Go Back   EQEmulator Home > EQEmulator Forums > Development > Development::Development

Development::Development Forum for development topics and for those interested in EQEMu development. (Not a support forum)

 
 
Thread Tools Display Modes
Prev Previous Post   Next Post Next
  #1  
Old 10-25-2008, 03:07 PM
Congdar
Developer
 
Join Date: Jul 2007
Location: my own little world
Posts: 751
Default some code logic discussion

in Attack.cpp at method NPC::Attack ~line 1900 you see
Code:
	float calcheading=CalculateHeadingToTarget(target->GetX(), target->GetY());
	if((calcheading)!=GetHeading()){
		SetHeading(calcheading);
		FaceTarget(target, true);
	}
This checks to see if the npc is facing its target when it attacks. If the npc's target never moves then its not a big issue, but if the target is moving around or the target changes due to death of the target or hate list target changes then some code here is made useless and other code doesn't get run.

CalculateHeadingToTarget() in waypoints.cpp has some heavy calculations that you don't want to call too often.
Code:
sint8 Mob::CalculateHeadingToTarget(float in_x, float in_y) {
	float angle;

	if (in_x-x_pos > 0)
		angle = - 90 + atan((float)(in_y-y_pos) / (float)(in_x-x_pos)) * 180 / M_PI;
	else if (in_x-x_pos < 0)
		angle = + 90 + atan((float)(in_y-y_pos) / (float)(in_x-x_pos)) * 180 / M_PI;
	else // Added?
	{
		if (in_y-y_pos > 0)
			angle = 0;
		else
			angle = 180;
	}
	if (angle < 0)
		angle += 360;
	if (angle > 360)
		angle -= 360;
	return (sint8) (256*(360-angle)/360.0f);
}
SetHeading() makes a call to Timer::GetCurrentTime() to update pLastChange and updates heading;
Mob.h ~line 771
Code:
	void				SetHeading(float iHeading) { if (heading != iHeading) { pLastChange = Timer::GetCurrentTime(); heading = iHeading; } }
FaceTarget() makes a check that there's a target and then calls CalculateHeadingToTarget() a second time but since heading was set in SetHeading is is the same as what it gets from the extra call and the code at the bottom of the method sends a graphical update to every client in the zone and oldheading == heading because of the previous call to SetHeading() so pLastChange doesn't get updated.
in Mob.cpp ~line 1928 is Mob::FaceTarget()
Code:
void Mob::FaceTarget(Mob* MobToFace, bool update) {
	if (MobToFace == 0)
		MobToFace = target;
	if (MobToFace == 0 || MobToFace == this)
		return;
	// TODO: Simplify?
	float oldheading = heading;
	heading=(CalculateHeadingToTarget(MobToFace->GetX(),MobToFace->GetY()));

	// 30+ lines of rem'd out code removed for easier reading

	SendPosUpdate();
	if (update && oldheading != heading)
		pLastChange = Timer::GetCurrentTime();
}
current execution summed up:
calc heading to target
if not facing target set heading to face target
calc heading to target again
update all(800 * 800 is a long ways) clients in zone of graphical heading change
don't update pLastChange even if bool is set to true

To clean this code up, I'm suggesting this:
calc heading to target
if not facing target set heading to face target
if heading changed send graphical update to clients

by changing:
Code:
	float calcheading=CalculateHeadingToTarget(target->GetX(), target->GetY());
	if((calcheading)!=GetHeading()){
		SetHeading(calcheading);
		FaceTarget(target, true);
	}
to:
Code:
             FaceTarget(target);
and changing FaceTarget() to
mob.h
Code:
	void				FaceTarget(Mob* MobToFace = 0);
Code:
void Mob::FaceTarget(Mob* MobToFace) {
	if(!MobToFace) {
		if(!target) {
			return;
		}
		else {
			MobToFace = target;
		}
	}

	float oldheading = heading;
	heading = CalculateHeadingToTarget(MobToFace->GetX(), MobToFace->GetY());
	if(oldheading != heading) {
		SetHeading(heading);
		SendPosUpdate();
	}
}
SetHeading() updates pLastChange but FaceTarget() had a bool to change it or not so what cases would pLastChange not need to be updated?
Reply With Quote
 


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

   

All times are GMT -4. The time now is 08:28 PM.


 

Everquest is a registered trademark of Daybreak Game Company LLC.
EQEmulator is not associated or affiliated in any way with Daybreak Game Company LLC.
Except where otherwise noted, this site is licensed under a Creative Commons License.
       
Powered by vBulletin®, Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Template by Bluepearl Design and vBulletin Templates - Ver3.3