Add support for (fast?) memory_view objects. If C++ passes a memory_view to JS, it gets converted into a typed array object on the other side. Intended for WebGL.

2 files changed, 41 insertions, 0 deletions

diff --git a/tests/embind/embind.test.js b/tests/embind/embind.test.js
index 52b2cad8..f9f035f2 100644
--- a/tests/embind/embind.test.js
+++ b/tests/embind/embind.test.js
@@ -1728,6 +1728,28 @@ module({
         e.delete();
         f.delete();
     });
+
+    BaseFixture.extend("memory view", function() {
+        test("can pass memory view from C++ to JS", function() {
+            var views = [];
+            cm.callWithMemoryView(function(view) {
+                views.push(view);
+            });
+            assert.equal(3, views.length);
+
+            assert.instanceof(views[0], Uint8Array);
+            assert.equal(8, views[0].length);
+            assert.deepEqual([0, 1, 2, 3, 4, 5, 6, 7], [].slice.call(new Uint8Array(views[0])));
+
+            assert.instanceof(views[1], Float32Array);
+            assert.equal(4, views[1].length);
+            assert.deepEqual([1.5, 2.5, 3.5, 4.5], [].slice.call(views[1]));
+
+            assert.instanceof(views[2], Int16Array);
+            assert.equal(4, views[2].length);
+            assert.deepEqual([1000, 100, 10, 1], [].slice.call(views[2]));
+        });
+    });
 });
 
 /* global run_all_tests */
diff --git a/tests/embind/embind_test.cpp b/tests/embind/embind_test.cpp
index 23761efc..e8ca0338 100644
--- a/tests/embind/embind_test.cpp
+++ b/tests/embind/embind_test.cpp
@@ -1148,6 +1148,25 @@ EMSCRIPTEN_BINDINGS(interface_tests) {
     function("callDifferentArguments", &callDifferentArguments);
 }
 
+template<typename T, size_t sizeOfArray>
+constexpr size_t getElementCount(T (&)[sizeOfArray]) {
+    return sizeOfArray;
+}
+
+static void callWithMemoryView(val v) {
+    // static so the JS test can read the memory after callTakeMemoryView runs
+    static unsigned char data[] = { 0, 1, 2, 3, 4, 5, 6, 7 };
+    v(memory_view(getElementCount(data), data));
+    static float f[] = { 1.5f, 2.5f, 3.5f, 4.5f };
+    v(typed_memory_view(getElementCount(f), f));
+    static short s[] = { 1000, 100, 10, 1 };
+    v(typed_memory_view(getElementCount(s), s));
+}
+
+EMSCRIPTEN_BINDINGS(memory_view_tests) {
+    function("callWithMemoryView", &callWithMemoryView);
+}
+
 class HasExternalConstructor {
 public:
     HasExternalConstructor(const std::string& str)