How do I limit speed on 2d vectors?

I began an attempt at implementing steering vectors with the 8direction behavior, but seem to have run into a wall early on. I would expect that the sprite orbits around the target when approaching at an angle, but it intermittently cuts most (but not all) of its horizontal or vertical velocity upon passing the target, but only sometimes... Am I approaching this wrong in the following?

+ System: Every tick

-> Sprite: Set 8Direction vector X to clamp(-1×abs(Self.8Direction.Maxspeed×cos(angle(Self.X,Self.Y,Target.X,Target.Y))),Self.8Direction.VectorX+Self.8Direction.Acceleration×dt×cos(angle(Self.X,Self.Y,Target.X,Target.Y)),abs(Self.8Direction.Maxspeed×cos(angle(Self.X,Self.Y,Target.X,Target.Y))))

-> Sprite: Set 8Direction vector Y to clamp(-1×abs(Self.8Direction.Maxspeed×sin(angle(Self.X,Self.Y,Target.X,Target.Y))),Self.8Direction.VectorY+Self.8Direction.Acceleration×dt×sin(angle(Self.X,Self.Y,Target.X,Target.Y)),abs(Self.8Direction.Maxspeed×sin(angle(Self.X,Self.Y,Target.X,Target.Y))))

dropbox.com/s/yyn5ab25aoq4vfb/steering.c3p

It’s a bit hard to debug big formulas like those, but basically you’re accelerating toward the target and limiting the the speed?

I’d break it up into multiple steps and once that works you can combine it again.

Local number a

Local number speed

Every tick

Set a to angle(sprite.x, sprite.y, target.x, target.y)

Set vectorX to vectorX + accel*dt*cos(a)

Set vectorY to vectorY + accel*dt*sin(a)

Set speed to sqrt(vectorX^2+vectorY^2)

Compare: speed>maxspeed

Set vectorX to vectorX/speed*maxspeed

Set vectorY to vectorY/speed*maxspeed

I was thinking this was a good one for ROJOhound! :)

that works nicely... we don't need to limit the speed because the 8Direction behavior does that automatically. it settles into an orbit around the target.

I have a feeling oosyrag might want the sprite to converge on the target - as if it has gravity.

how would you make the orbit shrink so that the sprite converges on the target?

https://www.rieperts.com/games/forum/orbit3.c3p

Well originally I had thought that the built in speed limit was causing issues resulting in unnatural paths if either the x or y vectors were already near or at the speed limit when attempting a turn, and prevent acceleration on the other axis when setting the vectors manually.

Eventually I was aiming for variable speed limits to allow for slingshotting and more responsive obstacle avoidance. But then when I tried to add a simple clamp for the max speed I already ran into more issues.

Seems like (I think?) clamping the vector with the sin and cos functions were not symmetrical, causing irregularities. Guess that's why all the articles I read normalize the vector first.

Regarding gravity and decay of orbit, that could be done with adding either an overall deceleration force, or a local one when near the target.

Thanks for the help!

Oh true. I forgot about the behavior enforcing the max speed for you.

He said he was expecting an orbit, but real gravity would be similar.

To stop the orbit you could apply a brake to the tangent speed so it would fall straight down. The break could be just a velocity opposite the tangent velocity and you could make it inversely proportional to the distance. Basically that would make it brake faster the closer it is.

a = angle(sprite to target)+90

tanvel = vectorX*cos(a)+vectorY*sin(a)

d = distance(sprite to target)

If d>0

vectorX = vectorX - tanvel/d*cos(a)

VectorY = vectorY - tanvel/d*sin(a)

Appreciate the advice!

The concept is a mix between the old arcade game Rampart by Atari and 2d artillery type games, except slinging varying types of missiles through space, also with a variety of obstacles that affect the projectiles on the field.

Although mostly I just like fooling around making different types of game mechanics. I've been loitering around here for years and have yet to actually finish any projects haha. Do not expect this to be different.

I searched Rampart and looks really interesting and unique!Let me know if you ever plan on posting anything.