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function lerp(a, b, c)
return a + (b - a) * c
end
function dlerp(a, b, c)
return lerp(b, a, 0.5^c)
end
function bton(bool)
return bool and 1 or 0
end
function min(a, b)
if a < b then
return a
end
return b
end
function normalize(x, y)
if x == 0 and y == 0 then
return 0, 0
end
local leng = math.sqrt(x*x + y*y)
return x / leng, y / leng
end
-- Top left corner
function point_in_rect(px, py, rx, ry, rw, rh)
return px > rx and px < rx + rw and py > ry and py < ry + rh
end
function dist(x1, y1, x2, y2)
local dx = x1 - x2
local dy = y1 - y2
return (dx*dx + dy*dy)^0.5
end
mathx = {}
mathx.tau = math.pi * 2
function mathx.sign(x)
if x == 0 then
return 0
end
return x < 0 and -1 or 1
end
function round(x)
return math.floor(x + 0.5)
end
function clamp(a, min, max)
return math.min(max, math.max(a, min))
end
function snap(x, step)
return math.floor(x / step) * step
end
function frac(x)
return x - math.floor(x)
end
local function angle_diff(a, b)
local diff = (b - a) % (math.pi * 2)
return (2 * diff) % (math.pi * 2) - diff
end
function lerp_angle(a, b, t)
return a + angle_diff(a, b) * (1 - 0.5^t)
end
function dot(x, y, xx, yy)
return x*xx + y*yy
end
function vec_sqlen(x, y)
return x*x + y*y
end
function vec_len(x, y)
return math.sqrt(x*x + y*y)
end
function rotate_vec(x, y, r)
local angle = math.atan2(y, x) + r
local len = mathx.vec_len(x, y)
return math.cos(angle) * len, math.sin(angle) * len
end
function table.shallow_copy(t)
local t2 = {}
for k,v in pairs(t) do
t2[k] = v
end
return t2
end
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