Refactored code heavily to be able to use a state stack - main function now does the basic init, looping, and shutdown, and each state is a pointer to an object that has its own event handling, rendering, etc

game.cpp

@@ -0,0 +1,52 @@
+#include "game.h"
+#include "mathutils.h"
+#include "debug.h"
+#include <SDL.h>
+
+int Game::NODE_RADIUS = 12;
+
+Game::~Game()
+{
+    renderer.cleanup();
+}
+
+
+void Game::execute(stack<GameState*> &state_stack) throw(StateExit)
+{
+    SDL_Event event;
+    while(SDL_PollEvent(&event))
+	handle_event(&event);
+    renderer.render(data);
+}
+
+
+bool Game::init()
+{
+    return renderer.init();
+}
+
+
+void Game::on_exit()
+{
+    throw StateExit();
+}
+
+
+void Game::on_lbutton_down(int x, int y)
+{
+    data.do_vertex(x, y, NODE_RADIUS);
+}
+
+
+void Game::on_rbutton_down(int mX, int mY)
+{
+    data.clear_current_vertex();
+}
+
+
+void Game::on_key_down(SDLKey sym, SDLMod mod, Uint16 unicode)
+{
+    if (sym == SDLK_q && mod & KMOD_CTRL) throw StateExit();
+    if (sym == SDLK_a) data.set_mode(MODE_ATTACK);
+    if (sym == SDLK_m) data.set_mode(MODE_MOVE);
+}