display-types 0.4.0

Shared display capability types for display connection negotiation.
Documentation 
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//! Resolved display configuration type.

use crate::cea861::HdmiForumFrl;
use crate::{ColorBitDepth, ColorFormat, VideoMode};

/// A resolved display configuration ready to program into hardware.
///
/// `ResolvedDisplayConfig` contains the hardware-relevant fields produced by a
/// display negotiation engine — the video mode, color encoding, transport
/// settings, and compression flags that a DRM driver or InfoFrame encoder
/// needs to configure the link.
///
/// # Design note
///
/// This type lives in `display-types` so that drivers, InfoFrame encoders, and
/// compositors can consume negotiation output without a direct dependency on the
/// negotiation engine. This mirrors how [`DisplayCapabilities`] lives here so
/// negotiation engines can consume parser output without depending on the parser.
///
/// [`DisplayCapabilities`]: crate::DisplayCapabilities
#[non_exhaustive]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
#[derive(Debug, Clone, PartialEq)]
pub struct ResolvedDisplayConfig {
    /// The resolved video mode.
    pub mode: VideoMode,

    /// Color encoding format for this configuration.
    pub color_encoding: ColorFormat,

    /// Color bit depth per channel.
    pub bit_depth: ColorBitDepth,

    /// FRL rate tier, or [`HdmiForumFrl::NotSupported`] for TMDS transport.
    pub frl_rate: HdmiForumFrl,

    /// Whether Display Stream Compression is required for this configuration.
    pub dsc_required: bool,

    /// Whether Variable Refresh Rate is applicable for this configuration.
    pub vrr_applicable: bool,
}

impl ResolvedDisplayConfig {
    /// Constructs a `ResolvedDisplayConfig`.
    pub fn new(
        mode: VideoMode,
        color_encoding: ColorFormat,
        bit_depth: ColorBitDepth,
        frl_rate: HdmiForumFrl,
        dsc_required: bool,
        vrr_applicable: bool,
    ) -> Self {
        Self {
            mode,
            color_encoding,
            bit_depth,
            frl_rate,
            dsc_required,
            vrr_applicable,
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::{ColorBitDepth, ColorFormat, VideoMode};

    #[test]
    fn new_roundtrips_all_fields() {
        let mode = VideoMode::new(3840, 2160, 60u32, false);
        let cfg = ResolvedDisplayConfig::new(
            mode.clone(),
            ColorFormat::Rgb444,
            ColorBitDepth::Depth10,
            HdmiForumFrl::Rate10Gbps4Lanes,
            true,
            false,
        );
        assert_eq!(cfg.mode, mode);
        assert_eq!(cfg.color_encoding, ColorFormat::Rgb444);
        assert_eq!(cfg.bit_depth, ColorBitDepth::Depth10);
        assert_eq!(cfg.frl_rate, HdmiForumFrl::Rate10Gbps4Lanes);
        assert!(cfg.dsc_required);
        assert!(!cfg.vrr_applicable);
    }

    #[test]
    fn tmds_config_uses_not_supported_frl() {
        let mode = VideoMode::new(1920, 1080, 60u32, false);
        let cfg = ResolvedDisplayConfig::new(
            mode,
            ColorFormat::Rgb444,
            ColorBitDepth::Depth8,
            HdmiForumFrl::NotSupported,
            false,
            true,
        );
        assert_eq!(cfg.frl_rate, HdmiForumFrl::NotSupported);
        assert!(cfg.vrr_applicable);
        assert!(!cfg.dsc_required);
    }
}