layer_mask.coffeelib/psd/ | |
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_ = require 'lodash'
Util = require './util.coffee'
Layer = require './layer.coffee' | |
The layer mask is the overarching data structure that describes both the layers/groups in the PSD document, and the global mask. This part of the document is ordered as such:
The file does not need to have a global mask. If there is none, then its length will be zero. | module.exports = class LayerMask
constructor: (@file, @header) ->
@layers = []
@mergedAlpha = false
@globalMask = null
skip: -> @file.seek @file.readInt(), true
parse: ->
maskSize = @file.readInt()
finish = maskSize + @file.tell()
return if maskSize <= 0
@parseLayers()
@parseGlobalMask() |
The layers are stored in the reverse order that we would like them. In other words, they're stored bottom to top and we want them top to bottom. | @layers.reverse()
@file.seek finish
parseLayers: ->
layerInfoSize = Util.pad2 @file.readInt()
if layerInfoSize > 0
layerCount = @file.readShort()
if layerCount < 0
layerCount = Math.abs layerCount
@mergedAlpha = true
for i in [0...layerCount]
@layers.push new Layer(@file, @header).parse()
layer.parseChannelImage() for layer in @layers
parseGlobalMask: ->
length = @file.readInt()
return if length <= 0
maskEnd = @file.tell() + length
@globalMask = _({}).tap (mask) =>
mask.overlayColorSpace = @file.readShort()
mask.colorComponents = [
@file.readShort() >> 8
@file.readShort() >> 8
@file.readShort() >> 8
@file.readShort() >> 8
]
mask.opacity = @file.readShort() / 16.0 |
0 = color selected, 1 = color protected, 128 = use value per layer | mask.kind = @file.readByte()
@file.seek maskEnd
|