1 files changed, 75 insertions, 0 deletions
diff --git a/src/wasm_api.rs b/src/wasm_api.rs
new file mode 100644
index 0000000..bb4dd45
--- /dev/null
+++ b/src/wasm_api.rs
@@ -0,0 +1,75 @@
+use model::Model;
+use signal::Signal;
+use pitch::Pitch;
+
+use std::os::raw::c_char;
+use std::os::raw::c_void;
+use std::mem;
+use std::ffi::CString;
+use std::slice;
+use std::f32;
+
+#[no_mangle]
+pub extern "C" fn malloc(size: usize) -> *mut c_void {
+    let mut buf = Vec::with_capacity(size);
+    let ptr = buf.as_mut_ptr();
+    mem::forget(buf);
+    return ptr as *mut c_void;
+}
+
+#[no_mangle]
+pub extern "C" fn free(ptr: *mut c_void, cap: usize) {
+    unsafe  {
+        // after it's in scope, it can go out of scope in the normal
+        // RAII cleanup.
+        let _buf = Vec::from_raw_parts(ptr, 0, cap);
+    }
+}
+
+#[no_mangle]
+pub extern "C" fn free_str(ptr: *mut c_char) {
+    unsafe {
+        let _ = CString::from_raw(ptr);
+    }
+}
+
+#[no_mangle]
+pub extern "C" fn find_fundamental_frequency(signal_ptr: *const f32, signal_length: usize, sample_rate: f32) -> f32 {
+    let signal_slice = unsafe {
+        &slice::from_raw_parts(signal_ptr, signal_length)
+    };
+    let signal = Signal::new(signal_slice, sample_rate);
+    let model = Model::from_signal(signal);
+
+    model.pitch.map_or(f32::NAN, |p| p.hz)
+}
+
+#[no_mangle]
+pub extern "C" fn hz_to_cents_error(hz: f32) -> f32 {
+    let pitch = Pitch::new(hz);
+    pitch.cents_error()
+}
+
+#[no_mangle]
+pub extern "C" fn hz_to_pitch(hz: f32) -> *mut c_char {
+    let pitch = Pitch::new(hz);
+    CString::new(format!("{}", pitch))
+		.unwrap()
+        .into_raw()
+}
+
+#[no_mangle]
+pub extern "C" fn correlation(signal_ptr: *mut f32, signal_length: usize, sample_rate: f32) {
+    let signal_slice = unsafe {
+        &slice::from_raw_parts(signal_ptr, signal_length)
+    };
+
+    let signal = Signal::new(signal_slice, sample_rate);
+    let model = Model::from_signal(signal);
+
+    unsafe {
+        for (i, cor) in model.correlation.value.iter().enumerate() {
+            *signal_ptr.offset(i as isize) = *cor;
+        }
+    }
+}