refactor(project): move settings, comp, layer, footage and item types out of lib.rs

crates/project/src/comp.rs

@@ -0,0 +1,427 @@
+use super::item::LayerId;
+use super::layer::{Layer, LayerSource};
+use super::settings::{Marker, yes};
+use super::*;
+
+/// 3D renderer of a composition.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum Renderer {
+    #[default]
+    Classic3D,
+    Advanced3D,
+}
+
+/// A composition's Resolution (the Composition panel's Resolution/Down Sample Factor popup, View ▸
+/// Resolution): how many of its pixels the viewer renders. Auto follows the magnification.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum Resolution {
+    #[default]
+    Auto,
+    Full,
+    Half,
+    Third,
+    Quarter,
+    /// View ▸ Resolution ▸ Custom: render every n-th pixel (2..=40).
+    Custom(u8),
+}
+
+impl Resolution {
+    pub const ALL: [Resolution; 5] = [Resolution::Auto, Resolution::Full, Resolution::Half, Resolution::Third, Resolution::Quarter];
+    pub fn label(self) -> &'static str {
+        match self {
+            Resolution::Auto => "Auto",
+            Resolution::Full => "Full",
+            Resolution::Half => "Half",
+            Resolution::Third => "Third",
+            Resolution::Quarter => "Quarter",
+            Resolution::Custom(_) => "Custom",
+        }
+    }
+    pub fn is_auto(&self) -> bool {
+        *self == Resolution::Auto
+    }
+    /// The down-sample factor (render every n-th pixel); `None` for Auto.
+    pub fn factor(self) -> Option<u8> {
+        match self {
+            Resolution::Auto => None,
+            Resolution::Full => Some(1),
+            Resolution::Half => Some(2),
+            Resolution::Third => Some(3),
+            Resolution::Quarter => Some(4),
+            Resolution::Custom(n) => Some(n),
+        }
+    }
+    /// The resolution that renders every `n`-th pixel (1 = Full … 4 = Quarter; up to 40).
+    pub fn from_factor(n: u64) -> Resolution {
+        match n.clamp(1, 40) {
+            1 => Resolution::Full,
+            2 => Resolution::Half,
+            3 => Resolution::Third,
+            4 => Resolution::Quarter,
+            n => Resolution::Custom(n as u8),
+        }
+    }
+    /// Render scale for a viewer magnification (and display pixel density).
+    pub fn scale(self, zoom: f32, ppp: f32) -> f64 {
+        match self.factor() {
+            Some(n) => 1.0 / f64::from(n.clamp(1, 40)),
+            // As in After Effects, Auto renders the pixels the magnification needs: the coarsest
+            // whole factor that still gives every screen pixel a rendered one (Full above 50 %,
+            // Half down to 33.3 %, Third down to 25 %, Quarter below), never fewer (#417).
+            None => {
+                let n = (1.0 / (zoom * ppp) as f64 + 1e-3).floor();
+                if n >= 1.0 { 1.0 / n.min(4.0) } else { 1.0 }
+            }
+        }
+    }
+}
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct Comp {
+    pub width: u32,
+    pub height: u32,
+    pub pixel_aspect: f64,
+    pub frame_rate: FrameRate,
+    pub duration: Tick,
+    /// Start timecode/frame shown for time 0.
+    pub display_start: Tick,
+    pub background: [f32; 3],
+    pub work_area: (Tick, Tick),
+    /// Layer #1 first (top of the stack).
+    pub layers: Vec<Layer>,
+    #[serde(default)]
+    pub markers: Vec<Marker>,
+    pub shutter_angle: f64,
+    pub shutter_phase: f64,
+    /// Samples Per Frame: the minimum motion-blur samples (and the count for 3D layers).
+    pub motion_blur_samples: u32,
+    /// Adaptive Sample Limit (Composition Settings ▸ Advanced): the most samples a 2D layer gets
+    /// when it moves far within the shutter.
+    #[serde(default = "adaptive_limit_default")]
+    pub motion_blur_adaptive_limit: u32,
+    #[serde(default)]
+    pub renderer: Renderer,
+    /// Comp switches (timeline toolbar).
+    #[serde(default)]
+    pub hide_shy: bool,
+    #[serde(default = "yes")]
+    pub enable_motion_blur: bool,
+    #[serde(default = "yes")]
+    pub enable_frame_blending: bool,
+    #[serde(default)]
+    pub draft_3d: bool,
+    /// Composition Settings ▸ Advanced ▸ Preserve frame rate when nested or in render queue:
+    /// nested in another comp, or rendered at another rate, it shows only its own frames.
+    #[serde(default)]
+    pub preserve_frame_rate: bool,
+    /// Composition Settings ▸ Advanced ▸ Preserve resolution when nested: nested in a comp
+    /// previewed at a lower resolution, it still renders at full size.
+    #[serde(default)]
+    pub preserve_resolution: bool,
+    #[serde(default)]
+    pub poster_time: Tick,
+    /// Global Light for layer styles (Layer ▸ Layer Styles ▸ Blending Options).
+    #[serde(default)]
+    pub global_light: styles::GlobalLight,
+    /// Viewer guides (View ▸ Add Guide…), in comp pixels.
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub guides: Vec<Guide>,
+    /// Essential Graphics: the controls this comp exposes to instances and templates.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub essential: Option<essential::EssentialGraphics>,
+    /// The Composition panel's Resolution, saved with the project as in After Effects. It changes
+    /// what the viewer renders, not the comp's pixels ([`Comp::same_pixels`]), and stays out of
+    /// the undo history.
+    #[serde(default, skip_serializing_if = "Resolution::is_auto")]
+    pub resolution: Resolution,
+}
+
+/// A viewer guide line: vertical guides sit at an x position, horizontal ones at a y position.
+#[derive(Clone, Copy, Debug, PartialEq, Serialize, Deserialize)]
+pub struct Guide {
+    pub vertical: bool,
+    /// Comp pixels, or percent of the comp's width (vertical) / height (horizontal) when
+    /// [`Guide::percent`] is set.
+    pub position: f64,
+    /// A percentage guide (After Effects 26.5): `position` is a percent of the comp's size, so the
+    /// guide keeps its relative place when the comp is resized. Absent in older projects.
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    pub percent: bool,
+}
+
+impl Guide {
+    /// The comp's extent along this guide's axis, never zero.
+    fn extent(&self, width: u32, height: u32) -> f64 {
+        f64::from(if self.vertical { width } else { height }).max(1.0)
+    }
+
+    /// The guide's position in comp pixels for a comp of this size.
+    pub fn px(&self, width: u32, height: u32) -> f64 {
+        if self.percent { self.position / 100.0 * self.extent(width, height) } else { self.position }
+    }
+
+    /// Place the guide at `px` comp pixels, keeping its unit.
+    pub fn set_px(&mut self, px: f64, width: u32, height: u32) {
+        self.position = if self.percent { px / self.extent(width, height) * 100.0 } else { px };
+    }
+
+    /// Switch between pixels and percent without moving the guide on the comp.
+    pub fn set_percent(&mut self, percent: bool, width: u32, height: u32) {
+        let px = self.px(width, height);
+        self.percent = percent;
+        self.set_px(px, width, height);
+    }
+}
+
+fn adaptive_limit_default() -> u32 {
+    128
+}
+
+impl Comp {
+    pub fn new(width: u32, height: u32, frame_rate: FrameRate, duration: Tick) -> Comp {
+        Comp {
+            width,
+            height,
+            pixel_aspect: 1.0,
+            frame_rate,
+            duration,
+            display_start: Tick::ZERO,
+            background: [0.0, 0.0, 0.0],
+            work_area: (Tick::ZERO, duration),
+            layers: vec![],
+            markers: vec![],
+            shutter_angle: 180.0,
+            shutter_phase: -90.0,
+            motion_blur_samples: 16,
+            motion_blur_adaptive_limit: 128,
+            renderer: Renderer::Classic3D,
+            hide_shy: false,
+            enable_motion_blur: true,
+            enable_frame_blending: true,
+            draft_3d: false,
+            preserve_frame_rate: false,
+            preserve_resolution: false,
+            poster_time: Tick::ZERO,
+            guides: vec![],
+            global_light: styles::GlobalLight::default(),
+            essential: None,
+            resolution: Resolution::Auto,
+        }
+    }
+
+    /// Whether the composition has a frame at its time `t`: nested, it shows nothing before it
+    /// starts or after it ends (a precomp layer trimmed or remapped past it).
+    pub fn covers(&self, t: Tick) -> bool {
+        t >= Tick::ZERO && t < self.duration
+    }
+
+    /// A new, empty composition with this one's settings (frame rate, pixel aspect, background,
+    /// motion blur, frame blending and the 3D renderer), as Pre-compose makes.
+    pub fn nested_like(&self, width: u32, height: u32, duration: Tick) -> Comp {
+        Comp {
+            pixel_aspect: self.pixel_aspect,
+            background: self.background,
+            shutter_angle: self.shutter_angle,
+            shutter_phase: self.shutter_phase,
+            motion_blur_samples: self.motion_blur_samples,
+            motion_blur_adaptive_limit: self.motion_blur_adaptive_limit,
+            renderer: self.renderer,
+            enable_motion_blur: self.enable_motion_blur,
+            enable_frame_blending: self.enable_frame_blending,
+            preserve_frame_rate: self.preserve_frame_rate,
+            preserve_resolution: self.preserve_resolution,
+            ..Comp::new(width, height, self.frame_rate, duration)
+        }
+    }
+
+    pub fn layer(&self, id: LayerId) -> Option<&Layer> {
+        self.layers.iter().find(|l| l.id == id)
+    }
+
+    pub fn layer_mut(&mut self, id: LayerId) -> Option<&mut Layer> {
+        self.layers.iter_mut().find(|l| l.id == id)
+    }
+
+    /// 1-based layer number (#) of a layer.
+    pub fn index_of(&self, id: LayerId) -> Option<usize> {
+        self.layers.iter().position(|l| l.id == id).map(|i| i + 1)
+    }
+
+    pub fn layer_by_name(&self, name: &str) -> Option<&Layer> {
+        self.layers.iter().find(|l| l.name == name)
+    }
+
+    pub fn frame_duration(&self) -> Tick {
+        self.frame_rate.frame_duration()
+    }
+
+    /// Any 3D layer present (camera/lights or a 3D switch).
+    pub fn has_3d(&self) -> bool {
+        self.layers.iter().any(|l| l.switches.three_d || matches!(l.source, LayerSource::Camera | LayerSource::Light { .. }))
+    }
+
+    /// The active camera at `t`: the topmost enabled camera layer active at that time.
+    pub fn active_camera(&self, t: Tick) -> Option<&Layer> {
+        self.layers.iter().find(|l| matches!(l.source, LayerSource::Camera) && l.switches.video && l.is_active_at(t))
+    }
+
+    /// Unique layer name with a numeric suffix (`Shape Layer 2`).
+    pub fn unique_layer_name(&self, base: &str) -> String {
+        if !self.layers.iter().any(|l| l.name == base) {
+            return base.to_string();
+        }
+        let stem = base.trim_end_matches(|c: char| c.is_ascii_digit()).trim_end();
+        (2..).map(|i| format!("{stem} {i}")).find(|n| !self.layers.iter().any(|l| &l.name == n)).unwrap_or_default()
+    }
+}
+
+impl Comp {
+    /// Draws the same pixels as `o`: equal but for its layers' Audio, Lock and Shy switches, Hide
+    /// Shy Layers and the viewer's Resolution.
+    pub fn same_pixels(&self, o: &Comp) -> bool {
+        self.same_settings(o) && self.layers.len() == o.layers.len() && self.layers.iter().zip(&o.layers).all(|(a, b)| a.same_pixels(b))
+    }
+
+    /// [`Self::same_pixels`] but for the layers.
+    fn same_settings(&self, o: &Comp) -> bool {
+        // Every field (no `..`: a new field must be considered here).
+        let Comp {
+            width,
+            height,
+            pixel_aspect,
+            frame_rate,
+            duration,
+            display_start,
+            background,
+            work_area,
+            layers: _,
+            markers,
+            shutter_angle,
+            shutter_phase,
+            motion_blur_samples,
+            motion_blur_adaptive_limit,
+            renderer,
+            hide_shy: _,
+            enable_motion_blur,
+            enable_frame_blending,
+            draft_3d,
+            preserve_frame_rate,
+            preserve_resolution,
+            poster_time,
+            global_light,
+            guides,
+            essential,
+            resolution: _,
+        } = self;
+        *width == o.width
+            && *height == o.height
+            && *pixel_aspect == o.pixel_aspect
+            && *frame_rate == o.frame_rate
+            && *duration == o.duration
+            && *display_start == o.display_start
+            && *background == o.background
+            && *work_area == o.work_area
+            && *markers == o.markers
+            && *shutter_angle == o.shutter_angle
+            && *shutter_phase == o.shutter_phase
+            && *motion_blur_samples == o.motion_blur_samples
+            && *motion_blur_adaptive_limit == o.motion_blur_adaptive_limit
+            && *renderer == o.renderer
+            && *enable_motion_blur == o.enable_motion_blur
+            && *enable_frame_blending == o.enable_frame_blending
+            && *draft_3d == o.draft_3d
+            && *preserve_frame_rate == o.preserve_frame_rate
+            && *preserve_resolution == o.preserve_resolution
+            && *poster_time == o.poster_time
+            && *global_light == o.global_light
+            && *guides == o.guides
+            && *essential == o.essential
+    }
+
+    /// The comp-time span (`in_point..out_point` of every layer changed, added or removed,
+    /// widened by the shutter) outside which `self` draws the same pixels as `o`, so cached
+    /// frames there stay valid (#1641). `None` when the edit can reach any frame: a comp setting,
+    /// a layer reorder, Solo turning on or off, an expression (it reads anything), or a changed
+    /// layer another layer parents to, mattes with or picks in an effect.
+    pub fn changed_span(&self, o: &Comp) -> Option<(Tick, Tick)> {
+        fn reads(g: &PropGroup, changed: &[LayerId]) -> bool {
+            g.children.iter().any(|c| match c {
+                Node::Prop(p) => {
+                    p.expr.is_some()
+                        || std::iter::once(&p.value)
+                            .chain(p.keys.iter().map(|k| &k.value))
+                            .any(|v| matches!(v, Value::Layer(Some(id)) if changed.contains(&LayerId(*id))))
+                }
+                Node::Group(g) => reads(g, changed),
+            })
+        }
+        // Solo hides every other layer at every frame.
+        if !self.same_settings(o) || self.any_solo() != o.any_solo() {
+            return None;
+        }
+        let common = |a: &Comp, b: &Comp| a.layers.iter().map(|l| l.id).filter(|id| b.layer(*id).is_some()).collect::<Vec<_>>();
+        if common(self, o) != common(o, self) {
+            return None;
+        }
+        let mut changed = Vec::new();
+        let mut span: Option<(Tick, Tick)> = None;
+        // Each changed layer comes up from both sides: its old and its new span.
+        for (l, other) in self.layers.iter().map(|l| (l, o.layer(l.id))).chain(o.layers.iter().map(|l| (l, self.layer(l.id)))) {
+            if other.is_some_and(|b| l.same_pixels(b)) {
+                continue;
+            }
+            changed.push(l.id);
+            let (s, e) = (l.in_point.min(l.out_point), l.in_point.max(l.out_point));
+            span = Some(span.map_or((s, e), |(a, b)| (a.min(s), b.max(e))));
+        }
+        let reaches = |l: &Layer| {
+            l.parent.is_some_and(|p| changed.contains(&p)) || l.track_matte.as_ref().is_some_and(|m| changed.contains(&m.layer)) || reads(&l.props, &changed)
+        };
+        if self.layers.iter().chain(&o.layers).any(reaches) {
+            return None;
+        }
+        // A frame at `t` samples cameras, lights and transforms over its shutter,
+        // `t + (phase + angle * 0..=1) / 360` frames, and draws the layers active at `t` itself.
+        let (a, p) = (self.shutter_angle / 360.0, self.shutter_phase / 360.0);
+        let fd = self.frame_duration().seconds();
+        let (before, after) = (Tick::from_seconds_f64(p.max(p + a).max(0.0) * fd), Tick::from_seconds_f64(-p.min(p + a).min(0.0) * fd));
+        span.map(|(s, e)| (s - before, e + after))
+    }
+
+    /// Some layer is soloed: only the soloed layers draw.
+    pub fn any_solo(&self) -> bool {
+        self.layers.iter().any(|l| l.switches.solo && l.source.is_av())
+    }
+
+    /// Draws the same pixels as `o` once plain markers are ignored: they change no pixels. Protected
+    /// time markers with a duration set the timing (Responsive Design), so those still count.
+    pub fn same_pixels_ignoring_markers(&self, o: &Comp) -> bool {
+        let protected =
+            |m: &[Marker]| -> Vec<(Tick, Tick)> { m.iter().filter(|m| m.protected && m.duration > Tick::ZERO).map(|m| (m.time, m.duration)).collect() };
+        if protected(&self.markers) != protected(&o.markers) {
+            return false;
+        }
+        let mut c = self.clone();
+        c.markers = o.markers.clone();
+        for (a, b) in c.layers.iter_mut().zip(&o.layers) {
+            a.markers = b.markers.clone();
+            a.markers_locked = b.markers_locked;
+        }
+        c.same_pixels(o)
+    }
+
+    /// The comp with those switches and the Resolution at their defaults (borrowed when they
+    /// already are), for keys that hash the whole comp.
+    pub fn pixel_form(&self) -> std::borrow::Cow<'_, Comp> {
+        if !self.hide_shy && self.resolution.is_auto() && self.layers.iter().all(|l| l.switches == l.switches.pixels()) {
+            return std::borrow::Cow::Borrowed(self);
+        }
+        let mut c = self.clone();
+        c.hide_shy = false;
+        c.resolution = Resolution::Auto;
+        for l in &mut c.layers {
+            l.switches = l.switches.pixels();
+        }
+        std::borrow::Cow::Owned(c)
+    }
+}

crates/project/src/footage.rs

@@ -0,0 +1,229 @@
+use super::settings::yes;
+use super::*;
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum FootageKind {
+    #[default]
+    Video,
+    Still,
+    Sequence,
+    Audio,
+    /// A 3D model (glTF 2.0 / OBJ), placed as a model layer.
+    Model,
+    /// A data file (JSON, CSV, TSV) for data-driven animation: read by expressions through
+    /// `footage(name).sourceData` / `sourceText` / `dataValue`; it has no pixels.
+    Data,
+}
+
+/// Interpret Footage ▸ Fields and Pulldown ▸ Separate Fields.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Hash, Serialize, Deserialize)]
+pub enum FieldOrder {
+    /// Progressive frames.
+    #[default]
+    Off,
+    /// Interlaced, upper (odd) field first: each field becomes a frame at twice the rate.
+    UpperFirst,
+    LowerFirst,
+}
+
+impl FieldOrder {
+    pub fn label(self) -> &'static str {
+        match self {
+            FieldOrder::Off => "Off",
+            FieldOrder::UpperFirst => "Upper Field First",
+            FieldOrder::LowerFirst => "Lower Field First",
+        }
+    }
+    pub fn parse(s: &str) -> Option<FieldOrder> {
+        match s.to_ascii_lowercase().replace([' ', '_', '-'], "").as_str() {
+            "off" | "none" | "progressive" => Some(FieldOrder::Off),
+            "upper" | "upperfirst" | "upperfieldfirst" => Some(FieldOrder::UpperFirst),
+            "lower" | "lowerfirst" | "lowerfieldfirst" => Some(FieldOrder::LowerFirst),
+            _ => None,
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum AlphaMode {
+    #[default]
+    Straight,
+    Premultiplied,
+    Ignore,
+}
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct Footage {
+    pub path: String,
+    pub kind: FootageKind,
+    pub width: u32,
+    pub height: u32,
+    pub pixel_aspect: f64,
+    pub frame_rate: FrameRate,
+    /// Native rate before "Conform to frame rate".
+    #[serde(default)]
+    pub native_rate: Option<FrameRate>,
+    pub duration: Tick,
+    pub has_video: bool,
+    pub has_audio: bool,
+    pub alpha: AlphaMode,
+    #[serde(default)]
+    pub premul_color: [f32; 3],
+    #[serde(default = "one")]
+    pub loop_count: u32,
+    #[serde(default)]
+    pub codec: String,
+    #[serde(default)]
+    pub missing: bool,
+    /// Image sequence files (when kind = Sequence).
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub sequence: Vec<String>,
+    /// Colour profile (from the file's metadata, or Interpret Footage). `None` = sRGB.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub color_profile: Option<ColorSpace>,
+    /// One layer of a layered file (Photoshop) instead of its merged image.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub layer: Option<SourceLayer>,
+    /// Interpret Footage ▸ Fields and Pulldown ▸ Separate Fields.
+    #[serde(default, skip_serializing_if = "is_default")]
+    pub fields: FieldOrder,
+    /// Interpret Footage ▸ Alpha ▸ Invert Alpha.
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    pub invert_alpha: bool,
+    /// Interpret Footage ▸ Color ▸ Interpret As Linear Light: the file's values are linear.
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    pub linear_light: bool,
+    /// Interpret Footage ▸ Color ▸ Preserve RGB: the file's values enter the composition
+    /// unconverted. Float footage (OpenEXR, float TIFF) is not sRGB-encoded on decode, and the
+    /// colour profile, Interpret As Linear Light and the working space don't apply.
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    pub preserve_rgb: bool,
+    /// Data footage ([`FootageKind::Data`]): the file's text (JSON, CSV or TSV), kept in the
+    /// project so expressions read it everywhere (and on the web).
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub data: Option<String>,
+    /// PDF / Illustrator footage: the page shown (0-based; File ▸ Import ▸ Page).
+    #[serde(default, skip_serializing_if = "is_default")]
+    pub page: u32,
+    /// Image sequences imported with Force Alphabetical Order: the files play one after another
+    /// and their numbering doesn't count (otherwise a gap in it shows a placeholder, as in After
+    /// Effects; [`sequence`]).
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    pub alphabetical: bool,
+    /// Interpret Footage ▸ Start Timecode ▸ Override Start: the frame (at the footage's frame
+    /// rate) its timecode shows at its first frame. `None` = Use Source File Timecode (0: file
+    /// timecode isn't read). It only relabels source time, as in After Effects.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub start_timecode: Option<i64>,
+}
+
+fn is_default<T: Default + PartialEq>(v: &T) -> bool {
+    *v == T::default()
+}
+
+impl Default for Footage {
+    fn default() -> Self {
+        Footage {
+            path: String::new(),
+            kind: FootageKind::Still,
+            width: 0,
+            height: 0,
+            pixel_aspect: 1.0,
+            frame_rate: FrameRate::FPS_30,
+            native_rate: None,
+            duration: Tick::ZERO,
+            has_video: false,
+            has_audio: false,
+            alpha: AlphaMode::Straight,
+            premul_color: [0.0; 3],
+            loop_count: 1,
+            codec: String::new(),
+            missing: false,
+            sequence: vec![],
+            color_profile: None,
+            fields: FieldOrder::Off,
+            invert_alpha: false,
+            linear_light: false,
+            preserve_rgb: false,
+            data: None,
+            layer: None,
+            page: 0,
+            alphabetical: false,
+            start_timecode: None,
+        }
+    }
+}
+
+impl Footage {
+    /// Interpret As Linear Light applies (Preserve RGB passes the file's values through).
+    pub fn linear_light_applies(&self) -> bool {
+        self.linear_light && !self.preserve_rgb
+    }
+
+    /// How long the footage plays: its duration times Interpret Footage ▸ Loop.
+    pub fn looped_duration(&self) -> Tick {
+        Tick(self.duration.0.saturating_mul(self.loop_count.max(1) as i64))
+    }
+
+    /// Source time as the footage's timecode: its frame `frame` from Start Timecode
+    /// (`0:00:41:20`), as the Footage panel shows it.
+    pub fn timecode(&self, frame: i64) -> String {
+        effectcraft_time::format_timecode_ae(frame.saturating_add(self.start_timecode.unwrap_or(0)), self.frame_rate, false)
+    }
+
+    /// The data format of data footage: `json`, `csv` or `tsv` (from the file extension).
+    pub fn data_format(&self) -> Option<&'static str> {
+        if self.kind != FootageKind::Data {
+            return None;
+        }
+        let ext = std::path::Path::new(&self.path).extension().and_then(std::ffi::OsStr::to_str).unwrap_or("").to_ascii_lowercase();
+        Some(match ext.as_str() {
+            "csv" => "csv",
+            "tsv" | "tab" => "tsv",
+            _ => "json",
+        })
+    }
+}
+
+/// A proxy: a stand-in file used instead of a footage item or composition (File ▸ Set Proxy /
+/// Create Proxy), when its Use Proxy switch is on and the render's Proxy Use allows it.
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct Proxy {
+    /// The proxy's footage (path, size, rate…; File ▸ Interpret Footage ▸ Proxy edits it).
+    pub footage: Footage,
+    /// Use Proxy (the Project panel's proxy indicator: filled = in use, hollow = set but off).
+    #[serde(default = "yes")]
+    pub enabled: bool,
+}
+
+/// A layer of a layered still (a Photoshop document, or a PDF / Illustrator / EPS file) used as
+/// footage (File ▸ Import ▸ Composition / Composition – Retain Layer Sizes, or Choose Layer).
+#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub struct SourceLayer {
+    /// Layer record index in the file (bottom of the stack = 0).
+    pub index: u32,
+    pub name: String,
+    /// The footage is the layer's own bounds (Retain Layer Sizes) rather than the document size.
+    #[serde(default)]
+    pub layer_size: bool,
+    /// A Photoshop smart object: the unique id of its embedded file (linked layer data), which
+    /// is the footage instead of the layer's pixels.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub embedded: Option<String>,
+    /// A smart object with a perspective quad or a warp: the footage is its embedded file baked
+    /// as placed (warped and pinned to its corners) over the placed bounds in document space.
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    pub placed: bool,
+}
+
+fn one() -> u32 {
+    1
+}
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct Solid {
+    pub color: [f32; 3],
+    pub width: u32,
+    pub height: u32,
+    pub pixel_aspect: f64,
+}

crates/project/src/item.rs

@@ -0,0 +1,308 @@
+use super::comp::Comp;
+use super::footage::{Footage, FootageKind, Proxy, Solid};
+use super::layer::LayerSource;
+use super::settings::{APP_VERSION, ProjectError, ProjectSettings, SCHEMA_VERSION, SavedView};
+use super::*;
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
+pub struct ItemId(pub u64);
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
+pub struct LayerId(pub u64);
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+#[serde(tag = "type")]
+#[allow(clippy::large_enum_variant)]
+pub enum ItemKind {
+    Folder,
+    Comp(Arc<Comp>),
+    Footage(Footage),
+    Solid(Solid),
+}
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct Item {
+    pub id: ItemId,
+    pub name: String,
+    pub label: Label,
+    #[serde(default)]
+    pub comment: String,
+    /// Containing folder (None = project root).
+    #[serde(default)]
+    pub parent: Option<ItemId>,
+    pub kind: ItemKind,
+    /// The item's proxy (footage and compositions).
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub proxy: Option<Box<Proxy>>,
+}
+
+impl Item {
+    pub fn type_name(&self) -> &'static str {
+        match &self.kind {
+            ItemKind::Folder => "Folder",
+            ItemKind::Comp(_) => "Composition",
+            ItemKind::Footage(f) => match f.kind {
+                FootageKind::Video => "Video",
+                FootageKind::Still => "Image",
+                FootageKind::Sequence => "Image Sequence",
+                FootageKind::Audio => "Audio",
+                FootageKind::Model => "3D Model",
+                FootageKind::Data => "Data",
+            },
+            ItemKind::Solid(_) => "Solid",
+        }
+    }
+    pub fn as_comp(&self) -> Option<&Comp> {
+        if let ItemKind::Comp(c) = &self.kind { Some(c) } else { None }
+    }
+    pub fn is_folder(&self) -> bool {
+        matches!(self.kind, ItemKind::Folder)
+    }
+    /// (width, height) for visual items.
+    pub fn dimensions(&self) -> Option<(u32, u32)> {
+        match &self.kind {
+            ItemKind::Comp(c) => Some((c.width, c.height)),
+            ItemKind::Footage(f) if f.has_video => Some((f.width, f.height)),
+            ItemKind::Solid(s) => Some((s.width, s.height)),
+            _ => None,
+        }
+    }
+    pub fn duration(&self) -> Option<Tick> {
+        match &self.kind {
+            ItemKind::Comp(c) => Some(c.duration),
+            ItemKind::Footage(f) if f.kind != FootageKind::Still => Some(f.looped_duration()),
+            _ => None,
+        }
+    }
+    pub fn frame_rate(&self) -> Option<FrameRate> {
+        match &self.kind {
+            ItemKind::Comp(c) => Some(c.frame_rate),
+            ItemKind::Footage(f) if f.kind == FootageKind::Video || f.kind == FootageKind::Sequence => Some(f.frame_rate),
+            _ => None,
+        }
+    }
+}
+
+impl Default for Project {
+    fn default() -> Self {
+        Project {
+            schema: SCHEMA_VERSION,
+            settings: ProjectSettings::default(),
+            items: BTreeMap::new(),
+            next_id: 1,
+            render_queue: Vec::new(),
+            render_templates: Default::default(),
+            render_prefs: Default::default(),
+        }
+    }
+}
+
+impl Project {
+    /// Allocate an id (items, layers and property uids share one counter).
+    pub fn alloc(&mut self) -> u64 {
+        let id = self.next_id;
+        self.next_id += 1;
+        id
+    }
+    pub fn item(&self, id: ItemId) -> Option<&Item> {
+        self.items.get(&id)
+    }
+    pub fn item_mut(&mut self, id: ItemId) -> Option<&mut Item> {
+        self.items.get_mut(&id)
+    }
+    pub fn comp(&self, id: ItemId) -> Option<&Comp> {
+        self.items.get(&id)?.as_comp()
+    }
+    /// A shared handle on a comp: a snapshot that costs a reference count, not a deep copy of
+    /// its layers (frontends hold one across a frame instead of cloning the comp).
+    pub fn comp_arc(&self, id: ItemId) -> Option<Arc<Comp>> {
+        match &self.items.get(&id)?.kind {
+            ItemKind::Comp(c) => Some(c.clone()),
+            _ => None,
+        }
+    }
+    /// Mutable comp (copy-on-write).
+    pub fn comp_mut(&mut self, id: ItemId) -> Option<&mut Comp> {
+        match &mut self.items.get_mut(&id)?.kind {
+            ItemKind::Comp(c) => Some(Arc::make_mut(c)),
+            _ => None,
+        }
+    }
+    /// Adds an item; its size, frame rate and the like are brought within [`limits`] first.
+    pub fn add_item(&mut self, name: &str, label: Label, parent: Option<ItemId>, mut kind: ItemKind) -> ItemId {
+        limits::repair_kind(name, &mut kind, &mut vec![]);
+        let id = ItemId(self.alloc());
+        self.items.insert(id, Item { id, name: name.into(), label, comment: String::new(), parent, kind, proxy: None });
+        id
+    }
+    /// Children of a folder (None = root), folders first then by name.
+    pub fn children(&self, folder: Option<ItemId>) -> Vec<&Item> {
+        let mut v: Vec<&Item> = self.items.values().filter(|i| i.parent == folder).collect();
+        v.sort_by(|a, b| b.is_folder().cmp(&a.is_folder()).then_with(|| a.name.to_lowercase().cmp(&b.name.to_lowercase())));
+        v
+    }
+    pub fn comps(&self) -> impl Iterator<Item = (&ItemId, &Comp)> {
+        self.items.iter().filter_map(|(id, i)| i.as_comp().map(|c| (id, c)))
+    }
+    pub fn find_by_name(&self, name: &str) -> Option<&Item> {
+        self.items.values().find(|i| i.name == name)
+    }
+    /// A numbered name for a copy of `base` that no project item has (Edit ▸ Duplicate): its
+    /// trailing number is dropped and the lowest free one from 2 is added (`Comp 1` → `Comp 2`,
+    /// `Name` → `Name 2`, then `Name 3`). Items for which `ignore` holds don't count.
+    pub fn numbered_item_name(&self, base: &str, ignore: impl Fn(&Item) -> bool) -> String {
+        let stem = base.trim_end_matches(|c: char| c.is_ascii_digit()).trim_end();
+        let taken = |n: &str| self.items.values().any(|i| i.name == n && !ignore(i));
+        (2u64..).map(|k| format!("{stem} {k}")).find(|n| !taken(n)).unwrap_or_default()
+    }
+    /// `base` when no project item has that name, else the next free numbered name as
+    /// [`Project::numbered_item_name`] gives it. Items for which `ignore` holds don't count.
+    pub fn unique_item_name(&self, base: &str, ignore: impl Fn(&Item) -> bool) -> String {
+        if self.items.values().any(|i| i.name == base && !ignore(i)) { self.numbered_item_name(base, ignore) } else { base.to_string() }
+    }
+    pub fn folder_named(&self, name: &str) -> Option<ItemId> {
+        self.items.values().find(|i| i.is_folder() && i.name == name).map(|i| i.id)
+    }
+    /// Find the comp that contains `layer`.
+    pub fn comp_of_layer(&self, layer: LayerId) -> Option<ItemId> {
+        self.comps().find(|(_, c)| c.layer(layer).is_some()).map(|(id, _)| *id)
+    }
+    /// The compositions whose layers use `item` as their source (footage, solid, 3D model or
+    /// precomp), each with how many of its layers do, ordered by comp name then id. Only direct
+    /// layers count, as in After Effects' Project panel ("used 3 times"): a solid inside a precomp
+    /// is used by the precomp, not by the comps that nest it. The total is the sum of the counts.
+    pub fn item_users(&self, item: ItemId) -> Vec<(ItemId, usize)> {
+        let mut users: Vec<(ItemId, String, usize)> = self
+            .items
+            .iter()
+            .filter_map(|(id, it)| {
+                let comp = it.as_comp()?;
+                let n = comp.layers.iter().filter(|l| l.source.item() == Some(item)).count();
+                (n > 0).then(|| (*id, it.name.to_lowercase(), n))
+            })
+            .collect();
+        users.sort_by(|a, b| a.1.cmp(&b.1).then(a.0.cmp(&b.0)));
+        users.into_iter().map(|(id, _, n)| (id, n)).collect()
+    }
+    /// Whether comp `inner` is (transitively) nested inside comp `outer` (to prevent cycles).
+    pub fn comp_contains(&self, outer: ItemId, inner: ItemId) -> bool {
+        // A walk with a stack and a visited set rather than recursion (#1237): a damaged project
+        // may hold a precomp cycle that doesn't pass `inner` (recursion never ended), a long
+        // chain must not use up the call stack, and comps shared by many paths are visited once
+        // (recursion re-walked them for every path).
+        if outer == inner {
+            return true;
+        }
+        let mut seen = std::collections::HashSet::new();
+        let mut stack = vec![outer];
+        while let Some(id) = stack.pop() {
+            if !seen.insert(id) {
+                continue;
+            }
+            let Some(c) = self.comp(id) else { continue };
+            for l in &c.layers {
+                if let LayerSource::Comp { item } = l.source {
+                    if item == inner {
+                        return true;
+                    }
+                    if !seen.contains(&item) {
+                        stack.push(item);
+                    }
+                }
+            }
+        }
+        false
+    }
+    /// Make sure `next_id` exceeds every id in the project (after loading or merging).
+    pub fn fix_next_id(&mut self) {
+        let mut m = self.next_id;
+        for (id, it) in &self.items {
+            // Saturating: a damaged file's ids must not overflow (the import then refuses it).
+            m = m.max(id.0.saturating_add(1));
+            if let ItemKind::Comp(c) = &it.kind {
+                for l in &c.layers {
+                    m = m.max(l.id.0.saturating_add(1)).max(l.props.max_uid().saturating_add(1));
+                }
+            }
+        }
+        self.next_id = m;
+    }
+    /// Whether `other` holds the same content. An allocated id counts (an edit may hand it out
+    /// beyond the project, so it must stay taken). Shared compositions compare by pointer first,
+    /// so after a copy-on-write edit only the comps it touched are compared field by field.
+    pub fn same_content(&self, other: &Project) -> bool {
+        let item_eq = |a: &Item, b: &Item| {
+            let kind = match (&a.kind, &b.kind) {
+                (ItemKind::Comp(x), ItemKind::Comp(y)) => Arc::ptr_eq(x, y) || x == y,
+                (x, y) => x == y,
+            };
+            kind && a.id == b.id && a.name == b.name && a.label == b.label && a.comment == b.comment && a.parent == b.parent && a.proxy == b.proxy
+        };
+        self.schema == other.schema
+            && self.next_id == other.next_id
+            && self.settings == other.settings
+            && self.items.len() == other.items.len()
+            && self.items.iter().zip(&other.items).all(|((ka, a), (kb, b))| ka == kb && item_eq(a, b))
+            && self.render_queue == other.render_queue
+            && self.render_templates == other.render_templates
+            && self.render_prefs == other.render_prefs
+    }
+    /// The project file's text: the project with the version that wrote it (`savedBy`), checked
+    /// to read back, so a save never writes a file that can't be opened. Values JSON can't hold
+    /// (NaN or infinity, written as `null`, and nesting too deep to parse) are refused on every
+    /// save; debug builds also read the text back.
+    pub fn to_file_json(&self) -> Result<String, ProjectError> {
+        self.to_file_json_with_view(&SavedView::default())
+    }
+    /// [`Project::to_file_json`] that also records the open compositions ([`SavedView`]).
+    pub fn to_file_json_with_view(&self, view: &SavedView) -> Result<String, ProjectError> {
+        if self.schema > SCHEMA_VERSION {
+            return Err(ProjectError::Invalid(format!(
+                "the project can't be saved: it holds a value a project file can't store (project schema {} is newer than this version supports ({SCHEMA_VERSION}))",
+                self.schema
+            )));
+        }
+        #[derive(Serialize)]
+        struct File<'a> {
+            #[serde(rename = "savedBy")]
+            saved_by: &'a str,
+            #[serde(flatten)]
+            view: &'a SavedView,
+            #[serde(flatten)]
+            project: &'a Project,
+        }
+        let file = File { saved_by: APP_VERSION, view, project: self };
+        file_check::check(&file)
+            .map_err(|e| ProjectError::Invalid(format!("the project can't be saved: it holds a value a project file can't store ({e})")))?;
+        let text = serde_json::to_string_pretty(&file).map_err(|e| ProjectError::Invalid(format!("the project can't be saved: {e}")))?;
+        #[cfg(debug_assertions)]
+        Project::from_json(&text)
+            .map_err(|e| ProjectError::Invalid(format!("the project can't be saved: it holds a value a project file can't store ({e})")))?;
+        Ok(text)
+    }
+    pub fn to_json(&self) -> String {
+        serde_json::to_string_pretty(self).unwrap_or_default()
+    }
+    /// [`Project::to_json`] without indentation: smaller and faster (auto-saves).
+    pub fn to_json_compact(&self) -> String {
+        serde_json::to_string(self).unwrap_or_default()
+    }
+    pub fn from_json(s: &str) -> Result<Project, ProjectError> {
+        Project::from_json_repaired(s).map(|(p, _)| p)
+    }
+    /// [`Project::from_json`], also returning one line per value that was out of [`limits`] and
+    /// was corrected (a composition of a billion pixels, a zero frame rate…), so a corrupt or
+    /// hostile file still opens, within bounds, and the user can be told what changed.
+    pub fn from_json_repaired(s: &str) -> Result<(Project, Vec<String>), ProjectError> {
+        let mut p: Project = serde_json::from_str(s).map_err(|e| ProjectError::Invalid(e.to_string()))?;
+        if p.schema > SCHEMA_VERSION {
+            return Err(ProjectError::Invalid(format!("project schema {} is newer than this version supports ({SCHEMA_VERSION})", p.schema)));
+        }
+        p.fix_next_id();
+        let mut notes = vec![];
+        for item in p.items.values_mut() {
+            limits::repair_item(item, &mut notes);
+        }
+        Ok((p, notes))
+    }
+}

crates/project/src/layer.rs

@@ -0,0 +1,370 @@
+use super::item::{ItemId, LayerId};
+use super::settings::Marker;
+use super::*;
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum LightKind {
+    Parallel,
+    Spot,
+    #[default]
+    Point,
+    Ambient,
+    Environment,
+}
+
+impl LightKind {
+    pub const ALL: [LightKind; 5] = [LightKind::Parallel, LightKind::Spot, LightKind::Point, LightKind::Ambient, LightKind::Environment];
+    pub fn label(self) -> &'static str {
+        match self {
+            LightKind::Parallel => "Parallel",
+            LightKind::Spot => "Spot",
+            LightKind::Point => "Point",
+            LightKind::Ambient => "Ambient",
+            LightKind::Environment => "Environment",
+        }
+    }
+}
+
+/// A parametric 3D primitive (Layer ▸ New ▸ Cube/Sphere/Plane/Torus/Cone/Cylinder).
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Hash, Serialize, Deserialize)]
+pub enum PrimitiveKind {
+    #[default]
+    Cube,
+    Sphere,
+    Plane,
+    Torus,
+    Cone,
+    Cylinder,
+}
+
+impl PrimitiveKind {
+    pub const ALL: [PrimitiveKind; 6] =
+        [PrimitiveKind::Cube, PrimitiveKind::Sphere, PrimitiveKind::Plane, PrimitiveKind::Torus, PrimitiveKind::Cone, PrimitiveKind::Cylinder];
+    pub fn label(self) -> &'static str {
+        match self {
+            PrimitiveKind::Cube => "Cube",
+            PrimitiveKind::Sphere => "Sphere",
+            PrimitiveKind::Plane => "Plane",
+            PrimitiveKind::Torus => "Torus",
+            PrimitiveKind::Cone => "Cone",
+            PrimitiveKind::Cylinder => "Cylinder",
+        }
+    }
+    pub fn parse(s: &str) -> Option<PrimitiveKind> {
+        PrimitiveKind::ALL.into_iter().find(|k| k.label().eq_ignore_ascii_case(s.trim()))
+    }
+}
+
+/// What a layer shows.
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+#[serde(tag = "type")]
+pub enum LayerSource {
+    /// Footage item (video, still, sequence, audio).
+    Footage {
+        item: ItemId,
+    },
+    /// Nested composition (precomp).
+    Comp {
+        item: ItemId,
+    },
+    /// Solid item (solids also back adjustment layers).
+    Solid {
+        item: ItemId,
+    },
+    Text,
+    Shape,
+    Null,
+    Camera,
+    Light {
+        kind: LightKind,
+    },
+    /// An imported 3D model (a footage item of kind [`FootageKind::Model`]; Advanced 3D).
+    Model {
+        item: ItemId,
+    },
+    /// A parametric 3D primitive (Advanced 3D).
+    Primitive {
+        kind: PrimitiveKind,
+    },
+}
+
+impl LayerSource {
+    pub fn item(&self) -> Option<ItemId> {
+        match self {
+            LayerSource::Footage { item } | LayerSource::Comp { item } | LayerSource::Solid { item } | LayerSource::Model { item } => Some(*item),
+            _ => None,
+        }
+    }
+    pub fn type_name(&self) -> &'static str {
+        match self {
+            LayerSource::Footage { .. } => "Footage",
+            LayerSource::Comp { .. } => "Composition",
+            LayerSource::Solid { .. } => "Solid",
+            LayerSource::Text => "Text",
+            LayerSource::Shape => "Shape",
+            LayerSource::Null => "Null",
+            LayerSource::Camera => "Camera",
+            LayerSource::Light { .. } => "Light",
+            LayerSource::Model { .. } => "3D Model",
+            LayerSource::Primitive { .. } => "3D Primitive",
+        }
+    }
+    /// Layers with pixels (cameras, lights and nulls have none).
+    pub fn is_av(&self) -> bool {
+        !matches!(self, LayerSource::Camera | LayerSource::Light { .. } | LayerSource::Null)
+    }
+    /// A 3D model or primitive layer (meshes; drawn by the Advanced 3D renderer).
+    pub fn is_model(&self) -> bool {
+        matches!(self, LayerSource::Model { .. } | LayerSource::Primitive { .. })
+    }
+}
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum Quality {
+    #[default]
+    Best,
+    Draft,
+    Wireframe,
+}
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum Sampling {
+    #[default]
+    Bilinear,
+    Bicubic,
+}
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum FrameBlend {
+    #[default]
+    Off,
+    FrameMix,
+    PixelMotion,
+}
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct Switches {
+    pub video: bool,
+    pub audio: bool,
+    pub solo: bool,
+    pub locked: bool,
+    pub shy: bool,
+    /// Collapse transformations (precomps) / continuously rasterize (vector layers).
+    pub collapse: bool,
+    pub quality: Quality,
+    pub sampling: Sampling,
+    pub effects: bool,
+    pub frame_blend: FrameBlend,
+    pub motion_blur: bool,
+    pub adjustment: bool,
+    pub three_d: bool,
+    pub guide: bool,
+}
+
+impl Default for Switches {
+    fn default() -> Self {
+        Switches {
+            video: true,
+            audio: true,
+            solo: false,
+            locked: false,
+            shy: false,
+            collapse: false,
+            quality: Quality::Best,
+            sampling: Sampling::Bilinear,
+            effects: true,
+            frame_blend: FrameBlend::Off,
+            motion_blur: false,
+            adjustment: false,
+            three_d: false,
+            guide: false,
+        }
+    }
+}
+
+// What a frame's pixels depend on. Caches key on it: the Audio, Lock and Shy switches and Hide
+// Shy Layers don't change pixels, so toggling them keeps cached frames (#103).
+
+impl Switches {
+    /// These switches with Audio, Lock and Shy at their defaults.
+    pub fn pixels(&self) -> Switches {
+        Switches { audio: true, locked: false, shy: false, ..self.clone() }
+    }
+}
+
+impl Layer {
+    /// Draws the same pixels as `o`: equal but for the Audio, Lock and Shy switches.
+    pub fn same_pixels(&self, o: &Layer) -> bool {
+        // Every field (no `..`: a new field must be considered here); the property tree last.
+        let Layer {
+            id,
+            name,
+            source,
+            label,
+            comment,
+            start_time,
+            in_point,
+            out_point,
+            stretch,
+            switches,
+            blend_mode,
+            preserve_transparency,
+            track_matte,
+            parent,
+            markers,
+            markers_locked,
+            auto_orient,
+            environment,
+            environment_background,
+            props,
+        } = self;
+        *id == o.id
+            && *name == o.name
+            && *source == o.source
+            && *label == o.label
+            && *comment == o.comment
+            && *start_time == o.start_time
+            && *in_point == o.in_point
+            && *out_point == o.out_point
+            && *stretch == o.stretch
+            && switches.pixels() == o.switches.pixels()
+            && *blend_mode == o.blend_mode
+            && *preserve_transparency == o.preserve_transparency
+            && *track_matte == o.track_matte
+            && *parent == o.parent
+            && *markers == o.markers
+            && *markers_locked == o.markers_locked
+            && *auto_orient == o.auto_orient
+            && *environment == o.environment
+            && *environment_background == o.environment_background
+            && *props == o.props
+    }
+}
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum MatteKind {
+    #[default]
+    Alpha,
+    AlphaInverted,
+    Luma,
+    LumaInverted,
+}
+
+impl MatteKind {
+    pub const ALL: [MatteKind; 4] = [MatteKind::Alpha, MatteKind::AlphaInverted, MatteKind::Luma, MatteKind::LumaInverted];
+    pub fn label(self) -> &'static str {
+        match self {
+            MatteKind::Alpha => "Alpha Matte",
+            MatteKind::AlphaInverted => "Alpha Inverted Matte",
+            MatteKind::Luma => "Luma Matte",
+            MatteKind::LumaInverted => "Luma Inverted Matte",
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize)]
+pub struct TrackMatte {
+    pub layer: LayerId,
+    pub kind: MatteKind,
+}
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum AutoOrient {
+    #[default]
+    Off,
+    AlongPath,
+    TowardsCamera,
+    TowardsPointOfInterest,
+}
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct Layer {
+    pub id: LayerId,
+    pub name: String,
+    pub source: LayerSource,
+    pub label: Label,
+    #[serde(default)]
+    pub comment: String,
+    /// Comp time where the layer's time 0 sits.
+    pub start_time: Tick,
+    /// Visible span in comp time.
+    pub in_point: Tick,
+    pub out_point: Tick,
+    /// Time stretch in percent (100 = normal, negative = reversed).
+    pub stretch: f64,
+    pub switches: Switches,
+    pub blend_mode: BlendMode,
+    #[serde(default)]
+    pub preserve_transparency: bool,
+    #[serde(default)]
+    pub track_matte: Option<TrackMatte>,
+    #[serde(default)]
+    pub parent: Option<LayerId>,
+    #[serde(default)]
+    pub markers: Vec<Marker>,
+    /// Layer ▸ Markers ▸ Lock Markers.
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    pub markers_locked: bool,
+    #[serde(default)]
+    pub auto_orient: AutoOrient,
+    /// Layer ▸ Environment Layer: the layer is the environment (image-based light and
+    /// reflections) of Advanced 3D comps instead of being drawn.
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    pub environment: bool,
+    /// Layer ▸ Light ▸ Create Environment Light Background Layer: the layer's (equirectangular)
+    /// image is drawn as the 3D scene's backdrop, seen through the camera, instead of as a card.
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    pub environment_background: bool,
+    /// The property tree (Masks, Effects, Transform, Text, Contents, Camera/Light options…).
+    pub props: PropGroup,
+}
+
+impl Layer {
+    pub fn is_active_at(&self, t: Tick) -> bool {
+        t >= self.in_point && t < self.out_point
+    }
+
+    /// Layer time for a comp time (stretch-aware).
+    pub fn layer_time(&self, comp_t: Tick) -> Tick {
+        let d = comp_t - self.start_time;
+        if (self.stretch - 100.0).abs() < 1e-9 { d } else { Tick((d.0 as f64 * 100.0 / self.stretch) as i64) }
+    }
+
+    /// Comp time for a layer time.
+    pub fn comp_time(&self, layer_t: Tick) -> Tick {
+        if (self.stretch - 100.0).abs() < 1e-9 { self.start_time + layer_t } else { self.start_time + Tick((layer_t.0 as f64 * self.stretch / 100.0) as i64) }
+    }
+
+    pub fn transform(&self) -> Option<&PropGroup> {
+        self.props.sub("transform")
+    }
+
+    pub fn transform_mut(&mut self) -> Option<&mut PropGroup> {
+        self.props.sub_mut("transform")
+    }
+
+    pub fn effects(&self) -> Option<&PropGroup> {
+        self.props.sub("effects")
+    }
+
+    pub fn masks(&self) -> Option<&PropGroup> {
+        self.props.sub("masks")
+    }
+
+    pub fn is_camera(&self) -> bool {
+        matches!(self.source, LayerSource::Camera)
+    }
+
+    pub fn is_light(&self) -> bool {
+        matches!(self.source, LayerSource::Light { .. })
+    }
+
+    /// The layer participates in 3D (3D switch, or cameras/lights which are always 3D).
+    pub fn is_3d(&self) -> bool {
+        self.switches.three_d || self.is_camera() || self.is_light()
+    }
+
+    pub fn has_video(&self) -> bool {
+        self.source.is_av() && self.switches.video
+    }
+}

crates/project/src/settings.rs

@@ -0,0 +1,314 @@
+use super::item::{ItemId, LayerId};
+use super::*;
+
+/// The project file schema. 2: effects on layers without a source rectangle (shape, text)
+/// measure positions from the top-left of their comp-sized bounds (effect space), not from
+/// the layer's origin; projects from schema 1 are converted when opened (#227).
+pub const SCHEMA_VERSION: u32 = 2;
+
+/// The first schema in which effect positions are in effect space (see [`SCHEMA_VERSION`]).
+pub const SCHEMA_EFFECT_SPACE: u32 = 2;
+
+/// The EffectCraft version, written into project files as `savedBy`.
+pub const APP_VERSION: &str = env!("CARGO_PKG_VERSION");
+
+/// The EffectCraft version that wrote a project file (its `savedBy`), when it says.
+pub fn saved_by(text: &str) -> Option<String> {
+    #[derive(Deserialize)]
+    struct Meta {
+        #[serde(rename = "savedBy", default)]
+        saved_by: Option<String>,
+    }
+    serde_json::from_str::<Meta>(text).ok()?.saved_by
+}
+
+/// The compositions that were open when a project file was saved and their current times
+/// (`activeComp`, `openComps` and `compTimes` next to `savedBy`), so it reopens where it was left
+/// (#748, #1714). Editor state rather than project
+/// content: opening a comp doesn't make the project unsaved, and it isn't part of
+/// [`Project`]. Older files have none; older versions ignore it.
+#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct SavedView {
+    /// The comp shown in the viewer and the Timeline.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub active_comp: Option<ItemId>,
+    /// The open comps (Timeline tabs), in tab order.
+    #[serde(skip_serializing_if = "Vec::is_empty")]
+    pub open_comps: Vec<ItemId>,
+    /// Each comp's current time, so a project reopens on the frame it was saved at rather than
+    /// at 0, where its layers may not have started yet (#1714).
+    #[serde(skip_serializing_if = "BTreeMap::is_empty")]
+    pub comp_times: BTreeMap<ItemId, Tick>,
+}
+
+/// The view a project file was saved with ([`SavedView`]); empty for older files. Values that
+/// aren't ids are ignored (whether an id still names a comp is up to the caller).
+pub fn saved_view(text: &str) -> SavedView {
+    #[derive(Deserialize)]
+    struct Meta {
+        #[serde(rename = "activeComp", default)]
+        active_comp: Option<serde_json::Value>,
+        #[serde(rename = "openComps", default)]
+        open_comps: Option<serde_json::Value>,
+        #[serde(rename = "compTimes", default)]
+        comp_times: Option<serde_json::Value>,
+    }
+    let Ok(m) = serde_json::from_str::<Meta>(text) else { return SavedView::default() };
+    SavedView {
+        active_comp: m.active_comp.as_ref().and_then(serde_json::Value::as_u64).map(ItemId),
+        open_comps: m
+            .open_comps
+            .as_ref()
+            .and_then(serde_json::Value::as_array)
+            .map_or_else(Vec::new, |a| a.iter().filter_map(serde_json::Value::as_u64).map(ItemId).collect()),
+        comp_times: m
+            .comp_times
+            .as_ref()
+            .and_then(serde_json::Value::as_object)
+            .map_or_else(BTreeMap::new, |o| o.iter().filter_map(|(k, v)| Some((ItemId(k.parse().ok()?), Tick(v.as_i64()?)))).collect()),
+    }
+}
+
+/// Whether version `a` (`major.minor.patch`, pre-release suffixes ignored) is newer than `b`.
+pub fn is_newer_version(a: &str, b: &str) -> bool {
+    let parts = |v: &str| -> [u64; 3] {
+        let mut n = v.split(['-', '+']).next().unwrap_or("").split('.').map(|x| x.parse().unwrap_or(0));
+        [n.next().unwrap_or(0), n.next().unwrap_or(0), n.next().unwrap_or(0)]
+    };
+    parts(a) > parts(b)
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum ProjectError {
+    #[error("no item {0:?}")]
+    NoItem(ItemId),
+    #[error("item {0:?} is not a composition")]
+    NotComp(ItemId),
+    #[error("no layer {0:?}")]
+    NoLayer(LayerId),
+    #[error("no property `{0}`")]
+    NoProperty(String),
+    #[error("{0}")]
+    Invalid(String),
+}
+
+/// Project bit depth.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum BitDepth {
+    #[default]
+    Bpc8,
+    Bpc16,
+    Bpc32,
+}
+
+impl BitDepth {
+    pub fn label(self) -> &'static str {
+        match self {
+            BitDepth::Bpc8 => "8 bpc",
+            BitDepth::Bpc16 => "16 bpc",
+            BitDepth::Bpc32 => "32 bpc",
+        }
+    }
+    pub fn next(self) -> BitDepth {
+        match self {
+            BitDepth::Bpc8 => BitDepth::Bpc16,
+            BitDepth::Bpc16 => BitDepth::Bpc32,
+            BitDepth::Bpc32 => BitDepth::Bpc8,
+        }
+    }
+    pub fn is_float(self) -> bool {
+        self == BitDepth::Bpc32
+    }
+    /// Quantisation levels per channel of the integer depths (8 bpc: 255; 16 bpc: 32768, After
+    /// Effects' "15 + 1" bit range), `None` for 32 bpc float.
+    pub fn levels(self) -> Option<f32> {
+        match self {
+            BitDepth::Bpc8 => Some(255.0),
+            BitDepth::Bpc16 => Some(32768.0),
+            BitDepth::Bpc32 => None,
+        }
+    }
+    pub fn bits(self) -> u32 {
+        match self {
+            BitDepth::Bpc8 => 8,
+            BitDepth::Bpc16 => 16,
+            BitDepth::Bpc32 => 32,
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum TimeDisplayStyle {
+    #[default]
+    Timecode,
+    Frames,
+    /// Feet + Frames, 35 mm film (16 frames per foot).
+    Feet35,
+    /// Feet + Frames, 16 mm film (40 frames per foot).
+    Feet16,
+}
+
+impl TimeDisplayStyle {
+    /// Frames per foot of the Feet + Frames styles.
+    pub fn frames_per_foot(self) -> Option<i64> {
+        match self {
+            TimeDisplayStyle::Feet35 => Some(16),
+            TimeDisplayStyle::Feet16 => Some(40),
+            _ => None,
+        }
+    }
+    pub fn id(self) -> &'static str {
+        match self {
+            TimeDisplayStyle::Timecode => "timecode",
+            TimeDisplayStyle::Frames => "frames",
+            TimeDisplayStyle::Feet35 => "feet35",
+            TimeDisplayStyle::Feet16 => "feet16",
+        }
+    }
+    pub fn parse(s: &str) -> Option<TimeDisplayStyle> {
+        let k: String = s.chars().filter(char::is_ascii_alphanumeric).collect::<String>().to_ascii_lowercase();
+        match k.as_str() {
+            "timecode" => Some(TimeDisplayStyle::Timecode),
+            "frames" => Some(TimeDisplayStyle::Frames),
+            "feet35" | "feetframes" | "feetandframes" | "feet35mm" | "35mm" | "feetframes35mm" => Some(TimeDisplayStyle::Feet35),
+            "feet16" | "feet16mm" | "16mm" | "feetframes16mm" => Some(TimeDisplayStyle::Feet16),
+            _ => None,
+        }
+    }
+}
+
+/// Project Settings ▸ Color ▸ Color Engine.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum ColorEngine {
+    /// Built-in colour management (ICC-style working spaces).
+    #[default]
+    Adobe,
+    /// OCIO managed, with the built-in configuration (ACES working spaces).
+    Ocio,
+}
+
+/// Project Settings ▸ Color ▸ HDR: how over-range (HDR) values reach a standard-dynamic-range
+/// display or output.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum HdrMode {
+    /// Values above 1.0 clip.
+    #[default]
+    Clip,
+    /// Highlights above 80% are companded (an exponential knee) into the remaining range.
+    Compand,
+    /// Extended Reinhard tone mapping of luminance (white at 4.0).
+    ToneMap,
+}
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct ProjectSettings {
+    pub bit_depth: BitDepth,
+    /// Linearize Working Space: the working space uses linear light (1.0 gamma) for everything
+    /// (sources, effects, blending). Needs a working space.
+    pub linearize: bool,
+    /// Working Space (colour management). `None` = no colour management.
+    #[serde(default)]
+    pub working_space: Option<ColorSpace>,
+    /// Blend Colors Using 1.0 Gamma: layers blend in linear light (sources and effects stay in
+    /// the working space's encoding).
+    #[serde(default)]
+    pub blend_linear: bool,
+    pub time_display: TimeDisplayStyle,
+    /// Frame numbering starts at 0 (or 1).
+    pub frame_start: i64,
+    pub audio_sample_rate: u32,
+    /// Video Rendering and Effects ▸ Use: Mercury GPU Acceleration (`true`, the default; used
+    /// when a GPU adapter exists) or Mercury Software Only (`false`, the CPU compositor).
+    #[serde(default = "yes")]
+    pub gpu_acceleration: bool,
+    /// The project's comment (Metadata panel).
+    #[serde(default, skip_serializing_if = "String::is_empty")]
+    pub comment: String,
+    /// Color Engine (Adobe-style built-in or OCIO with ACES working spaces).
+    #[serde(default)]
+    pub color_engine: ColorEngine,
+    /// HDR handling for standard-dynamic-range output (display and renders).
+    #[serde(default)]
+    pub hdr: HdrMode,
+    /// The space the top-level comp is output in (renders and the viewer's source). `None` =
+    /// sRGB; Rec. 2100 PQ / HLG give HDR output.
+    #[serde(default)]
+    pub output_space: Option<ColorSpace>,
+    /// Working Gamma, 2.2 or 2.4 (`app.project.workingGamma`): with no working space, the curve
+    /// Interpret As Linear Light footage is encoded with and Blend Colors Using 1.0 Gamma
+    /// linearizes with: the sRGB curve at 2.2, a pure 2.4 power curve at 2.4. Ignored with a
+    /// working space (as in After Effects).
+    #[serde(default = "gamma_22")]
+    pub working_gamma: f64,
+}
+
+fn gamma_22() -> f64 {
+    2.2
+}
+
+impl ProjectSettings {
+    /// Working Gamma is 2.4 (anything else reads as 2.2).
+    pub fn working_gamma_24(&self) -> bool {
+        (self.working_gamma - 2.4).abs() < 0.05
+    }
+}
+
+impl Default for ProjectSettings {
+    fn default() -> Self {
+        ProjectSettings {
+            bit_depth: BitDepth::Bpc8,
+            linearize: false,
+            working_space: None,
+            blend_linear: false,
+            time_display: TimeDisplayStyle::Timecode,
+            frame_start: 0,
+            audio_sample_rate: 48_000,
+            gpu_acceleration: true,
+            comment: String::new(),
+            color_engine: ColorEngine::Adobe,
+            hdr: HdrMode::Clip,
+            output_space: None,
+            working_gamma: 2.2,
+        }
+    }
+}
+
+#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize)]
+pub struct Marker {
+    pub time: Tick,
+    #[serde(default)]
+    pub duration: Tick,
+    #[serde(default)]
+    pub comment: String,
+    #[serde(default)]
+    pub label: Label,
+    #[serde(default)]
+    pub chapter: String,
+    #[serde(default)]
+    pub url: String,
+    #[serde(default)]
+    pub protected: bool,
+    /// Web link frame target (`_blank`, a frame name…).
+    #[serde(default, skip_serializing_if = "String::is_empty")]
+    pub frame_target: String,
+    /// Flash/video cue point (Event or Navigation) with name and parameters.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub cue_point: Option<CuePoint>,
+}
+
+/// A marker's cue point (Composition/Layer Marker dialog ▸ Cue Point).
+#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize)]
+pub struct CuePoint {
+    pub name: String,
+    /// Navigation (true) or Event cue point.
+    #[serde(default)]
+    pub navigation: bool,
+    /// (name, value) parameter pairs.
+    #[serde(default)]
+    pub params: Vec<(String, String)>,
+}
+
+pub(crate) fn yes() -> bool {
+    true
+}