Drawing mouse selection area (rubber band)

[Stiffler]

Hi,

I'm new in Pixi, and I have a new job 

We are using pixi, unfortunately it is Pixi v3. I have small task to do and I'm doing pretty well with pixi so far, but I have to do something more complex. 

Basically I would like to create selecting area called (as I googled) rubber band. It is the same like you selecting couple of icons on windows desktop but on canvas. I was wondering how to do it. 
I think that the best it would be to create rectangle what resize on mouse move and calculate it by the mouse start and end coordination, it would be not so hard to achieve if user would try to select only from left to right, because that how we draw rectangles in pixi. Am I right? I don't have idea how to do it if user would select from right to left, how to draw this rectangle to looks like "selecting area".

Or maybe I am totally wrong and there is easier solution?

Anyway I would be appreciated of any help.

Best regards

Artur

[ivan.popelyshev]

>  it would be not so hard to achieve if user would try to select only from left to right, because that how we draw rectangles in pixi.

I thought it works right-to-left too

[ClusterAtlas]

Uhm, I think identifying on which quadrant the mouse pointer currently is during the drag would be a good place to start  

I mean, if mouse_pointer_current_position.X > selection_origin.X = it's left to right;

otherwise if mouse_pointer_current_position.X < selection_origin.X = you get the difference between those two x-axis values, then subtract it from selection_origin.X then you get your rectangle's X1.. correct?

[ivan.popelyshev]

Oh, you are talking about rectangle.. Well , there is "Bounds" class that does not care about that: https://github.com/pixijs/pixi.js/blob/dev/src/core/display/Bounds.js , and it can save result to rectangle (getRectangle method)

[Kalith]

Seems fairly easy.

	var p1, p2 //your mouse points
	var x = Math.min(p1.x, p2.x)
	var y = Math.min(p1.y, p2.y)
	var width = Math.max(p1.x, p2.x) - x
	var height = Math.max(p1.y, p2.y) - y
	//draw your rectangle
	

[grosjardin]

Hi,

I am trying to achieve the same results with Pixi-viewport's world coordinates. I didnt find any event in the pixi-viewport API that would give me the mouse-down / mouse-up coordinates, except drag-start and drag-end, but using those without actually dragging doesnt seem possible. 

Any idea how to get the world coordinates mouse points ?

Thanks

[Jammy]

1 hour ago, grosjardin said:

Hi,

I am trying to achieve the same results with Pixi-viewport's world coordinates. I didnt find any event in the pixi-viewport API that would give me the mouse-down / mouse-up coordinates, except drag-start and drag-end, but using those without actually dragging doesnt seem possible. 

Any idea how to get the world coordinates mouse points ?

Thanks

Does toWorld work? https://davidfig.github.io/pixi-viewport/jsdoc/Viewport.html#toWorld

[grosjardin]

22 hours ago, Jammy said:

Does toWorld work? https://davidfig.github.io/pixi-viewport/jsdoc/Viewport.html#toWorld

I'm not sure I understand how PIXI Point can help me. I still need a click event no?

What do I pass to toWorld() ?

 

EDIT: Thanks, this works

this.app.renderer.plugins.interaction.on('pointerdown', (e) => {
    this.rectangleStart = this.viewport.toWorld(e.data.global.x, e.data.global.y)
})

Edited July 24, 2020 by grosjardin