| // 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/transform/first_index_offset.h" |
| |
| #include <memory> |
| #include <unordered_map> |
| #include <utility> |
| |
| #include "src/program_builder.h" |
| #include "src/sem/function.h" |
| #include "src/sem/member_accessor_expression.h" |
| #include "src/sem/struct.h" |
| #include "src/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 { |
| namespace transform { |
| namespace { |
| |
| // Uniform buffer member names |
| constexpr char kFirstVertexName[] = "first_vertex_index"; |
| constexpr char kFirstInstanceName[] = "first_instance_index"; |
| |
| } // 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_index, |
| bool has_inst_index, |
| uint32_t first_vtx_offset, |
| uint32_t first_inst_offset) |
| : has_vertex_index(has_vtx_index), |
| has_instance_index(has_inst_index), |
| first_vertex_offset(first_vtx_offset), |
| first_instance_offset(first_inst_offset) {} |
| FirstIndexOffset::Data::Data(const Data&) = default; |
| FirstIndexOffset::Data::~Data() = default; |
| |
| FirstIndexOffset::FirstIndexOffset() = default; |
| FirstIndexOffset::~FirstIndexOffset() = default; |
| |
| void FirstIndexOffset::Run(CloneContext& ctx, |
| const DataMap& inputs, |
| DataMap& outputs) { |
| // 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_index = false; |
| bool has_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* dec : var->decorations) { |
| if (auto* builtin_dec = dec->As<ast::BuiltinDecoration>()) { |
| ast::Builtin builtin = builtin_dec->builtin; |
| if (builtin == ast::Builtin::kVertexIndex) { |
| auto* sem_var = ctx.src->Sem().Get(var); |
| builtin_vars.emplace(sem_var, kFirstVertexName); |
| has_vertex_index = true; |
| } |
| if (builtin == ast::Builtin::kInstanceIndex) { |
| auto* sem_var = ctx.src->Sem().Get(var); |
| builtin_vars.emplace(sem_var, kFirstInstanceName); |
| has_instance_index = true; |
| } |
| } |
| } |
| } |
| if (auto* member = node->As<ast::StructMember>()) { |
| for (auto* dec : member->decorations) { |
| if (auto* builtin_dec = dec->As<ast::BuiltinDecoration>()) { |
| ast::Builtin builtin = builtin_dec->builtin; |
| if (builtin == ast::Builtin::kVertexIndex) { |
| auto* sem_mem = ctx.src->Sem().Get(member); |
| builtin_members.emplace(sem_mem, kFirstVertexName); |
| has_vertex_index = true; |
| } |
| if (builtin == ast::Builtin::kInstanceIndex) { |
| auto* sem_mem = ctx.src->Sem().Get(member); |
| builtin_members.emplace(sem_mem, kFirstInstanceName); |
| has_instance_index = true; |
| } |
| } |
| } |
| } |
| } |
| |
| // Byte offsets on the uniform buffer |
| uint32_t vertex_index_offset = 0; |
| uint32_t instance_index_offset = 0; |
| |
| if (has_vertex_index || has_instance_index) { |
| // Add uniform buffer members and calculate byte offsets |
| uint32_t offset = 0; |
| ast::StructMemberList members; |
| if (has_vertex_index) { |
| members.push_back(ctx.dst->Member(kFirstVertexName, ctx.dst->ty.u32())); |
| vertex_index_offset = offset; |
| offset += 4; |
| } |
| if (has_instance_index) { |
| members.push_back(ctx.dst->Member(kFirstInstanceName, ctx.dst->ty.u32())); |
| instance_index_offset = offset; |
| offset += 4; |
| } |
| auto* struct_ = ctx.dst->Structure(ctx.dst->Sym(), std::move(members)); |
| |
| // Create a global to hold the uniform buffer |
| Symbol buffer_name = ctx.dst->Sym(); |
| ctx.dst->Global(buffer_name, ctx.dst->ty.Of(struct_), |
| ast::StorageClass::kUniform, nullptr, |
| ast::DecorationList{ |
| ctx.dst->create<ast::BindingDecoration>(ub_binding), |
| ctx.dst->create<ast::GroupDecoration>(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 experssion. Just clone. |
| return nullptr; |
| }); |
| } |
| |
| ctx.Clone(); |
| |
| outputs.Add<Data>(has_vertex_index, has_instance_index, vertex_index_offset, |
| instance_index_offset); |
| } |
| |
| } // namespace transform |
| } // namespace tint |