Merge pull request #76 from CesiumGS/main

Optimize floatVectorToFloatArray for performance improvements

Author: drumath2237

packages/core/lib/spz-wasm/cppBufferUtil.ts

@@ -4,18 +4,28 @@ import type { MainModule, VectorFloat32, VectorUInt8T } from "./build/main";
  * create new Float32Array from cpp FloatVector
  * @param wasmModule emscripten main module
  * @param vec cpp float32 vector
+ * @param enhancementFunc function accepting a number and returning a number to perform processing
  * @returns copied float32 array
  */
 export const floatVectorToFloatArray = (
   wasmModule: MainModule,
   vec: VectorFloat32,
-  enhancementFunc: (n: number) => number = (n) => n,
+  enhancementFunc?: (n: number) => number,
 ): Float32Array => {
   const pointer = wasmModule.vf32_ptr(vec);
   const size = vec.size();
+  const floatOffset = pointer >> 2;
 
-  const buffer = new Float32Array(wasmModule.HEAPF32.buffer, pointer, size);
-  const copiedBuffer = buffer.map(enhancementFunc);
+  const copiedBuffer = wasmModule.HEAPF32.slice(
+    floatOffset,
+    floatOffset + size,
+  );
+
+  if (enhancementFunc !== undefined) {
+    for (let i = 0; i < size; i++) {
+      copiedBuffer[i] = enhancementFunc(copiedBuffer[i]);
+    }
+  }
 
   return copiedBuffer;
 };