cli arg for base program

src/graphics.cpp

@@ -1,4 +1,6 @@
+#include <boost/algorithm/string/case_conv.hpp>
 #include <boost/log/trivial.hpp>
+#include <boost/algorithm/string.hpp>
 #include <exception>
 #include <glad/glad.c>
 // glad must be loaded before GLFW
@@ -9,6 +11,22 @@
 
 using namespace std;
 
+ShaderProgram::Base ShaderProgram::baseFromName(string name) {
+  string lname = name;
+  boost::algorithm::to_lower(lname); // yes, cpp needs a library to do this.
+  // can't do a switch over strings in cpp.
+  if (lname == "empty") {
+    return Empty;
+  }
+  if (lname == "triangle") {
+    return Triangle;
+  }
+  else {
+    BOOST_LOG_TRIVIAL(fatal) << "unknown base program \"" << name << "\"";
+    exit(EXIT_USAGE);
+  }
+}
+
 /* class ShaderProgram Implementations */
 string ShaderProgram::baseName() {
   /*
@@ -64,6 +82,8 @@ int ShaderProgram::run() {
   return 0;
 }
 
+/* functions that run out graphics stuff */
+
 void framebuffer_size_callback(GLFWwindow *window, int width, int height) {
   glViewport(0, 0, width, height);
 }

src/graphics.hpp

@@ -9,6 +9,7 @@ class ShaderProgram {
 public:
   enum Base { Empty, Triangle };
   std::string baseName();
+  static Base baseFromName(std::string name);
   ShaderProgram(Base base, char** vertexSource, char** fragSource);
   int run();
 

src/main.cpp

@@ -15,14 +15,15 @@ int main(int argc, char **argv) {
   po::options_description desc("Available options");
   desc.add_options()("help,h", "show help")("verbose,v", "more verbose output")(
       "vert", po::value<string>()->required(), "vertex shader file")(
-      "frag", po::value<string>()->required(), "fragment shader file");
+      "frag", po::value<string>()->required(), "fragment shader file")(
+      "base,b", po::value<string>()->required(), "base program");
 
   /* unused for now */
   po::positional_options_description pdesc;
   // NOTE: if you want to add a positional argument,
   // you need to create and option for it as it seems.
-  pdesc.add("vert", 1);
-  pdesc.add("frag", 1);
+  /* pdesc.add("vert", 1); */
+  /* pdesc.add("frag", 1); */
 
   po::variables_map vm;
   try {
@@ -59,6 +60,9 @@ int main(int argc, char **argv) {
     return EXIT_GL;
   }
 
+  /* find the requested */
+  ShaderProgram::Base base = ShaderProgram::baseFromName(vm["base"].as<string>());
+
   /* setup the shader program */
   BOOST_LOG_TRIVIAL(trace) << "Reading shader files";
   auto fvert = fopen(vm["vert"].as<string>().c_str(), "r");
@@ -79,9 +83,11 @@ int main(int argc, char **argv) {
   char *frag = (char *)malloc(sfrag + 1);
   fread(vert, sizeof(char), svert, fvert);
   fread(frag, sizeof(char), sfrag, ffrag);
-  BOOST_LOG_TRIVIAL(debug) << "vert file:\n```glsl\n" << vert << "```\n"
+  BOOST_LOG_TRIVIAL(debug) << "vert file:\n```glsl\n"
+                           << vert << "```\n"
                            << svert << "B";
-  BOOST_LOG_TRIVIAL(debug) << "frag file:\n```glsl\n" << frag << "```\n"
+  BOOST_LOG_TRIVIAL(debug) << "frag file:\n```glsl\n"
+                           << frag << "```\n"
                            << sfrag << "B";
   fclose(fvert);
   fclose(ffrag);
@@ -89,7 +95,7 @@ int main(int argc, char **argv) {
   BOOST_LOG_TRIVIAL(trace) << "Creating ShaderProgram";
 
   // TODO: determinde ShaderProgram::Base with a CLI arg
-  ShaderProgram shaderProgram(ShaderProgram::Base::Empty, &vert, &frag);
+  ShaderProgram shaderProgram(base, &vert, &frag);
 
   /* Run our main program */
   BOOST_LOG_TRIVIAL(trace) << "Starting mainWindow";
@@ -106,12 +112,18 @@ void help(char *prog, po::options_description desc) {
        << endl
        << endl
        << "return values:" << endl
-       << "0\tSuccess"
-       << "1\tGeneric Failure"
-       << "2\tBad arguments"
+       << "0\tSuccess" << endl
+       << "1\tGeneric Failure" << endl
+       << "2\tBad arguments" << endl
        << "3\tI/O Error" << endl
        << "3\tOpenGL Error" << endl
        << endl
+       << endl
+       << "base programs:" << endl
+       << "Empty\t\t-\tEmpty window with colored background" << endl
+       << "Triangle\t-\tA static Triangle" << endl
+       << endl
+       << endl
        << desc << endl;
   // NOTE: constants for the error codes are defined in main.hpp
 }