On Sat, Mar 19, 2016 at 12:02 PM, Bas Nieuwenhuizen <b...@basnieuwenhuizen.nl> wrote: > On Sat, Mar 19, 2016 at 4:25 PM, Ilia Mirkin <imir...@alum.mit.edu> wrote: >> On Sat, Mar 19, 2016 at 11:14 AM, Bas Nieuwenhuizen >> <b...@basnieuwenhuizen.nl> wrote: >>> That would limit us to supporting sample counts for which we have >>> texture formats. >>> >>> As far as I understand with radeonsi we can support 16 samples without >>> any attachments, but all formats are limited to <= 8 samples. >> >> So you're going to end up with a situation where GL_MAX_SAMPLES is >> less than GL_MAX_FRAMEBUFFER_SAMPLES? I don't know that that's a >> useful thing to have. This implementation still has the problem of >> only supporting POT MSAA levels (although tbh I'm not 100% sure >> there's hw out there that supports NPOT MSAA levels). If people really >> want this, I think the way to go would be to make >> is_format_supported() work with PIPE_FORMAT_NONE and do it that way. >> >> Also, are you *sure* that's the case on radeonsi? I find it very odd >> that the rasterizer would support a higher MSAA level than the highest >> attachment would... > > I am pretty confident that this is the case. I just tested 16 samples > (although this series seems to miss changing MaxFramebufferSamples), > and the driver disallows any texture format with > 8 samples [1]. > Furthermore the proprietary driver on Windows seems to have > GL_MAX_SAMPLES=8 and GL_MAX_FRAMEBUFFER_SAMPLES=16 [2].
OK. I still think it's crazy, but it is what it is :) > > Using PIPE_FORMAT_NONE to query the driver would probably be a bit > less error prone than the current code that sets the masks, so that > would be fine with me. Actually my earlier criticism about it only doing POT levels is a bit off -- after reading some more of the code, I just think that the settings to drivers were off - it should have been (1 << 8) | (1 << 4), etc. This works up to 32x MSAA, which is not supported by anyone (for real, although NVIDIA blob drivers do fake it). I do still prefer to avoid having separate places where this info is encoded... so I maintain my vote for using PIPE_FORMAT_NONE in is_format_supported. -ilia _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
