How would you recommend using Spine to cover these aspects, for a horizontal scrolling game?

• Different characters (e.g. man, boy, girl etc)
• Different costumes clothes (even just colors of outfits) - maybe assume clothes options/colors are specific to the character
• Powerups (e.g. backpack, shield, jetpack on back, cape that fly in the wind behind someone)
• Same animations for them all really

For example would you:

• draw the main character bones
• then draw bones of powerups, take cape flying the character as an advanced case, Then
• Characters: Use Spine "skins" for this
• Costumes per Character: ??? What would be the best option here. Can I assume red, green, blue shirt for example should be just part of the body image for that character (skin), but then you would need multiple skins for the same character so that wouldn't really work, e.g. you might need a Boy_RedShirt_BlackPants skin for example. So do you do this as attachments & then change programmatically? How do you ensure the shirt alignment with the body is spot on?
• Power Ups - e.g. Cape Flying behind a character (any character could get a cape) - So do you just create this as part of the character (nothing to do with a skin) and then just programmatically hide/show (haven't check the runtime API how hoping this is possible)? Is there a way to refer to the cape as one item? (i.e. as it may be multiple bones)

So overall I guess my two questions are:
1) how to handle costumes (character specific)
2) how to handle powerups (e.g. cape flying behind) (non character specific)

(I'm on the Corona/Lua runtime, however I'm assuming this is a general non-runtime specific question)

PS. Some additional thoughts re my two questions...

1) how to handle costumes (character specific) - From what I can tell this my not be easy. May be better to try to stick to characters having predefined clothes/clothes colors, then if need be follow the below "power up concept" if required. Comments?

2) how to handle powerups (e.g. cape flying behind) (non character specific) - Seems like would need to use bones. How can one turn on/off however (programmatically) a number of bones & their attachments in one hit? For example say the cape was 5 bones with images on each of them. How could you effectively turn on/off the cape in one hit?

thanks Nate - how about this specific question I asked that was buried in my last post: "How can one turn on/off however (programmatically) a number of bones & their attachments in one hit? For example say the cape was 5 bones with images on each of them. How could you effectively turn on/off the cape in one hit?"

I guess I am asking is there a way to group these bones or attachments in a way that lets you turn them on/off in one hit? Assuming it would be better to remove/re-attachment whole thing includes bones ideally, as opposed to just changing visibility?

thanks Nate

If I were to go through/understand the lua spine code would there be the functions/associations I need to create a custom function like this:

state:setBoneAndItsChildrenVisibility( boneName, booleanValue )

So the function could get the bone, and then "walk" done/through all children bones, and for each one change the "isVisible" property of the display object associated with the bone. Should this be possible?

Then if my powerup's attachments had their starting/parent bone from the skeleton appropriately named, e.g. shield, jetpack, I could then do this:

player.spineState:setBoneAndItsChildrenVisibility( "shield", false )
player.spineState:setBoneAndItsChildrenVisibility( "jetpack", true )

thanks Nate - so I think my question is basically this then...

Assuming I have a setup for a "cape" powerup which in Spine is something like this:

- capeBone1
  - capeSlot1
    - capeImage1
  - capeBone2  
    - capeSlot3
      - capeImage2
    - capeBone3
      - capeSlot3
         - capeImage3

So I could just do:

function setCape(turnOn)
  local image = turnOn and "head" or nil
  skeleton:setAttachment("capeSlot1", image)
  skeleton:setAttachment("capeSlot2", image)
  skeleton:setAttachment("capeSlot3", image)
end

But if I wanted a function that would work for any powerup, and I could just say "show" or "hide" at the root bone or slot for that powerup is this possible. So I think my question is:

Question: Can I retrieve a list of all the slots (slot names) under (i.e. children of) a given starting bone, and their images? So for the above is there a way to create a function to pass back to me in this case, "getSlotsAndImagesForBone("capeBone1")" and get a table with effectively in the table:

{ 
  { "capeSlot1", {capeImage1} }, 
  { "capeSlot2", {capeImage2} },
  { "capeSlot3", {capeImage3} },
}

There is no existing bone hierarchy I can access then correct? That is, there is no existing function like "getChildBonesForParentBone(parentBoneName)" then? So I would need to iterate through the bones in the data & effectively build the hierarchy, and then from this I could easily implement a "getchildBonesForParentBone(parentBoneName)" right?

Hi Nate

I've managed to find/determine the bones under a parent bone (see code below - not sure if it's the best way).

QUESTION: I'm not sure now (can find the write functions) how to get for each bone the slots & attachments under them? Which Lua file/method would I need to use here. I note in the JSON export there is a slot section that does seem to get for Slot/Attachment/Bone combinations but trying to find in the Corona LUA API how to get this.

That is to ultimately then be able to do the required "skeleton:setAttachment("slotNameX", "attachmentNameX")" for each slot/attachment for each of the bones identified.

Getting all Bones Hierarchically Under the Parent (including the Parent)

local function getChildBoneNames(parentBoneName)
   local childBoneNames = {}
   for i,boneData in ipairs(skeletonData.bones) do
      if boneData.parent then
         if boneData.parent.name == parentBoneName then
            table.insert(childBoneNames, boneData.name)
         end
      end
   end
   return childBoneNames
end

local function getChildBoneNamesRecursive(parentBoneName, includeParent)
   local allBoneNames = {}
   if includeParent then
      table.insert(allBoneNames, parentBoneName)
   end
   local nextChildBoneNames = getChildBoneNames(parentBoneName)
   if nextChildBoneNames then
      for i,childBoneName in ipairs(nextChildBoneNames) do
         local grandchildrenBoneNames = getChildBoneNamesRecursive(childBoneName, true)
         for i,boneName in ipairs(grandchildrenBoneNames) do
            table.insert(allBoneNames, boneName)
         end
      end
   end
   return allBoneNames
end

local childrenBones = getChildBoneNamesRecursive("capeBone1", true)
pretty.dump(childrenBones)

Update:

Ok - think I have it - this seems to work If anyone happens to use/optimize I'd be interested is seeing:

local function getChildBoneNames(parentBoneName)
   local childBoneNames = {}
   for i,boneData in ipairs(skeletonData.bones) do
      if boneData.parent then
         if boneData.parent.name == parentBoneName then
            table.insert(childBoneNames, boneData.name)
         end
      end
   end
   return childBoneNames
end

local function getChildBoneNamesRecursive(parentBoneName, includeParent)
   local allBoneNames = {}
   if includeParent then
      table.insert(allBoneNames, parentBoneName)
   end
   local nextChildBoneNames = getChildBoneNames(parentBoneName)
   if nextChildBoneNames then
      for i,childBoneName in ipairs(nextChildBoneNames) do
         local grandchildrenBoneNames = getChildBoneNamesRecursive(childBoneName, true)
         for i,boneName in ipairs(grandchildrenBoneNames) do
            table.insert(allBoneNames, boneName)
         end
      end
   end
   return allBoneNames
end

local function getBoneSlotAttachmentTable()
   local outputTable = {}
   local slots = skeleton.slots
   for i,slot in ipairs(slots) do
      outputTable[slot.data.boneData.name] = { slotName = slot.data.name, attachmentName = slot.data.attachmentName}
   end
   return outputTable
end

local function getBSAforParentBone(parentBoneName)
   local outputTable = {}
   local boneSlotAttachments = getBoneSlotAttachmentTable()
   local childrenBones = getChildBoneNamesRecursive(parentBoneName, true)
   for i,boneName in ipairs(childrenBones) do
      local slotAttachment = boneSlotAttachments[boneName]
      if slotAttachment then
         outputTable[boneName] = slotAttachment
      end
   

   end
   return outputTable
end


local function setPowerUp(parentBoneName, turnOn)
   local BSA = getBSAforParentBone(parentBoneName)
   for k,v in pairs(BSA) do
      local attachmentNameValue = turnOn and v.attachmentName or nil
      skeleton:setAttachment(v.slotName, attachmentNameValue)
   end
   return BSA
end



---

 Testing

timer.performWithDelay(2000, function(event)
   setPowerUp("capeBone1", false)
end)

timer.performWithDelay(4000, function(event)
   setPowerUp("capeBone1", true)
end)