New Font features

TextFont has been expanded to include new fields:

pub struct TextFont {
    pub font: FontSource,
    pub font_size: FontSize,
    pub weight: FontWeight,
    pub width: FontWidth,
    pub style: FontStyle,
    pub font_smoothing: FontSmoothing,
    pub font_features: FontFeatures,
}

FontSource has two variants: Handle, which identifies a font by asset handle, and Family, which selects a font by its family name.

FontWidth is a newtype struct representing OpenType font stretch classifications ranging from ULTRA_CONDENSED (50%) to ULTRA_EXPANDED (200%).

FontStyle is an enum used to set the slant style of a font, with variants Normal, Italic, or Oblique.

The system font support is very basic for now. To load them, you must enable the bevy/system_font_discovery feature.

Then they are available to be selected by family name using FontSource::Family via the FontCx resource.

The font_size field is now a FontSize, enabling responsive font sizing.

FontSize is an enum with variants:

pub enum FontSize {
    /// Font Size in logical pixels.
    Px(f32),
    /// Font size as a percentage of the viewport width.
    Vw(f32),
    /// Font size as a percentage of the viewport height.
    Vh(f32),
    /// Font size as a percentage of the smaller of the viewport width and height.
    VMin(f32),
    /// Font size as a percentage of the larger of the viewport width and height.
    VMax(f32),
    /// Font Size relative to the value of the `RemSize` resource.
    Rem(f32),
}

Rem units are currently resolved using RemSize, which is a new Resource. RemSize just newtypes an f32 currently.

Text2d's support for viewport coords is limited. A Text2d entity's resolved font size is always based on the size of the primary window, not on the size of its render target(s).