On 15.12.2016 17:19, Ilia Mirkin wrote:
Perhaps this is a point-specific function, but if this is applying to all primitives, won't this end up culling primitives that have *any* clip distance value < 0?
Setting the cull bit here just enables the normal gl_CullDistance logic for whatever the current primitive type happens to be.
Cull distance logic is a subset of clip distance logic: when there's some distance value which is < 0 for all vertices, cull the primitive. Clipping also does that (+ of course it does more complicated things when only a subset of of the vertices have < 0 for a distance value). Just that for whatever reason, the hardware folks decided that clipping should just do nothing at all for points.
Cheers, Nicolai
On Thu, Dec 15, 2016 at 10:42 AM, Nicolai Hähnle <nhaeh...@gmail.com> wrote:From: Nicolai Hähnle <nicolai.haeh...@amd.com> The clipper hardware doesn't consider points as primitives that can be clipped. Simply setting the corresponding cull bits works, and should not have an adverse effect on other primitive types according to the hardware team. --- src/gallium/drivers/radeonsi/si_state.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/src/gallium/drivers/radeonsi/si_state.c b/src/gallium/drivers/radeonsi/si_state.c index d86b99f..f6f61a6 100644 --- a/src/gallium/drivers/radeonsi/si_state.c +++ b/src/gallium/drivers/radeonsi/si_state.c @@ -671,34 +671,42 @@ static void si_emit_clip_regs(struct si_context *sctx, struct r600_atom *atom) unsigned total_mask; bool misc_vec_ena; if (vs->key.opt.hw_vs.clip_disable) { assert(!info->culldist_writemask); clipdist_mask = 0; culldist_mask = 0; } total_mask = clipdist_mask | culldist_mask; + /* Clip distances on points have no effect, so need to be implemented + * as cull distances. This applies for the clipvertex case as well. + * + * Setting this for primitives other than points should have no adverse + * effects. + */ + clipdist_mask &= rs->clip_plane_enable; + culldist_mask |= clipdist_mask; + misc_vec_ena = info->writes_psize || info->writes_edgeflag || info->writes_layer || info->writes_viewport_index; radeon_set_context_reg(cs, R_02881C_PA_CL_VS_OUT_CNTL, S_02881C_USE_VTX_POINT_SIZE(info->writes_psize) | S_02881C_USE_VTX_EDGE_FLAG(info->writes_edgeflag) | S_02881C_USE_VTX_RENDER_TARGET_INDX(info->writes_layer) | S_02881C_USE_VTX_VIEWPORT_INDX(info->writes_viewport_index) | S_02881C_VS_OUT_CCDIST0_VEC_ENA((total_mask & 0x0F) != 0) | S_02881C_VS_OUT_CCDIST1_VEC_ENA((total_mask & 0xF0) != 0) | S_02881C_VS_OUT_MISC_VEC_ENA(misc_vec_ena) | S_02881C_VS_OUT_MISC_SIDE_BUS_ENA(misc_vec_ena) | - (rs->clip_plane_enable & - clipdist_mask) | (culldist_mask << 8)); + clipdist_mask | (culldist_mask << 8)); radeon_set_context_reg(cs, R_028810_PA_CL_CLIP_CNTL, rs->pa_cl_clip_cntl | ucp_mask | S_028810_CLIP_DISABLE(window_space)); /* reuse needs to be set off if we write oViewport */ radeon_set_context_reg(cs, R_028AB4_VGT_REUSE_OFF, S_028AB4_REUSE_OFF(info->writes_viewport_index)); } -- 2.7.4 _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
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