customblockanim

--customblockanim.lua by Enjl
--simple block animation helper to make multi-frame blocks easier as per version SMBX2bmx3
--ver 1.0

local cba = {}

local blocks = {}

local stock0 = Graphics.loadImage(Misc.resolveFile("graphics/stock-0.png"))

local deferred = {}

local firstFrame = true

local function registerBlock(id, args)
    args = args or {}
    if id == nil then
        error("ID must be specified when registering new block animation.")
        return
    end
    local image = args.image
    if image == nil then
        image = Graphics.sprites.block[id].img
        Graphics.sprites.block[id].img = stock0
    end
    local frames = args.frames or 4
    local framespeed = args.framespeed or 8
    local opacity = args.opacity or 1
    local priority = args.priority or -65
    local w = image.width
    local h = image.height / frames
    blocks[id] = {f = frames, fs = framespeed, img = image, w = w, h = h, o = opacity, p = priority}

    for k,v in ipairs(Block.get(id)) do
        v.width = w
        v.height = h
    end
end

-- Call this. ID is mandatory, args are:
---frames
---framespeed
---opacity
---priority
---image

function cba.register(id, args)
    if firstFrame then
        table.insert(deferred, {id = id, args = args})
    else
        registerBlock(id, args)
    end
end

function cba.onInitAPI()
    registerEvent(cba, "onCameraDraw")
    registerEvent(cba, "onStart")
end

local timer = 0

function cba.onStart()
    for k,v in ipairs(deferred) do
        registerBlock(v.id, v.args)
    end
end

function cba.onCameraDraw()
    timer = timer + 1
    for k,v in ipairs(Block.getIntersecting(camera.x, camera.y, camera.x + camera.width, camera.y + camera.height)) do
        if blocks[v.id] then
            if (not v.isHidden) and v:mem(0x5A, FIELD_WORD) == 0 then
                local bv = blocks[v.id]
                Graphics.drawImageToSceneWP(bv.img, v.x, v.y + v:mem(0x56, FIELD_WORD), 0, bv.h * (math.floor(timer/bv.fs)%bv.f), bv.w, bv.h, bv.o, bv.p)
            end
        end
    end
end

return cba