src/app/Application.cpp

   1 /*
   2  * Application.cpp
   3  *
   4  *  Created on: Apr 8, 2012
   5  *      Author: holy
   6  */
   7
   8 #include "Application.h"
   9
  10 #include "State.h"
  11
  12 #include <cassert>
  13
  14 namespace app {
  15
  16 Application::Application(sdl::InitScreen *screen, State *initialState)
  17 : screen(screen)
  18 , states()
  19 , last(SDL_GetTicks()) {
  20         assert(screen && "cannot create application without screen");
  21         assert(initialState && "cannot create application without initial state");
  22         RealPushState(initialState);
  23 }
  24
  25 Application::~Application(void) {
  26         PopAllStates();
  27 }
  28
  29
  30 State *Application::CurrentState(void) {
  31         return states.top();
  32 }
  33
  34 void Application::ChangeState(State *s) {
  35         RealPopState();
  36         RealPushState(s);
  37 }
  38
  39 void Application::PushState(State *s) {
  40         RealPushState(s);
  41 }
  42
  43 void Application::RealPushState(State *s) {
  44         states.push(s);
  45         s->EnterState(this, screen->Screen());
  46 }
  47
  48 void Application::PopState(void) {
  49         RealPopState();
  50 }
  51
  52 void Application::RealPopState(void) {
  53         if (states.empty()) return;
  54         states.top()->ExitState();
  55         delete states.top();
  56         states.pop();
  57 }
  58
  59 void Application::Quit(void) {
  60         PopAllStates();
  61 }
  62
  63 void Application::PopAllStates(void) {
  64         while (!states.empty()) {
  65                 RealPopState();
  66         }
  67 }
  68
  69
  70 void Application::Run(void) {
  71         while (CurrentState()) {
  72                 Loop();
  73         }
  74 }
  75
  76 void Application::Loop(void) {
  77         Uint32 now(SDL_GetTicks());
  78         Uint32 deltaT(now - last);
  79         if (deltaT > 34) deltaT = 34;
  80
  81         HandleEvents();
  82         UpdateWorld(deltaT);
  83         Render();
  84
  85         last = now;
  86 }
  87
  88
  89 void Application::HandleEvents(void) {
  90         if (!CurrentState()) return;
  91         SDL_Event event;
  92         while (SDL_PollEvent(&event)) {
  93                 switch (event.type) {
  94                         case SDL_QUIT:
  95                                 PopAllStates();
  96                                 break;
  97                         default:
  98                                 CurrentState()->HandleEvent(event);
  99                                 break;
 100                 }
 101         }
 102 }
 103
 104 void Application::UpdateWorld(Uint32 deltaT) {
 105         if (!CurrentState()) return;
 106         for (Uint32 i(0); i < deltaT; ++i) {
 107                 CurrentState()->UpdateWorld(0.001f);
 108         }
 109 }
 110
 111 void Application::Render(void) {
 112         if (!CurrentState()) return;
 113         CurrentState()->Render(screen->Screen());
 114         screen->Flip();
 115 }
 116
 117 }