(29 May 11, 06:36PM)Hellspell Wrote: also i dont think it would waste much fps, a white dot for snow or a short line for the rain i think would suffice
but an option to turn off the weather could do no harm
Dots/lines in the form of GL_POINTS and GL_LINES respectively will not work well. Neither has the ability to portray depth; a snowflake or raindrop made with a point or line will appear the same whether it is a centimeter from your face or a kilometer away.
You can use blend functions to alter the width of lines and size of points, but you'd need to calculate distances to cube surfaces and flip back and forth between varying specifications to properly simulate depth. And even then it'd be a shoddy effect. Line widths and point sizes are altered with the same function and are only available in pixel dimensions; snowflakes will either appear too small or too large and they will be square.
If that were a desirable trait the rendering process would indeed be very fast however the generation of depth information necessary to alter the width of lines and points would likely kill it.