Stupid math question

Delzhand

It's late and my brain isn't working and I can't figure out how to deal with this. I have two numbers, and I want to reduce them by a number such that their sum is a fixed number. Here's a set of equations I think might be helpful, but I'm not sure how to solve for n:

Xa/n = Xb
ya/n = Yb
Xb + Yb = 8

The only numbers I have to start with are Xa and Xb.

There's probably a very easy answer I can't see.

His Corkiness

Did you mean that you start with Xa and Ya? In either case, what are they? There aren't enough equations there to solve that many unknowns.

ecco the dolphin

His Corkiness wrote: »

Did you mean that you start with Xa and Ya? In either case, what are they? There aren't enough equations there to solve that many unknowns.

Running with being given Xa and Ya, and wanting to figure out n, then:

n = (Xa + Ya) / 8

?

His Corkiness

eeccccoo tthhee ddoollpphhiinn wrote: »

His Corkiness wrote: »

Did you mean that you start with Xa and Ya? In either case, what are they? There aren't enough equations there to solve that many unknowns.

Running with being given Xa and Ya, and wanting to figure out n, then:

n = (Xa + Ya) / 8

?

Oh, right, I misunderstood the question. Never mind me. I just checked, and you're correct.

Delzhand

Thanks! That's right. Hell, that's basic algebra, but for some reason I just couldn't see it.

Delzhand

Ha, I'm even more retarded than I initially thought. Despite the fact that I dealt with this same problem about a million times when I was working on Metroid Lightspeed, I totally forgot how to fire an angled projectile at a consistent speed.

float firingAngle = Statics.getAngleRadians(position, target.Position);
Vector2 shotDir = new Vector2(8 * (float)Math.Cos(firingAngle), 8 * (float)Math.Sin(firingAngle));

His Corkiness

Wouldn't the direction just be target.Position - position? Then normalise and multiply by the projectile's speed.