Add 'cordiceps.cpp'

cordiceps.cpp

@@ -0,0 +1,118 @@
+/*
+cmake_minimum_required(VERSION 3.28)
+project(codiceps)
+
+set(CMAKE_CXX_STANDARD 23)
+
+include(FetchContent)
+
+FetchContent_Declare(
+    raylib
+    GIT_REPOSITORY https://github.com/raysan5/raylib.git
+    GIT_TAG 5.0
+)
+
+FetchContent_MakeAvailable(raylib)
+
+add_executable(codiceps codiceps.cpp)
+target_link_libraries(codiceps PUBLIC raylib_static)
+*/
+
+#include <ranges>
+#include <iostream>
+#include <fstream>
+#include <sstream>
+#include <vector>
+#include <cassert>
+#include "raylib.h"
+
+std::string slurp(const char* filename) {
+    std::ifstream file{filename};
+    std::stringstream data;
+    file >> data.rdbuf();
+    return data.str();
+}
+
+std::vector<bool> to_bits(std::string str) {
+    std::vector<bool> d;
+    for(char c : str) {
+        d.push_back(c & 0b10000000);
+        d.push_back(c & 0b1000000);
+        d.push_back(c & 0b100000);
+        d.push_back(c & 0b10000);
+        d.push_back(c & 0b1000);
+        d.push_back(c & 0b100);
+        d.push_back(c & 0b10);
+        d.push_back(c & 0b1);
+    }
+    return d;
+}
+
+std::string from_bits(std::vector<bool> data) {
+    std::string d;
+    for(auto composite : data | std::views::chunk(8)) {
+        char c = 0;
+        for(auto b : composite) {
+            c *= 2;
+            c += b;
+        }
+        d.push_back(c);
+    }
+    return d;
+}
+
+void encode(const char* pic, const char* data_source) {
+    auto image = LoadImage(pic);
+    auto raw_data = slurp(data_source);
+    std::vector<bool> raw_bits = to_bits(raw_data);
+    assert(raw_bits.size() % 8 == 0);
+    assert(raw_bits.size() / 8 == raw_data.size());
+    size_t idx = 0;
+    for(auto j : std::ranges::iota_view(0, image.height)) {
+        for(auto i : std::ranges::iota_view(0, image.width)) {
+            auto c = GetImageColor(image, i, j);
+            c.r ^= c.r & 1;
+            c.g ^= c.g & 1;
+            c.b ^= c.b & 1;
+            c.r += idx < raw_bits.size() ? raw_bits[idx] : 0; idx++;
+            c.g += idx < raw_bits.size() ? raw_bits[idx] : 0; idx++;
+            c.b += idx < raw_bits.size() ? raw_bits[idx] : 0; idx++;
+            ImageDrawPixel(&image, i, j, c);
+        }
+    }
+    ExportImage(image, pic);
+    UnloadImage(image);
+    if(raw_bits.size() > idx) {
+        std::cout << "\x1b[1;31mWritten bits: " << raw_bits.size() << "/" << idx << std::endl;
+    } else {
+        std::cout << "\x1b[1;32mWritten bits: " << raw_bits.size() << "/" << idx << std::endl;
+    }
+}
+
+void decode(const char* pic) {
+    auto image = LoadImage(pic);
+    std::vector<bool> raw_bits;
+    size_t idx = 0;
+    for(auto j : std::ranges::iota_view(0, image.height)) {
+        for(auto i : std::ranges::iota_view(0, image.width)) {
+            auto c = GetImageColor(image, i, j);
+            raw_bits.push_back(c.r & 1);
+            raw_bits.push_back(c.g & 1);
+            raw_bits.push_back(c.b & 1);
+        }
+    }
+    UnloadImage(image);
+    std::cout << from_bits(raw_bits).c_str() << std::endl;
+}
+
+int main(int argc, char** argv) {
+    if(argc < 1) {
+        perror("arguments missing, expected: picture then datafile for coding, picture for decoding");
+    }
+    if(argc == 3) {
+        encode(argv[1], argv[2]);
+    } else if(argc == 2) {
+        decode(argv[1]);
+    }
+    return 0;
+}