Thread: Allegro help-o

I do not see player::draw()

player.draw(buffer);


i dunno if thats right or not... this is the first time ive even attempted oop ( classes).

any way here is where im at know

Code:

#include <allegro.h>

int counter;
int left = 0, right = 0;
BITMAP *buffer = NULL;

class player
{
   public:
       int x, y;
       BITMAP* ship;

       player(): x(300), y(425) { ship = load_bitmap ( "ship.bmp", NULL ); }
      ~player() { destroy_bitmap(ship); }

       void  getmove()
       {
           if ( x < 600 && key[KEY_LEFT] )
           {
              left = 1;
           }

           else
           {
              left = 0;
           }

           if ( x > 0 && key[KEY_RIGHT] )
           {
              right = 1;
           }

           else
           {
              right = 0;
           }
        }

        void draw(BITMAP* b)
        {
            draw_sprite ( b, ship, x, 425 );
        }
};

void update_counter()
{
     counter++;
}END_OF_FUNCTION(update_counter);

int main()
{
   allegro_init();
   install_keyboard();
   set_color_depth(32);
   set_gfx_mode(GFX_AUTODETECT_FULLSCREEN, 640, 480, 0, 0);
   buffer = create_bitmap( 640, 480 );

   LOCK_VARIABLE(counter);
   LOCK_FUNCTION(update_counter);
   install_int_ex( update_counter, BPS_TO_TIMER(60));

   player player1;

   do{
       while ( counter > 0 )
       {
           player1.getmove();

           if ( left == 1 ) player1.x -= 10;
           if ( right == 1 ) player1.x += 10;

           counter--;
       }

       clear(buffer);
       player1.draw(buffer);
       blit( buffer, screen, 0, 0, 0, 0, 640, 480);

   }
   while ( !key[KEY_ESC] );

   allegro_exit();
   return 0;
}
END_OF_MAIN();

it runs.. i see the ship.. i move the ship... when i close the app... it gives me the same error

I am not too good at OOP, but Maybe you should make a class called object, and it can draw itself, it has a bitmap loaded representing itself, then make a player class that is inherited from the object class, but adds the player specific stuff, and make an enemy class that is inherited from the object class. Then you do not have to recode as much stuff.

what the crap did you just say...

its all fixed now

Flicker free... no errors

Code:

#include <allegro.h>  
  
int counter;  
BITMAP *buffer = NULL;  
  
class player  
{  
   public:  
       int x, y, left, right;  
       BITMAP* ship;  
  
       player(): x(300), y(425), left(0), right(0) { ship = load_bitmap ( "ship.bmp", NULL ); }  
      ~player() { destroy_bitmap(ship); }  
  
       void  getmove()  
       {  
           if ( x > 0 && key[KEY_LEFT] )  
           {  
              left = 1;  
           }  
  
           else  
           {  
              left = 0;  
           }  
  
           if ( x < 600 && key[KEY_RIGHT] )  
           {  
              right = 1;  
           }  
  
           else  
           {  
              right = 0;  
           }  
  
           if ( left == 1 ) x -= 10;  
           if ( right == 1 ) x += 10;  
        }  
  
        void draw(BITMAP* b)  
        {  
            draw_sprite ( b, ship, x, 425 );  
        }  
};  
  
void update_counter()  
{  
     counter++;  
}END_OF_FUNCTION(update_counter);  
  
int main()  
{  
   allegro_init();  
   install_keyboard();  
   set_color_depth(32);  
   set_gfx_mode(GFX_AUTODETECT_FULLSCREEN, 640, 480, 0, 0);  
   buffer = create_bitmap( 640, 480 );  
  
   LOCK_VARIABLE(counter);  
   LOCK_FUNCTION(update_counter);  
   install_int_ex( update_counter, BPS_TO_TIMER(60));  
  
   player *player1 = new player;  
  
   do{  
       while ( counter > 0 )  
       {  
           player1->getmove();  
           counter--;  
       }  
  
       clear(buffer);  
       player1->draw(buffer);  
       blit( buffer, screen, 0, 0, 0, 0, 640, 480);  
  
   }  
   while ( !key[KEY_ESC] );  
 
   delete player1;  
   allegro_exit();  
   return 0;  
}  
END_OF_MAIN();

I use to have that problem, post the code you use to get the input. Here is mine:

Code:

while(!key[KEY_ESC])
  {
    if(key[KEY_UP] && y > 5)        // Move up
      y = y - 5;

    else if(key[KEY_DOWN] && y < 400)    // Move down
      y = y + 5;

    else if(key[KEY_LEFT] && x > 5)      // Move left
      x = x - 5;

    else if(key[KEY_RIGHT] && x < 525)   // Move right
      x = x + 5;

    else if(key[KEY_SPACE]) // Shoot, if there are already 10 bullets, do nothing
    {
      // Find an empty place in the bullets struct
      for(int i = 0; i < MAX_BULLETS; i++)
      {
        if(bullets[i].exists == 0) // We found an empty slot
        {
          bullets[i].exists = 1; // Make it exist and set its coords
          bullets[i].x = x;
          bullets[i].y = y;
        }
      }
    }

josh have you got working bullets... if so can you post some source to show how you did it....

and tech it sounds like a timer problem to me...

btw... all 3 of us are making a shooter? wierd... and cool

but not fair cause you guys are better than me

Ok, I've probably spent around 10 hours today trying to get multiple animations to go on at once. I was finally able to do that but it was flicking too much. I could probably go back (ctrl+z) and get to that point, and fix what I know was wrong with that. But I'd rather do it the way I'm doing it now...more time efficient in the drawing routine. But the problem is that it's not working. It compiles in all but it doesn't work the way it should (by should I mean the way I intended for it to work ).

Here's the problem: Even when I press space (shoot) twice the drawing routine only shows one shooting animation, and that is the old one. I can't display a new shooting animation until the old animation ends. Unless I start pressing the arrow keys and press shoot and then when I do this it's not what I want it do. It destroys the old animation and creates a new animation, but all that is beside the point right now.

here's the code...I don't see what's wrong with it???

Code:

void user_spacebar()
 {
        a[0] = y;   //setting 1st bullet's y to y
        b[0] = x;     //setting 1st bullet's x to x
        num[0] = a[0];   //setting 1st bullets num to a
         do
          { 
        a[0]-=3;    // moving the bullets upwards for the 1st
        num[0] = a[0];
        draw_sprite ( buffer, plane, x, y );   //drawing the plane because the buffer has been cleared
        if(num[0] > 119)                         
         {     
        draw_sprite ( buffer, bullets, b[0], a[0] );   //drawing the 1st bullet to the buffer
         }
        if(var[1] == 1 && num[1] > 119)  //if the 2nd bullet has been initialized to be drawn
         {                               //initialization can't take place until 1st bullet has been drawn at least once
           a[1]-=3;    //move the bullets upwards for the 2nd bullet
           num[1] = a[1];   //setting 2nd bullets num to a  
           draw_sprite ( buffer, bullets, b[1], a[1] );  //drawing the 2nd bullet to the buffer
         } 
        if(var[1] == 1 && num[1] < 119)   //if 2nd bullet drawing has ended
         {
         num[1] = 0;  //restoring values
         var[1] = 0;
         }
        blit( buffer, screen, 0, 0, 0, 0, 640, 480 );   //copying buffer to the screen
        show_video_bitmap(screen);   //displaying the screen
        clear_bitmap ( buffer );   //clearing the buffer *but not the screen*
               
     if( keypressed() && (key[KEY_SPACE]) && (var[1] != 1))   //if keypressed once while 2nd bullet isn't initialized
         {
           var[1] = 1;     //setting values
           a[1] = y;
           b[1] = x;    
         }     
      if( keypressed() && !key[KEY_SPACE] )       //if any other key besides space has been pressed
         {        
           key_detection();   //going to a key detection function
         } 
          }while((num[0] > 119 || num[1] > 119) && !key[KEY_ESC]);   //while 1st or 2nd bullet is initialized or while esc hasn't been pressed
          var[1] = 0;   //i don't remember lol
}

Btw, I commented the hell out of it to make it as easy as possible for any of you to read.

Thank you.

I did my bullets like this:

Code:

#define MAX_BULLETS 10

struct bullet {
  int x, y;
  int exists;
} bullets[MAX_BULLETS];

Then every time right before I draw to the screen (well, the backbuffer) I call the function updatebullets() which goes through each bullet and subtracts from y, to make it move up the screen. I also have that function change exists to 0 if the bullet goes off the screen, later I will have the code for when a bullet hits something. I loop through it like this

Code:

for(int i = 0; i < MAX_BULLETS; i++)
{
  if(bullets[i].exists == 1)
  {
    bullets[i].y -= 5;
  }
}

That code loops through the whole bullets array and for everyone that exists it subtract five from y, therfore all the bullets move up the screen.

When I create a bullet I have to loop through the bullets array and find the first empty space. If I had an integer for how many bullets are on the screen, and add to it everytime I add a bullet, and delete from it everytime a bullet disapears, I would overwrite them. Here is an example of how that would not work (using the bullet struct from above)

Code:

  int NumberOfBullets = 0;

  // Okay lets say the user presses space
  // We create a bullet

  bullets[NumberOfBullets].exists = 1;
  bullets[NumberOfBullets].x = 300;
  bullets[NumberOfBullets].y = 400;

    int NumberOfBullets++;

  // Now lets create another bullet
  // Note the first bullets location would be bullets[0] 

  bullets[NumberOfBullets].exists = 1;
  bullets[NumberOfBullets].x = 200;
  bullets[NumberOfBullets].y = 450;

  NumberOfBullets++;

  // Now lets say some time has passed in our game, the first
  // bullet is off screen now, but the second is still on screen.
  // Now our code would break

  // First since our first bullet went off screen we do this
  NumberOfBullets--;

  // Now what happends if we create a new bullet?

  bullets[NumberOfBullets].exists = 1;
  bullets[NumberOfBullets].x = 245;
  bullets[NumberOfBullets].y = 420;

  // Uh oh, we just over wrote our second bullet, they are both
  // bullet[1].

I tried that method first, it would not work, obviously. So now everytime I create a bullet, I have it loop through the bullets array and find the first place where exists = 0; The code for this is not hard, I will show you.

Code:

for(int i = 0; i < MAX_BULLETS; i++)
{
  if(bullets[i].exists == 0)
  {
    // We found a bullet in the array that does not exist yet
    // meaning we can use that place to hold a bullet
    // We want to give it coordinates, then set exists to 1 so
    // it gets drawn, and nothing overwrites it
    bullets[i].x = 200;
    bullets[i].y = 200;
    bullets[i].exists = 1;

    // A problem I had earlier was that I did not put a break
    // statement here, that made it create a bullet with the
    // same coordinates every place there was a empty bullet
    // which meant that I could only have one bullet at a time
    break;
  }
}

Well, I hope I explained everything, here is the code to my game so far, there are no enemies yet, but you can have up to 30 bullets on screen at once, there is no flicker in bullet movement or plane movement. I am still looking for a new plane graphic. I think I am gonna quit with this game, because it is starting to get lame. I need to design what I want the game to be more, before I code. I will work on another game shortly, probably either pong or a space attack game. Here is the full code to the airplane game:

Code:

#include <allegro.h>

#define MAX_BULLETS 10

                    // Draws ship and bullets to buffer, then
  void redraw();    // blits buffer to screen

                    // Initializes Allegro, sets screen mode
  void setup();     // and loads bitmaps

  void shutdown();  // Destroys bitmaps and calls allegro_exit()

  void updatebullets(); // Updates bullet coordinates

  BITMAP *background = NULL;    // Clouds background
  BITMAP *bullet     = NULL;    // A bullet...
  BITMAP *plane      = NULL;    // Da plane! Da plan!
  BITMAP *buffer     = NULL;    // The buffer, reduces flicker

  // I found the easiest way to implement bullets is to create
  // an array of structures, so it is easy to keep track of
  // each bullets coordinates and state (exists or not)
  struct bullet
  {
    int x, y;
    int exists;
  } bullets[MAX_BULLETS];

  // The ships coordinates, maybe I should make a ship structure...
  int x = 300, y = 375;

int main()
{
  setup();

  while(!key[KEY_ESC])
  {
    if(key[KEY_UP] && y > 5)        // Move up
      y = y - 5;

    else if(key[KEY_DOWN] && y < 400)    // Move down
      y = y + 5;

    else if(key[KEY_LEFT] && x > 5)      // Move left
      x = x - 5;

    else if(key[KEY_RIGHT] && x < 525)   // Move right
      x = x + 5;

    else if(key[KEY_SPACE]) // Shoot, if there are already 10 bullets, do nothing
    {
      // Find an empty place in the bullets struct
      for(int i = 0; i < MAX_BULLETS; i++)
      {
        if(bullets[i].exists == 0) // We found an empty slot
        {
          bullets[i].exists = 1; // Make it exist and set its coords
          bullets[i].x = x;
          bullets[i].y = y;
          break;
        }
      }
    }
    updatebullets();
    redraw();
  }

  shutdown();
  return 0;
}
END_OF_MAIN();

void redraw()
{
  blit(background, buffer, 0, 0, 0, 0, 640, 480);
  draw_sprite(buffer, plane, x, y);

  for(int i = 0; i < MAX_BULLETS; i++)
  {
    if(bullets[i].exists == 1)
    {
      draw_sprite(buffer, bullet, bullets[i].x, bullets[i].y);
    }
  }

  blit(buffer, screen, 0, 0, 0, 0, 640, 480);
}

void setup()
{
  allegro_init();
  install_keyboard();

  // Set colors depth and set graphics mode
  set_color_depth(32);
  set_gfx_mode(GFX_AUTODETECT_FULLSCREEN, 640, 480, 0, 0);

  // Load bitmaps
  background = load_bitmap("background.bmp", NULL);
  bullet     = load_bitmap("bullet.bmp", NULL);
  plane      = load_bitmap("plane.bmp", NULL);
  buffer     = create_bitmap(640, 480);

  // Make sure all bullets do not exist
  for(int i = 0; i < MAX_BULLETS; i++)
  {
    bullets[i].exists = 0;
  }
}

void shutdown()
{
  destroy_bitmap(background);
  destroy_bitmap(plane);

  allegro_exit();
}

void updatebullets()
{
   // Delete bullets that go past screen
  for(int j = 0; j < MAX_BULLETS; j++)
  {
    if(bullets[j].exists == 1)
    {
      if(bullets[j].y <= 0)
        bullets[j].exists = 0;
    }
  }

  // Move bullets up the screen
  for(int i = 0; i < MAX_BULLETS; i++)
  {
    if(bullets[i].exists == 1)
    {
      bullets[i].y -= 5;
    }
  }
}

I tried to attach a zip with the graphics, but it was too big. I will upload it to my website and post the url here if anyone wants it. I can also include the source and exec.

Sorry if my previous post did not make sense, it is 5:00 in the morning.

http://www.ciusa.net/~jrgrant/planeall.zip
That is the exec, source, and graphics

http://www.ciusa.net/~jrgrant/planegraphics.zip
That is just the graphics.

TechWins, I was looking through your code, and one of the things that makes it flicker is that you are drawing to the screen, and you do it in different places. The best way to do it, is to have code that parses the user input, it changes different variable, then you have one, and only one function that draws to the screen. Think about it, if you are moving the ship around, and redrawing it with code in the function moveship(), and you have bullets moving and drawing in the function user_space(), then you could not have the ship moving while the bullets are moving. Read that long ass example I just posted. I am learning how to animate sprites right now.

josh... i love you

my ship has bullets now

Code:

#include <allegro.h>

#define max_laser 15
  
int counter;
BITMAP *buffer = NULL;
BITMAP *laser = NULL;

void updatelasers();

struct laser
{
   int x, y;
   int exists;
}lasers[max_laser];
  
class player  
{  
   public:  
       int x, y, left, right, fire;
       BITMAP* ship;  
  
       player(): x(300), y(425), left(0), right(0) { ship = load_bitmap ( "ship.bmp", NULL ); }  
      ~player() { destroy_bitmap(ship); }  
  
       void  getmove()  
       {  
           if ( x > 0 && key[KEY_LEFT] )  
           {  
              left = 1;  
           }  
  
           else  
           {  
              left = 0;  
           }  
  
           if ( x < 600 && key[KEY_RIGHT] )  
           {  
              right = 1;  
           }  
  
           else  
           {  
              right = 0;  
           }

           if ( key[KEY_SPACE] )
           {
              for ( int i = 0; i < max_laser; i++ )
              {
                  if ( lasers[i].exists == 0 )
                  {
                      lasers[i].exists = 1;
                      lasers[i].x = x;
                      lasers[i].y = y;
                      break;
                   }
               }
           }
           updatelasers();

           if ( left == 1 ) x -= 10;  
           if ( right == 1 ) x += 10;  
        }  
  
        void draw(BITMAP* b)  
        {  
            draw_sprite ( b, ship, x, 425 );  
        }  
};
  
void update_counter()  
{  
     counter++;  
}END_OF_FUNCTION(update_counter);  
  
int main()  
{  
   allegro_init();  
   install_keyboard();  
   set_color_depth(32);  
   set_gfx_mode(GFX_AUTODETECT_FULLSCREEN, 640, 480, 0, 0);  
   buffer = create_bitmap( 640, 480 );
   laser = load_bitmap ( "laser.bmp", NULL );
  
   LOCK_VARIABLE(counter);  
   LOCK_FUNCTION(update_counter);  
   install_int_ex( update_counter, BPS_TO_TIMER(60));  
  
   player *player1 = new player;  
  
   do{  
       while ( counter > 0 )  
       {  
           player1->getmove();  
           counter--;  
       }  
  
       clear(buffer);  
       player1->draw(buffer);
       for(int i = 0; i < max_laser; i++)
       {
           if( lasers[i].exists == 1 )
           {
           draw_sprite(buffer, laser, lasers[i].x, lasers[i].y);
           }
       }
       blit( buffer, screen, 0, 0, 0, 0, 640, 480);  
  
   }  
   while ( !key[KEY_ESC] );  
 
   delete player1;
   allegro_exit();  
   return 0;  
}  
END_OF_MAIN();

void updatelasers()
{

  for(int j = 0; j < max_laser; j++)
  {
    if( lasers[j].exists == 1 )
    {
      if( lasers[j].y <= 0 )
        lasers[j].exists = 0;
    }
  }

  for(int i = 0; i < max_laser; i++)
  {
    if( lasers[i].exists == 1 )
    {
      lasers[i].y -= 10;
    }
  }
}

i need to tweak it so it will fire from the center of the ship though...

and josh... in your game your ship will not move diagonally...

i thought about making mine move up and down as well but im gonna leave it a simple first game...