Acceleration and deacceleration for custom movement?

[dnlhern]

Hello! I've decided to finally start work on a small 8-directional engine with my own events instead of using the pre-built movements that CF2.5 comes with. I have got basic movement implemented, but now I am wondering what could be a good way to add acceleration and deacceleration to the movement? Sorry for the incredibly noobish question, I'm rather new to all this!

I have provided an MFA file if anyone wants to tinker about.

Thank you!

GrimeAug20.mfa

[mobichan]

The basic idea is that you need to make a set of variables for XSpeed and YSpeed. These values will tell your character how much to move in X and Y every frame. Then make another set of variables for XSpeedDelta and YSpeedDelta. "Delta" is used to define the amount of change to something every frame, in this case it would be the amount of acceleration or deceleration. At the start of Frame, define the Delta variables to a value (best to use decimal values). Then, when you press the joystick begin adding the Delta value to your XSpeed and YSpeed (depending on which direction you are going, you might subtract the Delta value). Then add the XSpeed and YSpeed value to your X and Y positions.

Something like this:

Start of Frame
- Set XSpeedDelta to 0.1

+If Joystick is pressed Right
+XSpeed < Value (This is your Max speed)
-- Add XSpeedDelta to XSpeed

When you want to decelerate, simply do the opposite:

+If Joystick is not pressed
+XSpeed > 0.0
-- Subtract XSpeedDelta from XSpeed

Then always update the active's movement:

+ XSpeed different than 0.0 (you use "different" because the XSpeed value might be a positive or negative number)
-- Set X Position(active) to X(active) + XSpeed

Hope this helps.

Reg

[dnlhern]

Many thanks!

[dnlhern]

Excuse the double post, but I went by mobichan's directions regarding accel/deaccel with the 8 dir movement, but I've ran into a small hitch. For some reason, the X and Y speeds always manage to go over 3.0 because of the delta value added to the object's speed, creating some left over values, such as the speed being 0.3 or -0.3 even when there is no activity, or the speed being 3.3 or -3.3 or a mishmash of numbers when moving.

Can I get assistance on this, or is this a bug with Clickteam Fusion itself?

Thank you. I have attached the MFA I am working with to show this, and sorry if I sound a bit confusing.

GrimeAug26.mfa