What is the way Phaser3 uses to sync texture position with its Body position?

[j.c]

for example, `matter.add.image` this way I created a MatterImage to my scene, the texture is added to displayList, and the body is added to the world, but I have read the source code, I could not find any clue where Phaser set the texture position according to it's body position in every frame step?

I think other engine uses the way in the frame step to set sprite position by a bound matterBody?

I need to figure out how Phaser achieves this, thank you very much.

 

[j.c]

in short, when Matter.Body updates, how does Phaser know I need to update my display's position, rotation etc?

[samme]

See Phaser.Physics.Matter.Components.Transform.

[j.c]

23 hours ago, samme said:

See Phaser.Physics.Matter.Components.Transform.

all code are just set _tempVec2 and Body position, no sync code found in it.

I think _tempVec2 this variable must be used at somewhere for example in render pipleline, but still I can't find any clue.

[samme]

I'm not sure there's any syncing at all. I think the body's coordinates are mapped directly onto the transform coordinates.

[j.c]

13 hours ago, samme said:

I'm not sure there's any syncing at all. I think the body's coordinates are mapped directly onto the transform coordinates.

emmm, yes, sorry I was stupid, I found in TextureTintPipeline.js:

spriteMatrix.applyITRS(sprite.x, sprite.y, sprite.rotation, sprite.scaleX, sprite.scaleY);

so in every frame this sprite.x returns body.x. so MatterXXXX class is actually a mixture of Sprite + Matter.Body.

thanks Samme

[j.c]

by the way, I think there is no "dirty" concept in Phaser? so every frame the render gets the newest position from its body?

for example, in PIXI, there is dirty flag in the Sprite class, once you set x or y, the updateBounds flag set to true.

so in this case, if only its Body updated, the sprite's display will not change because Body update does not emit any event to notify the sprite to reset its dirty flag and then to update its bounds.

 

[roberto257]

@j.c Can you explain how you implemented this? I am having the same issue