> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of Alan Gauld > Sent: 12 July 2008 18:08 > To: tutor@python.org > Subject: Re: [Tutor] Classes v2, thoughts/suggestions please > > > "Paul Melvin" <[EMAIL PROTECTED]> wrote > > > i have come up with a working class for a square, > > Well done. It might not be the most elegant solution on the > inside but it isn't too bad from the users point of view and thats > what you should aim for IMHO. > > > I was thinking about using *args to get maybe the colour > > information in, > > I would define polygon to take a list of points as a parameter > of init so you put the onus on the user to pass in tbe points > in a list. That makes the init method easy: > > Class Polygon: > def __init__(self, pList, filled=True, line_width=1): > self.points = pList > self.filled = filled > self.line_width = line_width > > Your draw method is as before but instead of repeating > the code 4 times just put it into a loop that iterates over > the points list, something like: > > def draw(self): > if self.filled: > glBegin(GL_QUADS) > else: > glLineWidth(self.line_width) > glBegin(GL_LINE_LOOP) > for p in self.pList > glColor4f(p.col[0], p.col[1], p.col[2], p.col[3]) > glVertex2i(int(p.x), int(p.y)) > glEnd() > if not filled and line_width != 1: # reset to default > glLineWidth(1) > > Note that I put it as the draw method not as a separate > function. There is little point in having a class then calling > a separate function to which you have to pass all the > data in the class! > > > And how can i go about testing that i get appropriate values during > > the > > testing/building phase (generally speaking), is it lots of > > print/return > > statements and then remove them? > > I'm not sure what you mean by "appropriate values" in this context. > Since you are drawing graphics I suspect you will have to just > draw them in a simple canvas and visually ensure the result is > what you expect? > > You could try implementing a __str__ method in each class that > lets you print out a nicely formatted report of the Point and/or > Polygon data, which would allow you to do: > > p = Point(.....) > print p > s = Polygon([p,p2,p3,p4]) > print s > > That would allow you to see what the graphic parameters will > be before drawing. > > HTH, > > -- > Alan Gauld > Author of the Learn to Program web site > http://www.freenetpages.co.uk/hp/alan.gauld > Thanks again for your help, as for 'appropriate' values, in this specific case it would be numbers but I am also interested in the general design process, ie how you check your code during design/coding, is it print statements for example?
Before I start on my polygon class, Alan did mention that it was not 'elegant' which i know as I am only starting and I thought of it as dirty but working, can someone tell me how I could improve this code or write better code in the future Cheers paul __________ Information from ESET Smart Security, version of virus signature database 3263 (20080711) __________ The message was checked by ESET Smart Security. http://www.eset.com _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
