Posts tagged with “math”

Ability checks

Solar System vs Dungeon World dice rolls
SS0.74 2.96 7.41 12.59 17.04 18.52 17.04 12.59 7.41 2.96 0.74
DW 0.40 1.19 2.38 3.97 5.95 8.33 10.32 11.51 11.90 11.51 10.32 8.33 5.95 3.97 2.38 1.19 0.40

and more

Ok, so I've modified the sandbox so it's a regular memory bitmap & thus needs to be blitted to the screen. Not much of a performance hit (if at all) on my Mac. Now to see how it fares in Windows. Everything is still line drawing, so replacing it w/bitmaps should help a bit.

The tough part is going to be determining which quadrant each vector is in. & I really should run tests on this. But I need to know what the right answer is, 1st.

Before I even get to any of that, I need to figure out this performance problem. Look at some examples / tutorials... See if I can spot what I'm doing differently (wrong).

I wonder if there's some sort of objects-on-screen stress-test example? A blitting example, or something.

[trig. diagrams] vx1f = vx1 - m21 • dvxz vx1f = vx1 - m2 / m1 • -2(vx21 + a + vy21) / ((1 + a2)(1 + m21)) [I don't really know what this's about]

what?! d = √(dy2 + dx2)

So yeah, my math for that was completely wrong.

The flocking needs work. The little bit I did before work today, to implement an FOV for the bots, doesn't seem to work.

How wd I go about "overloading" the math operators for vectors in plain C?

Okay, the ships(!) flock now but it needs tweaking. They're pretty psychotic. I need to put a cap on their velocity... or something. And a better rule for when there's no other flockers in view. Then flocking for bullets.

Enemies need to have a rule for when & under what conditions to leave the screen. So do powerups.

Enemies that shoot at the player.

Handle player death / game over

Bullet paths. Enemies following paths, too. Probably clean up my code. Take more advantage of subclassing.

I know it's premature, but I'm thinking a bit about optimization, too.

I know unrolling loops is supposed to help, but I don't have any loops I can unroll.

Lasers. A secondary ship.

multiple kinds of powerups.

Ship animations?

accelleration / decelleration? (very slight)

Missles. That's what bullets w/variable paths should be used for. They'll need a timer. They seek until that timer runs out ("fuel"?) at which point they just continue offscreen.

Want to do something w/fluid dynamics. Not sure exactly... Probably some sort of background animation.

Not now, but I will want to niceify the OS X version (& probably the Windows, too) – make them behave more like native apps. Menus, being able to close the window from the title bar, etc.

Missles. Missles need trails. Now, I see 2 possibilities for this. Have each "segment" be a distinct element - say a square - that gets drawn w/o reference to the other elements. OR: draw the trail as polygons connecting 2 elements.

Treat missles as multiple seeking particles that all start moving in different directions, but converge on the same target.

Theme: steampunk. cyberspace. demonic?

Some forms of missles encircle the enemy & create a containing sigil... or something.

Story? I like the idea of a secondary story like in the 1st Katamari Damacy where it's about characters who are affected indirectly by the events in the game.


Ok; but that's not important now. Missles, there should be a cap (upgradeable) on how many are onscreen @ once. if (# < cap>) fire_missle();

while (ship) {
  if √(dx + dy) < d {
    target = ship
    d = √(dx + dy)
  ship = [ship next]

ok, missles are go. And they're quite powerful. Don't really like how they behave, though.

What next? New kinds of enemies? Further enhancements to weapons? Tweaks/improvements?

more math (coalesce notes)

m1v1 + m2v2 = m1v1f + m2v2f

m1v1f = m1v1 + m2v2 - m2v2f

m1v1f = m1v1 + m2(v2 - v2f) * v1f = (m1v1 + m2(v2 - v2f)) / m1 Then solve for v2f in the other equation & substitute? where exactly does the cosθ come from? I'd have to figure that out, anyways, and I'm not 100% sure how. (Hell, I don't have a clue.) m1v12 + m2v22 / 2 = ... wait ... why the x/2? Both sides of the equation are divided by 2. Couldn't I just get rid of it? The answer to that, of course, is yes. but basically I'm solving for 4 unknowns. 2 vectors = 2 sets of 2 values each. Either force + angle or dx + dy. And I can convert between those. m1v12 + m2v22 / 2 = m1v1f2 / 2 + m2v2f2 m1(v12 - v1f2) = m2(v22 - v2f2) m1(v12 - v1f2) / m2 = v22 - v2f2 v2f2 = v22 - m1(v12 - v1f2) / m2

So I should treat all collisions (that don't destroy both objects) as collisions between spherical objects, at least as far as determining the post-collision movement vectors. Then I need to determine the line connecting their centers, and calculate the objects' movement vectors (x,y components) relative to that line. The y component will remain unchanged. [some notes pertaining to a graph that won't make sense w/o the image] v1f =

this doesn't help me! a2 + b2 = c2 ? (Do I know either a or b? I don't think I do.) This can't be that hard. Hell, if it helps I can even tweak the equation so one body is at "rest". I need a good geometry / physics book. But I can't. I'm already behind on my bills. There's the internet, granted, but that's not the same. [many more trig. notes that would be useless w/o the diagrams accompanying]