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-rw-r--r--builtin/common/tests/vector_spec.lua142
1 files changed, 142 insertions, 0 deletions
diff --git a/builtin/common/tests/vector_spec.lua b/builtin/common/tests/vector_spec.lua
index 79f032f28..6f308a4a8 100644
--- a/builtin/common/tests/vector_spec.lua
+++ b/builtin/common/tests/vector_spec.lua
@@ -43,4 +43,146 @@ describe("vector", function()
it("add()", function()
assert.same({ x = 2, y = 4, z = 6 }, vector.add(vector.new(1, 2, 3), { x = 1, y = 2, z = 3 }))
end)
+
+ -- This function is needed because of floating point imprecision.
+ local function almost_equal(a, b)
+ if type(a) == "number" then
+ return math.abs(a - b) < 0.00000000001
+ end
+ return vector.distance(a, b) < 0.000000000001
+ end
+
+ describe("rotate_around_axis()", function()
+ it("rotates", function()
+ assert.True(almost_equal({x = -1, y = 0, z = 0},
+ vector.rotate_around_axis({x = 1, y = 0, z = 0}, {x = 0, y = 1, z = 0}, math.pi)))
+ assert.True(almost_equal({x = 0, y = 1, z = 0},
+ vector.rotate_around_axis({x = 0, y = 0, z = 1}, {x = 1, y = 0, z = 0}, math.pi / 2)))
+ assert.True(almost_equal({x = 4, y = 1, z = 1},
+ vector.rotate_around_axis({x = 4, y = 1, z = 1}, {x = 4, y = 1, z = 1}, math.pi / 6)))
+ end)
+ it("keeps distance to axis", function()
+ local rotate1 = {x = 1, y = 3, z = 1}
+ local axis1 = {x = 1, y = 3, z = 2}
+ local rotated1 = vector.rotate_around_axis(rotate1, axis1, math.pi / 13)
+ assert.True(almost_equal(vector.distance(axis1, rotate1), vector.distance(axis1, rotated1)))
+ local rotate2 = {x = 1, y = 1, z = 3}
+ local axis2 = {x = 2, y = 6, z = 100}
+ local rotated2 = vector.rotate_around_axis(rotate2, axis2, math.pi / 23)
+ assert.True(almost_equal(vector.distance(axis2, rotate2), vector.distance(axis2, rotated2)))
+ local rotate3 = {x = 1, y = -1, z = 3}
+ local axis3 = {x = 2, y = 6, z = 100}
+ local rotated3 = vector.rotate_around_axis(rotate3, axis3, math.pi / 2)
+ assert.True(almost_equal(vector.distance(axis3, rotate3), vector.distance(axis3, rotated3)))
+ end)
+ it("rotates back", function()
+ local rotate1 = {x = 1, y = 3, z = 1}
+ local axis1 = {x = 1, y = 3, z = 2}
+ local rotated1 = vector.rotate_around_axis(rotate1, axis1, math.pi / 13)
+ rotated1 = vector.rotate_around_axis(rotated1, axis1, -math.pi / 13)
+ assert.True(almost_equal(rotate1, rotated1))
+ local rotate2 = {x = 1, y = 1, z = 3}
+ local axis2 = {x = 2, y = 6, z = 100}
+ local rotated2 = vector.rotate_around_axis(rotate2, axis2, math.pi / 23)
+ rotated2 = vector.rotate_around_axis(rotated2, axis2, -math.pi / 23)
+ assert.True(almost_equal(rotate2, rotated2))
+ local rotate3 = {x = 1, y = -1, z = 3}
+ local axis3 = {x = 2, y = 6, z = 100}
+ local rotated3 = vector.rotate_around_axis(rotate3, axis3, math.pi / 2)
+ rotated3 = vector.rotate_around_axis(rotated3, axis3, -math.pi / 2)
+ assert.True(almost_equal(rotate3, rotated3))
+ end)
+ it("is right handed", function()
+ local v_before1 = {x = 0, y = 1, z = -1}
+ local v_after1 = vector.rotate_around_axis(v_before1, {x = 1, y = 0, z = 0}, math.pi / 4)
+ assert.True(almost_equal(vector.normalize(vector.cross(v_after1, v_before1)), {x = 1, y = 0, z = 0}))
+
+ local v_before2 = {x = 0, y = 3, z = 4}
+ local v_after2 = vector.rotate_around_axis(v_before2, {x = 1, y = 0, z = 0}, 2 * math.pi / 5)
+ assert.True(almost_equal(vector.normalize(vector.cross(v_after2, v_before2)), {x = 1, y = 0, z = 0}))
+
+ local v_before3 = {x = 1, y = 0, z = -1}
+ local v_after3 = vector.rotate_around_axis(v_before3, {x = 0, y = 1, z = 0}, math.pi / 4)
+ assert.True(almost_equal(vector.normalize(vector.cross(v_after3, v_before3)), {x = 0, y = 1, z = 0}))
+
+ local v_before4 = {x = 3, y = 0, z = 4}
+ local v_after4 = vector.rotate_around_axis(v_before4, {x = 0, y = 1, z = 0}, 2 * math.pi / 5)
+ assert.True(almost_equal(vector.normalize(vector.cross(v_after4, v_before4)), {x = 0, y = 1, z = 0}))
+
+ local v_before5 = {x = 1, y = -1, z = 0}
+ local v_after5 = vector.rotate_around_axis(v_before5, {x = 0, y = 0, z = 1}, math.pi / 4)
+ assert.True(almost_equal(vector.normalize(vector.cross(v_after5, v_before5)), {x = 0, y = 0, z = 1}))
+
+ local v_before6 = {x = 3, y = 4, z = 0}
+ local v_after6 = vector.rotate_around_axis(v_before6, {x = 0, y = 0, z = 1}, 2 * math.pi / 5)
+ assert.True(almost_equal(vector.normalize(vector.cross(v_after6, v_before6)), {x = 0, y = 0, z = 1}))
+ end)
+ end)
+
+ describe("rotate()", function()
+ it("rotates", function()
+ assert.True(almost_equal({x = -1, y = 0, z = 0},
+ vector.rotate({x = 1, y = 0, z = 0}, {x = 0, y = math.pi, z = 0})))
+ assert.True(almost_equal({x = 0, y = -1, z = 0},
+ vector.rotate({x = 1, y = 0, z = 0}, {x = 0, y = 0, z = math.pi / 2})))
+ assert.True(almost_equal({x = 1, y = 0, z = 0},
+ vector.rotate({x = 1, y = 0, z = 0}, {x = math.pi / 123, y = 0, z = 0})))
+ end)
+ it("is counterclockwise", function()
+ local v_before1 = {x = 0, y = 1, z = -1}
+ local v_after1 = vector.rotate(v_before1, {x = math.pi / 4, y = 0, z = 0})
+ assert.True(almost_equal(vector.normalize(vector.cross(v_after1, v_before1)), {x = 1, y = 0, z = 0}))
+
+ local v_before2 = {x = 0, y = 3, z = 4}
+ local v_after2 = vector.rotate(v_before2, {x = 2 * math.pi / 5, y = 0, z = 0})
+ assert.True(almost_equal(vector.normalize(vector.cross(v_after2, v_before2)), {x = 1, y = 0, z = 0}))
+
+ local v_before3 = {x = 1, y = 0, z = -1}
+ local v_after3 = vector.rotate(v_before3, {x = 0, y = math.pi / 4, z = 0})
+ assert.True(almost_equal(vector.normalize(vector.cross(v_after3, v_before3)), {x = 0, y = 1, z = 0}))
+
+ local v_before4 = {x = 3, y = 0, z = 4}
+ local v_after4 = vector.rotate(v_before4, {x = 0, y = 2 * math.pi / 5, z = 0})
+ assert.True(almost_equal(vector.normalize(vector.cross(v_after4, v_before4)), {x = 0, y = 1, z = 0}))
+
+ local v_before5 = {x = 1, y = -1, z = 0}
+ local v_after5 = vector.rotate(v_before5, {x = 0, y = 0, z = math.pi / 4})
+ assert.True(almost_equal(vector.normalize(vector.cross(v_after5, v_before5)), {x = 0, y = 0, z = 1}))
+
+ local v_before6 = {x = 3, y = 4, z = 0}
+ local v_after6 = vector.rotate(v_before6, {x = 0, y = 0, z = 2 * math.pi / 5})
+ assert.True(almost_equal(vector.normalize(vector.cross(v_after6, v_before6)), {x = 0, y = 0, z = 1}))
+ end)
+ end)
+
+ it("dir_to_rotation()", function()
+ -- Comparing rotations (pitch, yaw, roll) is hard because of certain ambiguities,
+ -- e.g. (pi, 0, pi) looks exactly the same as (0, pi, 0)
+ -- So instead we convert the rotation back to vectors and compare these.
+ local function forward_at_rot(rot)
+ return vector.rotate(vector.new(0, 0, 1), rot)
+ end
+ local function up_at_rot(rot)
+ return vector.rotate(vector.new(0, 1, 0), rot)
+ end
+ local rot1 = vector.dir_to_rotation({x = 1, y = 0, z = 0}, {x = 0, y = 1, z = 0})
+ assert.True(almost_equal({x = 1, y = 0, z = 0}, forward_at_rot(rot1)))
+ assert.True(almost_equal({x = 0, y = 1, z = 0}, up_at_rot(rot1)))
+ local rot2 = vector.dir_to_rotation({x = 1, y = 1, z = 0}, {x = 0, y = 0, z = 1})
+ assert.True(almost_equal({x = 1/math.sqrt(2), y = 1/math.sqrt(2), z = 0}, forward_at_rot(rot2)))
+ assert.True(almost_equal({x = 0, y = 0, z = 1}, up_at_rot(rot2)))
+ for i = 1, 1000 do
+ local rand_vec = vector.new(math.random(), math.random(), math.random())
+ if vector.length(rand_vec) ~= 0 then
+ local rot_1 = vector.dir_to_rotation(rand_vec)
+ local rot_2 = {
+ x = math.atan2(rand_vec.y, math.sqrt(rand_vec.z * rand_vec.z + rand_vec.x * rand_vec.x)),
+ y = -math.atan2(rand_vec.x, rand_vec.z),
+ z = 0
+ }
+ assert.True(almost_equal(rot_1, rot_2))
+ end
+ end
+
+ end)
end)
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