Added correlation function which updated array in place

1 files changed, 27 insertions, 1 deletions

diff --git a/web/main.js b/web/main.js
index 5b58f9d..ace739f 100644
--- a/web/main.js
+++ b/web/main.js
@@ -13,13 +13,31 @@ function jsArrayToF32ArrayPtr(jsArray, callback) {
     var dataHeap = new Uint8Array(Module.HEAPU8.buffer, dataPtr, nDataBytes);
     dataHeap.set(new Uint8Array(data.buffer));
 
-    var result = callback(dataHeap.byteOffset, jsArray.length);
+    var result = callback(dataPtr, jsArray.length);
 
     Module._free(dataPtr);
     
     return result;
 }
 
+function jsArrayToF32ArrayPtrMutateInPlace(jsArray, mutate) {
+    var data = new Float32Array(jsArray);
+    var nDataBytes = data.length * data.BYTES_PER_ELEMENT;
+    var dataPtr = Module._malloc(nDataBytes);
+
+    var dataHeap = new Uint8Array(Module.HEAPU8.buffer, dataPtr, nDataBytes);
+    dataHeap.set(new Uint8Array(data.buffer));
+
+    mutate(dataPtr, jsArray.length);
+
+    var mutatedData = new Float32Array(Module.HEAPU8.buffer, dataPtr, jsArray.length);
+    var result = Array.prototype.slice.call(mutatedData);
+    
+    Module._free(dataPtr);
+    
+    return result;
+}
+
 function findFundamentalFrequency(data, samplingRate) {
     return jsArrayToF32ArrayPtr(data, function(dataPtr, dataLength) {
         return Module._find_fundamental_frequency(dataPtr, dataLength, samplingRate);
@@ -35,13 +53,21 @@ function hzToPitch(hz) {
     return wrapped(hz);
 }
 
+function correlation(data) {
+    return jsArrayToF32ArrayPtrMutateInPlace(data, function(dataPtr, dataLength) {
+        Module._correlation(dataPtr, dataLength);
+    });
+}
+
 function main() {
     var data = [1, 0, -1, 0, 1, 0, -1, 0, 1, 0, -1, 0, 1, 0, -1, 0];
     var fundamental = findFundamentalFrequency(data, 44100.0);
+    var correlated = correlation(data);
 
     var error = hzToCentsError(450.0);
     var pitch = hzToPitch(450.0);
     
     console.log("Javascript here. Our fundamental frequency according to Rust is " + fundamental + "Hz");
     console.log("The other math shows a pitch of " + pitch + ", and an error of " + error);
+    console.log("Correlation of the array is " + correlated);
 }