Loading Spine atlases into Corona

Readme.md

Loading images from Spine atlases instead of separate files.

Add spine-atlas-loader.lua so you can require it, and use as shown in spineboy-demo-atlas.lua.

Make sure that directory has spineboy.json, spineboy.atlas and all spineboy.png.

So far only basic features are supported. Cropped sheets aren't supported.

Update: this version requires at least 2016.2892

Update: added support of min/mag filters, added warning about not currently supporting stripping whitespaces.

spine-atlas-loader.lua

local spineLoader = {}

local json = require "json"


local function parseAtlasFile( atlasPath )

	local function parseIntTuple4( l )
		local a,b,c,d = string.match( l , " ? ?%a+: ([+-]?%d+), ?([+-]?%d+), ?([+-]?%d+), ?([+-]?%d+)" )
		local a,b,c,d = tonumber( a ), tonumber( b ), tonumber( c ), tonumber( d )
		return a and b and c and d and {a, b, c ,d}
	end

	local function parseIntTuple2( l )
		local a,b = string.match( l , " ? ?%a+: ([+-]?%d+), ?([+-]?%d+)" )
		local a,b = tonumber( a ), tonumber( b )
		return a and b and {a, b}
	end
	
	if not atlasPath then
		print("Error: " .. path .. ".atlas" .. " doesn't exist!")
		return nil
	end 

	local atlasFile = io.open( atlasPath, "r" )
	if not atlasFile then
		print("Error: " .. path .. ".atlas" .. " doesn't exist!")
		return nil
	end

	local pages = {}

	local it = atlasFile:lines()
	for l in it do
		if #l == 0 then
			l = it()
			if l then
				local page = { name = l }
				l = it()
				page.size = parseIntTuple2( l )
				if page.size then
					l = it()
				end
				page.format = string.match( l, "%a+: (.+)" )
				page.filter = {string.match( it(), "%a+: (.+),(.+)" )}
				page.wrap = string.match( it(), "%a+: (.+)" )
				page.regions = {}
				table.insert( pages, page )
			else 
				break
			end
		else
			local region = {name = l}

			region.rotate = string.match( it(), "%a+: (.+)" ) == "true"
			region.xy = parseIntTuple2( it() )
			region.size = parseIntTuple2( it() )
			l = it()
			region.splits = parseIntTuple4(l)
			if region.splits then
				l = it()
				region.pad = parseIntTuple4(l)
				if region.pad then
					l = it()
				end
			end
			region.orig = parseIntTuple2( l )
			region.offset = parseIntTuple2( it() )
			region.index = tonumber( string.match( it() , "%a+: ([+-]?%d+)" ) )

			table.insert( pages[#pages].regions, region )
		end
	end
	atlasFile:close( )

	return pages
end


function spineLoader.load( name, dir )
	dir = dir or "/"
	if string.sub(dir, -1) ~= "/" then
		dir = dir .. "/"
	end

	local pages = parseAtlasFile( system.pathForFile( dir .. name ) )

	local sprites = {}

	for _,page in ipairs(pages) do
		local options = { frames={} }
		if page.size then
			options.sheetContentWidth, options.sheetContentHeight = unpack( page.size )
		end
		for i,region in ipairs(page.regions) do
			sprites[region.name] = { frame=i, region=region, page=page }
			local frame = {	}
			frame.x, frame.y = unpack(region.xy)
			frame.width, frame.height = unpack(region.size)
			if region.rotate then
				frame.width, frame.height = frame.height, frame.width
			end
			if region.offset[1] ~= 0 or region.offset[2] ~= 0 or region.size[1]  ~= region.orig[1] or region.size[2]  ~= region.orig[2] then
				print("WARNING: Corona currently does not srtipping whitespaces in Spine atlases")
			end
			table.insert( options.frames, frame )
		end

		local oldMag, oldMin = display.getDefault( "magTextureFilter" ), display.getDefault( "minTextureFilter" )
		local newMag, newMin = "linear", "linear"
		if string.find("Nearest", page.filter[1]) then
			newMin = "nearest"
		end
		if string.find("Nearest", page.filter[2]) then
			newMag = "nearest"
		end
		display.setDefault( "magTextureFilter", newMag )
		display.setDefault( "minTextureFilter", newMin )
		page.sheet = graphics.newImageSheet( dir..page.name, options )
		display.setDefault( "magTextureFilter", oldMag )
		display.setDefault( "minTextureFilter", oldMin )
	end
	
	function sprites.createImage(_, attachment)
		local sprite = sprites[attachment.name]
		local obj = display.newRect( 0, 0, 100, 100 ) 
		if sprite then
			obj.fill = { type="image", sheet=sprite.page.sheet, frame=sprite.frame}
			if sprite.region.rotate then
				obj.fill.rotation = 90
			end
		end
		return obj
	end
	function sprites.createMesh(_, attachment, meshParameters)
		local sprite = sprites[attachment.name]
		local obj = display.newMesh(meshParameters) 
		if sprite then
			obj.fill = { type="image", sheet=sprite.page.sheet, frame=sprite.frame}
			if sprite.region.rotate then
				obj.fill.rotation = 90
			end
		end
		return obj
	end

	function sprites.setupImageFunctions(skeleton)
		skeleton.createImage = sprites.createImage
		skeleton.createMesh = sprites.createMesh
	end

	return sprites
end


return spineLoader

spineboy-demo-atlas.lua

-- .....

local json = spine.SkeletonJson.new()
json.scale = 0.6
local skeletonData = json:readSkeletonDataFile("examples/spineboy-atlas/spineboy.json")

local skeleton = spine.Skeleton.new(skeletonData)

-- instead of setting up createImage/createMesh functions, use setupImageFunctions to do it
--                                 atlas filename,  directory with atlas and images
local sprites = atlasLoader.load( "spineboy.atlas", "examples/spineboy-atlas/" )
sprites.setupImageFunctions(skeleton)

-- ..... or setup manually

function skeleton:createImage(attachment)
	local obj = display.newRect( 0, 0, 100, 100 ) 
	local sprite = sprites[attachment.name]
	if sprite then
		obj.fill = { type="image", sheet=sprite.page.sheet, frame=sprite.frame}
		if sprite.region.rotate then
			obj.fill.rotation = 90
		end
	end
	return obj
end

function skeleton:createMesh(attachment, meshParameters)
	local obj = display.newMesh(meshParameters) 
	local sprite = sprites[attachment.name]
	print(attachment.name)
	if sprite then
		obj.fill = { type="image", sheet=sprite.page.sheet, frame=sprite.frame}
		if sprite.region.rotate then
			obj.fill.rotation = 90
		end
	end
	return obj
end