big bitmap as background. Performance?

MoKaLux

Hope you are all doing well
My question: how do you deal with big sprites as background?
For example I have a 5000 * 768 texture that I feed into a bitmap as a background for my game. It is quite big so I split it up into 6.
When I run my game it seems that it stutters at every image cut?!
How would you deal with this please?

I have read somewhere in the forum that I should hide (setvisible) my sprites until they are actually displayed. Any other tips?

MoKaLux

edit: found this thread http://forum.giderosmobile.com/discussion/comment/41861/#Comment_41861

MoKaLux

What about cutting it into tiles and then create a tilemap? Tiles are not drawn if outside the screen, is this the way to go?

I am going to try this (thank you antix for showing me how to use tilemaps )

rrraptor

Hm...no problem for me with 4k texture. Works fine on my phone aswell.

Test:

OBJ_NUM @ 10000 -- total amount of objects local minX, minY, maxX, maxY = application:getLogicalBounds()   local USE_BG = true local W = (maxX - minX) * 2 --4572 local H = (maxY - minY) * 2 --3328 local MX = W / 2 local MY = H / 2 local MID_DIST = math.length(MX, MY)   local Obj = Core.class(Sprite) local offset = 20 function Obj:init() self.dir = math.random(4) * (offset + math.random(90 - offset * 2)) * offset   self.w = math.random(10, 64) self.h = math.random(10, 64) self.speed = math.random(100, 500) self.vr = math.random(10,50) self.rotationDir = math.random() < 0.5 and 1 or -1 self.model = Pixel.new(math.random(0xffffff), 1, self.w, self.h) self:addChild(self.model)   --self:setPosition(MX, MY) end -- function Obj:update(dt) local x, y = self:getPosition()   self.dir += self.vr * self.rotationDir * dt   local theta = ^<self.dir local cosa = math.cos(theta) local sina = math.sin(theta) x += cosa * self.speed * dt y += sina * self.speed * dt   if x < 0 then x = W end if y < 0 then y = H end if x > W then x = 0 end if y > H then y = 0 end   local alpha = math.distance(x, y, MX, MY) / MID_DIST self:setAlpha(alpha) self:setRotation(self.dir) self:setPosition(x, y) end --   local scene = Sprite.new() local ind = 1 local mx, my = 0, 0 local objs = {} local timer = 0 scene:setScale(0.5)   if (USE_BG) then local tex = Texture.new("4k_texture.jpg", true) W = tex:getWidth() H = tex:getHeight() MX = W / 2 MY = H / 2 MID_DIST = math.length(MX, MY)   local img = Bitmap.new(tex) scene:addChild(img) ind = 2 end   stage:addChild(scene)   local tf = TextField.new(nil, "Fps: 00") tf:setPosition(40, 40) tf:setScale(2) stage:addChild(tf)   local function createObjects() for i = 1, OBJ_NUM do objs[i] = Obj.new() scene:addChildAt(objs[i], ind) end end   stage:addEventListener(Event.MOUSE_WHEEL, function(e) local s = scene:getScale() if (e.wheel < 0) then s -= 0.1 else s += 0.1 end scene:setScale(s) end)   stage:addEventListener("mouseDown", function(e) mx, my = e.x, e.y end)   stage:addEventListener("mouseMove", function(e) local x, y = scene:getPosition() x = x + e.x - mx y = y + e.y - my scene:setPosition(x, y) mx, my = e.x, e.y end)   stage:addEventListener("enterFrame", function(e) local dt = e.deltaTime timer += dt if (timer >= 1) then timer = 0 tf:setText(("Fps: %02d"):format(1 / dt)) end   for i = 1, #objs do objs[i]:update(dt) end end)   Core.asyncCall(createObjects)