separating-axis-test/test/flat2d.js

test for the intersection of convex polytopes in 2d or 3d, computing the minimum translation vector

var sat2d = require('../2d.js')
var test = require('tape')

test('flat axis-aligned boxes 2d', function (t) {
  t.deepEqual(sat2d(
    [],
    {
      separatingAxes:[0,1,1,0],
      positions: [0,1,1,1,1,0,0,0]
    },
    {
      separatingAxes:[0,1,1,0],
      positions: [-0.6,0.5,0.4,0.5,0.4,-0.5,-0.6,-0.5]
    }
  ), [0.4,0.0])
  t.deepEqual(sat2d(
    [],
    {
      separatingAxes:[0,1,1,0],
      positions: [0,1,1,1,1,0,0,0]
    },
    {
      separatingAxes:[0,1,1,0],
      positions: [-0.5,0.4,0.5,0.4,0.5,-0.6,-0.5,-0.6]
    }
  ), [0.0,0.4])
  t.deepEqual(sat2d(
    [],
    {
      separatingAxes:[0,1,1,0],
      positions: [0,1,1,1,1,0,0,0]
    },
    {
      separatingAxes:[0,1,1,0],
      positions: [-0.5,1.5,0.5,1.5,0.5,0.5,-0.5,0.5]
    }
  ), [0.5,0.0])
  t.notOk(sat2d(
    [],
    {
      separatingAxes:[0,1,1,0],
      positions: [0,1,1,1,1,0,0,0]
    },
    {
      separatingAxes:[0,1,1,0],
      positions: [-0.5,-0.5,0.5,-0.5,0.5,-1.5,-0.5,-1.5]
    }
  ))
  t.end()
})

test('flat oriented boxes 2d', function (t) {
  var sq22 = Math.sqrt(2)/2
  t.deepEqual(roundv2(1000,sat2d(
    [],
    {
      separatingAxes:[0,1,1,0],
      positions: [0,1,1,1,1,0,0,0]
    },
    {
      separatingAxes:[sq22,sq22,-sq22,sq22],
      positions: [-0.3,0.5,+0.2,0.0,-0.3,-0.5,-0.8,0.0]
    }
  )),[0.1,0.1])
  t.notOk(sat2d(
    [],
    {
      separatingAxes:[0,1,1,0],
      positions: [0,1,1,1,1,0,0,0]
    },
    {
      separatingAxes:[sq22,sq22,-sq22,sq22],
      positions: [-0.3,0.25,+0.2,-0.25,-0.3,-0.75,-0.8,-0.25]
    }
  ))
  t.end()
})

function roundv2 (n, v) {
  v[0] = Math.round(v[0]*n)/n
  v[1] = Math.round(v[1]*n)/n
  return v
}