recommend a graphics library for plotting by the pixel?

[Westley Martínez]

On Wed, Oct 05, 2011 at 02:29:38PM +0100, Adam Funk wrote:
> On 2011-10-04, Derek Simkowiak wrote:
> 
> >      If this is strictly for 2D pixel graphics, I recommend using PyGame 
> > (aka SDL).  Why do you not think it's the way to go?  It was built for 
> > this type of thing.
> 
> I only know PyGame because we did an exercise in recreating the old
> breakout game and messing around with it at a local Python group.
> 
> I was under the mistaken impression from that exercise that you have
> to maintain a set of all the objects on the screen and redraw them all
> every time through the loop that ends with pygame.display.flip() ---
> *but* I now see that the loop starts with these:
> 
>     clock.tick(tick_rate)
>     screen.fill((0,0,0))
>     # comes from screen = pygame.display.set_mode((screen_width,screen_height))
>     # before the loop    
> 
> and that I was then deleting hit bricks, calculating the new positions
> of the balls, and then redrawing everything that was left on the
> secondary screen because things were moving around and disappearing.
> 
> I guess if I don't clear the screen at the beginning of the loop but
> just blit pixels onto it, when I call display.flip(), it will add the
> new blittings to what was already there?  If that's true, this will be
> much easier than I thought.
> 
> The only buttons I have in mind are "pause", "step", "go", and "quit",
> and I can just as easily do those with keypresses.

Yep.  Blitting is replacing the old colors with new colors.  It doesn't
replace colors unless you tell it to.