Fix parabola calculation mistakes, parabola works

This commit is contained in:
Hybrid Dog 2017-06-18 13:47:54 +02:00
parent 2fce6dbdc9
commit c221f0eec3

103
init.lua
View File

@ -577,7 +577,7 @@ end
--~ vely(0) = b = vel.y
--~ posy(0) = c = pos.y
--~ posy(t) = -0.5gravity*tt + vel.y*t + pos.y
--~ posy(t) = -0.5 * gravity * t * t + vel.y * t + pos.y
--~ vely(t) = -gravity*t + vel.y
--~ Scheitel:
@ -585,31 +585,42 @@ end
--~ t = vel.y / gravity
--~ 45°
--~ vely(t) = +/-1 = -gravity*t + vel.y
--~ t = (vel.y - 1) / gravity //links
--~ t = (vel.y + 1) / gravity //rechts
--~ vely(t)^2 = velx(t)^2 + velz(t)^2
--~ (-gravity*t + vel.y)^2 = vel.x * vel.x + vel.z * vel.z
--~ gravity^2 * t^2 + vel.y^2 - -2*gravity*t*vel.y = vel.x * vel.x + vel.z * vel.z
--~ gravity^2 * t^2 - 2*gravity*vel.y * t + (vel.y^2 - vel.x^2 - vel.z^2) = 0
--~ t = (2*gravity*vel.y .. rt((2*gravity*vel.y)^2 - 4*gravity^2*(vel.y^2 - vel.x^2 - vel.z^2))) / (2*gravity^2)
--~ t = (2*gravity*vel.y .. rt(4*gravity^2*vel.y^2 - 4*gravity^2*(vel.y^2) + 4*gravity^2*(vel.x^2 + vel.z^2))) / (2*gravity^2)
--~ t = (2*gravity*vel.y .. 2*gravity*rt(vel.x^2 + vel.z^2)) / (2*gravity^2)
--~ t = (vel.y .. rt(vel.x^2 + vel.z^2)) / gravity
--~ t1 = (vel.y - math.sqrt(vel.x * vel.x + vel.z * vel.z)) / gravity
--~ t2 = (vel.y + math.sqrt(vel.x * vel.x + vel.z * vel.z)) / gravity
--~ yswitch = posy(t) //links und rechts gleich
--~ yswitch = -0.5gravity*((vel.y + 1) / gravity)^2 + vel.y*(vel.y + 1) / gravity + pos.y
--~ yswitch = -0.5(vel.y + 1)^2 / gravity + (vel.y^2 + vel.y) / gravity + pos.y
--~ yswitch = -0.5(vel.y^2 + 2vel.y + 1) / gravity + (vel.y^2 + vel.y) / gravity + pos.y
--~ yswitch = (-0.5vel.y^2 - vel.y - 0.5 + vel.y^2 + vel.y) / gravity + pos.y
--~ yswitch = (0.5vel.y^2 - 0.5) / gravity + pos.y
--~ yswitch = posy(t1) (= posy(t2)) //links und rechts gleich
--~ yswitch = -0.5 * gravity * ((vel.y + math.sqrt(vel.x * vel.x + vel.z * vel.z)) / gravity)^2 + vel.y * ((vel.y + math.sqrt(vel.x * vel.x + vel.z * vel.z)) / gravity) + pos.y
--~ yswitch = -0.5 * gravity * (vel.y + math.sqrt(vel.x * vel.x + vel.z * vel.z))^2 / gravity^2 + vel.y * ((vel.y + math.sqrt(vel.x * vel.x + vel.z * vel.z)) / gravity) + pos.y
--~ yswitch = -0.5 * (vel.y^2 + 2*vel.y*math.sqrt(vel.x * vel.x + vel.z * vel.z) + vel.x^2 + vel.z^2) / gravity + ((vel.y^2 + vel.y*math.sqrt(vel.x * vel.x + vel.z * vel.z)) / gravity) + pos.y
--~ yswitch = (-0.5 * (vel.y^2 + 2*vel.y*math.sqrt(vel.x * vel.x + vel.z * vel.z) + vel.x^2 + vel.z^2) + ((vel.y^2 + vel.y*math.sqrt(vel.x * vel.x + vel.z * vel.z)))) / gravity + pos.y
--~ yswitch = (-0.5 * vel.y^2 - vel.y*math.sqrt(vel.x * vel.x + vel.z * vel.z) - 0.5 * vel.x^2 - 0.5 * vel.z^2 + vel.y^2 + vel.y*math.sqrt(vel.x * vel.x + vel.z * vel.z)) / gravity + pos.y
--~ yswitch = (-0.5 * vel.y^2 - 0.5 * vel.x^2 - 0.5 * vel.z^2 + vel.y^2) / gravity + pos.y
--~ yswitch = (0.5 * vel.y^2 - 0.5 * vel.x^2 - 0.5 * vel.z^2) / gravity + pos.y
--~ yswitch = -0.5 * (vel.x * vel.x + vel.z * vel.z - vel.y * vel.y) / gravity + pos.y
--~ yswitch = -0.5gravity*((vel.y - 1) / gravity)^2 + vel.y*(vel.y - 1) / gravity + pos.y
--~ yswitch = -0.5(vel.y - 1)^2 / gravity + (vel.y^2 - vel.y) / gravity + pos.y
--~ yswitch = (-0.5(vel.y - 1)^2 + vel.y^2 - vel.y) / gravity + pos.y
--~ yswitch = (-0.5(vel.y^2 - 2vel.y + 1) + vel.y^2 - vel.y) / gravity + pos.y
--~ yswitch = (-0.5vel.y^2 + vel.y - 0.5 + vel.y^2 - vel.y) / gravity + pos.y
--~ yswitch = (0.5vel.y^2 - 0.5) / gravity + pos.y
--~ posy nach t umstellen, kleineres beim Aufstieg, größeres beim Fall
--~ posy = -0.5gravity*tt + vel.y*t + pos.y
--~ 0 = -0.5gravity*tt + vel.y*t + pos.y - posy //→Mitternachtsformel
--~ t = -vel.y +-rt(vel.y^2 -4(-0.5gravity)(pos.y - posy)) / 2(-0.5gravity)
--~ t = -vel.y +-rt(vel.y^2 +2gravity(pos.y - posy)) / gravity
--~ t_rise = -vel.y - rt(vel.y^2 +2gravity(pos.y - posy)) / gravity
--~ t_fall = -vel.y + rt(vel.y^2 +2gravity(pos.y - posy)) / gravity
--~ 45° Zeitpunkte kleineres beim Aufstieg, größeres beim Fall
--~ (-gravity*t + vel.y)^2 = vel.x * vel.x + vel.z * vel.z
--~ -gravity*t + vel.y = ..math.sqrt(vel.x * vel.x + vel.z * vel.z)
--~ t = (..math.sqrt(vel.x * vel.x + vel.z * vel.z) + vel.y) / gravity
--~ t_raise = (-math.sqrt(vel.x * vel.x + vel.z * vel.z) + vel.y) / gravity
--~ t_fall = (math.sqrt(vel.x * vel.x + vel.z * vel.z) + vel.y) / gravity
--~ posy nach t umstellen
--~ y = -0.5 * gravity * t * t + vel.y * t + pos.y
--~ 0 = -0.5 * gravity * t * t + vel.y * t + pos.y - y
--~ t = (-vel.y .. math.sqrt(vel.y^2 + 2 * gravity * (pos.y - y))) / (-gravity)
--~ t = (vel.y .. math.sqrt(vel.y^2 + 2 * gravity * (pos.y - y))) / gravity
--~ t_up = (vel.y - math.sqrt(vel.y^2 + 2 * gravity * (pos.y - y))) / gravity
--~ t_down = (vel.y + math.sqrt(vel.y^2 + 2 * gravity * (pos.y - y))) / gravity
--~ posx(t) = vel.x * t + pos.x
--~ posz(t) = vel.z * t + pos.z
@ -623,17 +634,19 @@ local function get_parabola_points(pos, vel, gravity, waypoints, max_pointcount)
local pointcount = 0
-- the height of the 45° angle point
local yswitch = 0.5 * (vel.y * vel.y - 1) / gravity + pos.y
local yswitch = -0.5 * (vel.x * vel.x + vel.z * vel.z - vel.y * vel.y)
/ gravity + pos.y
local t_fall_start = (vel.y + 1) / gravity
local t_raise_end = (vel.y - 1) / gravity
-- the times of the 45° angle point
t_raise_end = (-math.sqrt(vel.x * vel.x + vel.z * vel.z) + vel.y) / gravity
t_fall_start = (math.sqrt(vel.x * vel.x + vel.z * vel.z) + vel.y) / gravity
if t_fall_start > 0 then
-- the right 45° angle point wasn't passed yet
if t_raise_end > 0 then
-- put points from before the 45° angle
for y = math.ceil(pos.y), math.floor(yswitch +.5) do
local t = -vel.y
- math.sqrt(vel.y * vel.y - 2 * gravity * (y - pos.y)) / gravity
local t = (vel.y -
math.sqrt(vel.y^2 + 2 * gravity * (pos.y - y))) / gravity
local p = {
x = math.floor(vel.x * t + pos.x +.5),
y = y,
@ -684,10 +697,15 @@ local function get_parabola_points(pos, vel, gravity, waypoints, max_pointcount)
end
end
-- put points from after the 45° angle
local y = math.floor(math.min(yswitch, pos.y) +.5)
local y = yswitch
if vel.y < 0
and pos.y < yswitch then
y = pos.y
end
local y = math.floor(y +.5)
while pointcount < max_pointcount do
local t = -vel.y
+ math.sqrt(vel.y * vel.y + 2 * gravity * (pos.y - y)) / gravity
local t = (vel.y +
math.sqrt(vel.y^2 + 2 * gravity * (pos.y - y))) / gravity
local p = {
x = math.floor(vel.x * t + pos.x +.5),
y = y,
@ -699,11 +717,26 @@ local function get_parabola_points(pos, vel, gravity, waypoints, max_pointcount)
y = y-1
end
end
--~ local ps = vector.throw_parabola(player:getpos(), player:get_look_dir(),
--~ 0.03, 80, true)
--~ for i = 1,#ps do
--~ minetest.set_node(ps[i], ps[i])
--[[
minetest.override_item("default:axe_wood", {
on_use = function(_, player)
local dir = player:get_look_dir()
local pos = player:getpos()
local grav = 0.03
local ps = vector.throw_parabola(pos, dir, grav, 80, true)
for i = 1,#ps do
minetest.set_node(ps[i], ps[i])
end
--~ for t = 0,50,3 do
--~ local p = {
--~ x = dir.x * t + pos.x,
--~ y = -0.5*grav*t*t + dir.y*t + pos.y,
--~ z = dir.z * t + pos.z
--~ }
--~ minetest.set_node(p, {name="default:sandstone"})
--~ end
end,
})--]]
function funcs.throw_parabola(pos, vel, gravity, point_count, thicken)
local waypoints = {}