Command line parsing!

* Added MIT license.
    * Added cxxopts and gave it some basic things to parse.
    * Removed redundant "lib" from `libplip`.

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.16)
 set(product_name "Plip")
 set(gui_name "plip-sdl")
-set(lib_name "libplip")
+set(lib_name "plip")
 
 project(${gui_name})
 set(CMAKE_CXX_STANDARD 14)
@@ -52,7 +52,7 @@ target_include_directories(${gui_name}
 )
 
 target_link_libraries(${gui_name}
-        libplip
+        plip
         ${SDL2_INCLUDE_DIRS}
 )
 

LICENSE

@@ -0,0 +1,19 @@
+Copyright (c) 2020 Ian Burgmyer
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

plip-sdl/main.cpp

@@ -1,8 +1,90 @@
+/* main.cpp
+ *
+ * The big, magical entry point.
+ */
+
 #include <iostream>
 
-#include "Hello.h"
+#include "cxxopts.hpp"
+
+#include "version.h"
+
+cxxopts::ParseResult parseCmdLine(int argc, char **argv) {
+    try {
+        cxxopts::Options options(argv[0]);
+
+        options.positional_help("CORE FILENAME")
+                .show_positional_help();
+
+        options.add_options("Hidden")
+                ("c,core", "the core that should be used", cxxopts::value<std::string>())
+                ("f,filename", "the path to the ROM", cxxopts::value<std::string>())
+                ("positional", "", cxxopts::value<std::vector<std::string>>())
+        ;
+
+        options.add_options()
+                ("h,help", "shows this help screen and exits")
+                ("l,list-cores", "shows a list of all supported cores and exits")
+                ("V,version", "displays the version information and exits");
+
+        options.add_options("Video")
+                ("s,scale", "sets the default window scaling", cxxopts::value<int>()->default_value("1"));
+
+        options.parse_positional({"core", "filename", "positional"});
+
+        auto result = options.parse(argc, argv);
+
+        if(result.count("help")) {
+            // Icky hack. As far as I can tell there's no other way of hiding
+            // unwanted/positional arguments using cxxopts.
+            std::cout << options.help({
+                "",
+                "Video"
+            }) << std::endl;
+            exit(0);
+        }
+
+        return result;
+    } catch(cxxopts::argument_incorrect_type &ex) {
+        std::cerr << "Invalid argument type (" << ex.what() << ")" << std::endl;
+        exit(1);
+    } catch(cxxopts::missing_argument_exception &ex) {
+        std::cerr << ex.what() << std::endl;
+        exit(1);
+    } catch(cxxopts::OptionException &ex) {
+        std::cerr << "Error parsing arguments (" << ex.what() << ")" << std::endl;
+        exit(1);
+    }
+}
+
+int main(int argc, char **argv) {
+    #ifndef GIT_FOUND
+        const char *windowTitle = PRODUCT_NAME;
+    #else
+        #ifndef GIT_TAG
+            const char *windowTitle = PRODUCT_NAME " (" GIT_BRANCH "@" GIT_REVISION ")";
+        #else
+            const char *windowTitle = PRODUCT_NAME " " GIT_TAG;
+        #endif // GIT_TAG
+    #endif // GIT_FOUND
+
+    auto opts = parseCmdLine(argc, argv);
+
+    if(!opts.count("core") || !opts.count("filename")) {
+        std::cerr << "The name of the core and the filename must be specified!\n\n"
+                  << "Please see the usage information (" << argv[0] << " -h) for more information." << std::endl;
+        return 1;
+    }
+
+    if(opts.count("version")) {
+        std::cout << windowTitle << std::endl;
+        return 0;
+    }
+
+    std::cout << "scale: " << opts["scale"].as<int>()
+              << "\ncore: " << opts["core"].as<std::string>()
+              << "\nfile: " << opts["filename"].as<std::string>()
+              << std::endl;
 
-int main() {
-    std::cout << "Hello world! The answer is " << Hello::Calculate() << "." << std::endl;
     return 0;
 }