Am 11.12.2014 um 23:51 schrieb Marek Olšák: > What radeonsi does is: > > basevertex = info->indexed ? info->index_bias : info->start; > > This is also what the hardware does for indirect draws and we cannot > change it. The basevertex shader system value must contain start, > because it's used to fetch vertices in vertex shaders.
Ok then I'll stick with that I was hoping this would be the case. It would be GREAT if the GL spec could clarify that somewhere (probably in ARB_shader_draw_parameters unless it already does so somewhere else...). Roland > > Marek > > On Thu, Dec 11, 2014 at 7:50 PM, Roland Scheidegger <srol...@vmware.com> > wrote: >> Am 11.12.2014 um 17:49 schrieb Ilia Mirkin: >>> On Thu, Dec 11, 2014 at 11:39 AM, Jose Fonseca <jfons...@vmware.com> wrote: >>>> Overall I think this is a great cleanup. >>>> >>>> Just a remark about the chosen names. >>>> >>>> On 10/12/14 21:22, srol...@vmware.com wrote: >>>>> >>>>> From: Roland Scheidegger <srol...@vmware.com> >>>> >>>> >>>> >>>> >>>>> Plus a new PIPE_CAP_VERTEXID_NOOFFSET query. >>>> >>>> >>>> "Vertex offset" and "base vertex" are difference concepts, so I'd rather >>>> not >>>> mix them up. >>>> >>>> AFAICT, this is about base vertex, not offsets in vertex buffers, hence >>>> NOOFFSET seems to be a misnomer. Please pick "NOBASE" or "ZEROBASE" suffix >>>> and stick with it. >>>> >>>> Personally, I prefer "NOBASE". As "ZEROBASE" sounds like that base vertex >>>> must some how be zero, which is not the case. >>>> >>> >>> Is all this really just about the base vertex? The situation on, e.g., >>> a3xx is that the vertex id does not include any offset, even the >>> 'start' from glDrawArrays (which makes sense, since they use the same >>> general logic). >>> >>> -ilia >>> >> >> Well this is actually kind of unresolved. I thought that gl_BaseVertex >> would include "first" parameter and similar of DrawArrays, so that >> really gl_VertexID = gl_BaseVertex + "vertex id without basevertex >> included as known from d3d10". Always. And not just for DrawElements >> calls (which would be a pain - the ARB_shader_draw_parameters extension >> sort of implies it could be used to translate between different APIs, >> but it's mostly useless if it doesn't work for all kind of draw calls)! >> >> The discussion about this was here: >> https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.freedesktop.org_archives_mesa-2Ddev_2014-2DAugust_065172.html&d=AAIBaQ&c=Sqcl0Ez6M0X8aeM67LKIiDJAXVeAw-YihVMNtXt-uEs&r=Vjtt0vs_iqoI31UfJxBl7yv9I2FeiaeAYgMTLKRBc_I&m=yvAzSgghgk7I0SyY4IpQp17eF3KbGdo6vAUDzUp0WcA&s=DCH0a8trKArcjz7_D68a9m9ew5Bq-Bzlzv0y5Er9dGM&e= >> >> >> So, I have no idea if this is right. And you are right "BaseVertex" is >> sort of ambigous there, I guess if it doesn't include drawArrays "first" >> parameter the whole point of lowering is kinda lost. I've written this >> under the assumption that gl_Basevertex does include "first" from >> DrawArrays, so the ambigous name wasn't chosen by me in that case then :-). >> >> Roland >> >> _______________________________________________ >> mesa-dev mailing list >> mesa-dev@lists.freedesktop.org >> https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.freedesktop.org_mailman_listinfo_mesa-2Ddev&d=AAIBaQ&c=Sqcl0Ez6M0X8aeM67LKIiDJAXVeAw-YihVMNtXt-uEs&r=Vjtt0vs_iqoI31UfJxBl7yv9I2FeiaeAYgMTLKRBc_I&m=yvAzSgghgk7I0SyY4IpQp17eF3KbGdo6vAUDzUp0WcA&s=tXRzMLhFIZCBb261uxvBO-GgsAU8kYr5ncU-s7aEDQM&e= >> _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
