Hello,
Funny enough, I was also thinking a bit about the Sprite class. I remember
a discussion on this group (that I cannot find again) where it was shown
that if you move and rotate a Sprite, you will end up updating twice its
vertices.
I had a good look at how things are implemented. I was thinking about some
sort of lazy vertices update, but it's not possible as the data may be
actually in a batch. The batch knows nothing about Sprites, it only knows
about its VertexLists. So when the time comes to draw its data, it would be
cumbersome to go through that list, try to figure out to which Sprite it
belongs to and call its _update_position method.
So I would suggest to add a new method to the Sprite class which would
allow the user to move, rotate and scale the sprite altogether. Maybe call
it something like
def transform(self, position=(0.0, 0.0), rotate=None, scale=None):
if move != (0.0, 0.0):
self._x, self._y = position
if rotate is not None:
self._rotation = rotate
if scale is not None:
self._scale = scale
self._update_position()
For Sprites that only rotate, move and/or scale once in a while, this is
unnecessary. But for Sprites which do that on every frame, say an asteroid
which is rotating while moving slowly, there could be a nice speed up.
Adding a new method would not break any existing code. It should be added
to the documentation that if a Sprite is constantly moving, rotating and/or
scaling, this new method would be more efficient.
Daniel.
On Monday, March 28, 2016 at 7:02:01 AM UTC+2, Benjamin Moran wrote:
>
> Hi guys,
>
> I did a minor performance tweak to the Sprite class's _update_position
> method a while ago, and thought I'd share it. You can see it in my
> "sprite_optimization" branch here:
>
> https://bitbucket.org/treehousegames/pyglet/src/124e1fe4c0016cf9effcf3c1706c0124aa99712e/pyglet/sprite.py?at=sprite_optimization&fileviewer=file-view-default
> Basically it's just cutting out the temporary vertex list creation, and
> removing a if/else few checks. I've tested it with a few thousand sprites,
> and this nets a few extra FPS. Not a major improvement, but it's also a bit
> easier to read the method in my opinion.
>
> The only drawback to this tweak is that Sprite vertex_lists are always
> created as float arrays, even if sprite subpixel is not used. This is to
> avoid one of the if/else checks in the method. It is my understanding that
> on modern GPUs (last 10 years), floats are used internally anyway, so this
> shouldn't hurt performance any.
>
> Would this make sense to try to get merged in, or is there some glaring
> issue that I'm missing?
>
>
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