Python Engines

Creating python engines (display types)

Hello World Engine

import Avogadro

class Engine():
  def renderOpaque(self, pd):
    pd.painter.drawText(50, 50, "Hello World")

A real example: wireframe engine

Step 1: Render all bonds as green lines

wireframe1.py:

from PyQt4.Qt import *
import Avogadro

class Engine(QObject):
  # constructor
  def __init__(self):
    QObject.__init__(self)

  # pd = PainterDevice
  def renderOpaque(self, pd):
    # Painter 
    painter = pd.painter
    # Molecule
    molecule = pd.molecule

    # Set the color to green (red, green, blue, alpha)
    color = Avogadro.Color(0.0, 1.0, 0.0, 1.0)
    painter.setColor(color)

    for bond in molecule.bonds:
      # get the begin atom for this bond
      beginAtom = molecule.atomById(bond.beginAtomId)
      # get the end atom for this bond
      endAtom = molecule.atomById(bond.endAtomId)
      # draw the line between the atoms
      painter.drawLine(beginAtom.pos, endAtom.pos, 2.0)