A collection of functions for converting coordinates between different dimensions.

dimension.coffee

### Dimension Conversions ###

convertDimension =

    d2: {}
    d3: {}

### 2D Conversions ###

# Credit: https://stackoverflow.com/a/13091694/1544937
convertDimension.d2.d3 = d2$d3 = (x, y, zTarget = 0) ->

    vector = new THREE.Vector3()
    coordinates = new THREE.Vector3()

    vector.set (x / window.innerWidth) * 2 - 1, -(y / window.innerHeight) * 2 + 1, 0

    vector.unproject camera

    vector.sub(camera.position).normalize()

    distance = (zTarget - camera.position.z) / vector.z

    coordinates.copy(camera.position).add vector.multiplyScalar distance

    return coordinates

convertDimension.d2.d2 = d2$d2 = (x, y) -> new THREE.Vector2 x, y

### 3D Conversions ###

# Credit: https://stackoverflow.com/a/36706930/1544937
convertDimension.d3.d2 = d3$d2 = (x, y, z) ->

    halfWidth = window.innerWidth / 2
    halfHeight = window.innerHeight / 2

    coordinates = new THREE.Vector3 x, y, z

    coordinates.project camera

    coordinates.x = coordinates.x * halfWidth + halfWidth
    coordinates.y = -coordinates.y * halfHeight + halfHeight

    return new THREE.Vector2 coordinates.x, coordinates.y

convertDimension.d3.d3 = d3$d3 = (x, y, z) -> new THREE.Vector3 x, y, z

dimension.js

/* Dimension Conversions */

var convertDimension, d2$d2, d2$d3, d3$d2, d3$d3;

convertDimension = {
  d2: {},
  d3: {}
};

/* 2D Conversions */
// Credit: https://stackoverflow.com/a/13091694/1544937
convertDimension.d2.d3 = d2$d3 = function(x, y, zTarget = 0) {
  var coordinates, distance, vector;
  vector = new THREE.Vector3();
  coordinates = new THREE.Vector3();
  vector.set((x / window.innerWidth) * 2 - 1, -(y / window.innerHeight) * 2 + 1, 0);
  vector.unproject(camera);
  vector.sub(camera.position).normalize();
  distance = (zTarget - camera.position.z) / vector.z;
  coordinates.copy(camera.position).add(vector.multiplyScalar(distance));
  return coordinates;
};

convertDimension.d2.d2 = d2$d2 = function(x, y) {
  return new THREE.Vector2(x, y);
};

/* 3D Conversions */
// Credit: https://stackoverflow.com/a/36706930/1544937
convertDimension.d3.d2 = d3$d2 = function(x, y, z) {
  var coordinates, halfHeight, halfWidth;
  halfWidth = window.innerWidth / 2;
  halfHeight = window.innerHeight / 2;
  coordinates = new THREE.Vector3(x, y, z);
  coordinates.project(camera);
  coordinates.x = coordinates.x * halfWidth + halfWidth;
  coordinates.y = -coordinates.y * halfHeight + halfHeight;
  return new THREE.Vector2(coordinates.x, coordinates.y);
};

convertDimension.d3.d3 = d3$d3 = function(x, y, z) {
  return new THREE.Vector3(x, y, z);
};