cadcraft/crates/engine/src/cmd/draw2/rect.rs

use super::{
    Accept, EntityKind, Input, Interactive, PolyVertex, Prompt, Result, Session, Step, Value, Vec2, added, bad, bool_or, curves, f64_or, lwpoly,
    number, other, point_param, point_req, rect_with_corners, size_param,
};
use crate::last_used::RectangModes;

// =====================================================================================
// RECTANG with Area / Dimensions / Rotation / Width / Elevation / Thickness
// =====================================================================================

fn rect_kind(first: Vec2, (w, h): (f64, f64), rot: f64, fillet: f64, chamfer: (f64, f64), width: f64, elevation: f64) -> EntityKind {
    let local = rect_with_corners(Vec2::ZERO, Vec2::new(w, h), fillet, chamfer);
    let vs = local.into_iter().map(|v| PolyVertex { p: first + v.p.rotate(rot), ..v }).collect();
    let mut k = lwpoly(vs, true);
    if let EntityKind::LwPolyline(pl) = &mut k {
        pl.const_width = width.max(0.0);
        pl.elevation = elevation;
    }
    k
}

/// The width and height of a rectangle from its `dimensions`, its `p2` corner, its `area` with
/// `length` or `breadth`, or its second corner `p2`, rotated by `rot` about `a`.
fn rect_size(p: &Value, a: Vec2, rot: f64, centered: bool) -> Result<(f64, f64)> {
    Ok(if let Some(d) = p.get("dimensions").and_then(Value::as_array) {
        let l = d.first().and_then(Value::as_f64).filter(|v| v.is_finite()).ok_or_else(|| bad("rectang", "dimensions: [length, width]"))?;
        let wd = d.get(1).and_then(Value::as_f64).filter(|v| v.is_finite()).ok_or_else(|| bad("rectang", "dimensions: [length, width]"))?;
        let (sx, sy) = match point_param(p, "p2") {
            Some(q) => {
                let loc = (q - a).rotate(-rot);
                (if loc.x < 0.0 { -1.0 } else { 1.0 }, if loc.y < 0.0 { -1.0 } else { 1.0 })
            }
            None => (1.0, 1.0),
        };
        (l.abs() * sx, wd.abs() * sy)
    } else if let Some(area) = p.get("area").and_then(Value::as_f64).filter(|v| v.is_finite()) {
        if area <= 0.0 {
            return Err(bad("rectang", "area must be positive"));
        }
        match (p.get("length").and_then(Value::as_f64), p.get("breadth").and_then(Value::as_f64)) {
            (Some(l), _) if l.is_finite() && l > 0.0 => (l, area / l),
            (_, Some(b)) if b.is_finite() && b > 0.0 => (area / b, b),
            _ => return Err(bad("rectang", "area needs `length` or `breadth`")),
        }
    } else {
        let b = point_req("rectang", p, "p2")?;
        let loc = (b - a).rotate(-rot);
        // In centre mode the picked point is one corner, mirrored across the centre.
        if centered { (2.0 * loc.x, 2.0 * loc.y) } else { (loc.x, loc.y) }
    })
}

/// Draws a rectangle from the JSON form: `p1` is a corner, or the centre when `center` is
/// true, and the size comes from `p2`, `dimensions` or `area` plus `length`/`breadth`.
pub(crate) fn run_rectang2(s: &mut Session, p: &Value) -> Result<Value> {
    let a = point_req("rectang", p, "p1")?;
    // Centre mode: `p1` is the rectangle's centre, so the rectangle spans it evenly.
    let centered = bool_or(p, "center", false);
    let rot = f64_or(p, "rotation", 0.0).to_radians();
    let ch = p
        .get("chamfer")
        .and_then(Value::as_array)
        .map(|c| (c.first().and_then(Value::as_f64).unwrap_or(0.0), c.get(1).and_then(Value::as_f64).unwrap_or(0.0)))
        .map(|(x, y)| (if x.is_finite() { x } else { 0.0 }, if y.is_finite() { y } else { 0.0 }))
        .unwrap_or((0.0, 0.0));
    if ch.0 < 0.0 || ch.1 < 0.0 {
        return Err(bad("rectang", "`chamfer` distances must be zero or positive"));
    }
    let fillet = size_param("rectang", p, "fillet", true)?.unwrap_or(0.0);
    let width = size_param("rectang", p, "width", true)?.unwrap_or(0.0);
    let (w, h) = rect_size(p, a, rot, centered)?;
    if w.abs() < 1e-12 || h.abs() < 1e-12 || !w.is_finite() || !h.is_finite() {
        return Err(bad("rectang", "rectangle has no area"));
    }
    let first = if centered { a - Vec2::new(w / 2.0, h / 2.0).rotate(rot) } else { a };
    let k = rect_kind(first, (w, h), rot, fillet, ch, width, f64_or(p, "elevation", 0.0));
    let hd = s.add_entity(k)?;
    // A rectangle has its own thickness option and does not take THICKNESS.
    let th = f64_or(p, "thickness", 0.0);
    s.doc_mut()?.modify_entity(hd, |e| e.common.thickness = th)?;
    added(hd)
}

#[derive(Clone, Copy, Debug, PartialEq)]
enum RAsk {
    Chamfer1,
    Chamfer2,
    Fillet,
    Width,
    Elevation,
    Thickness,
    Area,
    AreaBasis,
    AreaLength,
    AreaWidth,
    DimL,
    DimW,
    Rotation,
    RotPick1,
    RotPick2(Vec2),
}

#[derive(Default)]
pub(crate) struct RectM2 {
    first: Option<Vec2>,
    /// The first point is the rectangle's centre (the `Center` option), not a corner.
    center: bool,
    fillet: f64,
    chamfer: (f64, f64),
    width: f64,
    elevation: f64,
    thickness: f64,
    rotation: f64,
    dims: Option<(f64, f64)>,
    area: f64,
    asking: Option<RAsk>,
}

/// A rectangle's rotation as AutoCAD 2024 shows it: degrees from 0 to 360, two decimals.
fn rotation_text(rotation: f64) -> String {
    let t = format!("{:.2}", rotation.to_degrees().rem_euclid(360.0));
    if t == "360.00" { "0.00".into() } else { t }
}

/// AutoCAD 2024's line listing the RECTANG modes that are set, `None` when none is ("Current
/// rectangle modes:  Chamfer=2.2518 x 3.7663  Rotation=50.50"): distances in the drawing's
/// units, the rotation as [`rotation_text`] shows it.
fn modes_line(s: &Session, m: &RectangModes) -> Option<String> {
    let (u, p) = s.doc().map(|d| (d.header.i64("LUNITS", 2), d.header.i64("LUPREC", 4))).unwrap_or((2, 4));
    let d = |v: f64| crate::units::format_distance(v, u, p);
    let mut parts = Vec::new();
    if m.chamfer.0 > 0.0 || m.chamfer.1 > 0.0 {
        parts.push(format!("Chamfer={} x {}", d(m.chamfer.0), d(m.chamfer.1)));
    }
    if m.fillet > 0.0 {
        parts.push(format!("Fillet={}", d(m.fillet)));
    }
    if m.elevation != 0.0 {
        parts.push(format!("Elevation={}", d(m.elevation)));
    }
    if m.thickness != 0.0 {
        parts.push(format!("Thickness={}", d(m.thickness)));
    }
    if m.width > 0.0 {
        parts.push(format!("Width={}", d(m.width)));
    }
    let rot = rotation_text(m.rotation);
    if rot != "0.00" {
        parts.push(format!("Rotation={rot}"));
    }
    (!parts.is_empty()).then(|| format!("Current rectangle modes:  {}", parts.join("  ")))
}

impl RectM2 {
    /// The modes the next rectangle starts from.
    fn modes(&self) -> RectangModes {
        RectangModes {
            chamfer: self.chamfer,
            fillet: self.fillet,
            width: self.width,
            elevation: self.elevation,
            thickness: self.thickness,
            rotation: self.rotation,
        }
    }
    /// Adds the rectangle of full size `w` × `h` with the collected options, drawing it from
    /// the centre when centre mode is on, then applies the requested thickness.
    fn make(&self, s: &mut Session, w: f64, h: f64) -> Result<Step> {
        let Some(a) = self.first else { return Ok(Step::Cancel) };
        s.last_used.rectang = self.modes();
        if w.abs() < 1e-12 || h.abs() < 1e-12 {
            return Err(other("The rectangle has no area."));
        }
        let first = self.origin(w, h).unwrap_or(a);
        let hd = s.add_entity(rect_kind(first, (w, h), self.rotation, self.fillet, self.chamfer, self.width, self.elevation))?;
        // A rectangle has its own thickness option and does not take THICKNESS.
        let t = self.thickness;
        s.doc_mut()?.modify_entity(hd, |e| e.common.thickness = t)?;
        Ok(Step::Done)
    }
    /// The rectangle's local origin (the corner `rect_kind` draws from) for a size: the first
    /// point itself as a corner, or the first point less half the size around the centre.
    fn origin(&self, w: f64, h: f64) -> Option<Vec2> {
        let a = self.first?;
        Some(if self.center { a - Vec2::new(w / 2.0, h / 2.0).rotate(self.rotation) } else { a })
    }
    /// The rectangle's signed full size implied by the picked point `p`: explicit `dims` only
    /// take their quadrant from `p`, otherwise `p` is a corner, doubled about the centre in
    /// centre mode.
    fn other_corner(&self, p: Vec2) -> Option<(f64, f64)> {
        let a = self.first?;
        let loc = (p - a).rotate(-self.rotation);
        Some(match self.dims {
            Some((l, w)) => (if loc.x < 0.0 { -l } else { l }, if loc.y < 0.0 { -w } else { w }),
            // In centre mode the picked point is one corner, mirrored across the centre.
            None if self.center => (2.0 * loc.x, 2.0 * loc.y),
            None => (loc.x, loc.y),
        })
    }
}

impl Interactive for RectM2 {
    fn name(&self) -> &'static str {
        "RECTANG"
    }
    /// Starts from the modes the last rectangle left, and lists the ones that are set.
    fn begin(&mut self, s: &mut Session) -> Result<Step> {
        let m = s.last_used.rectang;
        self.chamfer = m.chamfer;
        self.fillet = m.fillet;
        self.width = m.width;
        self.elevation = m.elevation;
        self.thickness = m.thickness;
        self.rotation = m.rotation;
        if let Some(line) = modes_line(s, &m) {
            s.echo(line);
        }
        Ok(Step::Continue)
    }
    /// Asks for the pending option's value, or for the first and second points; in centre mode
    /// the first prompt asks for the centre instead of a corner.
    fn prompt(&self, _s: &Session) -> Prompt {
        let num = |m: &str, d: f64| Prompt::new(m, Accept::NUMBER).default(format!("{d:.4}"));
        if let Some(a) = self.asking {
            return match a {
                RAsk::Chamfer1 => num("Specify first chamfer distance for rectangles", self.chamfer.0),
                RAsk::Chamfer2 => num("Specify second chamfer distance for rectangles", self.chamfer.1),
                RAsk::Fillet => num("Specify fillet radius for rectangles", self.fillet),
                RAsk::Width => num("Specify line width for rectangles", self.width),
                RAsk::Elevation => num("Specify the elevation for rectangles", self.elevation),
                RAsk::Thickness => num("Specify thickness for rectangles", self.thickness),
                RAsk::Area => num("Enter area of rectangle in current units", if self.area > 0.0 { self.area } else { 100.0 }),
                RAsk::AreaBasis => Prompt::new("Calculate rectangle dimensions based on", curves::KW).kw(&["Length", "Width"]).default("Length"),
                RAsk::AreaLength => num("Enter rectangle length", 10.0),
                RAsk::AreaWidth => num("Enter rectangle width", 10.0),
                RAsk::DimL => num("Specify length for rectangles", self.dims.map(|d| d.0).unwrap_or(10.0)),
                RAsk::DimW => num("Specify width for rectangles", self.dims.map(|d| d.1).unwrap_or(10.0)),
                RAsk::Rotation => Prompt::new("Specify rotation angle", Accept::POINT_OR_NUMBER)
                    .kw(&["Pick points"])
                    .default(rotation_text(self.rotation))
                    .base_opt(self.first),
                RAsk::RotPick1 => Prompt::new("Specify first point", Accept::POINT),
                RAsk::RotPick2(b) => Prompt::new("Specify second point", Accept::POINT).base(b),
            };
        }
        match self.first {
            None => {
                let msg = if self.center { "Specify center point for rectangle" } else { "Specify first corner point" };
                Prompt::new(msg, Accept::POINT).kw(&["Chamfer", "CEnter", "Elevation", "Fillet", "Thickness", "Width"])
            }
            Some(p) => Prompt::new("Specify other corner point", Accept::POINT).kw(&["Area", "Dimensions", "Rotation"]).corner(p),
        }
    }
    /// Consumes one input: option keywords (`Center` only switches the first point's meaning
    /// to the centre and asks nothing), option values, and the points that size the rectangle.
    fn input(&mut self, s: &mut Session, i: Input) -> Result<Step> {
        if let Some(a) = self.asking {
            let val = |i: &Input, default: f64| -> Result<f64> {
                match i {
                    Input::Text(t) => number(t).ok_or_else(|| other("Requires a number.")),
                    Input::Enter => Ok(default),
                    _ => Err(other("Requires a number.")),
                }
            };
            self.asking = None;
            match a {
                RAsk::Chamfer1 => {
                    self.chamfer.0 = val(&i, self.chamfer.0)?.max(0.0);
                    self.chamfer.1 = self.chamfer.0;
                    self.asking = Some(RAsk::Chamfer2);
                }
                RAsk::Chamfer2 => {
                    self.chamfer.1 = val(&i, self.chamfer.1)?.max(0.0);
                    self.fillet = 0.0;
                }
                RAsk::Fillet => {
                    self.fillet = val(&i, self.fillet)?.max(0.0);
                    self.chamfer = (0.0, 0.0);
                }
                RAsk::Width => self.width = val(&i, self.width)?.max(0.0),
                RAsk::Elevation => self.elevation = val(&i, self.elevation)?,
                RAsk::Thickness => self.thickness = val(&i, self.thickness)?,
                RAsk::Area => {
                    let v = val(&i, if self.area > 0.0 { self.area } else { 100.0 })?;
                    if v <= 0.0 {
                        self.asking = Some(RAsk::Area);
                        return Err(other("Value must be positive."));
                    }
                    self.area = v;
                    self.asking = Some(RAsk::AreaBasis);
                }
                RAsk::AreaBasis => {
                    let w = matches!(&i, Input::Keyword(k) | Input::Text(k) if k.to_ascii_lowercase().starts_with('w'));
                    self.asking = Some(if w { RAsk::AreaWidth } else { RAsk::AreaLength });
                }
                RAsk::AreaLength | RAsk::AreaWidth => {
                    let v = val(&i, 10.0)?;
                    if v <= 0.0 {
                        self.asking = Some(a);
                        return Err(other("Value must be positive."));
                    }
                    let (w, h) = if a == RAsk::AreaLength { (v, self.area / v) } else { (self.area / v, v) };
                    return self.make(s, w, h);
                }
                RAsk::DimL => {
                    let l = val(&i, self.dims.map(|d| d.0).unwrap_or(10.0))?.abs();
                    self.dims = Some((l, self.dims.map(|d| d.1).unwrap_or(10.0)));
                    self.asking = Some(RAsk::DimW);
                }
                RAsk::DimW => {
                    let w = val(&i, self.dims.map(|d| d.1).unwrap_or(10.0))?.abs();
                    self.dims = Some((self.dims.map(|d| d.0).unwrap_or(10.0), w));
                }
                RAsk::Rotation => match i {
                    Input::Keyword(_) => self.asking = Some(RAsk::RotPick1),
                    Input::Point(p) => self.rotation = self.first.map(|f| f.angle_to(p)).unwrap_or(0.0),
                    Input::Text(t) => self.rotation = s.angle_settings().direction(&t).ok_or_else(|| other("Requires a valid angle."))?,
                    _ => {}
                },
                RAsk::RotPick1 => {
                    if let Input::Point(p) = i {
                        self.asking = Some(RAsk::RotPick2(p));
                    }
                }
                RAsk::RotPick2(b) => {
                    if let Input::Point(p) = i {
                        self.rotation = b.angle_to(p);
                    }
                }
            }
            // A mode is kept as soon as it is set, even if no rectangle follows.
            s.last_used.rectang = self.modes();
            return Ok(Step::Continue);
        }
        match i {
            Input::Keyword(k) => {
                // `Center` only switches the first point's meaning; it asks nothing.
                if k == "CEnter" {
                    self.center = true;
                    return Ok(Step::Continue);
                }
                self.asking = Some(match k.as_str() {
                    "Chamfer" => RAsk::Chamfer1,
                    "Elevation" => RAsk::Elevation,
                    "Fillet" => RAsk::Fillet,
                    "Thickness" => RAsk::Thickness,
                    "Width" => RAsk::Width,
                    "Area" => RAsk::Area,
                    "Dimensions" => RAsk::DimL,
                    _ => RAsk::Rotation,
                });
                Ok(Step::Continue)
            }
            Input::Point(p) => match self.first {
                None => {
                    self.first = Some(p);
                    Ok(Step::Continue)
                }
                Some(_) => {
                    let (w, h) = self.other_corner(p).ok_or_else(|| other("No first corner."))?;
                    self.make(s, w, h)
                }
            },
            Input::Enter => Ok(Step::Cancel),
            _ => Ok(Step::Continue),
        }
    }
    /// The rubber-band rectangle for the cursor at `c`, mapped through the same size-and-origin
    /// rules as the committed entity so centre mode previews where it will land.
    fn preview(&self, _s: &Session, c: Vec2) -> Vec<EntityKind> {
        if self.asking.is_some() {
            return Vec::new();
        }
        match self.other_corner(c).and_then(|(w, h)| self.origin(w, h).map(|a| (a, w, h))) {
            Some((a, w, h)) if w.abs() > 1e-12 && h.abs() > 1e-12 => {
                vec![rect_kind(a, (w, h), self.rotation, self.fillet, self.chamfer, self.width, self.elevation)]
            }
            _ => Vec::new(),
        }
    }
}