vector_extras/init.lua

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local r_corr = 0.25 --remove a bit more nodes (if shooting diagonal) to let it look like a hole (sth like antialiasing)
-- this doesn't need to be calculated every time
local f_1 = 0.5-r_corr
local f_2 = 0.5+r_corr
--returns information about the direction
local function get_used_dir(dir)
local abs_dir = {x=math.abs(dir.x), y=math.abs(dir.y), z=math.abs(dir.z)}
local dir_max = math.max(abs_dir.x, abs_dir.y, abs_dir.z)
if dir_max == abs_dir.x then
local tab = {"x", {x=1, y=dir.y/dir.x, z=dir.z/dir.x}}
if dir.x >= 0 then
tab[3] = "+"
end
return tab
end
if dir_max == abs_dir.y then
local tab = {"y", {x=dir.x/dir.y, y=1, z=dir.z/dir.y}}
if dir.y >= 0 then
tab[3] = "+"
end
return tab
end
local tab = {"z", {x=dir.x/dir.z, y=dir.y/dir.z, z=1}}
if dir.z >= 0 then
tab[3] = "+"
end
return tab
end
local function node_tab(z, d)
local n1 = math.floor(z*d+f_1)
local n2 = math.floor(z*d+f_2)
if n1 == n2 then
return {n1}
end
return {n1, n2}
end
local function return_line(pos, dir, range) --range ~= length
local tab = {}
local num = 1
local t_dir = get_used_dir(dir)
local dir_typ = t_dir[1]
if t_dir[3] == "+" then
f_tab = {0, range, 1}
else
f_tab = {0, -range, -1}
end
local d_ch = t_dir[2]
if dir_typ == "x" then
for d = f_tab[1],f_tab[2],f_tab[3] do
local x = d
local ytab = node_tab(d_ch.y, d)
local ztab = node_tab(d_ch.z, d)
for _,y in ipairs(ytab) do
for _,z in ipairs(ztab) do
tab[num] = {x=pos.x+x, y=pos.y+y, z=pos.z+z}
num = num+1
end
end
end
elseif dir_typ == "y" then
for d = f_tab[1],f_tab[2],f_tab[3] do
local xtab = node_tab(d_ch.x, d)
local y = d
local ztab = node_tab(d_ch.z, d)
for _,x in ipairs(xtab) do
for _,z in ipairs(ztab) do
tab[num] = {x=pos.x+x, y=pos.y+y, z=pos.z+z}
num = num+1
end
end
end
else
for d = f_tab[1],f_tab[2],f_tab[3] do
local xtab = node_tab(d_ch.x, d)
local ytab = node_tab(d_ch.y, d)
local z = d
for _,x in ipairs(xtab) do
for _,y in ipairs(ytab) do
tab[num] = {x=pos.x+x, y=pos.y+y, z=pos.z+z}
num = num+1
end
end
end
end
return tab
end
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local function table_contains2(t, v)
for i = #t, 1, -1 do
if t[i] == v then
return true
end
end
return false
end
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local function return_fine_line(pos, dir, range, scale)
local ps1 = return_line(vector.round(vector.multiply(pos, scale)), dir, range*scale)
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local ps2 = {}
local ps2_num = 1
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for _,p1 in ipairs(ps1) do
local p2 = vector.round(vector.divide(p1, scale))
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if not table_contains2(ps2, p2) then
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ps2[ps2_num] = p2
ps2_num = ps2_num+1
end
end
return ps2
end
function vector.fine_line(pos, dir, range, scale)
--assert_vector(pos)
if not range then --dir = pos2
dir = vector.direction(pos, dir)
range = vector.distance(pos, dir)
end
return return_fine_line(pos, dir, range, scale)
end
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function vector.line(pos, dir, range)
--assert_vector(pos)
if not range then --dir = pos2
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dir = vector.direction(pos, dir)
range = vector.distance(pos, dir)
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end
return return_line(pos, dir, range)
end
function vector.straightdelay(s, v, a)
if not a then
return s/v
end
return (math.sqrt(v*v+2*a*s)-v)/a
end
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-- needs to get reworked
function vector.sun_dir(t)
if t < 0.25
or t > 0.75 then
return
end
local p2
if t > 0.5 then
p2 = {x=-4, y=1/(2*t-1), z=0}
else
p2 = {x=4, y=1/(1-2*t), z=0}
end
return vector.direction({x=0,y=0,z=0}, p2)
end