Discontinuous texture in ParallaxBackground if the texture has to be drawn more than twice on screen

[alexzheng]

Godot version:
3.1

OS/device including version:

Issue description:

if the width of the texture is smaller than the width of the device, there is a short gap between the textures.

Steps to reproduce:

Minimal reproduction project:

Uploading ParallaxBug.zip…

[akien-mga]

Your project upload did not complete, so it's a bit hard to do anything for this issue without more details.

[bojidar-bg]

@alexzheng Pretty bump, check above comment.

[alexzheng]

ParallaxBug.zip

[bojidar-bg]

I think this is sort-of by design, since ParallaxLayer's Mirroring shows things at most twice. See #15359.

[Xrayez]

I kinda work around this by setting Sprite/TextureRect region_rect/rect_size for them to repeat the texture and adjust mirroring size so that it matches viewport size or so (connecting size_changed in Viewport), and also multiply that by 2 to be sure. 😄

This "bug" is also very prominent when you zoom out big time with camera.

@bojidar-bg:

Mirroring shows things at most twice.

Should it repeat more than twice then? Something like mirror_count, which essentially translate to repeat_count which is a better name for this as you mentioned in #23243 (comment).

[Xrayez]

Also here's my hacky workaround snippet:

func _update_size():

	for canvas_idx in get_child_count():

		var canvas_layer = get_child(canvas_idx)
		if not canvas_layer is CanvasLayer:
			continue

		for idx in canvas_layer.get_child_count():

			var layer_node = canvas_layer.get_child(idx)
			if not layer_node is ParallaxLayer:
				continue

			var canvas = layer_node.get_node('canvas')

			var tex_size = canvas.texture.get_size()
			var vp_size = viewport.size
			var vp_scale = viewport.canvas_transform.get_scale()

			var q = vp_size / tex_size
			q = q / vp_scale
			q = q.ceil()

			var x = q.x * tex_size.x
			var y = q.y * tex_size.y

			var new_size = Vector2(x, y)
			new_size *= 2 # just to be sure it covers all

			# Update mirroring
			var mirroring = layer_node.motion_mirroring

			if mirroring.x > 0.0:
				mirroring.x = new_size.x

			if mirroring.y > 0.0:
				mirroring.y = new_size.y

			layer_node.motion_mirroring = mirroring

			# Update canvas size
			var canvas_size
			if canvas is TextureRect:
				canvas_size = canvas.rect_size
			elif canvas is Sprite:
				canvas_size = canvas.region_rect.size

			if mirroring.x > 0.0:
				canvas_size.x = new_size.x

			if mirroring.y > 0.0:
				canvas_size.y = new_size.y

			if canvas is TextureRect:
				canvas.rect_size = canvas_size
			elif canvas is Sprite:
				canvas.region_rect.size = canvas_size

[KoBeWi]

Still valid in 2ba96f0

[theBSH]

workaround might work but having mirror_count is something that I think should get added, don't think it will be hard to implement it.