vello/piet-gpu-types/src/ptcl.rs

use piet_gpu_derive::piet_gpu;

piet_gpu! {
    #[gpu_write]
    mod ptcl {
        struct CmdCircle {
            center: [f32; 2],
            radius: f32,
            rgba_color: u32,
        }
        struct CmdLine {
            start: [f32; 2],
            end: [f32; 2],
        }
        struct CmdStroke {
            // Consider a specialization to one segment.
            seg_ref: Ref<SegChunk>,
            half_width: f32,
            rgba_color: u32,
        }
        struct CmdFill {
            seg_ref: Ref<SegChunk>,
            backdrop: i32,
            rgba_color: u32,
        }
        struct CmdFillEdge {
            // The sign is only one bit.
            sign: i32,
            y: f32,
        }
        struct CmdDrawFill {
            backdrop: i32,
            rgba_color: u32,
        }
        struct CmdSolid {
            rgba_color: u32,
        }
        struct CmdJump {
            new_ref: u32,
        }
        enum Cmd {
            End,
            Circle(CmdCircle),
            Line(CmdLine),
            Fill(CmdFill),
            Stroke(CmdStroke),
            FillEdge(CmdFillEdge),
            DrawFill(CmdDrawFill),
            Solid(CmdSolid),
            Jump(CmdJump),
            Bail,
        }

        // TODO: strongly consider using f16. If so, these would be
        // relative to the tile. We're doing f32 for now to minimize
        // divergence from piet-metal originals.
        struct Segment {
            start: [f32; 2],
            end: [f32; 2],

            // This is used for fills only, but we're including it in
            // the general structure for simplicity.
            y_edge: f32,
        }

        struct SegChunk {
            n: u32,
            next: Ref<SegChunk>,
            // Actually a reference to a variable-sized slice.
            segs: Ref<Segment>,
        }
    }
}