# BitBlt

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1. ## Calculating "Spread" for shotgun shot

Why not? Intuitively, and experimentally, buck shot spreads out as it travels. The exact position of each pellet each time you fire will essentially be random (at least locally). However, the overall statistical behavior can be predicted and can be easily modeled as a Gaussian distribution in 2 dimensions. I imagine this was their motivation.
2. ## Angle of Launch if Source and Destination are not level

Those are probably fine, but notice that they are identical, modulo the sign. A simple test of the target location compared to the launch location should tell you which sign you need. For example, if target_x > start_x, then a negative x velocity will obviously not get you there. Ditto for the y velocity. So just code up these equations and do some quick tests to determine the sign. And I'm pretty sure a negative sign doesn't make sense, and probably correlates to the issue Kian was talking about.
3. ## Euler Integration & Collision Response

Just once per timestep. You are integrating a force over a time interval, so once that change in velocity is "in there", you don't have to integrate again until the next timestep. BTW, by updating your velocity before your positions, you are using a variant of euler integration called symplectic euler, or sometimes semi-implicit euler, that is significantly more stable than explicit euler. Point being, don't worry too much about RK4 unless a) you are interested (if so, kudos), or b) you need the additional accuracy. (b) seems unlikely.
4. ## Angle of Launch if Source and Destination are not level

If you know the impulse is 600, then that gives you the magnitude of the initial velocity, which I'll call m: v_x^2 + v_y^2 = m^2 = 600^2 This gives you 3 equations for 3 unknowns (v_x, v_y, t) which you can solve. Here are the equations explicitly: v_x t = x 1/2 g t^2 + v_y t = y v_x^2 + v_y^2 = m^2, Since they're non-linear they are a little messy, but you only have to do the algebra once and you'll have closed-form expressions. You could also stick them into Mathematica and solve. Keep in mind that you will get multiple solutions because v_x = +/- sqrt(m^2 - v_y^2), but it should be obvious whether to use the positive v_x or the negative, depending on where your target is. BTW, I could be overlooking some simpler way of solving this by using the angle directly instead of solving for (v_x, v_y) then computing the angle. Specifying the time of flight t would mean you don't need the extra eqn. to solve for (v_x, v_y), but it would also mean that the time of flight would be the same for all projectiles, no matter how far away they are from their target. This could look awkward.

10. ## Delete Account

This is kinda weird. You're not a goth kid trying to erase himself from existence, are you?
11. ## A year and a half, wasted...?

Do what real game developers do. Instead of "finishing" the engine, start making something with it, and fix bugs/features as they pop up. I ditto swapping out the SDL thing. If it was designed right, it shouldn't be more than a couple hours of work, depending on your experience. I think what everyone is trying to say is that you already have what you need, no need to pay money for Torque.
12. ## Who the hell is this?

Quote:Original post by Cold_Steel I really like Michael Romeo too. He's another underrated guitarist from an underrated band, Symphony X. I love his neo-classical flair. Very impressive Nice video, I love Symphony X. The video framerate can't keep up with his fingers! I wasn't too impressed with the original video posted. Somebody mentioned Phil Keaggy, who is one of my favorite guitarists. There aren't many videos of him online, but here's one where he uses many of the same things in the original video, just a little slower and with better results (IMO). Clickity Click
13. ## dangerous hairs in a swimming pool

Not to mention how much chlorine decreases the strength of hair, so hair that had been sitting in pool water for any length of time would easily break.