codecombat/app/lib/world/world_utils.coffee
2014-03-13 17:59:17 -07:00

146 lines
6.5 KiB
CoffeeScript

Vector = require './vector'
Rectangle = require './rectangle'
Grid = require './Grid'
module.exports.typedArraySupport = typedArraySupport = Float32Array? # Not in IE until IE 10; we'll fall back to normal arrays
#module.exports.typedArraySupport = typedArraySupport = false # imitate IE9 (and in God.coffee)
unless ArrayBufferView?
# https://code.google.com/p/chromium/issues/detail?id=60449
if typedArraySupport
# We have it, it's just not exposed
someArray = new Uint8Array(0)
if someArray.__proto__
# Most browsers
ArrayBufferView = someArray.__proto__.__proto__.constructor
else
# IE before 11
ArrayBufferView = Object.getPrototypeOf(Object.getPrototypeOf(someArray)).constructor
else
# If we don't have typed arrays, we don't need an ArrayBufferView
ArrayBufferView = null
module.exports.clone = clone = (obj, skipThangs=false) ->
# http://coffeescriptcookbook.com/chapters/classes_and_objects/cloning
if not obj? or typeof obj isnt 'object'
return obj
if obj instanceof Date
return new Date(obj.getTime())
if obj instanceof RegExp
flags = ''
flags += 'g' if obj.global?
flags += 'i' if obj.ignoreCase?
flags += 'm' if obj.multiline?
flags += 'y' if obj.sticky?
return new RegExp(obj.source, flags)
if (obj instanceof Vector) or (obj instanceof Rectangle)
return obj.copy()
if skipThangs and obj.isThang
return obj
if ArrayBufferView and obj instanceof ArrayBufferView
newInstance = new obj.constructor obj
else
newInstance = new obj.constructor()
for key of obj
newInstance[key] = clone obj[key]
newInstance
# Walk a key chain down to the value. Can optionally set newValue instead.
module.exports.downTheChain = downTheChain = (obj, keyChain, newValue=undefined) ->
return null unless obj
return obj[keyChain] unless _.isArray keyChain
value = obj
while keyChain.length and value
if newValue isnt undefined and keyChain.length is 1
value[keyChain[0]] = newValue
return newValue
value = value[keyChain[0]]
keyChain = keyChain[1..]
return value
module.exports.now = (if window?.performance?.now? then (-> window.performance.now()) else (-> new Date()))
module.exports.consolidateThangs = consolidateThangs = (thangs) ->
debug = false
isStructural = (t) -> t.stateless and t.collides and t.collisionCategory is 'obstacles' and t.shape in ['box', 'sheet'] and t.restitution is 1.5 and (t.pos.x - t.width / 2 >= 0) and (t.pos.y - t.height / 2 >= 0)
structural = _.remove thangs, isStructural
return unless structural.length
rightmost = _.max structural, (t) -> t.pos.x + t.width / 2
topmost = _.max structural, (t) -> t.pos.y + t.height / 2
leftmost = _.min structural, (t) -> t.pos.x - t.width / 2
bottommost = _.min structural, (t) -> t.pos.y - t.height / 2
console.log "got rightmost", rightmost.id, "topmost", topmost.id, "lefmostmost", leftmost.id, "bottommost", bottommost.id, "out of", structural.length, "structural thangs" if debug
left = Math.min 0, leftmost.pos.x - leftmost.width / 2
bottom = Math.min 0, bottommost.pos.y - bottommost.height / 2
if (left < 0) or (bottom < 0)
console.error "Negative structural Thangs aren't supported, sorry!" # TODO: largestRectangle, AI System, and anything else that accesses grid directly need updating to finish this
left = 0
bottom = 0
width = rightmost.pos.x + rightmost.width / 2 - left
height = topmost.pos.y + topmost.height / 2 - bottom
padding = 0
console.log "got max width", width, "height", height, "left", left, "bottom", bottom, "of thangs", thangs.length, "structural", structural.length if debug
grid = new Grid structural, width, height, padding, left, bottom
console.log grid.toString() if debug
# Approach: start at bottom left. Go right, then up. At each occupied grid square, find the largest rectangle we can make starting at that corner, add a corresponding Thang to the grid, and unmark all occupied grid squares.
# Since it's not like we're going to do any of these:
# http://stackoverflow.com/questions/5919298/algorithm-for-finding-the-fewest-rectangles-to-cover-a-set-of-rectangles
# http://stackoverflow.com/questions/4701887/find-the-set-of-largest-contiguous-rectangles-to-cover-multiple-areas
dissection = []
for y in grid.columns bottom, height
for x in grid.rows left, width
continue unless grid.grid[y][x].length
rect = largestRectangle grid, y, x, false, debug
vertices = rect.vertices()
for y2 in [vertices[0].y ... vertices[1].y] # maybe ..?
for x2 in [vertices[0].x ... vertices[2].x] # maybe ..?
grid.grid[y2][x2] = []
console.log grid.toString() if debug
thang = structural[dissection.length] # grab one we already know is configured properly
console.error "Hmm, our dissection has more Thangs than the original structural Thangs?", dissection.length unless thang
thang.width = rect.width
thang.height = rect.height
thang.pos.x = rect.x
thang.pos.y = rect.y
thang.createBodyDef()
dissection.push thang
console.log "Turned", structural.length, "structural Thangs into", dissection.length, "dissecting Thangs."
thangs.push dissection...
structural[dissection.length ... structural.length]
module.exports.largestRectangle = largestRectangle = (grid, bottomY, leftX, wantEmpty, debug) ->
# If wantEmpty, then we try to cover empty rectangles.
# Otherwise, we try to cover occupied rectangles.
coveredRows = []
shortestCoveredRow = grid.width - leftX
for y in grid.columns bottomY, grid.height
coveredRow = 0
for x in grid.rows leftX, leftX + shortestCoveredRow
if Boolean(grid.grid[y][x].length) isnt wantEmpty
++coveredRow
else
break
break unless coveredRow
coveredRows.push coveredRow
shortestCoveredRow = Math.min(shortestCoveredRow, coveredRow)
console.log "largestRectangle() for", bottomY, leftX, "got coveredRows", coveredRows if debug
[maxArea, maxAreaRows, maxAreaRowLength, shortestRow] = [0, 0, 0, 0]
for rowLength, rowIndex in coveredRows
shortestRow ||= rowLength
area = rowLength * (rowIndex + 1)
if area > maxArea
maxAreaRows = rowIndex + 1
maxAreaRowLength = shortestRow
maxArea = area
shortestRow = Math.min(rowLength, shortestRow)
console.log "So largest rect has area", maxArea, "with", maxAreaRows, "rows of length", maxAreaRowLength if debug
rect = new Rectangle leftX + maxAreaRowLength / 2, bottomY + maxAreaRows / 2, maxAreaRowLength, maxAreaRows
console.log "That corresponds to a rectangle", rect.toString() if debug
rect