Implemented PngRenderer

Cargo.toml

@@ -14,3 +14,5 @@ rgb = "0.8.14"
 svg = "0.5.12"
 rand = {version="0.7.0", features=["small_rng"]}
 cgmath = "0.17.0"
+usvg = "0.35.0"
+resvg = "0.35.0"

README.md

@@ -3,7 +3,7 @@
 
 A small Rust library for 2D drawing. 
 Simple display list and vector shapes. 
-Currently supports SVG output, designed to also support PNG and other formats.
+Currently supports SVG and PNG output, designed to also support other formats.
 
 ## Example
 ```rust
@@ -43,7 +43,7 @@ render::save(
 - [x] Draw anything other than a rectangle
 - [x] Positions
 - [x] Styles 
-- [ ] Bitmap image output
+- [x] Bitmap image output
 
 ## Useful Commands
 

src/lib.rs

@@ -56,6 +56,7 @@ pub mod style;
 
 pub use crate::canvas::Canvas;
 pub use crate::drawing::{DisplayList, Drawing};
+pub use crate::render::bitmap::PngRenderer;
 pub use crate::render::svg::SvgRenderer;
 pub use crate::shape::{LineBuilder, Shape};
 pub use crate::style::Color;

src/render/bitmap.rs

@@ -1,13 +1,31 @@
 //! Render Canvas to bitmap formats (PNG, JPG, etc...)
-use crate::render::Renderer;
+use crate::render::{svg::SvgRenderer, Renderer};
 use crate::Canvas;
+use usvg::TreeParsing;
 
 /// Renders `Canvas` to a PNG format
-/// todo: Implement!
-pub struct PNGRenderer {}
+pub struct PngRenderer {
+    svg_renderer: SvgRenderer,
+}
+
+impl PngRenderer {
+    pub fn new() -> Self {
+        PngRenderer {
+            svg_renderer: SvgRenderer::new(),
+        }
+    }
+}
+
+impl Renderer for PngRenderer {
+    fn render(&self, canvas: &Canvas) -> Vec<u8> {
+        let opt = usvg::Options::default();
+
+        let svg_data = self.svg_renderer.render(canvas);
+        let rtree = usvg::Tree::from_data(&svg_data, &opt).unwrap();
+        let mut pixmap = resvg::tiny_skia::Pixmap::new(canvas.width, canvas.height).unwrap();
+
+        resvg::Tree::from_usvg(&rtree).render(usvg::Transform::default(), &mut pixmap.as_mut());
 
-impl Renderer for PNGRenderer {
-    fn render(&self, _canvas: &Canvas) -> Vec<u8> {
-        unimplemented!()
+        pixmap.encode_png().unwrap()
     }
 }

tests/functional.rs

@@ -1,7 +1,6 @@
 use draw::*;
 
-#[test]
-fn basic_end_to_end() {
+fn test_canvas() -> Canvas {
     // create a canvas to draw on
     let mut canvas = Canvas::new(100, 100);
 
@@ -20,6 +19,13 @@ fn basic_end_to_end() {
     // add it to the canvas
     canvas.display_list.add(rect);
 
+    canvas
+}
+
+#[test]
+fn basic_end_to_end_svg() {
+    let canvas = test_canvas();
+
     // save the canvas as an svg
     render::save(
         &canvas,
@@ -28,3 +34,16 @@ fn basic_end_to_end() {
     )
     .expect("Failed to save");
 }
+
+#[test]
+fn basic_end_to_end_png() {
+    let canvas = test_canvas();
+
+    // save the canvas as a png
+    render::save(
+        &canvas,
+        "tests/png/basic_end_to_end.png",
+        PngRenderer::new(),
+    )
+    .expect("Failed to save");
+}

tests/integration.rs

@@ -2,8 +2,7 @@ use draw::*;
 use rand::rngs::SmallRng;
 use rand::{Rng, SeedableRng};
 
-#[test]
-fn lines() {
+fn lines_canvas() -> Canvas {
     let mut canvas = Canvas::new(100, 100);
 
     // create a line that starts in the top middle of the screen, then draw down the middle
@@ -19,12 +18,26 @@ fn lines() {
 
     canvas.display_list.add(drawing);
 
+    canvas
+}
+
+#[test]
+fn lines_svg() {
+    let canvas = lines_canvas();
+
     // save the canvas as an svg
     render::save(&canvas, "tests/svg/lines.svg", SvgRenderer::new()).expect("Failed to save");
 }
 
 #[test]
-fn random_circles() {
+fn lines_png() {
+    let canvas = lines_canvas();
+
+    // save the canvas as an png
+    render::save(&canvas, "tests/png/lines.png", PngRenderer::new()).expect("Failed to save");
+}
+
+fn random_circles_canvas() -> Canvas {
     let mut canvas = Canvas::new(1000, 1000);
     let mut rng = SmallRng::from_seed([0; 16]);
     let mut points = vec![];
@@ -44,6 +57,21 @@ fn random_circles() {
         canvas.display_list.add(circle);
     }
 
+    canvas
+}
+
+#[test]
+fn random_circles_svg() {
+    let canvas = random_circles_canvas();
+
     draw::render::save(&canvas, "tests/svg/random_circles.svg", SvgRenderer::new())
         .expect("Failed to save");
 }
+
+#[test]
+fn random_circles_png() {
+    let canvas = random_circles_canvas();
+
+    draw::render::save(&canvas, "tests/png/random_circles.png", PngRenderer::new())
+        .expect("Failed to save");
+}