https://github.com/bjornbytes/lutil

https://github.com/bjornbytes/lutil

Last synced: 6 months ago
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• Host: GitHub
• URL: https://github.com/bjornbytes/lutil
• Owner: bjornbytes
• License: mit
• Created: 2015-01-03T03:35:04.000Z (over 11 years ago)
• Default Branch: master
• Last Pushed: 2015-01-03T03:35:17.000Z (over 11 years ago)
• Last Synced: 2025-03-27T01:35:33.380Z (over 1 year ago)
• Language: Lua
• Size: 105 KB
• Stars: 5
• Watchers: 2
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

          
lutil

=====

My Lua utility file.

Class

---

Lutil provides a very lightweight class system.  Here's how you use it:

    -- Declare a class

    local Cat = class()

    

    Cat.sound = 'meow'

    function Cat:speak()

      print(self.sound)

    end

    function Cat:purr()

      print('purr')

    end

    -- Inheritance

    local Lion = extend(Cat)

    Lion.sound = 'rawr'

    -- Constructors

    function Lion:init(name)

      self.name = name

    end

    -- Instantiation

    local simba = Lion('simba') -- or new(Lion, 'simba')

    print(simba.name)

    simba:speak()

    simba:purr()

Math

---

- `math.sign(x)` returns the sign of `x` (-1, 0, or 1).

- `math.round(x)` rounds `x` to the nearest whole number away from zero.

- `math.clamp(x, min, max)` clamps `x` between `min` and `max`.

- `math.lerp(x1, x2, z)` linearly interpolates between `x1` and `x2`.  For example, passing in `.5` for `z` will return a value halfway between `x1` and `x2`.

- `math.anglerp(d1, d2, z)` linearly interpolates between two angles (in radians).

- `math.dx(length, direction)` returns the x-component of a vector with length `length` and direction `direction` (in radians).

- `math.dy(length, direction)` returns the y-component of a vector with length `length` and direction `direction` (in radians).

- `math.distance(x1, y1, x2, y2)` returns the distance between two points.

- `math.direction(x1, y1, x2, y2)` returns the direction between to points (in radians).

- `math.vector(x1, y1, x2, y2)` returns the distance and direction between two points.

- `math.inside(px, py, rx, ry, w, h)` returns true if the point (`px`, `py`) is inside the rectangle with the top-left corner located at (`rx`, `ry`), width equal to `rw` and height equal to `rh`.

- `math.anglediff(d1, d2)` returns the difference between two angles (in radians).