My Game runs Slow on PIII Machine

My Game runs Slow on PIII Machine

armond

Member #8,282

January 2007

I got a 192 MB RAM and 933 Mhz PIII Machine. I was wondering why would my game run so slow on PIII Machines or below(although still acceptable)... I suspect this line...

install_int(GameTimer::incrementGameTicker, 10);

My game deoesn't seem to run at constant speed... Here is my ticker function...

void GameTimer::incrementGameTicker()
{
game_ticker++;
}
END_OF_FUNCTION(incrementGameTicker);

Thanks!

Jeff Bernard

Member #6,698

December 2005

It runs so slow because you are telling the timer to be really slow. Instead you should try install_int_ex() as it gives better options for setting the speed of the timer (I like BPS_TO_TIMER). Or you can try to just fiddling with that 10, lowering it, until you get a speed that you like.

--
I thought I was wrong once, but I was mistaken.

Audric

Member #907

January 2001

This 100Hz timer (10ms) should run with no problem at all.
If something runs at varying speed, it's in your main program.
If you comment out the heaviest video operations (for example: background drawing), does it change the apparent speed?

armond

Member #8,282

January 2007

Hi! Sorry for the late response. I actually tried turning off everything leaving the ship to be the only thing visible. The scrolling background does take some time to process but it doesn't seem that heavy at all. I will try install_int_ex() and give you guys some feedback asap. Thanks!

weapon_S

Member #7,859

October 2006

Is the PIII the computer you compiled the program on?

Yes well, legibility and correct punctuation might not be "street"... but that's how I roll, motherfucker. -Edward.
Yes it sounds more authoritative to invoke some cute phrase every few sentences, but it doesn't actually make an argument any more impressive. Matthew Leverton

armond

Member #8,282

January 2007

weapon_S

Nope, it's not. But I was told that it wouldn't have any effect even if I compiled on that machine. I just run the binary there...

Tobias Dammers

Member #2,604

August 2002

Care to share some more code? As in, a 20-100 line example that compiles as-is and reproduces the problem?

---
Me make music: Triofobie
---
"We need Tobias and his awesome trombone, too." - Johan Halmén

Richard Phipps

Member #1,632

November 2001

Give us more details. If you are trying to scroll a 32bit screen on less than a 933Mhz Machine then I'm not surprised if you start getting slowdown.

Chaos Groove Development Blog
Free Logging System Code & Blog

armond

Member #8,282

January 2007

Sure thing. Here is the code for my PlayState class which functions as the main entry of the game. Perhaps you could point out some problems here...

#SelectExpand
   1#include "globals.h"
   2
   3PlayState::PlayState()
   4{
  currentLevel = 1;
   6
  GameManager::game_score = 0;
   8
  //create buffer image
  GameManager::buffer = create_bitmap(SCREEN_W, SCREEN_H);
  
  //load sprites
  BitmapManager::addBitmap(SHIP_SPRITE, "graphics/fs.bmp");
  BitmapManager::addBitmap(VULCAN_SPRITE, "graphics/vulcan.bmp");
  BitmapManager::addBitmap(ASTEROID_SPRITE_FLYING, "graphics/asteroid_flying.bmp");    
  BitmapManager::addBitmap(ASTEROID_SPRITE_DYING, "graphics/asteroid_destroyed.bmp");
  BitmapManager::addBitmap(BULLET_HEAD_SPRITE_FLYING, "graphics/bullet_head_flying.bmp");
  BitmapManager::addBitmap(SPRITE_EXPLOSION, "graphics/explosion.bmp");
  
  //load SFX
  SoundManager::addSample(VULCAN_GUN_FIRE, "sfx/vulcan.wav");
  
  //ship = new Ship(BitmapManager::SHIP_SPRITE, 50, 50, 50, 32, 1);
  //Ship(int x, int y, int w, int h, int speed, int recoveryRate, int recoveryTime, Status stat, int lfe);
  ship = new Ship(50, 50, 50, 45, 3, 5, 1000, ALIVE, MAX_PLAYER_LIFE);
  
  //add a weapon for the ship
  ship->addWeapon(VULCAN_GUN, WeaponFactory::getWeapon(VULCAN_GUN) );
  ship->setCurrentWeapon(VULCAN_GUN);
  ship->move(0, (SCREEN_H / 2) );
  31}    
  32
  33PlayState::~PlayState()
  34{
  BitmapManager::removeAll();
  
  destroy_bitmap(GameManager::buffer);
  
  delete ship;
  40}
  41
  42PlayState* PlayState::getInstance()
  43{
  if (instance == NULL)
  {
      instance = new PlayState();
  }
  
  return instance;    
  50}    
  51
  52void PlayState::init()
  53{
  54}
  55
  56void PlayState::pause()
  57{
  58}
  59
  60void PlayState::run()
  61{
  GameStateManager::pushState( GameOverState::getInstance() );     
      GameStateManager::getCurrentState()->run();//--execute run method
      GameStateManager::popState(); //--pop the element on top
                
  loadLevel(currentLevel);
  
  //begin main game loop
  while ( !key[KEY_ESC] )
  {   
      
      while (GameTimer::game_ticker > 0)
      {
          //move left
          if ( key[KEY_A] )
          {
              ship->move( ship->x - ship->getSpeed(), ship->y );
              if ( ship->x <= 0 )
              {
                  ship->move( ship->x + ship->getSpeed(), ship->y ); 
              }
          }    
          //move down
          if ( key[KEY_S] )
          {
              ship->move( ship->x, ship->y + ship->getSpeed() );
          
              if ( (ship->y + ship->height) >= SCREEN_H )
              {
                  ship->move( ship->x, ship->y - ship->getSpeed() );
              }
          }    
          //move right
          if ( key[KEY_D] )
          {
              ship->move( ship->x + ship->getSpeed(), ship->y );
              
              if ( (ship->x + ship->width) >= SCREEN_W )
              {
                   ship->move( ship->x - ship->getSpeed(), ship->y );
              }
          }    
          //move up
          if ( key[KEY_W] )
          {
              ship->move( ship->x, ship->y - ship->getSpeed() );
              
              if ( ship->y <= 20 )
              {
                  ship->move( ship->x, ship->y + ship->getSpeed() );     
              }
          }
          //fire weapon
          if ( key[KEY_K] )
          {
              ship->fireWeapon();
          }
          //change weapon
          if ( key[KEY_TAB] )
          {
               //ship->fireWeapon();
          }
          //fire special
          if ( key[KEY_L] )
          {
          }
          
          //exit to menu
          if ( key[KEY_ESC] )
          {
              break;
          }    
          
          //scroll the background
          bg->update();
          
          //animate the ship
          ship->update();
          
          bg->draw();    
          
          //move all projectiles
          for (std::vector<Projectile*>::iterator it = ProjectileFactory::projectilePool.begin(); it != ProjectileFactory::projectilePool.end(); ++it)
          {                    
              if ( (*it)->isVisible() == true )
              {
                  Projectile* p = *it;
                  p->update(); //(*it)->update();
                  p->draw(); //(*it)->draw();
                  
                  //check for collision on bullet and enemies
                  for(std::vector<Enemy*>::iterator eit = EnemyFactory::enemyPool.begin(); eit != EnemyFactory::enemyPool.end(); ++eit)
                  {                              
                      Enemy* e = *eit; 
                      
                      //projectile hits an enemy
                      if ( p->collides(e) && p->isActive() && e->isAlive() )
                      {
                           e->takeDamage(1); //TODO: change 1 to weapon power
                           p->makeInactive();
 161
                           //player killed the enemy                             
                           if ( !( e->isAlive() ) )
                           {
                               GameManager::game_score += 10;                                  
                           }
                           
                           //exit the inner loop
                           break;
                      }
                  }                    
                  
                  if ( !( p->isActive() ) )
                  {
                      Projectile* p = *it;
                      it = ProjectileFactory::projectilePool.erase(it);
                      // we must decrement, because it will be incremented when the loop starts over again
                      --it;
                      delete p;                         
                  }
                  
              }
              else
              { 
                  Projectile* p = *it;
                  it = ProjectileFactory::projectilePool.erase(it);
                  // we must decrement, because it will be incremented when the loop starts over again
                  --it;
                  delete p;
              }  
          }    
          
          //move all enemies
          for(std::vector<Enemy*>::iterator it = EnemyFactory::enemyPool.begin(); it != EnemyFactory::enemyPool.end(); ++it)
          {
              Enemy* e = *it;
              
              if ( e->isAlive() || e->isDying() )
              {
                  e->update();
                  e->draw();
                  
                  if ( e->isAlive() && ship->collides(e) )
                  {
                      ship->takeDamage(10); //TODO: change to enemy attack power
                      e->takeDamage(1);
                  }                     
              }
          }            
          
          //recharge weapon
          ship->getCurrentWeapon()->recharge();
          
          //control game speed
          GameTimer::game_ticker--;                                   
          
          ship->draw();
      
          textout_ex(GameManager::buffer, font, "Life: ", 10, 10, makecol(0, 0, 255), -1);
          //drawLifeBar(int x, int y, int length, height, BITMAP* bitmap); 
          drawLifeBar(50, 0, ship->getLife() , 20, GameManager::buffer);
          
          textprintf_centre_ex(GameManager::buffer, font, SCREEN_W/2, 10, makecol(255, 255, 255), makecol(0, 0, 0), "Current Weapon: %s", ship->getCurrentWeapon()->getWeaponName() );                      
          textprintf_centre_ex(GameManager::buffer, font, (SCREEN_W - (SCREEN_W/8) ), 10, makecol(255, 255, 255), makecol(0, 0, 0), "Score: %d", GameManager::game_score);                      
          
          textprintf_centre_ex(GameManager::buffer, font, SCREEN_W/2, 176, makecol(255, 255, 255), makecol(0, 0, 0), "num=%d", GameTimer::game_ticker);
      
          //blit buffer
          GameManager::blitBuffer();                      
      }    
                        
  }
  
  unloadLevel(currentLevel);    
 235}
 236
 237void PlayState::update()
 238{
 239}
 240
 241void PlayState::clean()
 242{
 243}                        
 244
 245void PlayState::loadLevel(int level)
 246{     
  PACKFILE* levelMap;
  
  switch(level)
  {
      case 1:             
          SoundManager::addSample(METEOR_DESTROYED, "sfx/meteordestroyed.wav"); 
           
          levelMap = pack_fopen("levels/level_01.lvl", "r");            
 255
          createLevel(levelMap);
 257
          bg = new GameBackground(BitmapManager::addBitmap(SPACE_BACKGROUND, "graphics/bg.bmp"), HORIZONTAL_LEFT, 3, SCREEN_W, SCREEN_H);
 259
          break;
      default:
          break;        
  }
  
  if (levelMap)
  {
      pack_fclose(levelMap);
  }                
 269}
 270
 271void PlayState::createLevel(PACKFILE* packFile)
 272{
  std::string line;
  char buf[255];
  
  int currX = 0;
  int currY = 0;
  int xIncrement = (SCREEN_W / 20);
  int yIncrement = (SCREEN_H / 20);     
   
  if (!packFile)
  {
      allegro_message("COULD NOT CREATE LEVEL!: %s", allegro_error);
  }    
          
  while ( pack_feof(packFile) == 0 )
  {
      //read a line from the file (levelMap)
      line = pack_fgets(buf, sizeof(buf), packFile);
              
      //loop through each character in the line
      for (int i = 0; i < line.length(); i++)
      {                           
          //only an empty space
          if ( line.at(i) == ' ')
          {
              currX += xIncrement;    
          }
          else //create an enemy object
          {
              Enemy* e = EnemyFactory::getEnemy( line.at(i) );
              //set initial position of the enemy
              e->move(currX, currY);
              EnemyFactory::enemyPool.push_back(e);
                      
              e = NULL;
                      
              currX += xIncrement;
          }        
      }
      
      currX = 0;
      currY += yIncrement;    
  }              
 315}
 316
 317void PlayState::unloadLevel(int level)
 318{
  switch(level)
  {
      case 1:
          std::vector<Enemy*>().swap(EnemyFactory::enemyPool);
          delete bg;
          break;
      default:
          break;
  }    
 328}
 329
 330void PlayState::drawLifeBar(int x, int y, int length, int height, BITMAP* bitmap)
 331{
  //rectfill(BITMAP *bmp, int x1, int y1, int x2, int y2, int color);
  if (length <= 0)
  {
      length = 0;
  }
  
  rectfill(bitmap, x, y, (x + length), height, 255);
 339}    
 340
 341PlayState* PlayState::instance;
 342int PlayState::currentLevel;

If you're interested on how the PlayState is loaded, here's my main cpp file.

#SelectExpand
  1#include "globals.h"
  2
  3//declare all functions used
  4int initAllegro();
  5void deinitAllegro();
  6
  7int main(int* argc, char* argv[])
  8{
  9    //initialize allegro
 10    if ( initAllegro() == -1 )
 11    {        
 12        return -1;
 13    }
 14
 15    //push states to gameManager stack
 16    GameStateManager::pushState( PlayState::getInstance() );
 17    
 18    
 19    //loop through gameManager stack
 20        GameStateManager::getCurrentState()->run();//--execute run method
 21        GameStateManager::popState(); //--pop the element on top
 22    
 23                    
 24    //deinitialize allegro
 25    deinitAllegro();
 26    
 27    return 0;
 28}
 29END_OF_MAIN()
 30
 31int initAllegro()
 32{
 33    allegro_init();
 34    install_keyboard();
 35   
 36    install_timer();
 37
 38    set_color_depth(GameManager::COLOR_DEPTH);    
 39
 40    if ( set_gfx_mode(GFX_AUTODETECT, GameManager::GAME_WIDTH, GameManager::GAME_HEIGHT, 0, 0) != 0 )
 41    {
 42        allegro_message("Graphics Mode Could Not Be Set!: %s", allegro_error);
 43        return -1;
 44    }
 45    
 46    if ( install_sound(DIGI_AUTODETECT, MIDI_AUTODETECT, 0) )
 47    {
 48        allegro_message("Sound Error: %s", allegro_error);
 49    }    
 50    
 51    set_volume(255, 255);
 52
 53    LOCK_VARIABLE(GameTimer::game_ticker);
 54    LOCK_FUNCTION(GameTimer::incrementGameTicker);
 55    
 56    install_int(GameTimer::incrementGameTicker, 10);
 57        
 58    return 0;
 59}
 60
 61void deinitAllegro()
 62{    
 63    allegro_exit();
 64}

Here are the constants that I used for the game width, height and color depth.

#SelectExpand
  1#include "globals.h"
  2
  3GameManager::GameManager()
  4{
  5}
  6
  7GameManager::~GameManager()
  8{
  9}
 10
 11void GameManager::blitBuffer()
 12{
 13    acquire_screen();
 14    
 15    blit(buffer, screen, 0, 0, 0, 0, GAME_WIDTH, GAME_HEIGHT);
 16    
 17    release_screen();
 18    
 19    clear_bitmap(buffer);
 20} 
 21
 22BITMAP* GameManager::buffer;
 23
 24const short int GameManager::GAME_WIDTH = 640;
 25const short int GameManager::GAME_HEIGHT = 480;
 26const short int GameManager::COLOR_DEPTH = 16;
 27
 28int GameManager::game_score;

Andrei Ellman

Member #3,434

April 2003

Quote:

//move all projectiles
for (std::vector<Projectile*>::iterator it = ProjectileFactory::projectilePool.begin(); it != ProjectileFactory::projectilePool.end(); ++it)
[...]
//check for collision on bullet and enemies
for(std::vector<Enemy*>::iterator eit = EnemyFactory::enemyPool.begin(); eit != EnemyFactory::enemyPool.end(); ++eit)

Howmany enemies and projectyles do you have? If checking each projectyle against each enemy, the execution-time can grow very fast according to howmany of each there are.

AE.

--
Don't let the illegitimates turn you into carbon.

Tobias Dammers

Member #2,604

August 2002

I agree with Andrei here.
Although game logic is usually the least of your problems, in this case you might want to optimize.
There are numerous optimization techniques you can use here, and virtually all of them try to reduce the number of iterations (read: try to loop through less objects). This is better than optimizing the collision test itself (rule of thumb: optimize algorithms, not code).
The key to this common problem is space partitioning, which means that you divide the total space in which objects can lie into regions, and you only test objects against each other that share a region. The art is to define your regions in such a way that they are easy and fast to calculate, and that they don't produce double checking. Here are a few approaches:
1. Axis sort. Sort all your objects by one of the cardinal axes (x or y). Check in both directions, and stop iterating when you hit an object that is too far away. This will usually restrict checking to the nearest 10 or so objects.
2. Tilemap. Divide your scene into a tile grid (you don't need to use this for drawing, but if you draw using a tilemap anyway, you may want to add the collision detection features to it while you're at it), and give each tile a list (a vector is probably your best choice, or maybe even a static array - just be careful not to produce overflows) with pointers to all checkable objects that touch it. If your tile size is a power of 2, then finding the tile a character is on is as trivial as a binary & with tilesize-1. Downside: enormous memory consumption, and you need to be careful with those character lists. Upside: you only check against 4 tiles max (provided your character isn't larger than the tile size).
3. Quadtrees. Google for it. The idea is that you divide your space into 4 sectors, and divide those 4 again, and so on, until a given minimum size is reached, OR a maximum number of characters is found in the sector. When checking for collisions, you only check against objects that share a sector with the current object. This is the hardest to code, but it is the most efficient one for complex scenes, with very little overhead and adaptable to the most uneven distributions of objects (e.g. a hundred objects crowding in one corner of the screen).

---
Me make music: Triofobie
---
"We need Tobias and his awesome trombone, too." - Johan Halmén

armond

Member #8,282

January 2007

Hi! I just tried doing

install_int_ex(GameTimer::incrementGameTicker, BPS_TO_TIMER(100) );

doesn't make any change...

I haven't tried Tobias Dammers's suggestion yet. But even when I don't fire any bullet(no instance created) and there is only 1 enemy it's still slow... Slow as in not as fast when I'm in a P-IV Machine... When I remove the scrolling background, it does get a little fast. But still not that fast... Here is the code for my scrolling bg BTW... I'd like to point out that this(the scrolling bg) isn't necessarily my problem.

1#include "globals.h"
2 
3 
4GameBackground::GameBackground(BITMAP* bitmap, BackgroundScrollType scrollType, int scrollSpeed, int x, int y)
5{
6    this->bitmap = bitmap;
7    this->scrollType = scrollType;
8    this->scrollSpeed = scrollSpeed;
9    this->x = x;
10    this->y = y;
11    
12    tmpBuffer = create_bitmap(SCREEN_W, SCREEN_H);
13}    
14 
15GameBackground::~GameBackground()
16{
17    destroy_bitmap(tmpBuffer);
18}
19 
20void GameBackground::update()
21{
22    scrollBackground();
23}
24 
25void GameBackground::scrollBackground()
26{
27    switch(scrollType)
28    {
29        case HORIZONTAL_LEFT:
30            scrollLeft();
31            break;
32        default:
33            break;
34    }    
35}
36 
37void GameBackground::draw()
38{
39    draw_sprite(GameManager::buffer, tmpBuffer, 0, 0);
40}    
41 
42void GameBackground::setScrollSpeed(int speed)
43{
44    scrollSpeed = speed;
45}    
46 
47void GameBackground::scrollLeft()
48{
49    x -= scrollSpeed;
50    
51    int bw = bitmap->w;
52    int bh = bitmap->h;
53    
54    int xOffSet = (SCREEN_W + bw);
55    
56    if ( x > bw || x < -(bw) )
57    { 
58        x = 0;
59    }    
60    
61    int newX = 0;
62    
63    for (int i = -(bw); i < (xOffSet); i += bw)
64    {
65        newX = (x + i);
66        
67        for (int j = 0; j < SCREEN_H; j += bh)
68        {
69            //draw tile
70            //Optimization: draw only parts that are visible to the screen            
71            if ( ( newX + bw) > 0 )
72            {
73                draw_sprite(tmpBuffer, bitmap, newX, j);    
74            }
75            else
76            {
77                break;
78            }    
79                    
80        }    
81    }
82}

I'm scrolling an 200x200 24-bit bitmap and drawing it repeatedly on screen to create an illusion of a scrolling background.

Audric

Member #907

January 2001

24 bit bitmap? But your screen is 16bit... try to avoid run-time color conversion.

If the animation is still choppy, the background drawing is not at fault and no optimization there will solve the problem.
I guess the final blit to screen takes the biggest toll, but you can't easily reduce this cost (dirty rectangles on a 840x680 hardware scrolling bitmap? Seems far-fetched)

Last step: profile, using your compiler's options.

edit: I just noticed you used draw_sprite() both times: If what you're copying is opaque, just blit() it, it will be quite faster.

Richard Phipps

Member #1,632

November 2001

On low end machines drawing a 24 bit bitmap to the screen every frame is just slow at high resolutions. There is not much you can do if you have scrolling on such a machine. Looking into Video bitmaps might be your best bet..

Chaos Groove Development Blog
Free Logging System Code & Blog

armond

Member #8,282

January 2007

Thank you for your reply! Could you please explain what you meant by "Looking into Video bitmaps might be your best bet.."?

Richard Phipps

Member #1,632

November 2001

Copying data from video bitmaps to the screen can be much faster that copying from a normal BITMAP if your card supports hardware acceleration. There is a section in the manual on it and many threads if you do a search on these forums.

Chaos Groove Development Blog
Free Logging System Code & Blog

armond

Member #8,282

January 2007

Hi! I quick search from google tells me that you're talking about page flipping...?

Richard Phipps

Member #1,632

November 2001

That's related, look in the manual in the gfx / bitmap sections.

Chaos Groove Development Blog
Free Logging System Code & Blog

nonnus29

Member #2,606

August 2002

Armond, your noob code doesn't look like noob code. I'm not complaining, it's a nice change....

link to my blog