Task

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A Task is an action that an NPC can perform. Schedules will run a list of tasks. Keep tasks as atomic as possible; don't squeeze two distinct actions into the same one.

Creating a task

Custom tasks are added by first declaring a new enum value.

enum 
{
	TASK_JUMP = LAST_SHARED_TASK,
	TASK_FIND_DODGE_DIRECTION, 
	LAST_MY_NPC_TASK,
};

After that, the task itself should be declared like this:

AI_BEGIN_CUSTOM_NPC( npc_custom, CNPC_Custom )
	DECLARE_TASK( TASK_FIND_DODGE_DIRECTION )
AI_END_CUSTOM_NPC()

Then you add the tasks in your custom schedule in the order you want them to execute. See Schedule for more details on the following code:

AI_BEGIN_CUSTOM_NPC( npc_custom, CNPC_Custom )
	DEFINE_SCHEDULE
	(
		SCHED_DODGE_ENEMY_FIRE,
 
		"	Tasks"
		"		TASK_FIND_DODGE_DIRECTION	3"
		"		TASK_JUMP	0"
		""
		"	Interrupts"
       	"		COND_LIGHT_DAMAGE"
	)
AI_END_CUSTOM_NPC()

Task logic

Now that everything is set up it's finally time to write some actual AI code.

  • Tasks are initiated from StartTask(Task_t *pTask), which should take the form of a switch statement that evaluates pTask->iTask.
    Note:Remember to have a default case that falls back on BaseClass::StartTask().
  • Each task has an associated float value, pTask->flTaskData, which can be used to change its outcome.
  • When the current task is complete, call TaskComplete(). The schedule will move on to the next task.
  • If the current task has failed, call TaskFail() with an error message. A new schedule will be selected.

Example

This code makes the NPC play the ACT_MP_JUMP activity endlessly.

void CNewNPC::StartTask( const Task_t *pTask )
{
	switch (pTask->iTask)
	{
	case TASK_MYCUSTOMTASK:
		if (FindGestureLayer(ACT_MP_JUMP) == -1)
			AddGesture(ACT_MP_JUMP);
		TaskComplete();
		break;
 
	default:
		BaseClass::StartTask( pTask );
	}
}

Navigation

To do

Animation

Combat

To do

Speech

See also



Creating an NPC
Creating a schedule
Giving an NPC Memory