enumized shape painting ops...

gistfile1.rs

#![allow(unused)]
use kurbo::{Affine, Point, Rect, Shape, Stroke};
use vello::peniko::{BlendMode, BrushRef, Fill};
use vello::SceneBuilder;

#[derive(Clone)]
pub enum ShapeOp<'a, 'b> {
    Fill {
        style: Fill,
        transform: Affine,
        brush: BrushRef<'b>,
        brush_transform: Option<Affine>,
    },
    Stroke {
        style: &'a Stroke,
        transform: Affine,
        brush: BrushRef<'b>,
        brush_transform: Option<Affine>,
    },
    PushLayer {
        blend: BlendMode,
        alpha: f32,
        transform: Affine,
    },
}

pub trait SceneBuilderWhisperer {
    fn paint_shape_op(&mut self, op: ShapeOp<'_, '_>, shape: &impl Shape);
    fn paint_shape_ops<'a, 'b, I>(&mut self, ops: I, shape: &impl Shape)
    where
        I: IntoIterator<Item = ShapeOp<'a, 'b>>;
}

impl SceneBuilderWhisperer for SceneBuilder<'_> {
    fn paint_shape_op(&mut self, op: ShapeOp<'_, '_>, shape: &impl Shape) {
        match op {
            ShapeOp::Fill {
                style,
                transform,
                brush,
                brush_transform,
            } => self.fill(style, transform, brush, brush_transform, shape),
            ShapeOp::Stroke {
                style,
                transform,
                brush,
                brush_transform,
            } => self.stroke(style, transform, brush, brush_transform, shape),
            ShapeOp::PushLayer {
                blend,
                alpha,
                transform,
            } => self.push_layer(blend, alpha, transform, shape),
        }
    }
    fn paint_shape_ops<'a, 'b, I>(&mut self, ops: I, shape: &impl Shape)
    where
        I: IntoIterator<Item = ShapeOp<'a, 'b>>,
    {
        for op in ops {
            self.paint_shape_op(op, shape)
        }
    }
}