PixiJS - Set sprite size to cover/contain

setSize.js

/*
    WIP
    Only works for full screen sprites.
    width: width of the sprite container
    height: height of the sprite container
    type: "cover" or "contain"
*/
PIXI.Sprite.prototype.setSize = function(width, height, type) {        
    var texture = { width: this.texture.width, height: this.texture.height },
        targetRatio = width / height,
        textureRatio = this.texture.width / this.texture.height,
        scale,
        pos = new PIXI.Point(0, 0);
        
    if (type == 'cover') {
        if (targetRatio > textureRatio) {            
            scale = width / texture.width;
            pos.y = -((texture.height * scale) - height) / 2
        } else {
            scale = height / texture.height;
            pos.x = -((texture.width * scale) - width) / 2
        }
    } else {
        if (targetRatio > textureRatio) {   
            scale = height / texture.height;
            pos.x = -((texture.width * scale) - width) / 2
        }
        else {
            scale = width / texture.width;
            pos.y = -((texture.height * scale) - height) / 2
        }
    }

    this.scale.set(scale);
    this.position = pos;
}

Usage:

sprite.setSize(width, height, "cover");

Example:

function setSpriteSize() {
    sprite.setSize(app.renderer.width, app.renderer.height, "cover");
}

window.addEventListener('resize', setSpriteSize);
setSpriteSize();