//! `gasp` — Grid-fitting And Scan-conversion Procedure Table

//!

//! <https://learn.microsoft.com/en-us/typography/opentype/spec/gasp>

use crate::binary::read::{ReadBinary, ReadCtxt};

use crate::error::ParseError;

/// Flags indicating grid-fitting and anti-aliasing behavior for a ppem range.

#[derive(Copy, Clone, Debug, Default, PartialEq, Eq)]

pub struct GaspBehavior {

    pub flags: u16,

}

impl GaspBehavior {

    /// Use gridfitting (bytecode hinting).

    pub const GRIDFIT: u16 = 0x0001;

    /// Use grayscale rendering (anti-aliasing).

    pub const DOGRAY: u16 = 0x0002;

    /// Use gridfitting with ClearType symmetric smoothing.

    pub const SYMMETRIC_GRIDFIT: u16 = 0x0004;

    /// Use smoothing along multiple axes with ClearType.

    pub const SYMMETRIC_SMOOTHING: u16 = 0x0008;

}

/// A single range entry in the `gasp` table.

#[derive(Copy, Clone, Debug)]

pub struct GaspRange {

    /// Upper ppem limit for this range (inclusive).

    pub range_max_ppem: u16,

    /// Behavior flags for ppem values in this range.

    pub behavior: GaspBehavior,

}

/// The `gasp` (Grid-fitting And Scan-conversion Procedure) table.

///

/// Maps ppem size ranges to rendering behavior flags that control whether

/// bytecode hinting and/or anti-aliasing should be applied.

#[derive(Clone, Debug)]

pub struct GaspTable {

    pub version: u16,

    pub ranges: Vec<GaspRange>,

}

impl GaspTable {

    /// Look up the rendering behavior flags for a given ppem size.

    ///

    /// Scans the ranges in order and returns the flags for the first range

    /// whose `range_max_ppem` is >= the given ppem. If no range matches,

    /// returns default flags (gridfit + dogray).

        }

        // Default: enable everything

}

impl ReadBinary for GaspTable {

    type HostType<'a> = GaspTable;

        }

}