[Freeciv-Dev] Re: (PR#4289) Pixel scroller

["a-l@xxxxxxx" <a-l@xxxxxxx>]

"Mike Kaufman" <kaufman@xxxxxxxxxxxxxxxxxxxxxx> wrote:

> On Fri, May 23, 2003 at 08:19:20PM -0700, a-l@xxxxxxx wrote:
> > A pixel scroller for Freeciv. Premature demo version.
> 
> ok, this is a fricking cool feature. to everybody out there, you really
> ought to try it.

> o why is 60fps the max? The timer should have a resolution of microseconds.

Sure, it converts to micoseconds.

I run a 1 GH box with whizbang gfx card. I would appreciate feedback
on how it runs on, say, 233-600 Mhz or so. In particular:

- If you have a slower machine, do you get any improvement in
smoothness from reducing the framerate below 60 fps?
It is self-timing and could become self-adjusting if there's an
appropriate algorithm to be found.

- If you have an older gfx card, does the screen totally fuck up?

There may or may not be an issue of blitting overlapping regions
(with gdk_draw_pixmap()) when the backing store is both source and
destination. It works for me, but there may or may not be an issue of 
the gfx card having separate read and write buffers. The Allegro
library documentation, which seems geared towards win32, mentions
this, but not gdk. Depending on the scrolling direction and endianness
of your system, there could be total screen chaos, if the problem
exists. Using an additional buffer step 60 times pr seconds would ruin
the performance... so I hope not.

Rafal: do you know anything about this from sdl?

> 
> however:

> o the mouse should become inactive when it leaves the map_canvas. This
>   should prevent the scroller from working when you're say changing your
>   local options (or manipulating any other dialog).

This was a bit of a problem. I agree it shouldnt scroll when mouse is
above the city list window, f.ex. Can I check this easily somehow?

The first idea was to just use the mouse movement event on the
mapview, but problem is I don't want the user to have to move the
pointer around in order to scroll. Just hover.


Arnstein