From 5ff848df7be34bdc4c2e0ad509ad43b4ae1fc3b9 Mon Sep 17 00:00:00 2001 From: Antia Puentes Date: Thu, 25 Jan 2018 19:15:38 +0100 Subject: [PATCH] compiler: Add SYSTEM_VALUE_FIRST_VERTEX and instrinsics This VS system value will contain the value passed as for indexed draw calls or the value passed as for non-indexed draw calls. It can be used to calculate the gl_VertexID as SYSTEM_VALUE_VERTEX_ID_ZERO_BASE plus SYSTEM_VALUE_FIRST_VERTEX. From the OpenGL 4.6 spec, 10.4 "Drawing Commands Using Vertex Arrays": - Page 352: "The index of any element transferred to the GL by DrawArraysOneInstance is referred to as its vertex ID, and may be read by a vertex shader as gl_VertexID. The vertex ID of the ith element transferred is first + i." - Page 355: "The index of any element transferred to the GL by DrawElementsOneInstance is referred to as its vertex ID, and may be read by a vertex shader as gl_VertexID. The vertex ID of the ith element transferred is the sum of basevertex and the value stored in the currently bound element array buffer at offset indices + i." Currently the gl_VertexID calculation uses SYSTEM_VALUE_BASE_VERTEX but this will have to change when the value of gl_BaseVertex is fixed. Currently its value is broken for non-indexed draw calls because it must be zero but we are setting it to . v2: use SYSTEM_VALUE_FIRST_VERTEX as name for the value, instead of SYSTEM_VALUE_BASE_VERTEX_ID (Kenneth). v3 (idr): Rebase on Rob Clark converting nir_intrinsics.h to be generated. Reformat commit message to 72 columns. Reviewed-by: Neil Roberts Reviewed-by: Kenneth Graunke --- src/compiler/nir/nir.c | 4 ++++ src/compiler/nir/nir_gather_info.c | 1 + src/compiler/nir/nir_intrinsics.py | 1 + src/compiler/shader_enums.c | 1 + src/compiler/shader_enums.h | 14 ++++++++++++++ 5 files changed, 21 insertions(+) diff --git a/src/compiler/nir/nir.c b/src/compiler/nir/nir.c index ef911540f37..ea28fbd1af5 100644 --- a/src/compiler/nir/nir.c +++ b/src/compiler/nir/nir.c @@ -1991,6 +1991,8 @@ nir_intrinsic_from_system_value(gl_system_value val) return nir_intrinsic_load_base_instance; case SYSTEM_VALUE_VERTEX_ID_ZERO_BASE: return nir_intrinsic_load_vertex_id_zero_base; + case SYSTEM_VALUE_FIRST_VERTEX: + return nir_intrinsic_load_first_vertex; case SYSTEM_VALUE_BASE_VERTEX: return nir_intrinsic_load_base_vertex; case SYSTEM_VALUE_INVOCATION_ID: @@ -2066,6 +2068,8 @@ nir_system_value_from_intrinsic(nir_intrinsic_op intrin) return SYSTEM_VALUE_BASE_INSTANCE; case nir_intrinsic_load_vertex_id_zero_base: return SYSTEM_VALUE_VERTEX_ID_ZERO_BASE; + case nir_intrinsic_load_first_vertex: + return SYSTEM_VALUE_FIRST_VERTEX; case nir_intrinsic_load_base_vertex: return SYSTEM_VALUE_BASE_VERTEX; case nir_intrinsic_load_invocation_id: diff --git a/src/compiler/nir/nir_gather_info.c b/src/compiler/nir/nir_gather_info.c index eaf0ca68b0f..a6a699ab25f 100644 --- a/src/compiler/nir/nir_gather_info.c +++ b/src/compiler/nir/nir_gather_info.c @@ -265,6 +265,7 @@ gather_intrinsic_info(nir_intrinsic_instr *instr, nir_shader *shader) case nir_intrinsic_load_vertex_id: case nir_intrinsic_load_vertex_id_zero_base: case nir_intrinsic_load_base_vertex: + case nir_intrinsic_load_first_vertex: case nir_intrinsic_load_base_instance: case nir_intrinsic_load_instance_id: case nir_intrinsic_load_sample_id: diff --git a/src/compiler/nir/nir_intrinsics.py b/src/compiler/nir/nir_intrinsics.py index 1bc99552cd7..f26aaf35ee3 100644 --- a/src/compiler/nir/nir_intrinsics.py +++ b/src/compiler/nir/nir_intrinsics.py @@ -413,6 +413,7 @@ system_value("frag_coord", 4) system_value("front_face", 1) system_value("vertex_id", 1) system_value("vertex_id_zero_base", 1) +system_value("first_vertex", 1) system_value("base_vertex", 1) system_value("instance_id", 1) system_value("base_instance", 1) diff --git a/src/compiler/shader_enums.c b/src/compiler/shader_enums.c index d0ff11b41e2..ebee076b43c 100644 --- a/src/compiler/shader_enums.c +++ b/src/compiler/shader_enums.c @@ -216,6 +216,7 @@ gl_system_value_name(gl_system_value sysval) ENUM(SYSTEM_VALUE_INSTANCE_ID), ENUM(SYSTEM_VALUE_INSTANCE_INDEX), ENUM(SYSTEM_VALUE_VERTEX_ID_ZERO_BASE), + ENUM(SYSTEM_VALUE_FIRST_VERTEX), ENUM(SYSTEM_VALUE_BASE_VERTEX), ENUM(SYSTEM_VALUE_BASE_INSTANCE), ENUM(SYSTEM_VALUE_DRAW_ID), diff --git a/src/compiler/shader_enums.h b/src/compiler/shader_enums.h index 2aedbb9b3fa..8a277a14f21 100644 --- a/src/compiler/shader_enums.h +++ b/src/compiler/shader_enums.h @@ -503,6 +503,20 @@ typedef enum */ SYSTEM_VALUE_BASE_VERTEX, + /** + * Depending on the type of the draw call (indexed or non-indexed), + * is the value of \c basevertex passed to \c glDrawElementsBaseVertex and + * similar, or is the value of \c first passed to \c glDrawArrays and + * similar. + * + * \note + * It can be used to calculate the \c SYSTEM_VALUE_VERTEX_ID as + * \c SYSTEM_VALUE_VERTEX_ID_ZERO_BASE plus \c SYSTEM_VALUE_FIRST_VERTEX. + * + * \sa SYSTEM_VALUE_VERTEX_ID_ZERO_BASE, SYSTEM_VALUE_VERTEX_ID + */ + SYSTEM_VALUE_FIRST_VERTEX, + /** * Value of \c baseinstance passed to instanced draw entry points * -- 2.30.2