Rescaler

A layout component that will resize its children to match its own size. It will always preserve aspect ratio while resizing.

Usage

Update request

POST: /api/output/example_output/update
Content-Type: application/json

{
  "video": {
    "root": {
      "type": "view",
      "background_color": "#52505b",
      "children": [
        {
          "type": "rescaler",
          "child": { "type": "image", "image_id": "example_image" }
        },
        {
          "type": "rescaler",
          "mode": "fill",
          "child": { "type": "image", "image_id": "example_image" }
        }
      ]
    }
  }
}

Example output

Positioning

Absolute

A component is absolutely positioned if it defines fields like top, left, right, bottom, or rotation. Those fields define the component’s position relative to its parent. However, to respect those values, the parent component has to be a layout component that supports absolute positioning.

• Rescaler does not support absolute positioning for its child components. A child component will still be rendered, but all fields like top, left, right, bottom, and rotation will be ignored.
• Rescaler can be absolutely positioned relative to its parent, if the parent component supports it.

Static

Rescaler always have exactly one child that will be proportionally rescaled to match the parent.

Transitions

On the scene update, a Rescaler component will animate between the original state and the new one if the transition field is defined. Both the original and the new scene need to define a component with the same id. Currently, only some of the fields support animated transitions:

• width / height - Only supported within the same positioning mode. If the positioning mode changes between the old scene and the new one, the transition will not work.
• bottom / top / left / right / rotation - Only supports transition when changing a value of the same field. If the old scene defines a left field and the new one does not, the transition will not work.

Reference

Type definitions

type Rescaler = {
  id?: string;
  child: Component;
  mode?: "fit" | "fill";
  horizontal_align?: "left" | "right" | "justified" | "center";
  vertical_align?: "top" | "center" | "bottom" | "justified";
  width?: f32;
  height?: f32;
  top?: f32;
  left?: f32;
  bottom?: f32;
  right?: f32;
  rotation?: f32;
  transition?: Transition;
  border_radius?: f32;
  border_width?: f32;
  border_color?: string;
  box_shadow?: BoxShadow[];
}

Properties

id

ID of a component.

• Type: string

---

child

Exactly one child component.

• Type: Component

---

mode

Content resize mode.

• Type: "fit" | "fill"
• Default value: "fit"
• Supported values:
  • "fit" - Resizes the component to match one dimension of the parent while ensuring it remains fully visible.
  • "fill" - Resizes the component to cover the entire area of the parent by matching at least one dimension; excess is clipped.

---

horizontal_align

Horizontal alignment.

• Type: "left" | "right" | "justified" | "center"
• Default value: "center"

---

vertical_align

Vertical alignment.

• Type: "top" | "center" | "bottom" | "justified"
• Default value: "center"

---

width

Width of a component in pixels.

• Type: f32

Caution

The behavior of the Rescaler component varies depending on the type of its parent component:

• Non-layout parent - When the parent is not a layout component, the width property is required.
• Layout parent - For parents that are layout components, please refer to the relevant component documentation.

---

height

Height of a component in pixels.

• Type: f32

Caution

The behavior of the Rescaler component varies depending on the type of its parent component:

• Non-layout parent - When the parent is not a layout component, the height property is required.
• Layout parent - For parents that are layout components, please refer to the relevant component documentation.

---

top

Specifies the distance in pixels from the top edge of this component to the top edge of its parent component. If this attribute is set, the element will be positioned absolutely, overriding any layout constraints imposed by its parent.

• Type: f32

---

left

Specifies the distance in pixels from the left edge of this component to the left edge of its parent component. If this attribute is set, the element will be positioned absolutely, overriding any layout constraints imposed by its parent.

• Type: f32

---

bottom

Specifies the distance in pixels from the bottom edge of this component to the bottom edge of its parent component. If this attribute is set, the element will be positioned absolutely, overriding any layout constraints imposed by its parent.

• Type: f32

---

right

Specifies the distance in pixels from the right edge of this component to the right edge of its parent component. If this attribute is set, the element will be positioned absolutely, overriding any layout constraints imposed by its parent.

• Type: f32

---

rotation

Specifies the rotation of a component, measured in degrees. If this attribute is set, the element will be positioned absolutely, overriding any layout constraints imposed by its parent.

• Type: f32

---

transition

Defines how this component will behave during a scene update. This will only have an effect if the previous scene already contained a Rescaler component with the same id.

• Type: Transition

---

border_radius

Radius of a rounded corner.

• Type: f32
• Default value: 0.0

---

border_width

Border width.

• Type: f32
• Default value: 0.0

---

border_color

Border color in a "#RRGGBBAA" format.

• Type: string
• Default value: "#00000000"

---

box_shadow

List of box shadows.

• Type: BoxShadow[]

Transition

type Transition = {
  duration_ms: f64;
  easing_function?: EasingFunction;
}

Properties

duration_ms

Duration of a transition in milliseconds.

• Type: f64

---

easing_function

Easing functions are used to interpolate between two values over time during transition.

• Type: EasingFunction
• Default value: "linear"

BoxShadow

type BoxShadow = {
  offset_x?: f32;
  offset_y?: f32;
  color?: string;
  blur_radius?: f32;
}

Properties

offset_x

Specifies the horizontal offset on the x-axis. Positive values move the element to the right, negative values move it to the left.

• Type: f32
• Default value: 0.0

---

offset_y

Specifies the vertical offset on the y-axis. Positive values move the element downward, negative values move it upward.

• Type: f32
• Default value: 0.0

---

color

Color in a "#RRGGBBAA" format.

• Type: string
• Default value: #FFFFFFFF

---

blur_radius

Defines the radius of the blur effect.

• Type: f32
• Default value: 0.0

EasingFunction

type EasingFunction =
  | { function_name: "linear"; }
  | { function_name: "bounce"; }
  | {
      function_name: "cubic_bezier";
      points: [f64, f64, f64, f64];
    }

Easing functions are used to interpolate between two values over time.

Custom easing functions can be implemented with cubic Bézier. The control points are defined with points field by providing four numerical values: x1, y1, x2 and y2. The x1 and x2 values have to be in the range [0; 1]. The cubic Bézier result is clamped to the range [0; 1]. You can find example control point configurations here.

Properties

function_name

Duration of a transition in milliseconds.

• Type: linear | bounce | cubic_bezier
• Default value: linear
• Supported values:
  • linear
  • bounce
  • cubic_bezier

---

points

Four numerical values in [0; 1] range used for cubic Bézier. The result is clamped to the range [0; 1].

• Type: [f64, f64, f64, f64]