obfs: Add readme

README.md

@@ -1,4 +1,111 @@
 # cpp-obfuscator
+[![License](https://img.shields.io/badge/Licence-MIT-blue.svg)](https://github.com/revsic/cpp-obfuscator/blob/master/LICENSE)
 [![Build Status](https://dev.azure.com/revsic99/cpp-obfuscator/_apis/build/status/revsic.cpp-obfuscator?branchName=master)](https://dev.azure.com/revsic99/cpp-obfuscator/_build/latest?definitionId=3&branchName=master)
 
 C++ implementation of compile time obfuscator
+
+## Compiler Support
+| Compiler | Version |
+| -- | -- |
+| Visual Studio | 2019 |
+| Clang++ | 8.0 |
+| g++ | 7.3 |
+| Apple Clang | Mojave |
+
+## Usage
+
+Use existing single header [obfuscator.hpp](./obfuscator.hpp) or run [script](./script/merge.py) to merge multiple headers in directory [obfuscator](./obfuscator).
+
+```bash
+python -m script.merge
+```
+
+Include [obfuscator.hpp](./obfuscator.hpp) to use it.
+```C++
+#include "../obfuscator.hpp"
+
+template <char key>
+constexpr char xor_(char c) {
+    return c ^ key;
+}
+
+std::cout << obfs::make_string<xor_<0x50>, xor_<0x50>>("Hello World !\n").decode();
+```
+
+## String
+
+Compile time string obfuscator. No more raw string in binary, sample [string_obfuscator](./sample/string_obfs.cpp).
+
+0. Sample encoder, decoder
+```C++
+template <char key>
+constexpr char xor_(char c) {
+    return c ^ key;
+}
+
+template <char Key>
+constexpr char add(char c) {
+    return c + Key;
+}
+
+template <char(*f)(char), char(*g)(char)>
+constexpr char comp(char c) {
+    return f(g(c));
+}
+```
+
+1. Single encoder, decoder.
+```C++
+std::cout << obfs::make_string<xor_<0x50>, xor_<0x50>>("Hello World !\n").decode();
+```
+
+2. Multiple encoder, decoder and random selection.
+```C++
+using table = obfs::make_table<
+    obfs::encoder_seq<xor_<0x50>, add<10>, comp<xor_<0x50>, add<10>>>,
+    obfs::decoder_seq<xor_<0x50>, add<-10>, comp<add<-10>, xor_<0x50>>>>;
+
+std::cout << obfs::make_string<table>("Hello World !\n").decode();
+```
+
+3. Multiple encoder, decoder as pair.
+```C++
+using table = obfs::make_pair_table<
+    obfs::encoder_pair<xor_<0x50>, xor_<0x50>>,
+    obfs::encoder_pair<add<10>, add<-10>>,
+    obfs::encoder_pair<comp<xor_<0x50>, add<10>>, comp<add<-10>, xor_<0x50>>>
+>;
+
+std::cout << obfs::make_string<table>("Hello World !\n").decode();
+```
+
+4. String obfuscator macro.
+```C++
+MAKE_STRING(str, "Hello World !\n", table);
+std::cout << str.decode();
+```
+
+## Finite state machine
+
+Compile time finite state machine based routine obfuscator, sample [state_machine](./sample/state_machine.cpp).
+
+0. Make state table.
+```C++
+using namespace obfs;
+using machine = StateMachine<
+    Stage<state1, Next<event5 , state2, Dummy::dummy1>,
+                  Next<event1 , state3, Dummy::dummy3>>,
+    Stage<state2, Next<event2 , state4>>,
+    Stage<state3, Next<None   , state3>>,
+    Stage<state4, Next<event4 , state1>,
+                  Next<event3 , state5, Dummy::dummy2>>,
+    Stage<state5, Next<Trigger, Final, Action::action>>>;
+```
+
+1. Run state machine, each execution returns next state.
+```C++
+auto next1 = machine::run(state1{}, event5{}); // dummy1 executed
+auto next2 = machine::run(next1, event2{});
+auto next3 = machine::run(next2, event3{});    // dummy2 executed
+auto next4 = machine::run(next3, Trigger{});   // action executed
+```