Fix "Error: src/lib/cpml/modules/_private_utils.lua:8: attempt to index
global 'utils' (a nil value)"
Looks like when round was moved to _private_utils, this didn't get
replaced. There is no utils defined and utils.round just points to
private.round.
Add a test. This never triggered test failures because test don't pass
precision.
Test
A love2d program with main.lua:
local Vec2 = require "cpml.modules.vec2"
local v = Vec2(1.234, 3.5326)
print(v:round(0.1))
angle_to was producing the angle from +x to the difference between a,b
which is unexpected. Instead, it should produce the smallest absolute
angle between the two vectors and be signed to indicate the direction of
rotation.
By using the old angle_to implementation and modifying equal() to print
out the failures, you can see the numbers that it was producing before
didn't make much sense:
right:angle_to(down) = 45.0
right:angle_to(left) = 0.0
right:angle_to(up) = -45.0
down:angle_to(right) = -135.0
down:angle_to(left) = -45.0
down:angle_to(up) = -90.0
left:angle_to(down) = 135.0
left:angle_to(up) = -135.0
up:angle_to(right) = 135.0
up:angle_to(down) = 90.0
up:angle_to(left) = 45.0
Now it produces numbers you'd expect:
right:angle_to(down) = -90.0
right:angle_to(left) = 180.0
right:angle_to(up) = 90.0
down:angle_to(right) = 90.0
down:angle_to(left) = -90.0
down:angle_to(up) = 180.0
left:angle_to(down) = 90.0
left:angle_to(up) = -90.0
up:angle_to(right) = -90.0
up:angle_to(down) = 180.0
up:angle_to(left) = 90.0
See also https://stackoverflow.com/questions/21483999/using-atan2-to-find-angle-between-two-vectors
Also added tests for angle_between.
On Github we run unit tests inside "busted". At the start of each test "busted" does some sort of trick (clearing package.loaded)? Which causes "require" to run again for all lua files. This breaks ffi.metatype with error "cannot change a protected metatable" if it is called twice with a single type name, since this is true global state. To work around this this patch wraps ffi.metatype calls in a xpcall() so that failure is silently ignored.
- vec2 to_polar/from_cartesian tests were testing for equality rather than using an epsilon.
- bound2.contains had two tests that were plain wrong.
- While I'm fixing the bounds test, bound2.contains and bound3.contains probably ought to test their own min and max values for inclusion.
- The implementation of mat4.look_at appears to be wrong. The final column was being set to 0,0,0,1 which comparing against other implementations does not seem to be correct. My replacement code is modeled on the method used in mat4x4_look_at() in linmath.h in GLFW, which says it's a reimplementation on the method from gluLookAt(). With this change the test passes as originally written.
