Wow, good answer! E
On Sat, Jun 6, 2015 at 4:34 PM, Sampo Syreeni <de...@iki.fi> wrote: > On 2015-06-06, Alan Wolfe wrote: > > I am so sorry... meant to send this to myself to investigate later, my >> name starts with A and my address book has this as "A" for some reason. >> >> Please ignore... or feel free to explain hehe. >> > > Not really an audio topic, no. But essentially an OpenGL multisampled > texture is a texture which holds multiple samples per pixel. Such textures > are used as intermediate stages in antialiasing computations. Essentially > the multiple samples per pixel are rendered separately using whatever > rendering algorithm you happen to have chosen, but are systematically > offset from the underlying pixel grid. Eventually the samples will be > averaged together, which is a simple, easily (embarrasingly) parallelized > form of numerical integration, suitable for the typical GPU's render > pipeline. > > The basic reason why you have to allocate a separate kind of render target > for multisampling is that the GPU rendering pipeline and/or the software > framework used to program it does not fully hide its internals, or in here > especially latency variance. When you multisample, the different subpixel > results arrive at slightly different times, and aren't fully coordinated so > that they could be averaged on the fly, to land texel per texel on a normal > texture patch. Instead the multiple samples need to be stored somewhere > first, in whatever order the GPU yields them, and then after an internal > synchronized barrier, run a second time around the pipeline to average > them. That calls for extra memory for the intermediate result; > GL_TEXTURE_2D_MULTISAMPLE typed render targets reserve that extra memory > and tell the graphics engine how to use it, instead of just going with the > one pixel per texel requirement of a normal texture. > > https://www.opengl.org/wiki/Multisampling > -- > Sampo Syreeni, aka decoy - de...@iki.fi, http://decoy.iki.fi/front > +358-40-3255353, 025E D175 ABE5 027C 9494 EEB0 E090 8BA9 0509 85C2 > > -- > dupswapdrop -- the music-dsp mailing list and website: > subscription info, FAQ, source code archive, list archive, book reviews, > dsp links > http://music.columbia.edu/cmc/music-dsp > http://music.columbia.edu/mailman/listinfo/music-dsp > -- dupswapdrop -- the music-dsp mailing list and website: subscription info, FAQ, source code archive, list archive, book reviews, dsp links http://music.columbia.edu/cmc/music-dsp http://music.columbia.edu/mailman/listinfo/music-dsp
