Creating your own stimuli in Python
-----------------------------------

Every mPsy stimulus contains at least two elements: function ``draw()`` and field ``params``.  The latter is an associative array: a fundamental object type such as `struct` in MATLAB and `named list` in R.

A definition of stimulus in mPsy is illustrated just below using stimulus ``Text``,  a simple yet functional example of text label:

.. code-block:: python

    from pyglet import text

    class Text:
        def __init__(self,**params):
            self.params = Params(\**params)
            self.text = text.Label(self.params.msg,anchor_x='center',halign='center')
        def draw(self):
            self.text.draw()



Each mPsy stimulus [is an independent program], for which several examples appear module ``stimuli.py``. The examples in ``stimuli.py`` (and the one above) can be used outside of mPsy, which is useful for the developing your own stimuli.

The following code shows how to set up a window and call the ``draw()`` function for an mPsy stimulus.

.. code-block:: python

    from pyglet import text

    class Text:
        def __init__(self,\**params):
            print params
            self.params = Params(\**params)
            self.text = text.Label(self.params.msg,halign='center',anchor_x='center')
        def draw(self):
            self.text.draw()

    if __name__ == "__main__":
        import sys
        sys.path[:0] = ['packages.zip']

        from pyglet.gl import *
        from pyglet.window import key
        from pyglet import clock, clock, font, graphics, window, text

        class Params:
            def __init__(self,**kwargs):
                self.__dict__.update(kwargs)
            def update(self,**kwargs):
                self.__dict__.update(kwargs)
            def __str__(self):
                return '\n'.join( '%s = %s'%x for x in self.__dict__.items() )
            def __repr__(self):
                return 'Params(%s)'%(', '.join( '%s=%s'%x for x in self.__dict__.items() ),)
            def default(self):
                return self.__dict__

        win = window.Window()
        stim = Text(msg='Welcome to Movable Psychophysics.')

        def update(dt):
            win.clear()
            glPushMatrix()
            glTranslatef(320,240,0)
            stim.draw()
            glPopMatrix()
        
        clock.schedule_interval(update,1/60.0)
        pyglet.app.run()