VoxelEngine/src/coders/GLSLExtension.cpp
2024-08-10 01:37:48 +03:00

151 lines
4.5 KiB
C++

#include "GLSLExtension.hpp"
#include <iostream>
#include <sstream>
#include <stdexcept>
#include <utility>
#include "files/engine_paths.hpp"
#include "files/files.hpp"
#include "typedefs.hpp"
#include "util/stringutil.hpp"
namespace fs = std::filesystem;
void GLSLExtension::setVersion(std::string version) {
this->version = std::move(version);
}
void GLSLExtension::setPaths(const ResPaths* paths) {
this->paths = paths;
}
void GLSLExtension::loadHeader(const std::string& name) {
fs::path file = paths->find("shaders/lib/" + name + ".glsl");
std::string source = files::read_string(file);
addHeader(name, "");
addHeader(name, process(file, source, true));
}
void GLSLExtension::addHeader(const std::string& name, std::string source) {
headers[name] = std::move(source);
}
void GLSLExtension::define(const std::string& name, std::string value) {
defines[name] = std::move(value);
}
const std::string& GLSLExtension::getHeader(const std::string& name) const {
auto found = headers.find(name);
if (found == headers.end()) {
throw std::runtime_error("no header '" + name + "' loaded");
}
return found->second;
}
const std::string& GLSLExtension::getDefine(const std::string& name) const {
auto found = defines.find(name);
if (found == defines.end()) {
throw std::runtime_error("name '" + name + "' is not defined");
}
return found->second;
}
bool GLSLExtension::hasDefine(const std::string& name) const {
return defines.find(name) != defines.end();
}
bool GLSLExtension::hasHeader(const std::string& name) const {
return headers.find(name) != headers.end();
}
void GLSLExtension::undefine(const std::string& name) {
if (hasDefine(name)) {
defines.erase(name);
}
}
inline std::runtime_error parsing_error(
const fs::path& file, uint linenum, const std::string& message
) {
return std::runtime_error(
"file " + file.string() + ": " + message + " at line " +
std::to_string(linenum)
);
}
inline void parsing_warning(
const fs::path& file, uint linenum, const std::string& message
) {
std::cerr << "file " + file.string() + ": warning: " + message +
" at line " + std::to_string(linenum)
<< std::endl;
}
inline void source_line(std::stringstream& ss, uint linenum) {
ss << "#line " << linenum << "\n";
}
std::string GLSLExtension::process(
const fs::path& file, const std::string& source, bool header
) {
std::stringstream ss;
size_t pos = 0;
uint linenum = 1;
if (!header) {
ss << "#version " << version << '\n';
}
for (auto& entry : defines) {
ss << "#define " << entry.first << " " << entry.second << '\n';
}
source_line(ss, linenum);
while (pos < source.length()) {
size_t endline = source.find('\n', pos);
if (endline == std::string::npos) {
endline = source.length();
}
// parsing preprocessor directives
if (source[pos] == '#') {
std::string line = source.substr(pos + 1, endline - pos);
util::trim(line);
// parsing 'include' directive
if (line.find("include") != std::string::npos) {
line = line.substr(7);
util::trim(line);
if (line.length() < 3) {
throw parsing_error(
file, linenum, "invalid 'include' syntax"
);
}
if (line[0] != '<' || line[line.length() - 1] != '>') {
throw parsing_error(
file, linenum, "expected '#include <filename>' syntax"
);
}
std::string name = line.substr(1, line.length() - 2);
if (!hasHeader(name)) {
loadHeader(name);
}
source_line(ss, 1);
ss << getHeader(name) << '\n';
pos = endline + 1;
linenum++;
source_line(ss, linenum);
continue;
}
// removing extra 'include' directives
else if (line.find("version") != std::string::npos) {
parsing_warning(file, linenum, "removed #version directive");
pos = endline + 1;
linenum++;
source_line(ss, linenum);
continue;
}
}
linenum++;
ss << source.substr(pos, endline + 1 - pos);
pos = endline + 1;
}
return ss.str();
}