GLSL2HLSL.cpp

#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <fstream>
#include <string>
#include <numeric>
#include <algorithm>
#include <vector>
#include <set>
#include <sstream>
#include <random>
#include <cstdio>
#include <cmath>
#include "windows.h"
#include "dirent.h"
using namespace std;

string ExePath() {
  char buffer[MAX_PATH];
	GetModuleFileName(NULL, buffer, MAX_PATH);
	string::size_type pos = string(buffer).find_last_of("\\/");
	return string(buffer).substr(0, pos);
}

bool replace(std::string& str, const std::string& from, const std::string& to) {
	size_t start_pos = str.find(from);
	if (start_pos == std::string::npos)
		return false;
	str.replace(start_pos, from.length(), to);
	return true;
}

bool replace_reverse(std::string& str, const std::string& from, const std::string& to) {
	size_t start_pos = str.rfind(from);
	if (start_pos == std::string::npos)
		return false;
	str.replace(start_pos, from.length(), to);
	return true;
}

void replaceAll(std::string& str, const std::string& from, const std::string& to) {
	if (from.empty()) return;
	size_t start_pos = 0;
	while ((start_pos = str.find(from, start_pos)) != std::string::npos) {
		str.replace(start_pos, from.length(), to);
		start_pos += to.length(); // In case 'to' contains 'from', like replacing 'x' with 'yx'
	}
}

// find vec2(, 3(, 4( and fill the rest
void findAddFill(std::string& str, const std::string& from, int count) {
	if (from.empty()) return;
	size_t start_pos = 0;
	while ((start_pos = str.find(from, start_pos)) != std::string::npos) {

		size_t end_pos = str.find(")", start_pos);
		string string_to_insert = "";
		// if find correspondence
		if (end_pos != string::npos) {
			size_t comma_pos = str.substr(start_pos, end_pos - start_pos).find(","); // str.find("\,", start_pos, end_pos - start_pos);

			if (comma_pos == string::npos) {
				auto number_str = str.substr(start_pos + from.size(), end_pos - start_pos - from.size());
				for (auto c = 0; c < count; ++c) {
					string_to_insert += ", " + number_str;
				}
				str.insert(end_pos, string_to_insert);
			}
		}
		start_pos += string_to_insert.length() + 1; // In case 'to' contains 'from', like replacing 'x' with 'yx'
	}
}

int main() {
	ios::fmtflags cin_screen(cin.flags());
	ios::fmtflags cout_screen(cout.flags());
	string exe_path = ExePath();
	cout << "Current directory is " << exe_path << "\n";

	DIR *dir;
	struct dirent *ent;
	string read_path = exe_path;

	set<string> set_files;
	if ((dir = opendir(read_path.c_str())) != NULL) {
		while ((ent = readdir(dir)) != NULL) {
			string file = string(ent->d_name);
			string prefix = file.substr(0, file.find("."));
			string suffix = file.substr(file.find_last_of("."));
			// find all files ended with .glsl
			if (!suffix.compare(".glsl")) {
				set_files.insert(prefix);
				printf("* %s\n", prefix.c_str());

				string input_file = read_path + "\\" + prefix + ".glsl";
				string output_file = read_path + "\\" + prefix + ".hlsl";

				/*freopen(input_file.c_str(), "r", stdin);
				freopen(output_file.c_str(), "w", stdout);*/

				//string text = "";
				//string line;
				//while (getline(cin, line))
				//{
				//	text += line + "\n";
				//}
				ifstream ifs(input_file);
				string text((istreambuf_iterator<char>(ifs)), (istreambuf_iterator<char>()));
				ofstream ofs(output_file);

				replace(text, "void mainImage( out vec4 fragColor, in vec2 fragCoord ) {", "float4 frag(v2f vert) : SV_Target {");
				replace(text, "void mainImage( out vec4 fragColor, in vec2 fragCoord )", "float4 frag(v2f vert) : SV_Target");
				findAddFill(text, "vec4(", 3);
				findAddFill(text, "vec3(", 2);
				findAddFill(text, "vec2(", 1);
				replaceAll(text, "ivec4", "int4");
				replaceAll(text, "ivec3", "int3");
				replaceAll(text, "ivec2", "int2");
				replaceAll(text, "vec4", "float4");
				replaceAll(text, "vec3", "float3");
				replaceAll(text, "vec2", "float2");
				replaceAll(text, "mat4", "float4x4");
				replaceAll(text, "mat3", "float3x3");
				replaceAll(text, "mat2", "float2x2");
				replaceAll(text, "iResolution", "_ScreenParams");
				replaceAll(text, "iGlobalTime", "_Time.y");
				replaceAll(text, "iTime", "_Time.y");
				replaceAll(text, "fragCoord", "(vert.uv.xy * _ScreenParams.xy)");
				replaceAll(text, "iChannel0", "_MainTex");
				replaceAll(text, "texture(", "tex2D(");
				replaceAll(text, "texture2D(", "tex2D(");
				replaceAll(text, "mod(", "fmod(");
				replaceAll(text, "fract(", "frac(");
				replaceAll(text, "mix(", "lerp(");
				replaceAll(text, "inversesqrt(", "rsqrt(");
				replace_reverse(text, "fragColor =", "return");

				ofs << text << endl;

				ifs.close();
				ofs.close();
			}
		}
		closedir(dir);
	}
	else {
		perror("");
		return EXIT_FAILURE;
	}
	cin.flags(cin_screen);
	cout.flags(cout_screen);

	system("pause");
	return 0;
}