For the series Reviewed-by: Chris Forbes <<a href="mailto:chrisf@ijw.co.nz">chrisf@ijw.co.nz</a>> <div class="gmail_quote">On Oct 27, 2015 7:03 AM, "Kenneth Graunke" <<a href="mailto:kenneth@whitecape.org">kenneth@whitecape.org</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Normally, we could read gl_Layer from bits 26:16 of R0.0. However, the specification requires that bogus out-of-range 32-bit values written by previous stages need to appear in the fragment shader as-written. Instead, we pass in the full 32-bit value from the VUE header as an extra flat-shaded varying. We have the SF override the value to 0 when the previous stage didn't actually write a value (it's actually defined to return 0). Signed-off-by: Kenneth Graunke <<a href="mailto:kenneth@whitecape.org">kenneth@whitecape.org</a>> Cc: Chris Forbes <<a href="mailto:chrisf@ijw.co.nz">chrisf@ijw.co.nz</a>> --- src/mesa/drivers/dri/i965/brw_fs.cpp | 7 ++++++- src/mesa/drivers/dri/i965/brw_fs_nir.cpp | 8 +++++++ src/mesa/drivers/dri/i965/gen6_sf_state.c | 31 ++++++++++++++++++++++++++++ src/mesa/drivers/dri/i965/intel_extensions.c | 1 + 4 files changed, 46 insertions(+), 1 deletion(-) diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp index 2eef7af..5a82b04 100644 --- a/src/mesa/drivers/dri/i965/brw_fs.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp @@ -1442,6 +1442,9 @@ fs_visitor::calculate_urb_setup() } } } else { + bool include_vue_header = + nir->info.inputs_read & (VARYING_BIT_LAYER | VARYING_BIT_VIEWPORT); + /* We have enough input varyings that the SF/SBE pipeline stage can't * arbitrarily rearrange them to suit our whim; we have to put them * in an order that matches the output of the previous pipeline stage @@ -1451,7 +1454,9 @@ fs_visitor::calculate_urb_setup() brw_compute_vue_map(devinfo, &prev_stage_vue_map, key->input_slots_valid, nir->info.separate_shader); - int first_slot = 2 * BRW_SF_URB_ENTRY_READ_OFFSET; + int first_slot = + include_vue_header ? 0 : 2 * BRW_SF_URB_ENTRY_READ_OFFSET; + assert(prev_stage_vue_map.num_slots <= first_slot + 32); for (int slot = first_slot; slot < prev_stage_vue_map.num_slots; slot++) { diff --git a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp index 4950ba4..9c1f95c 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp @@ -71,6 +71,14 @@ fs_visitor::nir_setup_inputs() var->data.origin_upper_left); emit_percomp(bld, fs_inst(BRW_OPCODE_MOV, bld.dispatch_width(), input, reg), 0xF); + } else if (var->data.location == VARYING_SLOT_LAYER) { + struct brw_reg reg = suboffset(interp_reg(VARYING_SLOT_LAYER, 1), 3); + reg.type = BRW_REGISTER_TYPE_D; + bld.emit(FS_OPCODE_CINTERP, retype(input, BRW_REGISTER_TYPE_D), reg); + } else if (var->data.location == VARYING_SLOT_VIEWPORT) { + struct brw_reg reg = suboffset(interp_reg(VARYING_SLOT_VIEWPORT, 2), 3); + reg.type = BRW_REGISTER_TYPE_D; + bld.emit(FS_OPCODE_CINTERP, retype(input, BRW_REGISTER_TYPE_D), reg); } else { emit_general_interpolation(input, var->name, var->type, (glsl_interp_qualifier) var->data.interpolation, diff --git a/src/mesa/drivers/dri/i965/gen6_sf_state.c b/src/mesa/drivers/dri/i965/gen6_sf_state.c index 0c8c053..2634e6b 100644 --- a/src/mesa/drivers/dri/i965/gen6_sf_state.c +++ b/src/mesa/drivers/dri/i965/gen6_sf_state.c @@ -60,6 +60,23 @@ get_attr_override(const struct brw_vue_map *vue_map, int urb_entry_read_offset, /* Find the VUE slot for this attribute. */ int slot = vue_map->varying_to_slot[fs_attr]; + /* Viewport and Layer are stored in the VUE header. We need to override + * them to zero if earlier stages didn't write them, as GL requires that + * they read back as zero when not explicitly set. + */ + if (fs_attr == VARYING_SLOT_VIEWPORT || fs_attr == VARYING_SLOT_LAYER) { + unsigned override = + ATTRIBUTE_0_OVERRIDE_X | ATTRIBUTE_0_OVERRIDE_W | + ATTRIBUTE_CONST_0000 << ATTRIBUTE_0_CONST_SOURCE_SHIFT; + + if (!(vue_map->slots_valid & VARYING_BIT_LAYER)) + override |= ATTRIBUTE_0_OVERRIDE_Y; + if (!(vue_map->slots_valid & VARYING_BIT_VIEWPORT)) + override |= ATTRIBUTE_0_OVERRIDE_Z; + + return override; + } + /* If there was only a back color written but not front, use back * as the color instead of undefined */ @@ -169,6 +186,20 @@ calculate_attr_overrides(const struct brw_context *brw, *urb_entry_read_offset = BRW_SF_URB_ENTRY_READ_OFFSET; + /* BRW_NEW_FRAGMENT_PROGRAM + * + * If the fragment shader reads VARYING_SLOT_LAYER, then we need to pass in + * the full vertex header. Otherwise, we can program the SF to start + * reading at an offset of 1 (2 varying slots) to skip unnecessary data: + * - VARYING_SLOT_PSIZ and BRW_VARYING_SLOT_NDC on gen4-5 + * - VARYING_SLOT_{PSIZ,LAYER} and VARYING_SLOT_POS on gen6+ + */ + + bool fs_needs_vue_header = brw->fragment_program->Base.InputsRead & + (VARYING_BIT_LAYER | VARYING_BIT_VIEWPORT); + + *urb_entry_read_offset = fs_needs_vue_header ? 0 : 1; + /* _NEW_LIGHT */ bool shade_model_flat = brw->ctx.Light.ShadeModel == GL_FLAT; diff --git a/src/mesa/drivers/dri/i965/intel_extensions.c b/src/mesa/drivers/dri/i965/intel_extensions.c index c6826d6..4433410 100644 --- a/src/mesa/drivers/dri/i965/intel_extensions.c +++ b/src/mesa/drivers/dri/i965/intel_extensions.c @@ -287,6 +287,7 @@ intelInitExtensions(struct gl_context *ctx) ctx->Extensions.ARB_conditional_render_inverted = true; ctx->Extensions.ARB_draw_buffers_blend = true; ctx->Extensions.ARB_ES3_compatibility = true; + ctx->Extensions.ARB_fragment_layer_viewport = true; ctx->Extensions.ARB_sample_shading = true; ctx->Extensions.ARB_shading_language_420pack = true; ctx->Extensions.ARB_shading_language_packing = true; -- 2.6.2 </blockquote></div>