On 4/11/08, Richard Jones <[EMAIL PROTECTED]> wrote: > > On Fri, 11 Apr 2008, Michael Halle wrote: > > In looking through the sprite code, I saw that computed vertices get > > rounded off to ints, and then passed in integer form to OpenGL. This > > process happens even when the sprite is scaled and rotated, where > > vertices would in general not fall on pixel boundaries. > > > > Seems like for small sprites, noticeable distortion or bad packing could > > happen. > > > So this is something you've not actually observed? > > > > > As far as I know, graphics cards usually use floats internally anyway -- > > are there real performance hits in removing the rounding and just > > passing the floats down to OpenGL? > > > The rounding is not done for performance. > > More often than not you'll get artifacts and fuzziness on raster graphics if > they're not pixel-aligned. The most common artifact is flickering border > where pixels bleed in from adjacent images (in the same texture).
Even without adjacent images, you'll get this flicker as any high frequency parts of the texture (lines, for example) pass in and out of pixel alignment. I've been thinking about providing a SubpixelSprite class, which would use v2f instead of v2i for coordinates. The onus on deciding which is appropriate (e.g. for scaled/rotated sprites it really isn't a problem) is on the developer. Alex. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "pyglet-users" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/pyglet-users?hl=en -~----------~----~----~----~------~----~------~--~---
