al_wait_for_event won't catch the timer.

al_wait_for_event won't catch the timer.

Darren Hoehna

Member #15,297

September 2013

Hey all,

I don't know if the problem is allegro or my I.D.E. But al_wait_for_event() won't catch the timer event unless I am stepping through my code; however, if I let my code run without any breakpoints, then my code will wait at al_wait_for_event() unless I press a button on the keyboard.

I tried looking online for the answer by I can't find any.

Any idea of where I could look?

Thanks,

Activfire.

P.S. Below is my code.

#SelectExpand
   1#include <allegro5/allegro.h>
   2#include <allegro5/allegro_image.h>
   3#include <allegro5/allegro_native_dialog.h>
   4#include <allegro5/allegro_primitives.h>
   5#include <stdio.h>
   6#include <math.h>
   7#include <iostream>
   8#include "Ship.h"
   9
  10
  11const int SCREEN_WIDTH = 640;
  12const int SCREEN_HEIGTH = 640;
  13
  14const int SHIP_WIDTH = 32;
  15const int SHIP_HEIGTH = 32;
  16
  17const double CHANGE_IN_ANGLE = 0.034906585;
  18const double SPEED_OF_SHIP = 4.0;
  19
  20const double FRAMES_PER_SECOND = 60.0;
  21
  22const enum KEYS {UP, DOWN, LEFT, RIGHT};
  23
  24//I keep track of the center and not a second point since the second point is never used.
  25//To get the secodn point the program uses First_X_Position + SHIP_WIDTH
  26
  27//The Center_X_Position and Center_Y_Position is used in the redraw step near the end of the program.
  28//The Center points are to make the square move around the center of the square.
  29//struct ShipStuff
  30//{
  31//  float First_X_Position;
  32//  float First_Y_Position;
  33//  float Center_X_Position;
  34//  float Center_Y_Position;
  35//  float Angle;
  36//};
  37
  38/* Function prototypes */
  39static Ship MakeShip(float Center_X_Position, float Center_Y_Position, float First_X_Position, float First_Y_Position, float Angle);
  40static ALLEGRO_DISPLAY* MakeDisplay(const int ScreenWidth, const int ScreenHeigth);
  41static ALLEGRO_TIMER* MakeTimer (const int FramerPerSecond);
  42static ALLEGRO_EVENT_QUEUE* MakeEventQueue();
  43static bool MakeAllegro();
  44static bool InstallPrimitives();
  45static bool InstallKeyboard();
  46
  47int main(int argc, char **argv)
  48{
  49  MakeAllegro();
  50  InstallKeyboard();
  51  InstallPrimitives();
  52  ALLEGRO_DISPLAY *Display = MakeDisplay(SCREEN_WIDTH, SCREEN_HEIGTH);
  53  ALLEGRO_TIMER *Timer = MakeTimer(FRAMES_PER_SECOND);
  54  ALLEGRO_EVENT_QUEUE *EventQueue = MakeEventQueue();
  55
  56
  57
  58  //UP, DOWN, LEFT, RIGHT
  59  bool KeyPresses[] = {false, false, false, false};
  60  bool Redraw = true;
  61
  62  al_register_event_source(EventQueue, al_get_display_event_source(Display));
  63  al_register_event_source(EventQueue, al_get_timer_event_source(Timer));
  64  al_register_event_source(EventQueue, al_get_keyboard_event_source());
  65
  66
  67  float First_X_Position = SCREEN_WIDTH / 2.0;
  68  float First_Y_Position = SCREEN_HEIGTH / 2.0;
  69  float Center_X_Position = First_X_Position + (SHIP_WIDTH / 2.0);
  70  float Center_Y_Position = First_Y_Position + (SHIP_HEIGTH / 2.0);
  71  float Angle = -ALLEGRO_PI/2;
  72
  73  Ship ThisShip(Center_X_Position, Center_Y_Position, First_X_Position, First_Y_Position, Angle);
  74  al_draw_filled_rectangle(ThisShip.GetFirst_X_Position(), ThisShip.GetFirst_Y_Position(), ThisShip.GetFirst_X_Position() + SHIP_WIDTH, 
  75    ThisShip.GetFirst_Y_Position() + SHIP_HEIGTH, al_map_rgb(255, 124, 68));
  76  al_flip_display();
  77  al_start_timer(Timer);
  78  float AngleInRadians = 0.0f;
  79  bool DoExit = false;
  80  while (!DoExit)
  81  {
  82    ALLEGRO_EVENT Event;
  83    al_wait_for_event(EventQueue, &Event);
  84    std::cout << "In while loop" << std::endl;
  85
  86    if(Event.type == ALLEGRO_EVENT_TIMER)
  87    {
  88      std::cout << "In if event type = ALLEGRO_EVENT_TIMER" << std::endl;
  89      if(KeyPresses[UP])
  90      {
  91        ThisShip.SetFirst_X_Position(ThisShip.GetFirst_X_Position() + cos(ThisShip.GetAngle() * SPEED_OF_SHIP));
  92        ThisShip.SetCenter_X_Position(ThisShip.GetCenter_X_Position() + cos(ThisShip.GetAngle() * SPEED_OF_SHIP));
  93
  94        ThisShip.SetFirst_Y_Position(ThisShip.GetFirst_Y_Position() + sin(ThisShip.GetAngle() * SPEED_OF_SHIP));
  95        ThisShip.SetCenter_Y_Position(ThisShip.GetCenter_Y_Position() + sin(ThisShip.GetAngle() * SPEED_OF_SHIP));
  96      }
  97      if (KeyPresses[DOWN])
  98      {
  99        ThisShip.SetFirst_X_Position(ThisShip.GetFirst_X_Position() - cos(ThisShip.GetAngle() * SPEED_OF_SHIP));
 100        ThisShip.SetCenter_X_Position(ThisShip.GetCenter_X_Position() - cos(ThisShip.GetAngle() * SPEED_OF_SHIP));
 101
 102        ThisShip.SetFirst_Y_Position(ThisShip.GetFirst_Y_Position() - sin(ThisShip.GetAngle() * SPEED_OF_SHIP));
 103        ThisShip.SetCenter_Y_Position(ThisShip.GetCenter_Y_Position() - sin(ThisShip.GetAngle() * SPEED_OF_SHIP));
 104
 105      }
 106      if(KeyPresses[LEFT])
 107      {
 108        ThisShip.SetAngle(ThisShip.GetAngle() - CHANGE_IN_ANGLE);
 109
 110      }
 111      if(KeyPresses[RIGHT])
 112      {
 113        ThisShip.SetAngle(ThisShip.GetAngle() + CHANGE_IN_ANGLE);
 114      }
 115      Redraw = true;
 116    }
 117    else if (Event.type == ALLEGRO_EVENT_DISPLAY_CLOSE)
 118    {
 119      break;
 120    }
 121    else if (Event.type == ALLEGRO_EVENT_KEY_DOWN)
 122    {
 123      std::cout << "In if ALLEGRO_EVENT_KEY_DOWN" << std::endl;
 124      switch (Event.keyboard.keycode)
 125      {
 126      case ALLEGRO_KEY_UP:
 127        KeyPresses[UP] = true;
 128        break;
 129      case ALLEGRO_KEY_DOWN:
 130        KeyPresses[DOWN] = true;
 131        break;
 132      case ALLEGRO_KEY_LEFT:
 133        KeyPresses[LEFT] = true;
 134        break;
 135      case ALLEGRO_KEY_RIGHT:
 136        KeyPresses[RIGHT] = true;
 137        break;
 138      }
 139    }
 140    else if (Event.type == ALLEGRO_EVENT_KEY_UP)
 141    {
 142      std::cout << "In If ALLEGRO_EVENT_KEY_UP" << std::endl;
 143      switch(Event.keyboard.keycode)
 144      {
 145      case ALLEGRO_KEY_UP:
 146        KeyPresses[UP] = false;
 147        break;
 148      case ALLEGRO_KEY_DOWN:
 149        KeyPresses[DOWN] = false;
 150        break;
 151      case ALLEGRO_KEY_LEFT:
 152        KeyPresses[LEFT] = false;
 153        break;
 154      case ALLEGRO_KEY_RIGHT:
 155        KeyPresses[RIGHT] = false;
 156        break;
 157      case ALLEGRO_KEY_ESCAPE:
 158        DoExit = true;
 159        break;
 160      }
 161    }
 162
 163    if(Redraw && al_is_event_queue_empty(EventQueue))
 164    {
 165      std::cout << "In If Redraw." << std::endl;
 166      Redraw = false;
 167      al_clear_to_color(al_map_rgb(0, 0, 0));
 168      ALLEGRO_TRANSFORM ShipTransformation, Old;
 169      al_identity_transform(&ShipTransformation);
 170      //al_translate_transform(&ShipTransformation, -Ship.Center_X_Position, -Ship.Center_Y_Position);
 171      al_translate_transform(&ShipTransformation, -ThisShip.GetCenter_X_Position(), -ThisShip.GetCenter_Y_Position());
 172      //al_rotate_transform(&ShipTransformation, Ship.Angle);
 173      al_rotate_transform(&ShipTransformation, ThisShip.GetAngle());
 174      //al_translate_transform(&ShipTransformation, (Ship.Center_X_Position), (Ship.Center_Y_Position));
 175      al_translate_transform(&ShipTransformation, ThisShip.GetCenter_X_Position(), ThisShip.GetCenter_Y_Position());
 176      al_use_transform(&ShipTransformation);
 177      //al_draw_filled_rectangle(Ship.First_X_Position, Ship.First_Y_Position, Ship.First_X_Position + SHIP_WIDTH, Ship.First_Y_Position + SHIP_HEIGTH, al_map_rgb(255,127,0));
 178      al_draw_filled_rectangle(ThisShip.GetFirst_X_Position(), ThisShip.GetFirst_Y_Position(), ThisShip.GetFirst_X_Position() - SHIP_WIDTH,
 179        ThisShip.GetFirst_Y_Position() + SHIP_HEIGTH, al_map_rgb(255, 127, 0));
 180      al_flip_display();
 181      al_use_transform(&Old);
 182    }
 183  }
 184  al_destroy_timer(Timer);
 185  al_destroy_event_queue(EventQueue);
 186  al_destroy_display(Display);
 187
 188  return 0;
 189}
 190
 191static ALLEGRO_DISPLAY* MakeDisplay(const int SCREEN_WIDTH, const int SCREEN_HEIGTH)
 192{
 193  ALLEGRO_DISPLAY *Display  = al_create_display(SCREEN_WIDTH, SCREEN_HEIGTH);
 194  if(!Display)
 195  {
 196    std::cout << "Sorry, but allegro can't make the display." << std::endl;
 197    std::cout << "Press any key to exit...";
 198    return NULL;
 199  }
 200  return Display;
 201}
 202
 203static ALLEGRO_TIMER* MakeTimer (const int FramerPerSecond)
 204{
 205  ALLEGRO_TIMER* Timer = al_create_timer(FramerPerSecond);
 206  if(!Timer)
 207  {
 208    std::cout << "Sorry, but allegro can't make the timer." << std::endl;
 209    std::cout << "Press any key to exit...";
 210    std::cin.get();
 211    return NULL;
 212  }
 213  return Timer;
 214}
 215
 216static ALLEGRO_EVENT_QUEUE* MakeEventQueue()
 217{
 218  ALLEGRO_EVENT_QUEUE* EventQueue = al_create_event_queue();
 219  if(!EventQueue)
 220  {
 221    std::cout << "Sorry, but allegro can't make the event queue." << std::endl;
 222    std::cout << "Press any key to exit...";
 223    std::cin.get();
 224    return NULL;
 225  }
 226  return EventQueue;
 227}
 228
 229
 230static bool MakeAllegro()
 231{
 232  if(!al_init())
 233  {
 234    std::cout << "Sorry, but Allegro did not install start correctly." << std::endl;
 235    std::cout << "Press any key to exit...";
 236    std::cin.get();
 237    return false;
 238  }
 239  return true;
 240}
 241
 242static bool InstallPrimitives()
 243{
 244  if(!al_init_primitives_addon())
 245  {
 246    std::cout << "Sorry but allegro could not install the primitives." << std::endl;
 247    std::cout << "Press any key to exit...";
 248    std::cin.get();
 249    return false;
 250  }
 251  return true;
 252}
 253
 254static bool InstallKeyboard()
 255{
 256  if(!al_install_keyboard())
 257  {
 258    std::cout << "Sorry, allegro could not install the keyboard." << std::endl;
 259    std::cout << "Press any key to exit...";
 260    std::cin.get();
 261    return false;
 262  }
 263  return true;
 264}