TheSeamau5

sphereMesh : Int -> Vec3 -> Float -> Mesh
sphereMesh tesselation center radius =
  let normalize = (flip (/)) (toFloat tesselation)
      shift     = (+) -0.5
      scale     = (*) (2 * radius)
      transform = normalize >> shift >> scale
      latitudes  = map transform (map toFloat [0..tesselation])
      longitudes = latitudes
      plotPoint longitude latitude =
        let cosLatitude  = cos (pi * latitude / (toFloat tesselation))

TheSeamau5

-- STACKS

type Stack a = Bottom | Element a (Stack a)

push : a -> Stack a -> Stack a
push element stack = 
  Element element stack
  
  
pop : Stack a -> (Maybe a, Stack a)

TheSeamau5

#include <string>
#include <functional>

using namespace std;

template <typename T>
struct Maybe{
  T just;
  bool isNothing;
};

TheSeamau5

#include <string>

using namespace std;

template <typename First, typename Second>
struct Tuple{
    First first;
    Second second;
};

TheSeamau5

compute : Int -> (a -> a) -> a -> a
compute iterations function argument = 
    if (iterations <= 0) then argument
    else compute (iterations - 1) function (function argument)

TheSeamau5

#Exploring Entity Component Systems in Elm

Entity-Component-System (or ECS) is a pattern for designing programs that is prevalent in the games industry. This pattern consists of three simple parts:

• Entity : A uniquely identifiable object that may contain any number of components
• Component : A property usually representing the raw data of one aspect of the object. (Position is a component, Velocity is a component, Strength is a component, etc...)
• System : A continuous process performing actions on every entity that possesses a component of the same aspect as that system

To understand this, let us try to make a simple example: Boxes that move in space:

TheSeamau5

updateComponent = (updater, componentName, entity, requirementList) ->
  requirementList = requirementList || [];
  if (requirementList[requirement] for requirement in requirementList)?
    output = clone entity
    output[componentName] = updater output[componentName], output
    return output

TheSeamau5

Vector = (x,y) ->
  x : x || 0,
  y : y || 0

vAdd = (v,w) -> Vector (v.x + w.x), (v.y + w.y)


clone = (obj) ->
  if not obj? or typeof obj isnt 'object'
    return obj

TheSeamau5

import List (map, (::))
import Color (Color, rgb)
import Keyboard (arrows)
import Signal (Signal, (<~), foldp)
import Graphics.Collage (square, circle, move, filled, collage, Form)
import Graphics.Element (Element)

type alias Vector = {
    x : Float,
    y : Float

TheSeamau5

type alias Entity = {
  position : Vector,
  velocity : Vector,
  scale    : Vector,
  ...
}

type alias World = List Entity
type alias ComponentCreator = Entity -> Entity