There are 3 method "this.add.rectangle()", "new Phaser.GameObjects.Rectangle()" and "fillRectShape()", when should I use which?

Solution 1:

The short Answer:

• if you need a Rectangle for bounderies or other calculations or so use: new Phaser.Geom.Rectangle(...)
• if you need a simple rectangle GameObject use: this.add.rectangle(...)
  • if you don't want to add it into the scene right away use: new Phaser.GameObjects.Rectangle(...)
• if you need special rectangle GameObject with more bells and whistles use: this.add.graphics(...)

The long Answer:

It depends on the task at hand. Since each Object creates more or less a differnet Object with different properties/methods.

• Type Phaser.GameObjects.Graphics:
  Is a GameObject but very "lowlevel", you can paint almost anything on it. like rectanlges, circles, ... but it's more work.
  Details can be found here https://photonstorm.github.io/phaser3-docs/Phaser.GameObjects.Graphics.html

Here an example of a special rectangle: https://phaser.io/examples/v3/view/game-objects/graphics/fill-rounded-rectangle

• Type Phaser.GameObjects.Rectangle:
  Is a GameObject as the Phaser.GameObjects.Graphics, but is specialized for creating rectangles.
  this.add.rectangle(...) and new Phaser.GameObjects.Rectangle(...) create both a rectangle of this type. this.add.rectangle is only a more convenient way to achive this, and adds it straight to the current scene.
  Details can be found here https://photonstorm.github.io/phaser3-docs/Phaser.GameObjects.Rectangle.html)

Here an example of basic rectangles: https://phaser.io/examples/v3/view/game-objects/shapes/rectangle

• Type Phaser.Geom.Rectangle:
  Is a geometric Shape, good for bounderies and/or other calculations (but you can also draw with it).
  Details can be found here https://photonstorm.github.io/phaser3-docs/Phaser.Geom.Rectangle.html

Here an example of how it is used to check if an GameObject is in a specific rectangle: https://phaser.io/examples/v3/view/geom/rectangle/contains-rect