| // Copyright 2020 The Tint Authors. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #include "src/tint/transform/first_index_offset.h" |
| |
| #include <memory> |
| #include <unordered_map> |
| #include <utility> |
| |
| #include "src/tint/program_builder.h" |
| #include "src/tint/sem/function.h" |
| #include "src/tint/sem/member_accessor_expression.h" |
| #include "src/tint/sem/struct.h" |
| #include "src/tint/sem/variable.h" |
| |
| TINT_INSTANTIATE_TYPEINFO(tint::transform::FirstIndexOffset); |
| TINT_INSTANTIATE_TYPEINFO(tint::transform::FirstIndexOffset::BindingPoint); |
| TINT_INSTANTIATE_TYPEINFO(tint::transform::FirstIndexOffset::Data); |
| |
| namespace tint::transform { |
| namespace { |
| |
| // Uniform buffer member names |
| constexpr char kFirstVertexName[] = "first_vertex_index"; |
| constexpr char kFirstInstanceName[] = "first_instance_index"; |
| |
| bool ShouldRun(const Program* program) { |
| for (auto* fn : program->AST().Functions()) { |
| if (fn->PipelineStage() == ast::PipelineStage::kVertex) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| } // namespace |
| |
| FirstIndexOffset::BindingPoint::BindingPoint() = default; |
| FirstIndexOffset::BindingPoint::BindingPoint(uint32_t b, uint32_t g) : binding(b), group(g) {} |
| FirstIndexOffset::BindingPoint::~BindingPoint() = default; |
| |
| FirstIndexOffset::Data::Data(bool has_vtx_or_inst_index) |
| : has_vertex_or_instance_index(has_vtx_or_inst_index) {} |
| FirstIndexOffset::Data::Data(const Data&) = default; |
| FirstIndexOffset::Data::~Data() = default; |
| |
| FirstIndexOffset::FirstIndexOffset() = default; |
| FirstIndexOffset::~FirstIndexOffset() = default; |
| |
| Transform::ApplyResult FirstIndexOffset::Apply(const Program* src, |
| const DataMap& inputs, |
| DataMap& outputs) const { |
| if (!ShouldRun(src)) { |
| return SkipTransform; |
| } |
| |
| ProgramBuilder b; |
| CloneContext ctx{&b, src, /* auto_clone_symbols */ true}; |
| |
| // Get the uniform buffer binding point |
| uint32_t ub_binding = binding_; |
| uint32_t ub_group = group_; |
| if (auto* binding_point = inputs.Get<BindingPoint>()) { |
| ub_binding = binding_point->binding; |
| ub_group = binding_point->group; |
| } |
| |
| // Map of builtin usages |
| std::unordered_map<const sem::Variable*, const char*> builtin_vars; |
| std::unordered_map<const sem::StructMember*, const char*> builtin_members; |
| |
| bool has_vertex_or_instance_index = false; |
| |
| // Traverse the AST scanning for builtin accesses via variables (includes |
| // parameters) or structure member accesses. |
| for (auto* node : ctx.src->ASTNodes().Objects()) { |
| if (auto* var = node->As<ast::Variable>()) { |
| for (auto* attr : var->attributes) { |
| if (auto* builtin_attr = attr->As<ast::BuiltinAttribute>()) { |
| ast::BuiltinValue builtin = builtin_attr->builtin; |
| if (builtin == ast::BuiltinValue::kVertexIndex) { |
| auto* sem_var = ctx.src->Sem().Get(var); |
| builtin_vars.emplace(sem_var, kFirstVertexName); |
| has_vertex_or_instance_index = true; |
| } |
| if (builtin == ast::BuiltinValue::kInstanceIndex) { |
| auto* sem_var = ctx.src->Sem().Get(var); |
| builtin_vars.emplace(sem_var, kFirstInstanceName); |
| has_vertex_or_instance_index = true; |
| } |
| } |
| } |
| } |
| if (auto* member = node->As<ast::StructMember>()) { |
| for (auto* attr : member->attributes) { |
| if (auto* builtin_attr = attr->As<ast::BuiltinAttribute>()) { |
| ast::BuiltinValue builtin = builtin_attr->builtin; |
| if (builtin == ast::BuiltinValue::kVertexIndex) { |
| auto* sem_mem = ctx.src->Sem().Get(member); |
| builtin_members.emplace(sem_mem, kFirstVertexName); |
| has_vertex_or_instance_index = true; |
| } |
| if (builtin == ast::BuiltinValue::kInstanceIndex) { |
| auto* sem_mem = ctx.src->Sem().Get(member); |
| builtin_members.emplace(sem_mem, kFirstInstanceName); |
| has_vertex_or_instance_index = true; |
| } |
| } |
| } |
| } |
| } |
| |
| if (has_vertex_or_instance_index) { |
| // Add uniform buffer members and calculate byte offsets |
| utils::Vector<const ast::StructMember*, 8> members; |
| members.Push(b.Member(kFirstVertexName, b.ty.u32())); |
| members.Push(b.Member(kFirstInstanceName, b.ty.u32())); |
| auto* struct_ = b.Structure(b.Sym(), std::move(members)); |
| |
| // Create a global to hold the uniform buffer |
| Symbol buffer_name = b.Sym(); |
| b.GlobalVar(buffer_name, b.ty.Of(struct_), ast::AddressSpace::kUniform, |
| utils::Vector{ |
| b.Binding(AInt(ub_binding)), |
| b.Group(AInt(ub_group)), |
| }); |
| |
| // Fix up all references to the builtins with the offsets |
| ctx.ReplaceAll([=, &ctx](const ast::Expression* expr) -> const ast::Expression* { |
| if (auto* sem = ctx.src->Sem().Get(expr)) { |
| if (auto* user = sem->As<sem::VariableUser>()) { |
| auto it = builtin_vars.find(user->Variable()); |
| if (it != builtin_vars.end()) { |
| return ctx.dst->Add(ctx.CloneWithoutTransform(expr), |
| ctx.dst->MemberAccessor(buffer_name, it->second)); |
| } |
| } |
| if (auto* access = sem->As<sem::StructMemberAccess>()) { |
| auto it = builtin_members.find(access->Member()); |
| if (it != builtin_members.end()) { |
| return ctx.dst->Add(ctx.CloneWithoutTransform(expr), |
| ctx.dst->MemberAccessor(buffer_name, it->second)); |
| } |
| } |
| } |
| // Not interested in this expression. Just clone. |
| return nullptr; |
| }); |
| } |
| |
| outputs.Add<Data>(has_vertex_or_instance_index); |
| |
| ctx.Clone(); |
| return Program(std::move(b)); |
| } |
| |
| } // namespace tint::transform |