I'll try to answer a few...
Corbin Simpson 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? ~ An explanation of dual-source blends and how they work would be nice.
Marek provided a pointer, but I don't think we've done anything with this in gallium yet.
~ If logicop_enable and independent_blend_enable are set, are lops performed for all render targets, or only those that have blend_enable set?
The GL_ARB_drawbuffers2 spec is a bit vague on this but in swrast logicop had precedence over blending and either applies to all color buffers or none.
~ PIPE_CAP_TEXTURE_SHADOW_MAP and PIPE_CAP_MAX_PREDICATE_REGISTERS aren't explained.
I'm updating these now.
~ PIPE_CAP_GUARD_BAND_* obviously refers to the guard bands, but what exactly do they mean as capabilities? Maximum guard band settings? Minimum?
They're probably the guard band width in pixels.
~ 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)
Looks like a clamped reciprocol to avoid +/-inf that can come from RCP.
~ 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? ~ "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?
See the newly updated docs.
~ Can somebody explain the format of TGSI_SEMANTIC_EDGEFLAG?
I've updated the docs for this.
~ 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.
-Brian _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
