| // 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/emit_vertex_point_size_transform.h" |
| |
| #include <memory> |
| #include <utility> |
| |
| #include "src/ast/assignment_statement.h" |
| #include "src/ast/block_statement.h" |
| #include "src/ast/decorated_variable.h" |
| #include "src/ast/float_literal.h" |
| #include "src/ast/identifier_expression.h" |
| #include "src/ast/scalar_constructor_expression.h" |
| #include "src/ast/type/f32_type.h" |
| #include "src/ast/type_manager.h" |
| |
| namespace tint { |
| namespace transform { |
| namespace { |
| |
| const char kPointSizeVar[] = "tint_pointsize"; |
| |
| } // namespace |
| |
| EmitVertexPointSizeTransform::EmitVertexPointSizeTransform(ast::Module* mod) |
| : Transformer(mod) {} |
| |
| EmitVertexPointSizeTransform::~EmitVertexPointSizeTransform() = default; |
| |
| bool EmitVertexPointSizeTransform::Run() { |
| if (!mod_->HasStage(ast::PipelineStage::kVertex)) { |
| // If the module doesn't have any vertex stages, then there's nothing to do. |
| return true; |
| } |
| |
| auto* f32 = mod_->create<ast::type::F32>(); |
| |
| // Declare the pointsize builtin output variable. |
| auto* pointsize_var = |
| mod_->create<ast::DecoratedVariable>(mod_->create<ast::Variable>( |
| kPointSizeVar, ast::StorageClass::kOutput, f32)); |
| pointsize_var->set_decorations({ |
| mod_->create<ast::BuiltinDecoration>(ast::Builtin::kPointSize, Source{}), |
| }); |
| mod_->AddGlobalVariable(pointsize_var); |
| |
| // Build the AST expression & statement for assigning pointsize one. |
| auto* one = mod_->create<ast::ScalarConstructorExpression>( |
| mod_->create<ast::FloatLiteral>(f32, 1.0f)); |
| auto* pointsize_ident = |
| mod_->create<ast::IdentifierExpression>(Source{}, kPointSizeVar); |
| auto* pointsize_assign = |
| mod_->create<ast::AssignmentStatement>(pointsize_ident, one); |
| |
| // Add the pointsize assignment statement to the front of all vertex stages. |
| for (auto* func : mod_->functions()) { |
| if (func->pipeline_stage() == ast::PipelineStage::kVertex) { |
| func->body()->insert(0, pointsize_assign); |
| } |
| } |
| |
| return true; |
| } |
| |
| } // namespace transform |
| } // namespace tint |