+
- Helper Utilities for a Multitude of Problems is a set of lightweight helpers + for the excellent LÖVE Engine.
+ +It currently features +
hump differs from other libraries in that every component is independent of the + remaining ones (apart from camera.lua, which depends on the vector type). + hump's footprint is very small and thus should fit nicely into your projects.
+ + +A vector class implementing everything you want to do with vectors, and some more.
+Overview (click item for more details): +
| vector(x,y) | constructor |
| isvector(v) | type check |
| Vector:clone() | deep copy |
| Vector:unpack() | element unfolding |
| Operators | Arithmetics and ordering |
| vector:permul(other) | per-element multiplication |
| vector:len() | vector length |
| vector:len2() | squared vector length |
| vector:dist(other) | distance to vector |
| vector:normalized() | normalize vector |
| vector:normalize_inplace() | normalize vector in-place |
| Vector:rotated(phi) | rotate vector |
| Vector:rotate_inplace(phi) | rotate vector in-place |
v.x and v.y.
+ | Parameters: | [number]x: | x coordinate |
|---|---|---|
[number]y: | y coordinate | |
| Returns: | the vector | |
| Parameters: | v | variable to test |
|---|---|---|
| Returns: | true if v is a vector | |
| Returns: | New vector with the same coordinates. | |
|---|---|---|
| Returns: | the coordinate tuple x, y | |
|---|---|---|
| Example: | ||
v = vector(1,2) +print(v:unpack()) -- prints "1 2" | ||
Arithmetic (+, -, *, /) and
+ comparative operators (==, <=, <) are defined:
+ and - only work on vectors. - is also
+ the unary minus (e.g. print(-vector(1,2)) -- prints (-1,-2))a * b works on vectors and numbers:a is a number and b is a vector (or vice versa),
+ the result the scalar multiplication.a and b both are vectors, then the result is the
+ dot product.a / b is only defined for a being a vector and b
+ being a number. Same as a * 1/b.<= and < sort lexically, i.e. a < b
+ is true if it holds: a.x < b.x or a.y < b.y if
+ a.x == b.x
| Example: |
|---|
a,b = vector(0,1), vector(1,0) +print(a:dist(b)) -- prints 1.4142135623731 |
Warning: This will change the state of all references to this vector.
+| Parameters: | [number]phi: | Rotation angle in radians. |
|---|
Warning: This will change the state of all references to this vector.
+class.lua provides a simple and easy to use class system. Albeit it's + limitations, class.lua offers multiple inheritance and minimal + reflection capabilities. Note that only methods will be inherited + and runtime changes of a superclass won't affect subclasses.
+The module only consists of three functions: +
| Class(constructor) | define class |
| Class{name = name, constructor} | define named class |
| Interface(name) | define interface |
| Inherit(class, super, ...) | subclassing |
For an example, see below. Also be sure to read the + warning regarding metamethods.
+ + +| Parameters: | [optional function]constructor |
+ A function used to construct the class. The first parameter of this function + is the object, the others are parameters given upon construction. |
|---|---|---|
| Returns: | the new class | |
| Example | ||
Feline = Class(function(self, size, weight)
+ self.size = size self.weight = weight
+end)
+
+function Feline:stats()
+ return string.format("size: %.02f, weight %.02f", self.size, self.weight)
+end
+
+garfield = Feline(.7, 45)
+felix = Feline(.8, 12)
+
+print("Garfield: " .. garfield:stats(), "Felix: " .. felix:stats()) | ||
__tostring metamethod. Parameters are the same as above.
+ Great for debugging. Both name and constructor can be omitted (but why would you want to?)
+
+ | Example: |
|---|
Feline = Class{name = "Feline", function(self, size, weight)
+ self.size = size self.weight = weight
+end}
+
+print(Feline) -- prints 'Feline' |
Class{name = name}, i.e. a possibly named class without constructor.
+ super to class. Multiple interfaces can be defined.
+ super's constructor can be accessed via super.construct(self). See example below.
Feline = Class{name = "Feline", function(self, size, weight)
+ self.size = size self.weight = weight
+end}
+
+function Feline:stats()
+ return string.format("size: %.02f, weight %.02f", self.size, self.weight)
+end
+
+function Feline:speak() print("meow") end
+
+
+Cat = Class{name = "Cat", function(self, name, size, weight)
+ Feline.construct(self, size, weight)
+ self.name = name
+end}
+Inherit(Cat, Feline)
+
+function Cat:stats()
+ return string.format("name: %s, %s", self.name, Feline.stats(self))
+end
+
+
+Tiger = Class{name = "tiger", function(self, size, weight)
+ Feline.construct(self, size, weight)
+end}
+Inherit(Tiger, Feline)
+
+function Tiger:speak() print("ROAR!") end
+
+felix = Cat("Felix", .8, 12)
+hobbes = Tiger(2.2, 68)
+
+print(felix:stats(), hobbes:stats())
+felix:speak()
+hobbes:speak()
+ Be careful when using metamethods like __add or __mul:
+ When subclass inherits those methods from a superclass, but does not overwrite
+ them, the result of the operation may be of the type superclass. Consider the following:
A = Class(function(self, x) self.x = x end)
+function A:__add(other) return A(self.x + other.x) end
+function A:print() print("A:", self.x) end
+
+B = Class(function(self, x, y) A.construct(self, x) self.y = y end)
+Inherit(B, A)
+function B:print() print("B:", self.x, self.y) end
+function B:foo() print("foo") end
+
+one, two = B(1,2), B(3,4)
+result = one + two
+result:print() -- prints "A: 4"
+result:foo() -- error: method does not exist
+ Camera object to display only a partial region of the game world. The region + can be zoomed and rotated. You can transform camera coordinates to world coordinated + (e.g. get the location of the mouse in the game world). It is possible to have + more than one camera per game.
+Yay, free software:
+ ++ + +Copyright (c) 2010 Matthias Richter
+Permission is hereby granted, free of charge, to any person obtaining a copy + of this software and associated documentation files (the "Software"), to deal + in the Software without restriction, including without limitation the rights + to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + copies of the Software, and to permit persons to whom the Software is + furnished to do so, subject to the following conditions:
+ +The above copyright notice and this permission notice shall be included in + all copies or substantial portions of the Software.
+ +Except as contained in this notice, the name(s) of the above copyright holders + shall not be used in advertising or otherwise to promote the sale, use or + other dealings in this Software without prior written authorization.
+ +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + THE SOFTWARE.
You can download this project in either + zip or + tar formats.
+You can also clone the project with Git by running: +
$ git clone git://github.com/vrld/hump+ + - -
vrld
- - -- You can download this project in either - zip or - tar formats. -
-You can also clone the project with Git - by running: -
$ git clone git://github.com/vrld/hump- - - - -
