On Wed, Jun 23, 2010 at 11:51 PM, Corbin Simpson <mostawesomed...@gmail.com>wrote:
> Yep, it's that time again. These are just things marked in the docs as > unknown, so I'm not grinding any axes, just cleaning stuff up. > > ~ "If a surface includes several layers/slices (XXX: not yet...) then > all layers will be cleared." From the information on > pipe_context::clear(). Is this just wishful thinking, or do drivers > need to implement this? > I believe this has something to do with geometry shaders where you can select a layer (slice, face) you want to emit a primitive to. This way you may e.g. render to a whole cubemap in one pass. > ~ An explanation of dual-source blends and how they work would be nice. > http://www.opengl.org/registry/specs/ARB/blend_func_extended.txt > > ~ If logicop_enable and independent_blend_enable are set, are lops > performed for all render targets, or only those that have blend_enable > set? > > ~ PIPE_CAP_TEXTURE_SHADOW_MAP and PIPE_CAP_MAX_PREDICATE_REGISTERS > aren't explained. > I think PIPE_CAP_TEXTURE_SHADOW_MAP means shadow samplers. > ~ PIPE_CAP_GUARD_BAND_* obviously refers to the guard bands, but what > exactly do they mean as capabilities? Maximum guard band settings? > Minimum? > > ~ Could somebody explain exactly what's up with the RCC opcode? Its > definition is kind of ridiculous: dst = (1 / src.x) > 0 ? clamp(1 / > src.x, 5.42101e-020, 1.884467e+019) : clamp(1 / src.x, -1.884467e+019, > -5.42101e-020) > > ~ Are we going to introduce new cap bits for parts of the TGSI ISA? > (I'll understand if this is off the table for now.) > > ~ TGSI_SEMANTIC_POSITION is (x, y, z, w) where x, y, and z are > position, and w is the homogeneous coordinate. Is w also for > perspective divide? Is the perspective divide configurable, or is it > always done in shaders? > The perspective divide is done per-pixel after the rasterization and before the fragment shader, and there is no way to disable it in Gallium. It's never done in shaders, it's rather a fixed functionality and imposing additional restrictions on it would make it hard to implement in drivers. > ~ "Position, if not specified, usually defaults to (0, 0, 0, 1), and > can be partially specified as (x, y, 0, 1) or (x, y, z, 1)." > "Usually" is probably Corbin-speak for "I'm just guessing here." Is > that actually how it goes, or is position mandatory? > > ~ Can somebody explain the format of TGSI_SEMANTIC_EDGEFLAG? > > ~ What are the components of textures in the UV or Z format when > sampled? For UV, current candidates are (0, 0, 0, 1) and (u, v, 1, 1). > The latter seems more reasonable given that Gallium is shaderful. For > Z, it could be (z, z, z, 1), (0, z, 0, 1), (0, 0, 0, z), or (z, z, z, > z) and is configurable in GL. Maybe we want to have this be > configurable? > > Thanks! > > ~ C. > > -- > When the facts change, I change my mind. What do you do, sir? ~ Keynes > > Corbin Simpson > <mostawesomed...@gmail.com> > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/mesa-dev >
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