Idea bullet physics

yeah the title basically

I think this should be implemented for the sake of making weapons slightly more tweakable and therefore more balance-able -- bullet physics would give us a lot more stats to tinker around with. Additionally, it would raise the skill cap on several weapons by forcing players to learn how to compensate for physics and would also force to choose different weapons situationally instead of always picking the most powerful weapon in a set of weapons with absolutely increasing power.

Specifically, I'd like to see two core mechanics concerning bullet physics:

• Bullets are affected by gravity
• Bullets are affected by drag

Just these two simple mechanics introduce a lot more nuance into the function of a gun. Specifically, unique weapons will produce projectiles with different speeds, different drag coefficients, and different masses.

We know from elementary physics that the attraction of gravity is constant (or constant enough, anyways) for any given mass at the same height, and so bullets should theoretically all drop at the same rate. However, when this is combined with different projectile speeds and drag coefficients, bullets fired from the same point at the same angle but at different speeds will reach a fixed-distance target at different altitudes because their flight time is lengthened.

Bullet damage should also then be affected by these physics. We know that we can calculate the kinetic energy of an object Ek = 0.5mv^2, which is a reasonable (not really, but let's just pretend it is) approximation for the amount of damage dealt by a bullet. Thus, bullets with higher mass will deal more damage than a bullet with lower mass at the same velocity, and a bullet with higher velocity will deal more damage than a bullet with lower velocity at the same mass.

Two big factors come into play when determining velocity: gravity and drag. Suppose all bullets from a weapon start with the same speed (which is technically true in our game world). Bullets fired at an upwards or downwards angle will have higher vertical velocity but lower horizontal velocity than a bullet fired straight forwards. However, a bullet angled upwards will gradually lose velocity as gravity lowers its vertical velocity -- similarly, a bullet angled straight forwards or downwards will gradually gain velocity. Recall that velocity is calculated in the equation v = sqrt(x^2 + y^2) for x := horizontal and y := vertical velocity; if y starts positive and decreases steadily, v will decrease too, but if y starts negative or 0 and decreases, v will increase.

Drag is similar to gravity in that it steadily changes the horizontal velocity of a bullet. The difference is that, regardless of firing angle, the bullet's velocity will always decrease as a result of drag. Thus, weapons that are designed to be powerful at short range should shoot projectiles with a high coefficient of drag and weapons designed to be used at long range should produce a comparatively low coefficient of drag.

Put into practice, we can produce a simple mapping of comparative weapon statistics to associated classes. For initial velocity V, coefficient of drag D, and bullet mass M:
V- D- M+ -> sniper rifle: will fly a great distance and will accumulate damage through velocity imparted by gravity
V+ D= M- -> assault rifle: flies a shorter distance than a sniper bullet but deals greater damage through velocity
V= D+ M+ -> shotgun: flies a very short distance but deals great damage due to high bullet mass
V+ D- M- -> machine gun: flies a great distance but has relatively low damage due to low bullet mass
etc. etc.

also don't you dare go "no this is a video game u suck"