coalesce notes (now with numbers)

So the Mac version begins to experience slowdown at around 50 objects (on my computer, at least). The Windows version: 13. What the hell? It’s got me stumped. What the hell? Spending most of its time in some directx_unlock fn. I don’t know what that does. I should probably post a plea for help on allegro.cc.

---

m₁v₁ + m₂v₂ = m₁v_1f + m₂v_2f I know the momentum & stuff is conserved, but how do I figure it out? I’m looking for 2 variables! Say m₁ & m₂ are both 1. v₁ + v₂ = v_1f + v_2f 2 + -2 = 0 + 0

2 + -2

-2 + 2 seems this is “right” That’s if it’s head-on, however. I’m not sure about otherwise

I need to add the vectors somehow. But which vectors is key – it’s not velocity. Momentum. But momentum needs to be conserved.

So if they have the same mass, the velocities just switch. Different masses, though?

m₁v₁ + m₂v₂ = m₁v_1f + m₂v_2f

m₁v₁²/2 + m₂v₂²/2 = m₁v_1f²/2 + m₂v_2f²/2

v₁ + v_1f = v₂ + v_2f or v₁ - v₂ = v_2f - v_1f v_1f = v₁(m₁ - m₂)/(m₁ + m₂) + v₂(2m₂)/m₁ + m₂)

v_2f = v₁(2m₁)/(m₁ + m₂) + v₂(m₂ - m₁)/(m₂ + m₁) </strong> sm = m₁ + m₂

But that’s only good for head-on collisions. “scattering” is more complicated.

v₂ = v((2m₁) / (m₁ + m₂))cosΘ v₁¹ = v …