Initial commit of piet-next API sketch

Cargo.toml

@@ -10,7 +10,7 @@ members = [
     "piet-web",
     "piet-web/examples/basic",
     "piet-svg"
-]
+, "piet-next", "cpu-sparse"]
 
 default-members = [
     "piet",

cpu-sparse/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "cpu-sparse"
+version = "0.1.0"
+authors = ["Raph Levien <[email protected]>"]
+description = "An experimental CPU 2D renderer based on sparse strips"
+license = "Apache-2.0 OR MIT"
+edition = "2021"
+keywords = ["graphics", "2d"]
+categories = ["graphics"]
+
+[dependencies]
+piet-next = { path = "../piet-next" }
+flatten = { git = "https://github.com/linebender/gpu-stroke-expansion-paper", rev = "827ccf6" }
+
+[dev-dependencies]
+png = "0.17.14"
+roxmltree = "0.20.0"

cpu-sparse/examples/simple.rs

@@ -0,0 +1,38 @@
+// Copyright 2024 the Piet Authors
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+
+use std::io::BufWriter;
+
+use cpu_sparse::{CsRenderCtx, Pixmap};
+use piet_next::peniko::color::palette;
+use piet_next::peniko::kurbo::{BezPath, Stroke};
+use piet_next::RenderCtx;
+
+const WIDTH: usize = 1024;
+const HEIGHT: usize = 256;
+
+pub fn main() {
+    let mut ctx = CsRenderCtx::new(WIDTH, HEIGHT);
+    let mut path = BezPath::new();
+    path.move_to((10.0, 10.0));
+    path.line_to((180.0, 20.0));
+    path.line_to((30.0, 40.0));
+    path.close_path();
+    let piet_path = path.into();
+    ctx.fill(&piet_path, palette::css::REBECCA_PURPLE.into());
+    let stroke = Stroke::new(5.0);
+    ctx.stroke(&piet_path, &stroke, palette::css::DARK_BLUE.into());
+    if let Some(filename) = std::env::args().nth(1) {
+        let mut pixmap = Pixmap::new(WIDTH, HEIGHT);
+        ctx.render_to_pixmap(&mut pixmap);
+        pixmap.unpremultiply();
+        let file = std::fs::File::create(filename).unwrap();
+        let w = BufWriter::new(file);
+        let mut encoder = png::Encoder::new(w, WIDTH as u32, HEIGHT as u32);
+        encoder.set_color(png::ColorType::Rgba);
+        let mut writer = encoder.write_header().unwrap();
+        writer.write_image_data(pixmap.data()).unwrap();
+    } else {
+        ctx.debug_dump();
+    }
+}