How do i speed check

I must have a checker to speed of flying fireballs. How can i create condition-

when fireball impact with wall with low speed, fireball inflict 10-20 damage

when fireball impact with wall with medium speed fireball substract 21- 35 damage.

I have use angrynerds example in this tutorial i can set power of shotting projectiles from 0 to 100 power

Its all dependent on your current code and behaviors. what behavior is the fire ball using? if its using physics then you can get its velocity.

if you use Physics you can get the speed of an object like that

distance(0,0,Sprite.Physics.VelocityX,Sprite.Physics.VelocityY)

Yeah i use physics.

I must have add that code in condition editor or event editor?

What I wrote isn't a condition nor an action. It's an expression. Expression can be used anywhere. This one return the speed of your object, so if you want to compare speed you can use that in System: compare two values or if you want to use speed to calculate damage you can do a System: set damage to distance(0,0,Sprite.Physics.VelocityX,Sprite.Physics.VelocityY)*anyKindOfMultiplier

So yeah... you do what you want.

thanks Yann i check this soon :)

Yann Thank you for good hint :)

If you're confused about the distance expression..

another way of doing it is:

sqrt(sprite.Physics.VelocityX^2)+(sprite.physics.VelocityY^2)

because it's basically that.. maths thing.. you know.. working out the long side of a triangle and sh*t. yeah.

I don't think most people would have thought about using the distance expression... but hey it all works.

This sounds professional :)

By the way, talking of using function to do something they weren't meant to, you can do a :

cos(angle(0,0,number,0))

I can use this all in System: compare two values? (confused)

you can compare any expression to any other expression via the 'System: compare two values' yes

One question, how slow down volecity of fired ball? i mean if bal hit the box( box destroy) ball rushes on to the front and another box... every time when ball destroy box, ball slows down a little ?