[Tutor] Fwd: circular movement in pygame

[Alan Gauld]

On 28/04/15 16:38, diliup gabadamudalige wrote:
> ---------- Forwarded message ----------
> From: diliup gabadamudalige <diliupg at gmail.com>
> Date: Tue, Apr 28, 2015 at 6:22 PM
> Subject: circular movement in pygame
> To: pygame-users at seul.org

It's good that you tried the python-game list for a
pygame question. But if pygame-users can't give a
definitive answer then its even less likely that the
tutor list will. Although you might need to allow
a full 24 hours to get answers, email is not an
instant delivery mechanism.

> Looking at the code on this page lines 47 & 48
>
> http://programarcadegames.com/python_examples/show_file.php?file=sprite_circle_movement.py

I didn't look at the code in that tutorial, but...

> is there a way to do
> self.rect.x +*= some value*
> self.rect.y += some value

Yes, that's just normal Python syntax. It adds/multiplies
the current value of self.rect with "some value"...

> rather than
>
> self.rect.x = self.radius * math.sin(self.angle) + self.center_x
> self.rect.y = self.radius * math.cos(self.angle) + self.center_y

But its unlikely to have the same effect as this since the
above two lines are calculating a new value based on radius,
angle, and centre rather than one based on the current
values of self.rect

> I tired it in the code attached and strangely it works ok but only OUTSIDE
> THE class. When I implement the exact code in a class it does something
> weird.  I can't find where I have gone wrong.

I can't see your code but are you sure you are using self in
all the appropriate places in your class based code?


-- 
Alan G
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