget(self.glWidget)
          mainLayout.addWidget(self.xSlider)
          mainLayout.addWidget(self.ySlider)
          mainLayout.addWidget(self.zSlider)
          self.setLayout(mainLayout)
  
          self.xSlider.setValue(15 * 16)
          self.ySlider.setValue(345 * 16)
          self.zSlider.setValue(0 * 16)
  
          self.setWindowTitle(self.tr("Hello GL"))
  
      def createSlider(self, changedSignal, setterSlot):
          slider = QSlider(Qt.Vertical)
  
          slider.setRange(0, 360 * 16)
          slider.setSingleStep(16)
          slider.setPageStep(15 * 16)
          slider.setTickInterval(15 * 16)
          slider.setTickPosition(QSlider.TicksRight)
  
          self.glWidget.connect(slider, SIGNAL("valueChanged(int)"), setterSlot)
          self.connect(self.glWidget, changedSignal, slider, SLOT("setValue(int)"))
  
          return slider
  
      def keyPressEvent(self, event):
          if event.key() == Qt.Key_Escape:
              self.close()
          else:
              super(Window, self).keyPressEvent(event)
  
  class Logo():
      def __init__(self):
          self.m_count = 0
          self.i = 0
          self.m_data = numpy.empty(2500 * 6, dtype = ctypes.c_float)
  
          x1 = +0.06
          y1 = -0.14
          x2 = +0.14
          y2 = -0.06
          x3 = +0.08
          y3 = +0.00
          x4 = +0.30
          y4 = +0.22
  
          self.quad(x1, y1, x2, y2, y2, x2, y1, x1)
          self.quad(x3, y3, x4, y4, y4, x4, y3, x3)
  
          self.extrude(x1, y1, x2, y2)
          self.extrude(x2, y2, y2, x2)
          self.extrude(y2, x2, y1, x1)
          self.extrude(y1, x1, x1, y1)
          self.extrude(x3, y3, x4, y4)
          self.extrude(x4, y4, y4, x4)
          self.extrude(y4, x4, y3, x3)
  
          Pi = 3.14159265358979323846
          NumSectors = 100
  
          for i in range(NumSectors):
              angle = (i * 2 * Pi) / NumSectors
              x5 = 0.30 * math.sin(angle)
              y5 = 0.30 * math.cos(angle)
              x6 = 0.20 * math.sin(angle)
              y6 = 0.20 * math.cos(angle)
  
              angle = ((i + 1) * 2 * Pi) / NumSectors
              x7 = 0.20 * math.sin(angle)
              y7 = 0.20 * math.cos(angle)
              x8 = 0.30 * math.sin(angle)
              y8 = 0.30 * math.cos(angle)
  
              self.quad(x5, y5, x6, y6, x7, y7, x8, y8)
  
              self.extrude(x6, y6, x7, y7)
              self.extrude(x8, y8, x5, y5)
  
      def constData(self):
          return self.m_data.tobytes()
  
      def count(self):
          return self.m_count
  
      def vertexCount(self):
          return self.m_count / 6
  
      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)
  
      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 add(self, v, n):
          self.m_data[self.i] = v.x()
          self.i += 1
          self.m_data[self.i] = v.y()
          self.i += 1
          self.m_data[self.i] = v.z()
          self.i += 1
          self.m_data[self.i] = n.x()
          self.i += 1
          self.m_data[self.i] = n.y()
          self.i += 1
          self.m_data[self.i] = n.z()
          self.i += 1
          self.m_count += 6
  
  class GLWidget(QOpenGLWidget, QOpenGLFunctions):
      xRotationChanged = Signal(int)
      yRotationChanged = Signal(int)
      zRotationChanged = Signal(int)
  
      def __init__(self, parent=None):
          QOpenGLWidget.__init__(self, parent)
          QOpenGLFunctions.__init__(self)
  
          self.core = "--coreprofile" in QCoreApplication.arguments()
          self.xRot = 0
          self.yRot = 0
          self.zRot = 0
          self.lastPos = QPointF()
          self.logo = Logo()
          self.vao = QOpenGLVertexArrayObject()
          self.logoVbo = QOpenGLBuffer()
          self.program = QOpenGLShaderProgram()
          self.projMatrixLoc = 0
          self.mvMatrixLoc = 0
          self.normalMatrixLoc = 0
          self.lightPosLoc = 0
          self.proj = QMatrix4x4()
          self.camera = QMatrix4x4()
          self.world = QMatrix4x4()
          self.transparent = "--transparent" in QCoreApplication.arguments()
          if self.transparent:
              fmt = self.format()
              fmt.setAlphaBufferSize(8)
              self.setFormat(fmt)
  
      def xRotation(self):
          return self.xRot
  
      def yRotation(self):
          return self.yRot
  
      def zRotation(self):
          return self.zRot
  
      def minimumSizeHint(self):
          return QSize(50, 50)
  
      def sizeHint(self):
          return QSize(400, 400)
  
      def normalizeAngle(self, angle):
          while angle < 0:
              angle += 360 * 16
          while angle > 360 * 16:
              angle -= 360 * 16
          return angle
  
      def setXRotation(self, angle):
          angle = self.normalizeAngle(angle)
          if angle != self.xRot:
              self.xRot = angle
              self.emit(SIGNAL("xRotationChanged(int)"), angle)
              self.update()
  
      def setYRotation(self, angle):
          angle = self.normalizeAngle(angle)
          if angle != self.yRot:
              self.yRot = angle
              self.emit(SIGNAL("yRotationChanged(int)"), angle)
              self.update()
  
      def setZRotation(self, angle):
          angle = self.normalizeAngle(angle)
          if angle != self.zRot:
              self.zRot = angle
              self.emit(SIGNAL("zRotationChanged(int)"), angle)
              self.update()
  
      def cleanup(self):
          self.makeCurrent()
          self.logoVbo.destroy()
          del self.program
          self.program = None
          self.doneCurrent()
  
      def vertexShaderSourceCore(self):
          return """#version 150
                  in vec4 vertex;
                  in vec3 normal;
                  out vec3 vert;
                  out vec3 vertNormal;
                  uniform mat4 projMatrix;
                  uniform mat4 mvMatrix;
                  uniform mat3 normalMatrix;
                  void main() {
                     vert = vertex.xyz;
                     vertNormal = normalMatrix * normal;
                     gl_Position = projMatrix * mvMatrix * vertex;
                  }"""
  
      def fragmentShaderSourceCore(self):
          return """#version 150
                  in highp vec3 vert;
                  in highp vec3 vertNormal;
                  out highp vec4 fragColor;
                  uniform highp vec3 lightPos;
                  void main() {
                     highp vec3 L = normalize(lightPos - vert);
                     highp float NL = max(dot(normalize(vertNormal), L), 0.0);
                     highp vec3 color = vec3(0.39, 1.0, 0.0);
                     highp vec3 col = clamp(color * 0.2 + color * 0.8 * NL, 0.0, 1.0);
                     fragColor = vec4(col, 1.0);
                  }"""
  
  
      def vertexShaderSource(self):
          return """attribute vec4 vertex;
                  attribute vec3 normal;
                  varying vec3 vert;
                  varying vec3 vertNormal;
                  uniform mat4 projMatrix;
                  uniform mat4 mvMatrix;
                  uniform mat3 normalMatrix;
                  void main() {
                     vert = vertex.xyz;
                     vertNormal = normalMatrix * normal;
                     gl_Position = projMatrix * mvMatrix * vertex;
                  }"""
  
      def fragmentShaderSource(self):
          return """varying highp vec3 vert;
                  varying highp vec3 vertNormal;
                  uniform highp vec3 lightPos;
                  void main() {
                     highp vec3 L = normalize(lightPos - vert);
                     highp float NL = max(dot(normalize(vertNormal), L), 0.0);
                     highp vec3 color = vec3(0.39, 1.0, 0.0);
                     highp vec3 col = clamp(color * 0.2 + color * 0.8 * NL, 0.0, 1.0);
                     gl_FragColor = vec4(col, 1.0);
                  }"""
  
      def initializeGL(self):
          self.context().aboutToBeDestroyed.connect(self.cleanup)
          self.initializeOpenGLFunctions()
          self.glClearColor(0, 0, 0, 1)
  
          self.program = QOpenGLShaderProgram()
  
          if self.core:
              self.vertexShader = self.vertexShaderSourceCore()
              self.fragmentShader = self.fragmentShaderSourceCore()
          else:
              self.vertexShader = self.vertexShaderSource()
              self.fragmentShader = self.fragmentShaderSource()
  
          self.program.addShaderFromSourceCode(QOpenGLShader.Vertex, self.vertexShader)
          self.program.addShaderFromSourceCode(QOpenGLShader.Fragment, self.fragmentShader)
          self.program.bindAttributeLocation("vertex", 0)
          self.program.bindAttributeLocation("normal", 1)
          self.program.link()
  
          self.program.bind()
          self.projMatrixLoc = self.program.uniformLocation("projMatrix")
          self.mvMatrixLoc = self.program.uniformLocation("mvMatrix")
          self.normalMatrixLoc = self.program.uniformLocation("normalMatrix")
          self.lightPosLoc = self.program.uniformLocation("lightPos")
  
          self.vao.create()
          vaoBinder = QOpenGLVertexArrayObject.Binder(self.vao)
  
          self.logoVbo.create()
          self.logoVbo.bind()
          float_size = ctypes.sizeof(ctypes.c_float)
          self.logoVbo.allocate(self.logo.constData(), self.logo.count() * float_size)
  
          self.setupVertexAttribs()
  
          self.camera.setToIdentity()
          self.camera.translate(0, 0, -1)
  
          self.program.setUniformValue(self.lightPosLoc, QVector3D(0, 0, 70))
          self.program.release()
          vaoBinder = None
  
      def setupVertexAttribs(self):
          self.logoVbo.bind()
          f = QOpenGLContext.currentContext().functions()
          f.glEnableVertexAttribArray(0)
          f.glEnableVertexAttribArray(1)
          float_size = ctypes.sizeof(ctypes.c_float)
  
          null = VoidPtr(0)
          pointer = VoidPtr(3 * float_size)
          f.glVertexAttribPointer(0, 3, int(GL.GL_FLOAT), int(GL.GL_FALSE), 6 * float_size, null)
          f.glVertexAttribPointer(1, 3, int(GL.GL_FLOAT), int(GL.GL_FALSE), 6 * float_size, pointer)
          self.logoVbo.release()
  
      def paintGL(self):
          self.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT)
          self.glEnable(GL.GL_DEPTH_TEST)
          self.glEnable(GL.GL_CULL_FACE)
  
          self.world.setToIdentity()
          self.world.rotate(180 - (self.xRot / 16), 1, 0, 0)
          self.world.rotate(self.yRot / 16, 0, 1, 0)
          self.world.rotate(self.zRot / 16, 0, 0, 1)
  
          vaoBinder = QOpenGLVertexArrayObject.Binder(self.vao)
          self.program.bind()
          self.program.setUniformValue(self.projMatrixLoc, self.proj)
          self.program.setUniformValue(self.mvMatrixLoc, self.camera * self.world)
          normalMatrix = self.world.normalMatrix()
          self.program.setUniformValue(self.normalMatrixLoc, normalMatrix)
  
          self.glDrawArrays(GL.GL_TRIANGLES, 0, self.logo.vertexCount())
          self.program.release()
          vaoBinder = None
  
      def resizeGL(self, width, height):
          self.proj.setToIdentity()
          self.proj.perspective(45, width / height, 0.01, 100)
  
      def mousePressEvent(self, event):
          self.lastPos = event.position()
  
      def mouseMoveEvent(self, event):
          pos = event.position()
          dx = pos.x() - self.lastPos.x()
          dy = pos.y() - self.lastPos.y()
  
          if event.buttons() & Qt.LeftButton:
              self.setXRotation(self.xRot + 8 * dy)
              self.setYRotation(self.yRot + 8 * dx)
          elif event.buttons() & Qt.RightButton:
              self.setXRotation(self.xRot + 8 * dy)
              self.setZRotation(self.zRot + 8 * dx)
  
          self.lastPos = pos
  
  if __name__ == '__main__':
      app = QApplication(sys.argv)
  
      fmt = QSurfaceFormat()
      fmt.setDepthBufferSize(24)
      if "--multisample" in QCoreApplication.arguments():
          fmt.setSamples(4)
      if "--coreprofile" in QCoreApplication.arguments():
          fmt.setVersion(3, 2)
          fmt.setProfile(QSurfaceFormat.CoreProfile)
      QSurfaceFormat.setDefaultFormat(fmt)
  
      mainWindow = Window()
      if "--transparent" in QCoreApplication.arguments():
          mainWindow.setAttribute(Qt.WA_TranslucentBackground)
          mainWindow.setAttribute(Qt.WA_NoSystemBackground, False)
  
      mainWindow.resize(mainWindow.sizeHint())
      mainWindow.show()
  
      res = app.exec_()
      sys.exit(res)
  