[wasm] Add rust example

src/wasm/sample/rust/hello-wasm/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "hello-wasm"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+#externref = "0.1.0"
+wasm-bindgen = "0.2.0"
+tiny-rng = "0.2.0"
+harfbuzz-wasm = { path="../../rust/harfbuzz-wasm"}

src/wasm/sample/rust/hello-wasm/src/lib.rs

@@ -0,0 +1,18 @@
+use harfbuzz_wasm::{Font, GlyphBuffer};
+use tiny_rng::{Rand, Rng};
+use wasm_bindgen::prelude::*;
+
+#[wasm_bindgen]
+pub fn shape(font_ref: u32, buf_ref: u32) -> i32 {
+    let mut rng = Rng::from_seed(123456);
+    let font = Font::from_ref(font_ref);
+    font.shape_with(buf_ref, "ot");
+    let mut buffer = GlyphBuffer::from_ref(buf_ref);
+    for mut item in buffer.glyphs.iter_mut() {
+        // Randomize it!
+        item.x_offset = ((rng.rand_u32() as i32) >> 24) - 120;
+        item.y_offset = ((rng.rand_u32() as i32) >> 24) - 120;
+    }
+    // Buffer is written back to HB on drop
+    1
+}