<div class="gmail_quote">On Wed, Jun 23, 2010 at 11:51 PM, Corbin Simpson <<a href="mailto:mostawesomedude@gmail.com">mostawesomedude@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> 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? </blockquote><div> 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. </div><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> ~ An explanation of dual-source blends and how they work would be nice. </blockquote><div> <a href="http://www.opengl.org/registry/specs/ARB/blend_func_extended.txt">http://www.opengl.org/registry/specs/ARB/blend_func_extended.txt</a> </div><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> ~ 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. </blockquote><div> I think PIPE_CAP_TEXTURE_SHADOW_MAP means shadow samplers. </div><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> ~ 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? </blockquote><div> 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. </div><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> ~ "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 <<a href="mailto:MostAwesomeDude@gmail.com">MostAwesomeDude@gmail.com</a>> _______________________________________________ mesa-dev mailing list <a href="mailto:mesa-dev@lists.freedesktop.org">mesa-dev@lists.freedesktop.org</a> <a href="http://lists.freedesktop.org/mailman/listinfo/mesa-dev" target="_blank">http://lists.freedesktop.org/mailman/listinfo/mesa-dev</a> </blockquote></div>