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.

4 files changed, 78 insertions, 1 deletions

diff --git a/system/include/emscripten/bind.h b/system/include/emscripten/bind.h
index d6d4f2c5..4be50c9d 100644
--- a/system/include/emscripten/bind.h
+++ b/system/include/emscripten/bind.h
@@ -59,6 +59,10 @@ namespace emscripten {
                 TYPEID emvalType,
                 const char* name);
 
+            void _embind_register_memory_view(
+                TYPEID memoryViewType,
+                const char* name);
+
             void _embind_register_function(
                 const char* name,
                 unsigned argCount,
diff --git a/system/include/emscripten/val.h b/system/include/emscripten/val.h
index 185cc935..b712d164 100644
--- a/system/include/emscripten/val.h
+++ b/system/include/emscripten/val.h
@@ -10,7 +10,6 @@ namespace emscripten {
         extern "C" {
             void _emval_register_symbol(const char*);
 
-            typedef struct _EM_SIG* EM_SIG;
             typedef struct _EM_VAL* EM_VAL;
         
             void _emval_incref(EM_VAL value);
diff --git a/system/include/emscripten/wire.h b/system/include/emscripten/wire.h
index e4ddfd04..32080e54 100644
--- a/system/include/emscripten/wire.h
+++ b/system/include/emscripten/wire.h
@@ -312,4 +312,77 @@ namespace emscripten {
             WireType wt;
         };
     }
+
+    struct memory_view {
+        enum class Type {
+            Int8Array,
+            Uint8Array,
+            Int16Array,
+            Uint16Array,
+            Int32Array,
+            Uint32Array,
+            Float32Array,
+            Float64Array,
+        };
+
+        memory_view() = delete;
+        explicit memory_view(size_t size, const void* data)
+            : type(Type::Uint8Array)
+            , size(size)
+            , data(data)
+        {}
+        explicit memory_view(Type type, size_t size, const void* data)
+            : type(type)
+            , size(size)
+            , data(data)
+        {}
+
+        const Type type;
+        const size_t size; // in elements, not bytes
+        const void* const data;
+    };
+
+    inline memory_view typed_memory_view(size_t size, const int8_t* data) {
+        return memory_view(memory_view::Type::Int8Array, size, data);
+    }
+
+    inline memory_view typed_memory_view(size_t size, const uint8_t* data) {
+        return memory_view(memory_view::Type::Uint8Array, size, data);
+    }
+
+    inline memory_view typed_memory_view(size_t size, const int16_t* data) {
+        return memory_view(memory_view::Type::Int16Array, size, data);
+    }
+
+    inline memory_view typed_memory_view(size_t size, const uint16_t* data) {
+        return memory_view(memory_view::Type::Uint16Array, size, data);
+    }
+
+    inline memory_view typed_memory_view(size_t size, const int32_t* data) {
+        return memory_view(memory_view::Type::Int32Array, size, data);
+    }
+
+    inline memory_view typed_memory_view(size_t size, const uint32_t* data) {
+        return memory_view(memory_view::Type::Uint32Array, size, data);
+    }
+
+    inline memory_view typed_memory_view(size_t size, const float* data) {
+        return memory_view(memory_view::Type::Float32Array, size, data);
+    }
+
+    inline memory_view typed_memory_view(size_t size, const double* data) {
+        return memory_view(memory_view::Type::Float64Array, size, data);
+    }
+
+    namespace internal {
+        template<>
+        struct BindingType<memory_view> {
+            typedef memory_view* WireType;
+            static WireType toWireType(const memory_view& mv) {
+                WireType wt = (WireType)malloc(sizeof(memory_view));
+                new(wt) memory_view(mv);
+                return wt;
+            }
+        };
+    }
 }
diff --git a/system/lib/embind/bind.cpp b/system/lib/embind/bind.cpp
index ec1648a9..12264dfd 100644
--- a/system/lib/embind/bind.cpp
+++ b/system/lib/embind/bind.cpp
@@ -59,4 +59,5 @@ EMSCRIPTEN_BINDINGS(native_and_builtin_types) {
     _embind_register_std_string(TypeID<std::string>::get(), "std::string");

     _embind_register_std_wstring(TypeID<std::wstring>::get(), sizeof(wchar_t), "std::wstring");

     _embind_register_emval(TypeID<val>::get(), "emscripten::val");

+    _embind_register_memory_view(TypeID<memory_view>::get(), "emscripten::memory_view");

 }