[librsvg/wip/rust-api: 6/11] librsvg_crate/examples/render.rs - Basic rendering example with the Rust API

[Federico Mena Quintero <federico src gnome org>]

commit 3939feb08142665b01d0eb18580af65202bb5c08
Author: Federico Mena Quintero <federico gnome org>
Date:   Wed Feb 13 17:48:26 2019 -0600

    librsvg_crate/examples/render.rs - Basic rendering example with the Rust API
    
    Doesn't build yet; we need to link the C dependencies by hand :(

 librsvg_crate/Cargo.toml         |  3 +++
 librsvg_crate/examples/render.rs | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+)
---
diff --git a/librsvg_crate/Cargo.toml b/librsvg_crate/Cargo.toml
index 041f270b..16309072 100644
--- a/librsvg_crate/Cargo.toml
+++ b/librsvg_crate/Cargo.toml
@@ -13,3 +13,6 @@ glib = "0.6.0"
 gio = { version="0.5.1", features=["v2_48"] } # per configure.ac
 rsvg_internals = { path = "../rsvg_internals" }
 url = "1.7.2"
+
+[dev-dependencies]
+cairo-rs = { version = "0.5.0", features = ["png"] }
diff --git a/librsvg_crate/examples/render.rs b/librsvg_crate/examples/render.rs
new file mode 100644
index 00000000..cefb2f3a
--- /dev/null
+++ b/librsvg_crate/examples/render.rs
@@ -0,0 +1,34 @@
+extern crate cairo;
+extern crate librsvg;
+
+use std::fs::File;
+use std::io::BufWriter;
+use std::process;
+
+fn main() {
+    let args = std::env::args_os();
+
+    if args.len() != 3 {
+        eprintln!("usage: render <input.svg> <output.png>");
+        process::exit(1);
+    }
+
+    let mut args = args.skip(1);
+
+    let input = args.next().unwrap();
+    let output = args.next().unwrap();
+
+    let handle = librsvg::LoadOptions::new().read_path(input).unwrap();
+
+    let renderer = handle.get_cairo_renderer();
+
+    let (w, h) = renderer.get_dimensions().unwrap();
+
+    let surface = cairo::ImageSurface::create(cairo::Format::ARgb32, w, h).unwrap();
+    let cr = cairo::Context::new(&surface);
+    renderer.render(&cr).unwrap();
+
+    let mut file = BufWriter::new(File::create(output).unwrap());
+
+    surface.write_to_png(&mut file).unwrap();
+}