luanti-extended-engine-features/leef-math-cd2025
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Add tests to identity-quat patch and also take an axis not a full value for the identity fallback

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mcc 2020-04-25 18:32:48 -04:00
parent f27f5520b1
commit 9cd858a0ef
2 changed files with 23 additions and 6 deletions
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13
modules/quat.lua
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@ -364,12 +364,12 @@ end
--- Convert a quaternion into an angle plus axis components.
-- @tparam quat a Quaternion to convert
-- @tparam identity an optional table to return on identity/degenerate quaternions (by default returns 0,0,0,1)
-- @tparam identityAxis vec3 of axis to use on identity/degenerate quaternions (optional, default returns 0,0,0,1)
-- @treturn number angle
-- @treturn x axis-x
-- @treturn y axis-y
-- @treturn z axis-z
function quat.to_angle_axis_unpack(a, identity)
function quat.to_angle_axis_unpack(a, identityAxis)
if a.w > 1 or a.w < -1 then
a = a:normalize()
end
@ -378,8 +378,8 @@ function quat.to_angle_axis_unpack(a, identity)
-- Normally an identity quat would return a nonsense answer, so we return an arbitrary zero rotation early.
-- FIXME: Is it safe to assume there are *no* valid quaternions with nonzero degenerate lengths?
if a.x*a.x + a.y*a.y + a.z*a.z < constants.DBL_EPSILON*constants.DBL_EPSILON then
if identity then
return unpack(identity)
if identityAxis then
return 0,identityAxis:unpack()
else
return 0,0,0,1
end
@ -404,10 +404,11 @@ end
--- Convert a quaternion into an angle/axis pair.
-- @tparam quat a Quaternion to convert
-- @tparam identityAxis vec3 of axis to use on identity/degenerate quaternions (optional, default returns 0,vec3(0,0,1))
-- @treturn number angle
-- @treturn vec3 axis
function quat.to_angle_axis(a, default)
local angle, x, y, z = a:to_angle_axis_unpack(default)
function quat.to_angle_axis(a, identityAxis)
local angle, x, y, z = a:to_angle_axis_unpack(identityAxis)
return angle, vec3(x, y, z)
end

16
spec/quat_spec.lua
View File

@ -310,6 +310,22 @@ describe("quat:", function()
assert.is.equal(3, axis.z)
end)
it("converts between a quaternion and angle/axis (identity quaternion) (by component)", function()
local angle, x,y,z = quat():to_angle_axis_unpack()
assert.is.equal(0, angle)
assert.is.equal(0, x)
assert.is.equal(0, y)
assert.is.equal(1, z)
end)
it("converts between a quaternion and angle/axis (identity quaternion with fallback)", function()
local angle, axis = quat():to_angle_axis(vec3(2,3,4))
assert.is.equal(0, angle)
assert.is.equal(2, axis.x)
assert.is.equal(3, axis.y)
assert.is.equal(4, axis.z)
end)
it("gets a string representation of a quaternion", function()
local a = quat():to_string()
assert.is.equal("(+0.000,+0.000,+0.000,+1.000)", a)