motion-canvas-rs 0.2.1

use crate::assets::hash::Hasher;
use crate::core::animation::base::Node;
use crate::core::animation::tween::Signal;
use glam::Vec2;
use kurbo::{Affine, BezPath, Stroke};
use peniko::{Brush, Color};
use std::time::Duration;
#[cfg(feature = "runtime")]
use vello::Scene;

/// A procedural grid shape.
///
/// `GridNode` draws a series of vertical and horizontal lines to form a grid,
/// centered around its position.
///
/// ### Example
/// ```rust
/// # use motion_canvas_rs::prelude::*;
/// let grid = GridNode::default()
///     .with_position(Vec2::new(640.0, 360.0))
///     .with_columns(20.0)
///     .with_rows(20.0)
///     .with_spacing_all(40.0)
///     .with_stroke(Color::rgb8(40, 40, 40), 1.0);
/// ```
#[derive(Clone)]
pub struct GridNode {
    /// The absolute position of the grid's center.
    pub position: Signal<Vec2>,
    /// The number of vertical columns.
    pub columns: Signal<f32>,
    /// The number of horizontal rows.
    pub rows: Signal<f32>,
    /// The distance between adjacent grid lines.
    pub spacing: Signal<Vec2>,
    /// The color of the grid lines.
    pub stroke_color: Signal<Color>,
    /// The width of the grid lines.
    pub stroke_width: Signal<f32>,
    /// Opacity from 0.0 (transparent) to 1.0 (opaque).
    pub opacity: Signal<f32>,
}

impl Default for GridNode {
    fn default() -> Self {
        Self {
            position: Signal::new(Vec2::ZERO),
            columns: Signal::new(10.0),
            rows: Signal::new(10.0),
            spacing: Signal::new(Vec2::new(50.0, 50.0)),
            stroke_color: Signal::new(Color::rgb8(100, 100, 100)),
            stroke_width: Signal::new(1.0),
            opacity: Signal::new(1.0),
        }
    }
}

impl GridNode {
    /// Creates a new grid at the given position with default settings.
    pub fn new(position: Vec2) -> Self {
        Self::default().with_position(position)
    }

    /// Creates a square grid with equal columns/rows and uniform spacing.
    pub fn square(position: Vec2, count: f32, spacing: f32) -> Self {
        Self::default()
            .with_position(position)
            .with_columns(count)
            .with_rows(count)
            .with_spacing(Vec2::splat(spacing))
    }

    /// Sets the absolute position of the grid.
    pub fn with_position(mut self, pos: Vec2) -> Self {
        self.position = Signal::new(pos);
        self
    }

    /// Sets the number of columns.
    pub fn with_columns(mut self, cols: f32) -> Self {
        self.columns = Signal::new(cols);
        self
    }

    /// Sets the number of rows.
    pub fn with_rows(mut self, rows: f32) -> Self {
        self.rows = Signal::new(rows);
        self
    }

    /// Sets the spacing between grid lines.
    pub fn with_spacing(mut self, spacing: Vec2) -> Self {
        self.spacing = Signal::new(spacing);
        self
    }

    /// Sets uniform spacing between grid lines on both axes.
    pub fn with_spacing_all(mut self, spacing: f32) -> Self {
        self.spacing = Signal::new(Vec2::splat(spacing));
        self
    }

    /// Sets the stroke color and width for the grid lines.
    pub fn with_stroke(mut self, color: Color, width: f32) -> Self {
        self.stroke_color = Signal::new(color);
        self.stroke_width = Signal::new(width);
        self
    }

    /// Sets the opacity of the grid (0.0 to 1.0).
    pub fn with_opacity(mut self, opacity: f32) -> Self {
        self.opacity = Signal::new(opacity);
        self
    }
}

impl Node for GridNode {
    #[cfg(feature = "runtime")]
    fn render(&self, scene: &mut Scene, parent_transform: Affine, parent_opacity: f32) {
        let opacity = self.opacity.get() * parent_opacity;
        if opacity <= 0.0 {
            return;
        }

        let pos = self.position.get();
        let cols = self.columns.get().max(0.0);
        let rows = self.rows.get().max(0.0);
        let spacing = self.spacing.get();
        let stroke_color = self.stroke_color.get().with_alpha_factor(opacity);
        let stroke_width = self.stroke_width.get();

        let transform = parent_transform * Affine::translate((pos.x as f64, pos.y as f64));
        let brush = Brush::Solid(stroke_color);
        let stroke = Stroke::new(stroke_width as f64);

        let width = cols * spacing.x;
        let height = rows * spacing.y;
        let start_x = -width / 2.0;
        let start_y = -height / 2.0;

        // Vertical lines
        for i in 0..=(cols.ceil() as i32) {
            let x = start_x + i as f32 * spacing.x;
            if x > width / 2.0 {
                break;
            }
            let mut path = BezPath::new();
            path.move_to((x as f64, start_y as f64));
            path.line_to((x as f64, (start_y + height) as f64));
            scene.stroke(&stroke, transform, &brush, None, &path);
        }

        // Horizontal lines
        for i in 0..=(rows.ceil() as i32) {
            let y = start_y + i as f32 * spacing.y;
            if y > height / 2.0 {
                break;
            }
            let mut path = BezPath::new();
            path.move_to((start_x as f64, y as f64));
            path.line_to(((start_x + width) as f64, y as f64));
            scene.stroke(&stroke, transform, &brush, None, &path);
        }
    }

    fn update(&mut self, _dt: Duration) {}

    fn state_hash(&self) -> u64 {
        let mut h = Hasher::new();
        h.update_u64(self.position.state_hash());
        h.update_u64(self.columns.state_hash());
        h.update_u64(self.rows.state_hash());
        h.update_u64(self.spacing.state_hash());
        h.update_u64(self.stroke_color.state_hash());
        h.update_u64(self.stroke_width.state_hash());
        h.update_u64(self.opacity.state_hash());
        h.finish()
    }

    fn clone_node(&self) -> Box<dyn Node> {
        Box::new(self.clone())
    }

    fn reset(&mut self) {
        self.position.reset();
        self.columns.reset();
        self.rows.reset();
        self.spacing.reset();
        self.stroke_color.reset();
        self.stroke_width.reset();
        self.opacity.reset();
    }
}