ces.c

// ces.c -- Component Entity System implementation.

#include "7drltypes.h"

World world;

int getEntityAt( int Y, int X )
{
   unsigned int entity;

   for ( entity = 0 ; entity < MAX_ENTITIES ; entity++ )
   {
      if (world.location[ entity ].X == X && world.location[ entity ].Y == Y )
      {
         return entity;
      }
   }

   return entity;
}

unsigned int createEntity( )
{ 
   unsigned int entity;

   for ( entity = 0 ; entity < MAX_ENTITIES ; entity++ )
   {
      if ( world.mask[ entity ] == COMPONENT_NONE )
      {
         world.id[ entity ] = entity;
         return entity;
      }
   }

   return MAX_ENTITIES;
}

void destroyEntity( unsigned int entity )
{
   world.mask[ entity ] = COMPONENT_NONE;

   return;
}


unsigned int createProjectile( void )
{
   int entity;
   int y, x;
   int dY, dX;

   entity = createEntity( );

   if ( entity < MAX_ENTITIES )
   {
      y = GetPlayerLocationY( );
      x = GetPlayerLocationX( );
      dY = GetPlayerLocationdY( );
      dX = GetPlayerLocationdX( );

      world.mask[ entity ] = COMPONENT_LOCATION  |
                             COMPONENT_TARGET    |
                             COMPONENT_ATTACK    |
                             COMPONENT_MOVEMENT;

      // Place the projectile in the environment.
      world.location[ entity ].Y = y+dY;
      world.location[ entity ].X = x+dX;

      world.target[ entity ].dY = dY;
      world.target[ entity ].dX = dX;
      world.target[ entity ].distance = 0;

      world.attack  [ entity ].Attack = GetShotPower( );

      world.movement[ entity ].Speed = 4;
      world.movement[ entity ].State = 0;

if ( 0 ) {
   char line[80];
   sprintf( line, "Projectile entity %d running %d, %d", entity, y+dY, x+dX );
   add_message( line );
}

      if ( map_get_item( world.location[ entity ].Y, 
                         world.location[ entity ].X ) == SPACE_ICON )
      {
         map_place_item( world.location[ entity ].Y, world.location[ entity ].X,
                           PROJECTILE_ICON );
      }
      else
      {
         // player attack.
         IncrementProjectiles( );
         destroyEntity( entity );
         Attack( world.attack[ entity ].Attack, 
                 world.location[ entity ].Y, world.location[ entity ].X,
                 PROJECTILE_ICON );
      }
   }

   return entity;
}


unsigned int createAnimal( )
{
   int entity;
   int y, x;

   entity = createEntity( );

   if ( entity < MAX_ENTITIES )
   {

      world.mask[ entity ] = COMPONENT_LOCATION  |
                             COMPONENT_HEALTH    |
                             COMPONENT_XPVALUE   |
                             COMPONENT_ANIMAL    |
                             COMPONENT_MOVEMENT;

      // Place the animal in the environment.
      do {
         y = getRand( Y_MAP_MAX );
         x = getRand( X_MAP_MAX );
      } while ( !IsAreaClear( y, x ) );

      world.location[ entity ].Y = y;
      world.location[ entity ].X = x;

      world.movement[ entity ].Speed = 13 + getRand( 5 );
      world.movement[ entity ].State = 0;

      world.health[ entity ].Health = 5;
      world.XPValue[ entity].XP = 5;

      map_place_item( y, x, ANIMAL_ICON );
   }

   return entity;
}


unsigned int createProtector( )
{
   int entity;
   int y, x;

   entity = createEntity( );

   if ( entity < MAX_ENTITIES )
   {

      world.mask[ entity ] = COMPONENT_LOCATION  |
                             COMPONENT_HEALTH    |
                             COMPONENT_ATTACK    |
                             COMPONENT_XPVALUE   |
                             COMPONENT_PROTECTOR |
                             COMPONENT_MOVEMENT;

      // Place the animal in the environment.
      do {
         y = getRand( Y_MAP_MAX );
         x = getRand( X_MAP_MAX );
      } while ( !IsAreaClear( y, x ) );

      world.location[ entity ].Y = y;
      world.location[ entity ].X = x;

      world.movement[ entity ].Speed = 9 + getRand( 5 );
      world.movement[ entity ].State = 0;

      world.attack[ entity ].Attack = 2;

      world.health[ entity ].Health = 20;
      world.XPValue[ entity].XP = 20;

      map_place_item( y, x, PROTECTOR_ICON );
   }

   return entity;
}

void InitEntities( )
{
   unsigned int entity;

   // Initialize the entities to null
   for ( entity = 0 ; entity < MAX_ENTITIES ; entity++ )
   {
      destroyEntity( entity );
   }

   // Create some number of animals.
   for ( entity = 0 ; entity < NUMBER_OF_ANIMALS ; entity++ )
   {
      createAnimal( );
   }

   // Create some number of protectors.
   for ( entity = 0 ; entity < NUMBER_OF_PROTECTORS ; entity++ )
   {
      createProtector( );
   }

   return;
}