RectBase2D

The RectBase2D node is an abstract node that is the base of almost all 2D user interface nodes. It cannot be used itself.

It contains all the parameters that enable placement of 2D content.

Platform support

This node is fully supported on XR-Windows platform.

It is partially supported on XR-Portable Windows, XR-Portable iOS, XR-Portable Android, and XR-P WASM platforms.

Due to different input/output management systems, the joyInputEnable, keyInputEnable and mouseInputEnable fields are not supported in the portable platforms.

Features

The main features of this new 2D content are:

• Better integration with XR Studio Graphic Context handler.

• Content parenting based on a parent field.

• Support for context rendering on a Texture2D object.

Position

The 2D nodes can be positioned inside a context node, such as Context or Global, or be children of other 2D nodes.

User interaction

Most of the 2D nodes support user interaction. For this reason, the 2D nodes have been designed to automatically support interaction by mouse, keyboard, and joypad without any further activity from the developer.

In order to let the user design new interaction behaviors, there are specific fields to disable automatic interaction management for gamepad (joyInputEnable) and keyboard (keyInputEnable).

Rendering modes

RectBase2D-derived class objects can be rendered on the screen in overlay or inside a Texture2D object.

They can be used to implement simulation of terminals inside the 3D world, or to give new interaction functionalities to 3D objects.

Content types for Images

Most RectBase2D nodes will load and display images.

The following content types can be used.

Updating mode

By default, all 2D content is updated by the so-called dirty system.

• When 2D content must be updated, its texture is added to the dirty system list.

• The update of the elements in the list is managed by the dirty system trying to optimize rendering performance.

• When elements request updating simultaneously, the 2D element update might be delayed, depending on FPS performance.

  You can set the updateMode for all the RectBase2D-derived nodes.

  Value	Description
  dirty	Content update is managed by the dirty system.
  direct	Content is instantly updated when item is visible. If content is hidden, update does not occur until item is made visible.

Setting the update mode to direct enables you to exclude items from control by the dirty management system.

Note: The updateMode parameter does not work when the 2D component is rendered in a Texture2D node, because the texture has its own refresh rate.

Size mode and anchoring

stretchToGrid

The StretchToGrid mode is the typical mode for fullscreen applications. Size and position of the 2D node are expressed in grid points.

• Grid points are defined by the set fullscreen resolution.

• When application is run in fullscreen, grid size and resolution are the same and the grid points correspond to pixels.

• When the application is windowed, the same grid points are represented in smaller area size (window area). This causes the 2D node to be stretched according to the ratio between window size and grid size.

keepSize

Use keepSize mode to avoid stretching 2D interfaces.

• When the 2D node is set to keepSize, the size and position are always expressed in pixels.

• When content is set to keepSize, it not only keeps the size but also the position. This is done using anchorH and anchorV parameters.

For horizontal anchoring:

• left—The content left border is kept to position.x pixels from left window border (positive values).

• right—The content right border is kept to position.x pixels from right window border (negative values).

• center—The content center is kept to position.x pixels from window half width (negative for going left, positive for going right)

• none—The content positioning behaves as in stretchToGrid mode by keeping the distance from left border proportional to screen width.

For vertical anchoring:

• top—The content top border is kept to position.y pixels from top window border (positive values).

• bottom—The content bottom border is kept to position.y pixels from bottom window border (negative values).

• center—The content center is kept to position.y pixels from window half height (negative for going up, positive for going down).

• none—The content positioning behaves as in stretchToGrid mode by keeping the distance from top border proportional to screen height.

Parenting

By using the parent field, RectBase2D-derived nodes can be grouped together. See parent and children fields in the fields table below.

Children nodes will inherit the position and scale of the parent. Therefore, parenting enables you to create composite 2D interfaces that can be moved and scaled together easily.

Parented 2D interface

When creating a parented 2D GUI:

• Set root node to keepSize sizeMode.

• Set its anchoring.

• Position it.

For all child nodes:

• Set node to keepSize sizeMode.

• Keep Top Left anchoring.

• Position child node with an offset referred to top left position of parent.

Mouse event propagation

RectBase2D nodes can be placed one over the other to create a complex UI. They are represented according to their order.

When a mouse event happens on a point where two or more RectBase2D nodes are overlying, the event is captured only by the RectBase2D that is on top.

In some cases, you might want to propagate the mouse event to the underlying RectBase2D node. For example, if a Rect2D with an image is positioned over a Button2D, you might want the button to react to click even when the pointer is over the image. You can achieve this by setting the propagateEvent field to true.

By default, the propagateEvent is set to false for all RectBase2D nodes—with the exception of Text2D and DynamicText2D.

Note: Mouse event propagation impacts Hotspotnstances of mode2D type. This means that any RectBase2D element drawn on the 2D overlay layer with propagateEvent set to false will prevent underlying hotspot interaction.

RectBase2D fields

These are the fields for RectBase2D node. Only the node-specific fields are indicated, not fields obtained by inheritance.

Field inheritance: NodeBase > RectBase2D