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Make the dist function callable #11

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22 changes: 11 additions & 11 deletions pico8lib/math.lua
Original file line number Diff line number Diff line change
Expand Up @@ -85,17 +85,6 @@ end

-- partially thanks to https://www.lexaloffle.com/bbs/?pid=119363

--- Distance to a point
-- Uses `dist_naive` for small values, `dist_trig` for large
-- tokens: 46
-- @tparam number x X coordinate of the point
-- @tparam number y Y coordinate of the point
-- @treturn number Distance from 0,0 to x,y
local function dist(x,y)
if (abs(x) < 128 and abs(y) < 128) return dist_naive(x,y)
return dist_trig(x,y)
end

--- Distance to a point
-- Naive distance calculation
-- Overflows for dist^2>=32768
Expand All @@ -121,6 +110,17 @@ local function dist_trig(x,y)
return x*cos(a)+y*sin(a)
end

--- Distance to a point
-- Uses `dist_naive` for small values, `dist_trig` for large
-- tokens: 46
-- @tparam number x X coordinate of the point
-- @tparam number y Y coordinate of the point
-- @treturn number Distance from 0,0 to x,y
local function dist(x,y)
if (abs(x) < 128 and abs(y) < 128) return dist_naive(x,y)
return dist_trig(x,y)
end

--- Distance squared to a point
-- @tparam number x X coordinate of the point
-- @tparam number y Y coordinate of the point
Expand Down
13 changes: 13 additions & 0 deletions tests/test_math.p8
Original file line number Diff line number Diff line change
Expand Up @@ -117,6 +117,19 @@ suite:add_test_case(Nthroot)
-- Distancefunctions
local Distance = TestCase("distance")

function Distance:test_dist_exact ()
for _,v in ipairs({
{0,0,0},
{1,1,sqrt(2)},
{3,4,5},
{44,117,125},
})
do
self:assert_equal(dist(v[1],v[2]), v[3])
self:assert_equal(dist(v[2],v[1]), v[3])
end
end

function Distance:test_dist_naive_exact ()
for _,v in ipairs({
{0,0,0},
Expand Down