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() {
  26         PopAllStates();
  27 }
  28
  29
  30 State *Application::CurrentState() {
  31         return states.top();
  32 }
  33
  34 void Application::UpdateState() {
  35         while (!stateChanges.empty()) {
  36                 switch (stateChanges.front().type) {
  37                         case StateCommand::PUSH:
  38                                 RealPushState(stateChanges.front().state);
  39                                 break;
  40                         case StateCommand::POP:
  41                                 RealPopState();
  42                                 break;
  43                         case StateCommand::CHANGE:
  44                                 RealChangeState(stateChanges.front().state);
  45                                 break;
  46                 }
  47                 stateChanges.pop();
  48         }
  49 }
  50
  51 void Application::ChangeState(State *s) {
  52         StateCommand cmd;
  53         cmd.type = StateCommand::CHANGE;
  54         cmd.state = s;
  55         stateChanges.push(cmd);
  56 }
  57
  58 void Application::PushState(State *s) {
  59         StateCommand cmd;
  60         cmd.type = StateCommand::PUSH;
  61         cmd.state = s;
  62         stateChanges.push(cmd);
  63 }
  64
  65 void Application::PopState() {
  66         StateCommand cmd;
  67         cmd.type = StateCommand::POP;
  68         cmd.state = 0;
  69         stateChanges.push(cmd);
  70 }
  71
  72 void Application::RealChangeState(State *s) {
  73         if (!states.empty()) {
  74                 states.top()->PauseState(*this, screen->Screen());
  75                 states.top()->ExitState(*this, screen->Screen());
  76                 states.pop();
  77         }
  78         states.push(s);
  79         s->EnterState(*this, screen->Screen());
  80         s->ResumeState(*this, screen->Screen());
  81 }
  82
  83 void Application::RealPushState(State *s) {
  84         if (!states.empty()) {
  85                 states.top()->PauseState(*this, screen->Screen());
  86         }
  87         states.push(s);
  88         s->EnterState(*this, screen->Screen());
  89         s->ResumeState(*this, screen->Screen());
  90 }
  91
  92 void Application::RealPopState() {
  93         if (states.empty()) return;
  94         states.top()->PauseState(*this, screen->Screen());
  95         states.top()->ExitState(*this, screen->Screen());
  96         delete states.top();
  97         states.pop();
  98         if (!states.empty()) {
  99                 states.top()->ResumeState(*this, screen->Screen());
 100         }
 101 }
 102
 103 void Application::Quit() {
 104         PopAllStates();
 105 }
 106
 107 void Application::PopAllStates() {
 108         while (!states.empty()) {
 109                 RealPopState();
 110         }
 111 }
 112
 113
 114 void Application::Run() {
 115         while (CurrentState()) {
 116                 Loop();
 117         }
 118 }
 119
 120 void Application::Loop() {
 121         Uint32 now(SDL_GetTicks());
 122         Uint32 deltaT(now - last);
 123         if (deltaT > 34) deltaT = 34;
 124
 125         HandleEvents();
 126         if (!StateChangePending()) {
 127                 UpdateWorld(deltaT);
 128                 Render();
 129         }
 130
 131         last = now;
 132         UpdateState();
 133 }
 134
 135
 136 void Application::HandleEvents() {
 137         if (!CurrentState()) return;
 138         input.ResetInteractiveState();
 139         SDL_Event event;
 140         while (SDL_PollEvent(&event)) {
 141                 switch (event.type) {
 142                         case SDL_QUIT:
 143                                 PopAllStates();
 144                                 break;
 145                         case SDL_VIDEORESIZE:
 146                                 screen->Resize(event.resize.w, event.resize.h);
 147                                 CurrentState()->Resize(event.resize.w, event.resize.h);
 148                                 break;
 149                         case SDL_KEYDOWN:
 150                         case SDL_KEYUP:
 151                                 input.HandleKeyboardEvent(event.key);
 152                                 break;
 153                         default:
 154                                 // skip event
 155                                 break;
 156                 }
 157         }
 158         CurrentState()->HandleInput(input);
 159 }
 160
 161 void Application::UpdateWorld(Uint32 deltaT) {
 162         if (!CurrentState()) return;
 163         for (Uint32 i(0); i < deltaT; ++i) {
 164                 CurrentState()->UpdateWorld(0.001f);
 165         }
 166 }
 167
 168 void Application::Render(void) {
 169         if (!CurrentState()) return;
 170         CurrentState()->Render(screen->Screen());
 171         screen->Flip();
 172 }
 173
 174 }