### Overview

Niri has several animations which you can configure in the same way.
Additionally, you can disable or slow down all animations at once.

Here's a quick glance at the available animations with their default values.

```
animations {
    // Uncomment to turn off all animations.
    // You can also put "off" into each individual animation to disable it.
    // off

    // Slow down all animations by this factor. Values below 1 speed them up instead.
    // slowdown 3.0

    // Individual animations.

    workspace-switch {
        spring damping-ratio=1.0 stiffness=1000 epsilon=0.0001
    }

    window-open {
        duration-ms 150
        curve "ease-out-expo"
    }

    window-close {
        duration-ms 150
        curve "ease-out-quad"
    }

    horizontal-view-movement {
        spring damping-ratio=1.0 stiffness=800 epsilon=0.0001
    }

    window-movement {
        spring damping-ratio=1.0 stiffness=800 epsilon=0.0001
    }

    window-resize {
        spring damping-ratio=1.0 stiffness=800 epsilon=0.0001
    }

    config-notification-open-close {
        spring damping-ratio=0.6 stiffness=1000 epsilon=0.001
    }
}
```

### Animation Types

There are two animation types: easing and spring.
Each animation can be either an easing or a spring.

#### Easing

This is a relatively common animation type that changes the value over a set duration using an interpolation curve.

To use this animation, set the following parameters:

- `duration-ms`: duration of the animation in milliseconds.
- `curve`: the easing curve to use.

```
animations {
    window-open {
        duration-ms 150
        curve "ease-out-expo"
    }
}
```

Currently, niri only supports three curves:

- `ease-out-quad` <sup>Since: 0.1.5</sup>
- `ease-out-cubic`
- `ease-out-expo`

You can get a feel for them on pages like [easings.net](https://easings.net/).

#### Spring

Spring animations use a model of a physical spring to animate the value.
They notably feel better with touchpad gestures, because they take into account the velocity of your fingers as you release the swipe.
Springs can also oscillate / bounce at the end with the right parameters if you like that sort of thing, but they don't have to (and by default they mostly don't).

Due to springs using a physical model, the animation parameters are less obvious and generally should be tuned with trial and error.
Notably, you cannot directly set the duration.
You can use the [Elastic](https://flathub.org/apps/app.drey.Elastic) app to help visualize how the spring parameters change the animation.

A spring animation is configured like this, with three mandatory parameters:

```
animations {
    workspace-switch {
        spring damping-ratio=1.0 stiffness=1000 epsilon=0.0001
    }
}
```

The `damping-ratio` goes from 0.1 to 10.0 and has the following properties:

- below 1.0: underdamped spring, will oscillate in the end.
- above 1.0: overdamped spring, won't oscillate.
- 1.0: critically damped spring, comes to rest in minimum possible time without oscillations.

However, even with damping ratio = 1.0, the spring animation may oscillate if "launched" with enough velocity from a touchpad swipe.

> [!WARNING]
> Overdamped springs currently have some numerical stability issues and may cause graphical glitches.
> Therefore, setting `damping-ratio` above `1.0` is not recommended.

Lower `stiffness` will result in a slower animation more prone to oscillation.

Set `epsilon` to a lower value if the animation "jumps" at the end.

> [!TIP]
> The spring *mass* (which you can see in Elastic) is hardcoded to 1.0 and cannot be changed.
> Instead, change `stiffness` proportionally.
> E.g. increasing mass by 2× is the same as decreasing stiffness by 2×.

### Animations

Now let's go into more detail on the animations that you can configure.

#### `workspace-switch`

Animation when switching workspaces up and down, including after the vertical touchpad gesture (a spring is recommended).

```
animations {
    workspace-switch {
        spring damping-ratio=1.0 stiffness=1000 epsilon=0.0001
    }
}
```

#### `window-open`

Window opening animation.

This one uses an easing type by default.

```
animations {
    window-open {
        duration-ms 150
        curve "ease-out-expo"
    }
}
```

#### `window-close`

<sup>Since: 0.1.5</sup>

Window closing animation.

This one uses an easing type by default.

```
animations {
    window-open {
        duration-ms 150
        curve "ease-out-quad"
    }
}
```

#### `horizontal-view-movement`

All horizontal camera view movement animations, such as:

- When a window off-screen is focused and the camera scrolls to it.
- When a new window appears off-screen and the camera scrolls to it.
- After a horizontal touchpad gesture (a spring is recommended).

```
animations {
    horizontal-view-movement {
        spring damping-ratio=1.0 stiffness=800 epsilon=0.0001
    }
}
```

#### `window-movement`

<sup>Since: 0.1.5</sup>

Movement of individual windows within a workspace.

Includes:

- Moving window columns with `move-column-left` and `move-column-right`.
- Moving windows inside a column with `move-window-up` and `move-window-down`.
- Moving windows out of the way upon window opening and closing.
- Window movement between columns when consuming/expelling.

This animation *does not* include the camera view movement, such as scrolling the workspace left and right.

```
animations {
    window-movement {
        spring damping-ratio=1.0 stiffness=800 epsilon=0.0001
    }
}
```

#### `window-resize`

<sup>Since: 0.1.5</sup>

Window resize animation.

Only manual window resizes are animated, i.e. when you resize the window with `switch-preset-column-width` or `maximize-column`.
Also, very small resizes (up to 10 pixels) are not animated.

```
animations {
    window-resize {
        spring damping-ratio=1.0 stiffness=800 epsilon=0.0001
    }
}
```

#### `config-notification-open-close`

The open/close animation of the config parse error and new default config notifications.

This one uses an underdamped spring by default (`damping-ratio=0.6`) which causes a slight oscillation in the end.

```
animations {
    config-notification-open-close {
        spring damping-ratio=0.6 stiffness=1000 epsilon=0.001
    }
}
```

### Synchronized Animations

<sup>Since: 0.1.5</sup>

Sometimes, when two animations are meant to play together synchronized, niri will drive them both with the same configuration.

For example, if a window resize causes the view to move, then that view movement animation will also use the `window-resize` configuration (rather than the `horizontal-view-movement` configuration).
This is especially important for animated resizes to look good when using `center-focused-column "always"`.

As another example, resizing a window in a column vertically causes other windows to move up or down into their new position.
This movement will use the `window-resize` configuration, rather than the `window-movement` configuration, to keep the animations synchronized.

A few actions are still missing this synchronization logic, since in some cases it is difficult to implement properly.
Therefore, for the best results, consider using the same parameters for related animations (they are all the same by default):

- `horizontal-view-movement`
- `window-movement`
- `window-resize`