Supporting Multiple Platforms in C++ - Learn C++ for Game Development - page 264

Listing 26-6. WindowsEnemy , AndroidEnemy , and iOSEnemy
class WindowsEnemy
: public EnemyBase
{
public:
WindowsEnemy(EnemyType type, const uint32_t serializableId)
: EnemyBase(type, serializableId)
{
std::cout << "Created Windows Enemy!" << std::endl;
}
};
class AndroidEnemy
: public EnemyBase
{
public:
AndroidEnemy(EnemyType type, const uint32_t serializableId)
: EnemyBase( type , serializableId )
{
std::cout << "Created Android Enemy!" << std::endl;
}
};
class iOSEnemy
: public EnemyBase
{
public:
iOSEnemy(EnemyType type, const uint32_t serializableId)
: EnemyBase(type, serializableId)
{
std::cout << "Created iOS Enemy!" << std::endl;
}
};
These three classes rely on polymorphism to allow the rest of the program to work with the
EnemyBase class rather than the platform-specific implementations. The last problem to solve is how
to create these classes. Fortunately the Factory pattern gives us a ready-made solution. Listing 26-7
updates EnemyFactory to create the correct type of EnemyBase for our implementation.
Listing 26-7. Updating EnemyFactory with Platform-Specific Types
namespace
{
#if PLATFORM_WINDOWS
#include "WindowsEnemy.h"
using Enemy = WindowsEnemy;
#elif PLATFORM_ANDROID
#include "AndroidEnemy.h"
using Enemy = AndroidEnemy;