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- /*
- * Copyright (C) 2021 Christopher J. Howard
- *
- * This file is part of Antkeeper source code.
- *
- * Antkeeper source code is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * Antkeeper source code is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with Antkeeper source code. If not, see <http://www.gnu.org/licenses/>.
- */
-
- #include "renderer/shader-template.hpp"
- #include <algorithm>
- #include <sstream>
-
- shader_template::shader_template(const std::string& source_code)
- {
- source(source_code);
- }
-
- shader_template::shader_template()
- {}
-
- void shader_template::source(const std::string& source)
- {
- // Reset template
- template_source.clear();
- vertex_directives.clear();
- fragment_directives.clear();
- geometry_directives.clear();
- define_directives.clear();
-
- // Iterate through source line-by-line
- std::istringstream source_stream(source);
- std::string line;
- while (std::getline(source_stream, line))
- {
- std::string token;
- std::istringstream line_stream(line);
-
- // Detect `#pragma` directives
- if (line_stream >> token && token == "#pragma")
- {
- if (line_stream >> token)
- {
- // Map line numbers of supported directives
- if (token == "define")
- {
- if (line_stream >> token)
- define_directives.insert({token, template_source.size()});
- }
- else if (token == "vertex")
- vertex_directives.insert(template_source.size());
- else if (token == "fragment")
- fragment_directives.insert(template_source.size());
- else if (token == "geometry")
- geometry_directives.insert(template_source.size());
- }
- }
-
- // Append line to template source
- template_source.push_back(line);
- }
- }
-
- std::string shader_template::configure(gl::shader_stage stage, const dictionary_type& definitions) const
- {
- replace_stage_directives(stage);
- replace_define_directives(definitions);
-
- // Join vector of source lines into single string
- std::ostringstream stream;
- std::copy(template_source.begin(), template_source.end(), std::ostream_iterator<std::string>(stream, "\n"));
- return stream.str();
- }
-
- gl::shader_object* shader_template::compile(gl::shader_stage stage, const dictionary_type& definitions) const
- {
- // Generate shader object source
- std::string object_source = configure(stage, definitions);
-
- // Create new shader object
- gl::shader_object* object = new gl::shader_object(stage);
-
- // Set shader object source
- object->source(object_source);
-
- // Compile shader object
- object->compile();
-
- return object;
- }
-
- gl::shader_program* shader_template::build(const dictionary_type& definitions) const
- {
- gl::shader_object* vertex_object = nullptr;
- gl::shader_object* fragment_object = nullptr;
- gl::shader_object* geometry_object = nullptr;
-
- // Create shader program
- gl::shader_program* program = new gl::shader_program();
-
- if (has_vertex_directive())
- {
- // Compile vertex shader object and attach to shader program
- vertex_object = compile(gl::shader_stage::vertex, definitions);
- program->attach(vertex_object);
- }
-
- if (has_fragment_directive())
- {
- // Compile fragment shader object and attach to shader program
- fragment_object = compile(gl::shader_stage::fragment, definitions);
- program->attach(fragment_object);
- }
-
- if (has_geometry_directive())
- {
- // Compile fragment shader object and attach to shader program
- geometry_object = compile(gl::shader_stage::geometry, definitions);
- program->attach(geometry_object);
- }
-
- // Link attached shader objects into shader program
- program->link();
-
- if (vertex_object)
- {
- // Detach and delete vertex shader object
- program->detach(vertex_object);
- delete vertex_object;
- }
-
- if (fragment_object)
- {
- // Detach and delete fragment shader object
- program->detach(fragment_object);
- delete fragment_object;
- }
-
- if (geometry_object)
- {
- // Detach and delete geometry shader object
- program->detach(geometry_object);
- delete geometry_object;
- }
-
- return program;
- }
-
- void shader_template::replace_stage_directives(gl::shader_stage stage) const
- {
- // Determine stage directives according to the shader stage being generated
- const std::string vertex_directive = (stage == gl::shader_stage::vertex) ? "#define __VERTEX__" : "/* #undef __VERTEX__ */";
- const std::string fragment_directive = (stage == gl::shader_stage::fragment) ? "#define __FRAGMENT__" : "/* #undef __FRAGMENT__ */";
- const std::string geometry_directive = (stage == gl::shader_stage::geometry) ? "#define __GEOMETRY__" : "/* #undef __GEOMETRY__ */";
-
- // Handle `#pragma <stage>` directives
- for (std::size_t i: vertex_directives)
- template_source[i] = vertex_directive;
- for (std::size_t i: fragment_directives)
- template_source[i] = fragment_directive;
- for (std::size_t i: geometry_directives)
- template_source[i] = geometry_directive;
- }
-
- void shader_template::replace_define_directives(const dictionary_type& definitions) const
- {
- // For each `#pragma define <key>` directive
- for (const auto& define_directive: define_directives)
- {
- // Get a reference to the directive line
- std::string& line = template_source[define_directive.second];
-
- // Check if the corresponding definition was given by the configuration
- auto definitions_it = definitions.find(define_directive.first);
- if (definitions_it != definitions.end())
- {
- // Definition found, Replace `#pragma define <key>` with `#define <key>` or `#define <key> <value>`
- line = "#define " + define_directive.first;
- if (!definitions_it->second.empty())
- line += " " + definitions_it->second;
- }
- else
- {
- // Definition not found, replace `#pragma define <key>` with the comment `/* #undef <key> */`.
- line = "/* #undef " + define_directive.first + " */";
- }
- }
- }
-
- bool shader_template::has_vertex_directive() const
- {
- return !vertex_directives.empty();
- }
-
- bool shader_template::has_fragment_directive() const
- {
- return !fragment_directives.empty();
- }
-
- bool shader_template::has_geometry_directive() const
- {
- return !geometry_directives.empty();
- }
-
- bool shader_template::has_define_directive(const std::string& key) const
- {
- return (define_directives.find(key) != define_directives.end());
- }
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