Performance Tips

General

• Only optimize when you need to! PixiJS can handle a fair amount of content off the bat
• Be mindful of the complexity of your scene. The more objects you add the slower things will end up
• Order can help, for example sprite / graphic / sprite / graphic is slower than sprite / sprite / graphic / graphic
• Some older mobile devices run things a little slower. Passing in the option useContextAlpha: false and antialias: false to the Renderer or Application can help with performance
• Culling is disabled by default as it's often better to do this at an application level or set objects to be cullable = true. If you are GPU-bound it will improve performance; if you are CPU-bound it will degrade performance

Sprites

• Use Spritesheets where possible to minimize total textures
• Sprites can be batched with up to 16 different textures (dependent on hardware)
• This is the fastest way to render content
• On older devices use smaller low resolution textures
• Add the extention @0.5x.png to the 50% scale-down spritesheet so PixiJS will visually-double them automatically
• Draw order can be important

Graphics

• Graphics objects are fastest when they are not modified constantly (not including the transform, alpha or tint!)
• Graphics objects are batched when under a certain size (100 points or smaller)
• Small Graphics objects are as fast as Sprites (rectangles, triangles)
• Using 100s of graphics complex objects can be slow, in this instance use sprites (you can create a texture)

Texture

• Textures are automatically managed by a Texture Garbage Collector
• You can also manage them yourself by using texture.destroy()
• If you plan to destroy more than one at once add a random delay to their destruction to remove freezing
• Delay texture destroy if you plan to delete a lot of textures yourself

Text

• Avoid changing it on every frame as this can be expensive (each time it draws to a canvas and then uploads to GPU)
• Bitmap Text gives much better performance for dynamically changing text
• Text resolution matches the renderer resolution, decrease resolution yourself by setting the resolution property, which can consume less memory

Masks

• Masks can be expensive if too many are used: e.g., 100s of masks will really slow things down
• Axis-aligned Rectangle masks are the fastest (as the use scissor rect)
• Graphics masks are second fastest (as they use the stencil buffer)
• Sprite masks are the third fastest (they uses filters). They are really expensive. Do not use too many in your scene!

Filters

• Release memory: displayObject.filters = null
• If you know the size of them: displayObject.filterArea = new PIXI.Rectangle(x,y,w,h). This can speed things up as it means the object does not need to be measured
• Filters are expensive, using too many will start to slow things down!

BlendModes

• Different blend modes will cause batches to break (de-optimize)
• SceenSprite / NormalSprite / SceenSprite / NormalSprite would be 4 draw calls
• SceenSprite / SceenSprite / NormalSprite / NormalSprite would be 2 draw calls

CacheAsBitmap

• Setting to true turns an object into a Sprite by caching it as a Texture
• It has a one time cost when it is activated as it draws the object to a Texture
• Avoid changing this on elements frequently
• If you have a complicated item that has lots of sprites / filters AND does not move then this will speed up rendering!
• Do not need apply to sprites as they are already Textures
• Do not use if the object where its children are constantly changing as this will slow things down

Events

• If an object has no interactive children use interactiveChildren = false. The event system will then be able to avoid crawling through the object
• Setting hitArea = new PIXI.Rectangle(x,y,w,h) as above should stop the event system from crawling through the object