add macOS implementation

macos/include/backend/AcquiredImage.h

@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TNT_FILAMENT_BACKEND_PRIVATE_ACQUIREDIMAGE_H
+#define TNT_FILAMENT_BACKEND_PRIVATE_ACQUIREDIMAGE_H
+
+#include <backend/DriverEnums.h>
+
+namespace filament::backend {
+
+class CallbackHandler;
+
+// This lightweight POD allows us to bundle the state required to process an ACQUIRED stream.
+// Since these types of external images need to be moved around and queued up, an encapsulation is
+// very useful.
+
+struct AcquiredImage {
+    void* image = nullptr;
+    backend::StreamCallback callback = nullptr;
+    void* userData = nullptr;
+    CallbackHandler* handler = nullptr;
+};
+
+} // namespace filament::backend
+
+#endif // TNT_FILAMENT_BACKEND_PRIVATE_ACQUIREDIMAGE_H

macos/include/backend/BufferDescriptor.h

@@ -0,0 +1,223 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//! \file
+
+#ifndef TNT_FILAMENT_BACKEND_BUFFERDESCRIPTOR_H
+#define TNT_FILAMENT_BACKEND_BUFFERDESCRIPTOR_H
+
+#include <utils/compiler.h>
+#include <utils/ostream.h>
+
+#include <stddef.h>
+#include <stdint.h>
+
+namespace filament::backend {
+
+class CallbackHandler;
+
+/**
+ * A CPU memory-buffer descriptor, typically used to transfer data from the CPU to the GPU.
+ *
+ * A BufferDescriptor owns the memory buffer it references, therefore BufferDescriptor cannot
+ * be copied, but can be moved.
+ *
+ * BufferDescriptor releases ownership of the memory-buffer when it's destroyed.
+ */
+class UTILS_PUBLIC BufferDescriptor {
+public:
+    /**
+     * Callback used to destroy the buffer data.
+     * Guarantees:
+     *      Called on the main filament thread.
+     *
+     * Limitations:
+     *      Must be lightweight.
+     *      Must not call filament APIs.
+     */
+    using Callback = void(*)(void* buffer, size_t size, void* user);
+
+    //! creates an empty descriptor
+    BufferDescriptor() noexcept = default;
+
+    //! calls the callback to advertise BufferDescriptor no-longer owns the buffer
+    ~BufferDescriptor() noexcept {
+        if (mCallback) {
+            mCallback(buffer, size, mUser);
+        }
+    }
+
+    BufferDescriptor(const BufferDescriptor& rhs) = delete;
+    BufferDescriptor& operator=(const BufferDescriptor& rhs) = delete;
+
+    BufferDescriptor(BufferDescriptor&& rhs) noexcept
+        : buffer(rhs.buffer), size(rhs.size),
+          mCallback(rhs.mCallback), mUser(rhs.mUser), mHandler(rhs.mHandler) {
+            rhs.buffer = nullptr;
+            rhs.mCallback = nullptr;
+    }
+
+    BufferDescriptor& operator=(BufferDescriptor&& rhs) noexcept {
+        if (this != &rhs) {
+            buffer = rhs.buffer;
+            size = rhs.size;
+            mCallback = rhs.mCallback;
+            mUser = rhs.mUser;
+            mHandler = rhs.mHandler;
+            rhs.buffer = nullptr;
+            rhs.mCallback = nullptr;
+        }
+        return *this;
+    }
+
+    /**
+     * Creates a BufferDescriptor that references a CPU memory-buffer
+     * @param buffer    Memory address of the CPU buffer to reference
+     * @param size      Size of the CPU buffer in bytes
+     * @param callback  A callback used to release the CPU buffer from this BufferDescriptor
+     * @param user      An opaque user pointer passed to the callback function when it's called
+     */
+    BufferDescriptor(void const* buffer, size_t size,
+            Callback callback = nullptr, void* user = nullptr) noexcept
+                : buffer(const_cast<void*>(buffer)), size(size), mCallback(callback), mUser(user) {
+    }
+
+    /**
+     * Creates a BufferDescriptor that references a CPU memory-buffer
+     * @param buffer    Memory address of the CPU buffer to reference
+     * @param size      Size of the CPU buffer in bytes
+     * @param callback  A callback used to release the CPU buffer from this BufferDescriptor
+     * @param user      An opaque user pointer passed to the callback function when it's called
+     */
+    BufferDescriptor(void const* buffer, size_t size,
+            CallbackHandler* handler, Callback callback, void* user = nullptr) noexcept
+                : buffer(const_cast<void*>(buffer)), size(size),
+                mCallback(callback), mUser(user), mHandler(handler) {
+    }
+
+    // --------------------------------------------------------------------------------------------
+
+    /**
+     * Helper to create a BufferDescriptor that uses a KNOWN method pointer w/ object passed
+     * by pointer as the callback. e.g.:
+     *     auto bd = BufferDescriptor::make(buffer, size, &Foo::method, foo);
+     *
+     * @param buffer    Memory address of the CPU buffer to reference
+     * @param size      Size of the CPU buffer in bytes
+     * @param handler   Handler to use to dispatch the callback, or nullptr for the default handler
+     * @return          a new BufferDescriptor
+     */
+    template<typename T, void(T::*method)(void const*, size_t)>
+    static BufferDescriptor make(
+            void const* buffer, size_t size, T* data, CallbackHandler* handler = nullptr) noexcept {
+        return {
+                buffer, size,
+                handler, [](void* b, size_t s, void* u) {
+                    (*static_cast<T**>(u)->*method)(b, s);
+                }, data
+        };
+    }
+
+    /**
+     * Helper to create a BufferDescriptor that uses a functor as the callback.
+     *
+     * Caveats:
+     *      - DO NOT CALL setCallback() when using this helper.
+     *      - This make a heap allocation
+     *
+     * @param buffer    Memory address of the CPU buffer to reference
+     * @param size      Size of the CPU buffer in bytes
+     * @param functor   functor of type f(void const* buffer, size_t size)
+     * @param handler   Handler to use to dispatch the callback, or nullptr for the default handler
+     * @return          a new BufferDescriptor
+     */
+    template<typename T>
+    static BufferDescriptor make(
+            void const* buffer, size_t size, T&& functor, CallbackHandler* handler = nullptr) noexcept {
+        return {
+                buffer, size,
+                handler, [](void* b, size_t s, void* u) {
+                    T& that = *static_cast<T*>(u);
+                    that(b, s);
+                    delete &that;
+                },
+                new T(std::forward<T>(functor))
+        };
+    }
+
+    // --------------------------------------------------------------------------------------------
+
+    /**
+     * Set or replace the release callback function
+     * @param callback  The new callback function
+     * @param user      An opaque user pointer passed to the callbeck function when it's called
+     */
+    void setCallback(Callback callback, void* user = nullptr) noexcept {
+        this->mCallback = callback;
+        this->mUser = user;
+        this->mHandler = nullptr;
+    }
+
+    /**
+     * Set or replace the release callback function
+     * @param handler   The Handler to use to dispatch the callback
+     * @param callback  The new callback function
+     * @param user      An opaque user pointer passed to the callbeck function when it's called
+     */
+    void setCallback(CallbackHandler* handler, Callback callback, void* user = nullptr) noexcept {
+        mCallback = callback;
+        mUser = user;
+        mHandler = handler;
+    }
+
+    //! Returns whether a release callback is set
+    bool hasCallback() const noexcept { return mCallback != nullptr; }
+
+    //! Returns the currently set release callback function
+    Callback getCallback() const noexcept {
+        return mCallback;
+    }
+
+    //! Returns the handler for this callback or nullptr if the default handler is to be used.
+    CallbackHandler* getHandler() const noexcept {
+        return mHandler;
+    }
+
+    //! Returns the user opaque pointer associated to this BufferDescriptor
+    void* getUser() const noexcept {
+        return mUser;
+    }
+
+    //! CPU mempry-buffer virtual address
+    void* buffer = nullptr;
+
+    //! CPU memory-buffer size in bytes
+    size_t size = 0;
+
+private:
+    // callback when the buffer is consumed.
+    Callback mCallback = nullptr;
+    void* mUser = nullptr;
+    CallbackHandler* mHandler = nullptr;
+};
+
+} // namespace filament::backend
+
+#if !defined(NDEBUG)
+utils::io::ostream& operator<<(utils::io::ostream& out, const filament::backend::BufferDescriptor& b);
+#endif
+
+#endif // TNT_FILAMENT_BACKEND_BUFFERDESCRIPTOR_H

macos/include/backend/CallbackHandler.h

@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TNT_FILAMENT_BACKEND_CALLBACKHANDLER_H
+#define TNT_FILAMENT_BACKEND_CALLBACKHANDLER_H
+
+#include <utils/compiler.h>
+
+namespace filament::backend {
+
+/**
+ * A generic interface to dispatch callbacks.
+ *
+ * All APIs that take a callback as argument also take a
+ * CallbackHandler* which is used to dispatch the
+ * callback: CallbackHandler::post() method is called from a service thread as soon
+ * as possible (this will NEVER be the main thread), CallbackHandler::post()
+ * is  responsible for scheduling the callback onto the thread the
+ * user desires.
+ *
+ * This is intended to make callbacks interoperate with
+ * the platform/OS's own messaging system.
+ *
+ * CallbackHandler* can always be nullptr in which case the default handler is used. The
+ * default handler always dispatches callbacks on filament's main thread opportunistically.
+ *
+ * Life time:
+ * ---------
+ *
+ * Filament make no attempts to manage the life time of the CallbackHandler* and never takes
+ * ownership.
+ * In particular, this means that the CallbackHandler instance must stay valid until all
+ * pending callbacks are been dispatched.
+ *
+ * Similarly, when shutting down filament, care must be taken to ensure that all pending callbacks
+ * that might access filament's state have been dispatched. Filament can no longer ensure this
+ * because callback execution is the responsibility of the CallbackHandler, which is external to
+ * filament.
+ * Typically, the concrete CallbackHandler would have a mechanism to drain and/or wait for all
+ * callbacks to be processed.
+ *
+ */
+class CallbackHandler {
+public:
+    using Callback = void(*)(void* user);
+
+    /**
+     * Schedules the callback to be called onto the appropriate thread.
+     * Typically this will be the application's main thead.
+     *
+     * Must be thread-safe.
+     */
+    virtual void post(void* user, Callback callback) = 0;
+
+protected:
+    virtual ~CallbackHandler();
+};
+
+} // namespace filament::backend
+
+#endif // TNT_FILAMENT_BACKEND_CALLBACKHANDLER_H

macos/include/backend/DriverApiForward.h

@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TNT_FILAMENT_BACKEND_PRIVATE_DRIVERAPIFORWARD_H
+#define TNT_FILAMENT_BACKEND_PRIVATE_DRIVERAPIFORWARD_H
+
+namespace filament::backend {
+
+class CommandStream;
+
+using DriverApi = CommandStream;
+
+} // namespace filament::backend
+
+#endif // TNT_FILAMENT_BACKEND_PRIVATE_DRIVERAPIFORWARD_H

macos/include/backend/Handle.h

@@ -0,0 +1,134 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TNT_FILAMENT_BACKEND_HANDLE_H
+#define TNT_FILAMENT_BACKEND_HANDLE_H
+
+#include <utils/compiler.h>
+#if !defined(NDEBUG)
+#include <utils/Log.h>
+#endif
+#include <utils/debug.h>
+
+#include <stdint.h>
+
+#include <limits>
+#include <type_traits>
+
+namespace filament::backend {
+
+struct HwBufferObject;
+struct HwFence;
+struct HwIndexBuffer;
+struct HwProgram;
+struct HwRenderPrimitive;
+struct HwRenderTarget;
+struct HwSamplerGroup;
+struct HwStream;
+struct HwSwapChain;
+struct HwTexture;
+struct HwTimerQuery;
+struct HwVertexBuffer;
+
+/*
+ * A handle to a backend resource. HandleBase is for internal use only.
+ * HandleBase *must* be a trivial for the purposes of calls, that is, it cannot have user-defined
+ * copy or move constructors.
+ */
+
+//! \privatesection
+
+class HandleBase {
+public:
+    using HandleId = uint32_t;
+    static constexpr const HandleId nullid = HandleId{ std::numeric_limits<HandleId>::max() };
+
+    constexpr HandleBase() noexcept: object(nullid) {}
+
+    // whether this Handle is initialized
+    explicit operator bool() const noexcept { return object != nullid; }
+
+    // clear the handle, this doesn't free associated resources
+    void clear() noexcept { object = nullid; }
+
+    // compare handles
+    bool operator==(const HandleBase& rhs) const noexcept { return object == rhs.object; }
+    bool operator!=(const HandleBase& rhs) const noexcept { return object != rhs.object; }
+    bool operator<(const HandleBase& rhs) const noexcept { return object < rhs.object; }
+    bool operator<=(const HandleBase& rhs) const noexcept { return object <= rhs.object; }
+    bool operator>(const HandleBase& rhs) const noexcept { return object > rhs.object; }
+    bool operator>=(const HandleBase& rhs) const noexcept { return object >= rhs.object; }
+
+    // get this handle's handleId
+    HandleId getId() const noexcept { return object; }
+
+    // initialize a handle, for internal use only.
+    explicit HandleBase(HandleId id) noexcept : object(id) {
+        assert_invariant(object != nullid); // usually means an uninitialized handle is used
+    }
+
+protected:
+    HandleBase(HandleBase const& rhs) noexcept = default;
+    HandleBase& operator=(HandleBase const& rhs) noexcept = default;
+
+private:
+    HandleId object;
+};
+
+/**
+ * Type-safe handle to backend resources
+ * @tparam T Type of the resource
+ */
+template<typename T>
+struct Handle : public HandleBase {
+
+    Handle() noexcept = default;
+
+    Handle(Handle const& rhs) noexcept = default;
+
+    Handle& operator=(Handle const& rhs) noexcept = default;
+
+    explicit Handle(HandleId id) noexcept : HandleBase(id) { }
+
+    // type-safe Handle cast
+    template<typename B, typename = std::enable_if_t<std::is_base_of<T, B>::value> >
+    Handle(Handle<B> const& base) noexcept : HandleBase(base) { } // NOLINT(hicpp-explicit-conversions,google-explicit-constructor)
+
+private:
+#if !defined(NDEBUG)
+    template <typename U>
+    friend utils::io::ostream& operator<<(utils::io::ostream& out, const Handle<U>& h) noexcept;
+#endif
+};
+
+// Types used by the command stream
+// (we use this renaming because the macro-system doesn't deal well with "<" and ">")
+using BufferObjectHandle    = Handle<HwBufferObject>;
+using FenceHandle           = Handle<HwFence>;
+using IndexBufferHandle     = Handle<HwIndexBuffer>;
+using ProgramHandle         = Handle<HwProgram>;
+using RenderPrimitiveHandle = Handle<HwRenderPrimitive>;
+using RenderTargetHandle    = Handle<HwRenderTarget>;
+using SamplerGroupHandle    = Handle<HwSamplerGroup>;
+using StreamHandle          = Handle<HwStream>;
+using SwapChainHandle       = Handle<HwSwapChain>;
+using TextureHandle         = Handle<HwTexture>;
+using TimerQueryHandle      = Handle<HwTimerQuery>;
+using VertexBufferHandle    = Handle<HwVertexBuffer>;
+
+} // namespace filament::backend
+
+#endif // TNT_FILAMENT_BACKEND_HANDLE_H

macos/include/backend/PipelineState.h

@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TNT_FILAMENT_BACKEND_PIPELINESTATE_H
+#define TNT_FILAMENT_BACKEND_PIPELINESTATE_H
+
+#include <backend/DriverEnums.h>
+#include <backend/Handle.h>
+
+#include <limits>
+
+#include <stdint.h>
+
+namespace filament::backend {
+
+//! \privatesection
+
+struct PipelineState {
+    Handle<HwProgram> program;
+    RasterState rasterState;
+    StencilState stencilState;
+    PolygonOffset polygonOffset;
+    Viewport scissor{ 0, 0,
+                      (uint32_t)std::numeric_limits<int32_t>::max(),
+                      (uint32_t)std::numeric_limits<int32_t>::max()
+    };
+};
+
+} // namespace filament::backend
+
+#if !defined(NDEBUG)
+utils::io::ostream& operator<<(utils::io::ostream& out, const filament::backend::PipelineState& ps);
+#endif
+
+#endif //TNT_FILAMENT_BACKEND_PIPELINESTATE_H

macos/include/backend/PixelBufferDescriptor.h

@@ -0,0 +1,317 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//! \file
+
+#ifndef TNT_FILAMENT_BACKEND_PIXELBUFFERDESCRIPTOR_H
+#define TNT_FILAMENT_BACKEND_PIXELBUFFERDESCRIPTOR_H
+
+#include <backend/BufferDescriptor.h>
+#include <backend/DriverEnums.h>
+
+#include <utils/compiler.h>
+#include <utils/debug.h>
+
+#include <stddef.h>
+#include <stdint.h>
+
+namespace filament::backend {
+
+/**
+ * A descriptor to an image in main memory, typically used to transfer image data from the CPU
+ * to the GPU.
+ *
+ * A PixelBufferDescriptor owns the memory buffer it references, therefore PixelBufferDescriptor
+ * cannot be copied, but can be moved.
+ *
+ * PixelBufferDescriptor releases ownership of the memory-buffer when it's destroyed.
+ */
+class UTILS_PUBLIC PixelBufferDescriptor : public BufferDescriptor {
+public:
+    using PixelDataFormat = backend::PixelDataFormat;
+    using PixelDataType = backend::PixelDataType;
+
+    PixelBufferDescriptor() = default;
+
+    /**
+     * Creates a new PixelBufferDescriptor referencing an image in main memory
+     *
+     * @param buffer    Virtual address of the buffer containing the image
+     * @param size      Size in bytes of the buffer containing the image
+     * @param format    Format of the image pixels
+     * @param type      Type of the image pixels
+     * @param alignment Alignment in bytes of pixel rows
+     * @param left      Left coordinate in pixels
+     * @param top       Top coordinate in pixels
+     * @param stride    Stride of a row in pixels
+     * @param handler   Handler to dispatch the callback or nullptr for the default handler
+     * @param callback  A callback used to release the CPU buffer
+     * @param user      An opaque user pointer passed to the callback function when it's called
+     */
+    PixelBufferDescriptor(void const* buffer, size_t size,
+            PixelDataFormat format, PixelDataType type, uint8_t alignment,
+            uint32_t left, uint32_t top, uint32_t stride,
+            CallbackHandler* handler, Callback callback, void* user = nullptr) noexcept
+            : BufferDescriptor(buffer, size, handler, callback, user),
+              left(left), top(top), stride(stride),
+              format(format), type(type), alignment(alignment) {
+    }
+
+    PixelBufferDescriptor(void const* buffer, size_t size,
+            PixelDataFormat format, PixelDataType type, uint8_t alignment = 1,
+            uint32_t left = 0, uint32_t top = 0, uint32_t stride = 0,
+            Callback callback = nullptr, void* user = nullptr) noexcept
+            : BufferDescriptor(buffer, size, callback, user),
+              left(left), top(top), stride(stride),
+              format(format), type(type), alignment(alignment) {
+    }
+
+    /**
+     * Creates a new PixelBufferDescriptor referencing an image in main memory
+     *
+     * @param buffer    Virtual address of the buffer containing the image
+     * @param size      Size in bytes of the buffer containing the image
+     * @param format    Format of the image pixels
+     * @param type      Type of the image pixels
+     * @param handler   Handler to dispatch the callback or nullptr for the default handler
+     * @param callback  A callback used to release the CPU buffer
+     * @param user      An opaque user pointer passed to the callback function when it's called
+     */
+    PixelBufferDescriptor(void const* buffer, size_t size,
+            PixelDataFormat format, PixelDataType type,
+            CallbackHandler* handler, Callback callback, void* user = nullptr) noexcept
+            : BufferDescriptor(buffer, size, handler, callback, user),
+              stride(0), format(format), type(type), alignment(1) {
+    }
+
+    PixelBufferDescriptor(void const* buffer, size_t size,
+            PixelDataFormat format, PixelDataType type,
+            Callback callback, void* user = nullptr) noexcept
+            : BufferDescriptor(buffer, size, callback, user),
+              stride(0), format(format), type(type), alignment(1) {
+    }
+
+
+    /**
+     * Creates a new PixelBufferDescriptor referencing a compressed image in main memory
+     *
+     * @param buffer    Virtual address of the buffer containing the image
+     * @param size      Size in bytes of the buffer containing the image
+     * @param format    Compressed format of the image
+     * @param imageSize Compressed size of the image
+     * @param handler   Handler to dispatch the callback or nullptr for the default handler
+     * @param callback  A callback used to release the CPU buffer
+     * @param user      An opaque user pointer passed to the callback function when it's called
+     */
+    PixelBufferDescriptor(void const* buffer, size_t size,
+            backend::CompressedPixelDataType format, uint32_t imageSize,
+            CallbackHandler* handler, Callback callback, void* user = nullptr) noexcept
+            : BufferDescriptor(buffer, size, handler, callback, user),
+              imageSize(imageSize), compressedFormat(format), type(PixelDataType::COMPRESSED),
+              alignment(1) {
+    }
+
+    PixelBufferDescriptor(void const* buffer, size_t size,
+            backend::CompressedPixelDataType format, uint32_t imageSize,
+            Callback callback, void* user = nullptr) noexcept
+            : BufferDescriptor(buffer, size, callback, user),
+              imageSize(imageSize), compressedFormat(format), type(PixelDataType::COMPRESSED),
+              alignment(1) {
+    }
+
+    // --------------------------------------------------------------------------------------------
+
+    template<typename T, void(T::*method)(void const*, size_t)>
+    static PixelBufferDescriptor make(void const* buffer, size_t size,
+            PixelDataFormat format, PixelDataType type, uint8_t alignment,
+            uint32_t left, uint32_t top, uint32_t stride, T* data,
+            CallbackHandler* handler = nullptr) noexcept {
+        return { buffer, size, format, type, alignment, left, top, stride,
+                handler, [](void* b, size_t s, void* u) {
+                    (*static_cast<T**>(u)->*method)(b, s); }, data };
+    }
+
+    template<typename T, void(T::*method)(void const*, size_t)>
+    static PixelBufferDescriptor make(void const* buffer, size_t size,
+            PixelDataFormat format, PixelDataType type, T* data,
+            CallbackHandler* handler = nullptr) noexcept {
+        return { buffer, size, format, type, handler, [](void* b, size_t s, void* u) {
+                    (*static_cast<T**>(u)->*method)(b, s); }, data };
+    }
+
+    template<typename T, void(T::*method)(void const*, size_t)>
+    static PixelBufferDescriptor make(void const* buffer, size_t size,
+            backend::CompressedPixelDataType format, uint32_t imageSize, T* data,
+            CallbackHandler* handler = nullptr) noexcept {
+        return { buffer, size, format, imageSize, handler, [](void* b, size_t s, void* u) {
+                    (*static_cast<T**>(u)->*method)(b, s); }, data
+        };
+    }
+
+    template<typename T>
+    static PixelBufferDescriptor make(void const* buffer, size_t size,
+            PixelDataFormat format, PixelDataType type, uint8_t alignment,
+            uint32_t left, uint32_t top, uint32_t stride, T&& functor,
+            CallbackHandler* handler = nullptr) noexcept {
+        return { buffer, size, format, type, alignment, left, top, stride,
+                handler, [](void* b, size_t s, void* u) {
+                    T& that = *static_cast<T*>(u);
+                    that(b, s);
+                    delete &that;
+                }, new T(std::forward<T>(functor))
+        };
+    }
+
+    template<typename T>
+    static PixelBufferDescriptor make(void const* buffer, size_t size,
+            PixelDataFormat format, PixelDataType type, T&& functor,
+            CallbackHandler* handler = nullptr) noexcept {
+        return { buffer, size, format, type,
+                 handler, [](void* b, size_t s, void* u) {
+                    T& that = *static_cast<T*>(u);
+                    that(b, s);
+                    delete &that;
+                }, new T(std::forward<T>(functor))
+        };
+    }
+
+    template<typename T>
+    static PixelBufferDescriptor make(void const* buffer, size_t size,
+            backend::CompressedPixelDataType format, uint32_t imageSize, T&& functor,
+            CallbackHandler* handler = nullptr) noexcept {
+        return { buffer, size, format, imageSize,
+                 handler, [](void* b, size_t s, void* u) {
+                    T& that = *static_cast<T*>(u);
+                    that(b, s);
+                    delete &that;
+                }, new T(std::forward<T>(functor))
+        };
+    }
+
+    // --------------------------------------------------------------------------------------------
+
+    /**
+     * Computes the size in bytes needed to fit an image of given dimensions and format
+     *
+     * @param format    Format of the image pixels
+     * @param type      Type of the image pixels
+     * @param stride    Stride of a row in pixels
+     * @param height    Height of the image in rows
+     * @param alignment Alignment in bytes of pixel rows
+     * @return The buffer size needed to fit this image in bytes
+     */
+    static constexpr size_t computeDataSize(PixelDataFormat format, PixelDataType type,
+            size_t stride, size_t height, size_t alignment) noexcept {
+        assert_invariant(alignment);
+
+        if (type == PixelDataType::COMPRESSED) {
+            return 0;
+        }
+
+        size_t n = 0;
+        switch (format) {
+            case PixelDataFormat::R:
+            case PixelDataFormat::R_INTEGER:
+            case PixelDataFormat::DEPTH_COMPONENT:
+            case PixelDataFormat::ALPHA:
+                n = 1;
+                break;
+            case PixelDataFormat::RG:
+            case PixelDataFormat::RG_INTEGER:
+            case PixelDataFormat::DEPTH_STENCIL:
+                n = 2;
+                break;
+            case PixelDataFormat::RGB:
+            case PixelDataFormat::RGB_INTEGER:
+                n = 3;
+                break;
+            case PixelDataFormat::UNUSED: // shouldn't happen (used to be rgbm)
+            case PixelDataFormat::RGBA:
+            case PixelDataFormat::RGBA_INTEGER:
+                n = 4;
+                break;
+        }
+
+        size_t bpp = n;
+        switch (type) {
+            case PixelDataType::COMPRESSED: // Impossible -- to squash the IDE warnings
+            case PixelDataType::UBYTE:
+            case PixelDataType::BYTE:
+                // nothing to do
+                break;
+            case PixelDataType::USHORT:
+            case PixelDataType::SHORT:
+            case PixelDataType::HALF:
+                bpp *= 2;
+                break;
+            case PixelDataType::UINT:
+            case PixelDataType::INT:
+            case PixelDataType::FLOAT:
+                bpp *= 4;
+                break;
+            case PixelDataType::UINT_10F_11F_11F_REV:
+                // Special case, format must be RGB and uses 4 bytes
+                assert_invariant(format == PixelDataFormat::RGB);
+                bpp = 4;
+                break;
+            case PixelDataType::UINT_2_10_10_10_REV:
+                // Special case, format must be RGBA and uses 4 bytes
+                assert_invariant(format == PixelDataFormat::RGBA);
+                bpp = 4;
+                break;
+            case PixelDataType::USHORT_565:
+                // Special case, format must be RGB and uses 2 bytes
+                assert_invariant(format == PixelDataFormat::RGB);
+                bpp = 2;
+                break;
+        }
+
+        size_t const bpr = bpp * stride;
+        size_t const bprAligned = (bpr + (alignment - 1)) & (~alignment + 1);
+        return bprAligned * height;
+    }
+
+    //! left coordinate in pixels
+    uint32_t left   = 0;
+    //! top coordinate in pixels
+    uint32_t top    = 0;
+    union {
+        struct {
+            //! stride in pixels
+            uint32_t stride;
+            //! Pixel data format
+            PixelDataFormat format;
+        };
+        struct {
+            //! compressed image size
+            uint32_t imageSize;
+            //! compressed image format
+            backend::CompressedPixelDataType compressedFormat;
+        };
+    };
+    //! pixel data type
+    PixelDataType type : 4;
+    //! row alignment in bytes
+    uint8_t alignment  : 4;
+};
+
+} // namespace backend::filament
+
+#if !defined(NDEBUG)
+utils::io::ostream& operator<<(utils::io::ostream& out, const filament::backend::PixelBufferDescriptor& b);
+#endif
+
+#endif // TNT_FILAMENT_BACKEND_PIXELBUFFERDESCRIPTOR_H

macos/include/backend/Platform.h

@@ -0,0 +1,168 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//! \file
+
+#ifndef TNT_FILAMENT_BACKEND_PLATFORM_H
+#define TNT_FILAMENT_BACKEND_PLATFORM_H
+
+#include <backend/DriverEnums.h>
+
+#include <utils/compiler.h>
+#include <utils/Invocable.h>
+
+namespace filament::backend {
+
+class Driver;
+
+/**
+ * Platform is an interface that abstracts how the backend (also referred to as Driver) is
+ * created. The backend provides several common Platform concrete implementations, which are
+ * selected automatically. It is possible however to provide a custom Platform when creating
+ * the filament Engine.
+ */
+class UTILS_PUBLIC Platform {
+public:
+    struct SwapChain {};
+    struct Fence {};
+    struct Stream {};
+
+    struct DriverConfig {
+        /*
+         * size of handle arena in bytes. Setting to 0 indicates default value is to be used.
+         * Driver clamps to valid values.
+         */
+        size_t handleArenaSize = 0;
+    };
+
+    Platform() noexcept;
+
+    virtual ~Platform() noexcept;
+
+    /**
+     * Queries the underlying OS version.
+     * @return The OS version.
+     */
+    virtual int getOSVersion() const noexcept = 0;
+
+    /**
+     * Creates and initializes the low-level API (e.g. an OpenGL context or Vulkan instance),
+     * then creates the concrete Driver.
+     * The caller takes ownership of the returned Driver* and must destroy it with delete.
+     *
+     * @param sharedContext an optional shared context. This is not meaningful with all graphic
+     *                      APIs and platforms.
+     *                      For EGL platforms, this is an EGLContext.
+     * 
+     * @param driverConfig  specifies driver initialization parameters
+     *
+     * @return nullptr on failure, or a pointer to the newly created driver.
+     */
+    virtual backend::Driver* createDriver(void* sharedContext,
+            const DriverConfig& driverConfig) noexcept = 0;
+
+    /**
+     * Processes the platform's event queue when called from its primary event-handling thread.
+     *
+     * Internally, Filament might need to call this when waiting on a fence. It is only implemented
+     * on platforms that need it, such as macOS + OpenGL. Returns false if this is not the main
+     * thread, or if the platform does not need to perform any special processing.
+     */
+    virtual bool pumpEvents() noexcept;
+
+    /**
+     * InsertBlobFunc is an Invocable to an application-provided function that a
+     * backend implementation may use to insert a key/value pair into the
+     * cache.
+     */
+    using InsertBlobFunc = utils::Invocable<
+            void(const void* key, size_t keySize, const void* value, size_t valueSize)>;
+
+    /*
+     * RetrieveBlobFunc is an Invocable to an application-provided function that a
+     * backend implementation may use to retrieve a cached value from the
+     * cache.
+     */
+    using RetrieveBlobFunc = utils::Invocable<
+            size_t(const void* key, size_t keySize, void* value, size_t valueSize)>;
+
+    /**
+     * Sets the callback functions that the backend can use to interact with caching functionality
+     * provided by the application.
+     *
+     * Cache functions may only be specified once during the lifetime of a
+     * Platform.  The <insert> and <retrieve> Invocables may be called at any time and
+     * from any thread from the time at which setBlobFunc is called until the time that Platform
+     * is destroyed. Concurrent calls to these functions from different threads is also allowed.
+     *
+     * @param insertBlob    an Invocable that inserts a new value into the cache and associates
+     *                      it with the given key
+     * @param retrieveBlob  an Invocable that retrieves from the cache the value associated with a
+     *                      given key
+     */
+    void setBlobFunc(InsertBlobFunc&& insertBlob, RetrieveBlobFunc&& retrieveBlob) noexcept;
+
+    /**
+     * @return true if setBlobFunc was called.
+     */
+    bool hasBlobFunc() const noexcept;
+
+    /**
+     * To insert a new binary value into the cache and associate it with a given
+     * key, the backend implementation can call the application-provided callback
+     * function insertBlob.
+     *
+     * No guarantees are made as to whether a given key/value pair is present in
+     * the cache after the set call.  If a different value has been associated
+     * with the given key in the past then it is undefined which value, if any, is
+     * associated with the key after the set call.  Note that while there are no
+     * guarantees, the cache implementation should attempt to cache the most
+     * recently set value for a given key.
+     *
+     * @param key           pointer to the beginning of the key data that is to be inserted
+     * @param keySize       specifies the size in byte of the data pointed to by <key>
+     * @param value         pointer to the beginning of the value data that is to be inserted
+     * @param valueSize     specifies the size in byte of the data pointed to by <value>
+     */
+    void insertBlob(const void* key, size_t keySize, const void* value, size_t valueSize);
+
+    /**
+     * To retrieve the binary value associated with a given key from the cache, a
+     * the backend implementation can call the application-provided callback
+     * function retrieveBlob.
+     *
+     * If the cache contains a value for the given key and its size in bytes is
+     * less than or equal to <valueSize> then the value is written to the memory
+     * pointed to by <value>.  Otherwise nothing is written to the memory pointed
+     * to by <value>.
+     *
+     * @param key          pointer to the beginning of the key
+     * @param keySize      specifies the size in bytes of the binary key pointed to by <key>
+     * @param value        pointer to a buffer to receive the cached binary data, if it exists
+     * @param valueSize    specifies the size in bytes of the memory pointed to by <value>
+     * @return             If the cache contains a value associated with the given key then the
+     *                     size of that binary value in bytes is returned. Otherwise 0 is returned.
+     */
+    size_t retrieveBlob(const void* key, size_t keySize, void* value, size_t valueSize);
+
+private:
+    InsertBlobFunc mInsertBlob;
+    RetrieveBlobFunc mRetrieveBlob;
+};
+
+} // namespace filament
+
+#endif // TNT_FILAMENT_BACKEND_PLATFORM_H

macos/include/backend/PresentCallable.h

@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//! \file
+
+#ifndef TNT_FILAMENT_BACKEND_PRESENTCALLABLE
+#define TNT_FILAMENT_BACKEND_PRESENTCALLABLE
+
+#include <utils/compiler.h>
+
+namespace filament {
+namespace backend {
+
+/**
+ * A PresentCallable is a callable object that, when called, schedules a frame for presentation on
+ * a SwapChain.
+ *
+ * Typically, Filament's backend is responsible scheduling a frame's presentation. However, there
+ * are certain cases where the application might want to control when a frame is scheduled for
+ * presentation.
+ *
+ * For example, on iOS, UIKit elements can be synchronized to 3D content by scheduling a present
+ * within a CATransation:
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ * void myFrameScheduledCallback(PresentCallable presentCallable, void* user) {
+ *     [CATransaction begin];
+ *     // Update other UI elements...
+ *     presentCallable();
+ *     [CATransaction commit];
+ * }
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * To obtain a PresentCallable, set a SwapChain::FrameScheduledCallback on a SwapChain with the
+ * SwapChain::setFrameScheduledCallback method. The callback is called with a PresentCallable object
+ * and optional user data:
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ * swapChain->setFrameScheduledCallback(myFrameScheduledCallback, nullptr);
+ * if (renderer->beginFrame(swapChain)) {
+ *     renderer->render(view);
+ *     renderer->endFrame();
+ * }
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * @remark Only Filament's Metal backend supports PresentCallables and frame callbacks. Other
+ * backends ignore the callback (which will never be called) and proceed normally.
+ *
+ * @remark The SwapChain::FrameScheduledCallback is called on an arbitrary thread.
+ *
+ * Applications *must* call each PresentCallable they receive. Each PresentCallable represents a
+ * frame that is waiting to be presented. If an application fails to call a PresentCallable, a
+ * memory leak could occur. To "cancel" the presentation of a frame, pass false to the
+ * PresentCallable, which will cancel the presentation of the frame and release associated memory.
+ *
+ * @see Renderer, SwapChain::setFrameScheduledCallback
+ */
+class UTILS_PUBLIC PresentCallable {
+public:
+
+    using PresentFn = void(*)(bool presentFrame, void* user);
+
+    PresentCallable(PresentFn fn, void* user) noexcept;
+    ~PresentCallable() noexcept = default;
+    PresentCallable(const PresentCallable& rhs) = default;
+    PresentCallable& operator=(const PresentCallable& rhs) = default;
+
+    /**
+     * Call this PresentCallable, scheduling the associated frame for presentation. Pass false for
+     * presentFrame to effectively "cancel" the presentation of the frame.
+     *
+     * @param presentFrame if false, will not present the frame but releases associated memory
+     */
+    void operator()(bool presentFrame = true) noexcept;
+
+private:
+
+    PresentFn mPresentFn;
+    void* mUser = nullptr;
+
+};
+
+/**
+ * @deprecated, FrameFinishedCallback has been renamed to SwapChain::FrameScheduledCallback.
+ */
+using FrameFinishedCallback UTILS_DEPRECATED = void(*)(PresentCallable callable, void* user);
+
+} // namespace backend
+} // namespace filament
+
+#endif // TNT_FILAMENT_BACKEND_PRESENTCALLABLE

macos/include/backend/Program.h

@@ -0,0 +1,162 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TNT_FILAMENT_BACKEND_PRIVATE_PROGRAM_H
+#define TNT_FILAMENT_BACKEND_PRIVATE_PROGRAM_H
+
+#include <utils/compiler.h>
+#include <utils/CString.h>
+#include <utils/FixedCapacityVector.h>
+#include <utils/Invocable.h>
+#include <utils/Log.h>
+#include <utils/ostream.h>
+
+#include <backend/DriverEnums.h>
+
+#include <array>
+#include <variant>
+
+namespace filament::backend {
+
+class Program {
+public:
+
+    static constexpr size_t SHADER_TYPE_COUNT = 3;
+    static constexpr size_t UNIFORM_BINDING_COUNT = CONFIG_UNIFORM_BINDING_COUNT;
+    static constexpr size_t SAMPLER_BINDING_COUNT = CONFIG_SAMPLER_BINDING_COUNT;
+
+    struct Sampler {
+        utils::CString name = {};   // name of the sampler in the shader
+        uint32_t binding = 0;       // binding point of the sampler in the shader
+    };
+
+    struct SamplerGroupData {
+        utils::FixedCapacityVector<Sampler> samplers;
+        ShaderStageFlags stageFlags = ShaderStageFlags::ALL_SHADER_STAGE_FLAGS;
+    };
+
+    struct Uniform {
+        utils::CString name;    // full qualified name of the uniform field
+        uint16_t offset;        // offset in 'uint32_t' into the uniform buffer
+        uint8_t size;           // >1 for arrays
+        UniformType type;       // uniform type
+    };
+
+    using UniformBlockInfo = std::array<utils::CString, UNIFORM_BINDING_COUNT>;
+    using UniformInfo = utils::FixedCapacityVector<Uniform>;
+    using SamplerGroupInfo = std::array<SamplerGroupData, SAMPLER_BINDING_COUNT>;
+    using ShaderBlob = utils::FixedCapacityVector<uint8_t>;
+    using ShaderSource = std::array<ShaderBlob, SHADER_TYPE_COUNT>;
+
+    Program() noexcept;
+
+    Program(const Program& rhs) = delete;
+    Program& operator=(const Program& rhs) = delete;
+
+    Program(Program&& rhs) noexcept;
+    Program& operator=(Program&& rhs) noexcept;
+
+    ~Program() noexcept;
+
+    Program& priorityQueue(CompilerPriorityQueue priorityQueue) noexcept;
+
+    // sets the material name and variant for diagnostic purposes only
+    Program& diagnostics(utils::CString const& name,
+            utils::Invocable<utils::io::ostream&(utils::io::ostream& out)>&& logger);
+
+    // sets one of the program's shader (e.g. vertex, fragment)
+    // string-based shaders are null terminated, consequently the size parameter must include the
+    // null terminating character.
+    Program& shader(ShaderStage shader, void const* data, size_t size);
+
+    // Note: This is only needed for GLES3.0 backends, because the layout(binding=) syntax is
+    //       not permitted in glsl. The backend needs a way to associate a uniform block
+    //       to a binding point.
+    Program& uniformBlockBindings(
+            utils::FixedCapacityVector<std::pair<utils::CString, uint8_t>> const& uniformBlockBindings) noexcept;
+
+    // Note: This is only needed for GLES2.0, this is used to emulate UBO. This function tells
+    // the program everything it needs to know about the uniforms at a given binding
+    Program& uniforms(uint32_t index, UniformInfo const& uniforms) noexcept;
+
+    // Note: This is only needed for GLES2.0.
+    Program& attributes(
+            utils::FixedCapacityVector<std::pair<utils::CString, uint8_t>> attributes) noexcept;
+
+    // sets the 'bindingPoint' sampler group descriptor for this program.
+    // 'samplers' can be destroyed after this call.
+    // This effectively associates a set of (BindingPoints, index) to a texture unit in the shader.
+    // Or more precisely, what layout(binding=) is set to in GLSL.
+    Program& setSamplerGroup(size_t bindingPoint, ShaderStageFlags stageFlags,
+            Sampler const* samplers, size_t count) noexcept;
+
+    struct SpecializationConstant {
+        uint32_t id;                                // id set in glsl
+        std::variant<int32_t, float, bool> value;   // value and type
+    };
+
+    Program& specializationConstants(
+            utils::FixedCapacityVector<SpecializationConstant> specConstants) noexcept;
+
+    Program& cacheId(uint64_t cacheId) noexcept;
+
+    ShaderSource const& getShadersSource() const noexcept { return mShadersSource; }
+    ShaderSource& getShadersSource() noexcept { return mShadersSource; }
+
+    UniformBlockInfo const& getUniformBlockBindings() const noexcept { return mUniformBlocks; }
+    UniformBlockInfo& getUniformBlockBindings() noexcept { return mUniformBlocks; }
+
+    SamplerGroupInfo const& getSamplerGroupInfo() const { return mSamplerGroups; }
+    SamplerGroupInfo& getSamplerGroupInfo() { return mSamplerGroups; }
+
+    auto const& getBindingUniformInfo() const { return mBindingUniformInfo; }
+    auto& getBindingUniformInfo() { return mBindingUniformInfo; }
+
+    auto const& getAttributes() const { return mAttributes; }
+    auto& getAttributes() { return mAttributes; }
+
+    utils::CString const& getName() const noexcept { return mName; }
+    utils::CString& getName() noexcept { return mName; }
+
+    utils::FixedCapacityVector<SpecializationConstant> const& getSpecializationConstants() const noexcept {
+        return mSpecializationConstants;
+    }
+    utils::FixedCapacityVector<SpecializationConstant>& getSpecializationConstants() noexcept {
+        return mSpecializationConstants;
+    }
+
+    uint64_t getCacheId() const noexcept { return mCacheId; }
+
+    CompilerPriorityQueue getPriorityQueue() const noexcept { return mPriorityQueue; }
+
+private:
+    friend utils::io::ostream& operator<<(utils::io::ostream& out, const Program& builder);
+
+    UniformBlockInfo mUniformBlocks = {};
+    SamplerGroupInfo mSamplerGroups = {};
+    ShaderSource mShadersSource;
+    utils::CString mName;
+    uint64_t mCacheId{};
+    utils::Invocable<utils::io::ostream&(utils::io::ostream& out)> mLogger;
+    utils::FixedCapacityVector<SpecializationConstant> mSpecializationConstants;
+    utils::FixedCapacityVector<std::pair<utils::CString, uint8_t>> mAttributes;
+    std::array<UniformInfo, Program::UNIFORM_BINDING_COUNT> mBindingUniformInfo;
+    CompilerPriorityQueue mPriorityQueue = CompilerPriorityQueue::HIGH;
+};
+
+} // namespace filament::backend
+
+#endif // TNT_FILAMENT_BACKEND_PRIVATE_PROGRAM_H

macos/include/backend/README.md

@@ -0,0 +1,4 @@
+# include/backend Headers
+
+Headers in `include/backend/` are fully public, in particular they can be included in filament's
+public headers.

macos/include/backend/SamplerDescriptor.h

@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//! \file
+
+#ifndef TNT_FILAMENT_BACKEND_SAMPLERDESCRIPTOR_H
+#define TNT_FILAMENT_BACKEND_SAMPLERDESCRIPTOR_H
+
+#include <backend/DriverEnums.h>
+#include <backend/Handle.h>
+
+#include <utils/compiler.h>
+
+#include <stddef.h>
+#include <stdint.h>
+
+namespace filament::backend {
+
+struct UTILS_PUBLIC SamplerDescriptor {
+    Handle<HwTexture> t;
+    SamplerParams s{};
+};
+
+} // namespace filament::backend
+
+#endif // TNT_FILAMENT_BACKEND_SAMPLERDESCRIPTOR_H

macos/include/backend/TargetBufferInfo.h

@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TNT_FILAMENT_BACKEND_TARGETBUFFERINFO_H
+#define TNT_FILAMENT_BACKEND_TARGETBUFFERINFO_H
+
+#include <backend/DriverEnums.h>
+#include <backend/Handle.h>
+
+#include <stdint.h>
+
+namespace filament::backend {
+
+//! \privatesection
+
+struct TargetBufferInfo {
+    // texture to be used as render target
+    Handle<HwTexture> handle;
+
+    // level to be used
+    uint8_t level = 0;
+
+    // for cubemaps and 3D textures. See TextureCubemapFace for the face->layer mapping
+    uint16_t layer = 0;
+};
+
+class MRT {
+public:
+    static constexpr uint8_t MIN_SUPPORTED_RENDER_TARGET_COUNT = 4u;
+
+    // When updating this, make sure to also take care of RenderTarget.java
+    static constexpr uint8_t MAX_SUPPORTED_RENDER_TARGET_COUNT = 8u;
+
+private:
+    TargetBufferInfo mInfos[MAX_SUPPORTED_RENDER_TARGET_COUNT];
+
+public:
+    TargetBufferInfo const& operator[](size_t i) const noexcept {
+        return mInfos[i];
+    }
+
+    TargetBufferInfo& operator[](size_t i) noexcept {
+        return mInfos[i];
+    }
+
+    MRT() noexcept = default;
+
+    MRT(TargetBufferInfo const& color) noexcept // NOLINT(hicpp-explicit-conversions)
+            : mInfos{ color } {
+    }
+
+    MRT(TargetBufferInfo const& color0, TargetBufferInfo const& color1) noexcept
+            : mInfos{ color0, color1 } {
+    }
+
+    MRT(TargetBufferInfo const& color0, TargetBufferInfo const& color1,
+        TargetBufferInfo const& color2) noexcept
+            : mInfos{ color0, color1, color2 } {
+    }
+
+    MRT(TargetBufferInfo const& color0, TargetBufferInfo const& color1,
+        TargetBufferInfo const& color2, TargetBufferInfo const& color3) noexcept
+            : mInfos{ color0, color1, color2, color3 } {
+    }
+
+    // this is here for backward compatibility
+    MRT(Handle<HwTexture> handle, uint8_t level, uint16_t layer) noexcept
+            : mInfos{{ handle, level, layer }} {
+    }
+};
+
+} // namespace filament::backend
+
+#if !defined(NDEBUG)
+utils::io::ostream& operator<<(utils::io::ostream& out, const filament::backend::TargetBufferInfo& tbi);
+utils::io::ostream& operator<<(utils::io::ostream& out, const filament::backend::MRT& mrt);
+#endif
+
+#endif //TNT_FILAMENT_BACKEND_TARGETBUFFERINFO_H

macos/include/backend/platforms/OpenGLPlatform.h

@@ -0,0 +1,295 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TNT_FILAMENT_BACKEND_PRIVATE_OPENGLPLATFORM_H
+#define TNT_FILAMENT_BACKEND_PRIVATE_OPENGLPLATFORM_H
+
+#include <backend/AcquiredImage.h>
+#include <backend/Platform.h>
+
+namespace filament::backend {
+
+class Driver;
+
+/**
+ * A Platform interface that creates an OpenGL backend.
+ *
+ * WARNING: None of the methods below are allowed to change the GL state and must restore it
+ *          upon return.
+ *
+ */
+class OpenGLPlatform : public Platform {
+protected:
+
+    /*
+     * Derived classes can use this to instantiate the default OpenGLDriver backend.
+     * This is typically called from your implementation of createDriver()
+     */
+    static Driver* createDefaultDriver(OpenGLPlatform* platform,
+            void* sharedContext, const DriverConfig& driverConfig);
+
+    ~OpenGLPlatform() noexcept override;
+
+public:
+
+    struct ExternalTexture {
+        unsigned int target;            // GLenum target
+        unsigned int id;                // GLuint id
+    };
+
+    /**
+     * Called by the driver to destroy the OpenGL context. This should clean up any windows
+     * or buffers from initialization. This is for instance where `eglDestroyContext` would be
+     * called.
+     */
+    virtual void terminate() noexcept = 0;
+
+    /**
+     * Called by the driver to create a SwapChain for this driver.
+     *
+     * @param nativeWindow  a token representing the native window. See concrete implementation
+     *                      for details.
+     * @param flags         extra flags used by the implementation, see filament::SwapChain
+     * @return              The driver's SwapChain object.
+     *
+     */
+    virtual SwapChain* createSwapChain(void* nativeWindow, uint64_t flags) noexcept = 0;
+
+    /**
+     * Return whether createSwapChain supports the SWAP_CHAIN_CONFIG_SRGB_COLORSPACE flag.
+     * The default implementation returns false.
+     *
+     * @return true if SWAP_CHAIN_CONFIG_SRGB_COLORSPACE is supported, false otherwise.
+     */
+    virtual bool isSRGBSwapChainSupported() const noexcept;
+
+    /**
+     * Called by the driver create a headless SwapChain.
+     *
+     * @param width     width of the buffer
+     * @param height    height of the buffer
+     * @param flags     extra flags used by the implementation, see filament::SwapChain
+     * @return          The driver's SwapChain object.
+     *
+     * TODO: we need a more generic way of passing construction parameters
+     *       A void* might be enough.
+     */
+    virtual SwapChain* createSwapChain(uint32_t width, uint32_t height, uint64_t flags) noexcept = 0;
+
+    /**
+     * Called by the driver to destroys the SwapChain
+     * @param swapChain SwapChain to be destroyed.
+     */
+    virtual void destroySwapChain(SwapChain* swapChain) noexcept = 0;
+
+    /**
+     * Returns the set of buffers that must be preserved up to the call to commit().
+     * The default value is TargetBufferFlags::NONE.
+     * The color buffer is always preserved, however ancillary buffers, such as the depth buffer
+     * are generally discarded. The preserve flags can be used to make sure those ancillary
+     * buffers are preserved until the call to commit.
+     *
+     * @param swapChain
+     * @return buffer that must be preserved
+     * @see commit()
+     */
+    virtual TargetBufferFlags getPreservedFlags(SwapChain* swapChain) noexcept;
+
+    /**
+     * Called by the driver to establish the default FBO. The default implementation returns 0.
+      * @return a GLuint casted to a uint32_t that is an OpenGL framebuffer object.
+     */
+    virtual uint32_t createDefaultRenderTarget() noexcept;
+
+    /**
+     * Called by the driver to make the OpenGL context active on the calling thread and bind
+     * the drawSwapChain to the default render target (FBO) created with createDefaultRenderTarget.
+     * @param drawSwapChain SwapChain to draw to. It must be bound to the default FBO.
+     * @param readSwapChain SwapChain to read from (for operation like `glBlitFramebuffer`)
+     */
+    virtual void makeCurrent(SwapChain* drawSwapChain, SwapChain* readSwapChain) noexcept = 0;
+
+    /**
+     * Called by the driver once the current frame finishes drawing. Typically, this should present
+     * the drawSwapChain. This is for example where `eglMakeCurrent()` would be called.
+     * @param swapChain the SwapChain to present.
+     */
+    virtual void commit(SwapChain* swapChain) noexcept = 0;
+
+    /**
+     * Set the time the next committed buffer should be presented to the user at.
+     *
+     * @param presentationTimeInNanosecond  time in the future in nanosecond. The clock used depends
+     *                                      on the concrete platform implementation.
+     */
+    virtual void setPresentationTime(int64_t presentationTimeInNanosecond) noexcept;
+
+    // --------------------------------------------------------------------------------------------
+    // Fence support
+
+    /**
+     * Can this implementation create a Fence.
+     * @return true if supported, false otherwise. The default implementation returns false.
+     */
+    virtual bool canCreateFence() noexcept;
+
+    /**
+     * Creates a Fence (e.g. eglCreateSyncKHR). This must be implemented if `canCreateFence`
+     * returns true. Fences are used for frame pacing.
+     *
+     * @return A Fence object. The default implementation returns nullptr.
+     */
+    virtual Fence* createFence() noexcept;
+
+    /**
+     * Destroys a Fence object. The default implementation does nothing.
+     *
+     * @param fence Fence to destroy.
+     */
+    virtual void destroyFence(Fence* fence) noexcept;
+
+    /**
+     * Waits on a Fence.
+     *
+     * @param fence   Fence to wait on.
+     * @param timeout Timeout.
+     * @return Whether the fence signaled or timed out. See backend::FenceStatus.
+     *         The default implementation always return backend::FenceStatus::ERROR.
+     */
+    virtual backend::FenceStatus waitFence(Fence* fence, uint64_t timeout) noexcept;
+
+
+    // --------------------------------------------------------------------------------------------
+    // Streaming support
+
+    /**
+     * Creates a Stream from a native Stream.
+     *
+     * WARNING: This is called synchronously from the application thread (NOT the Driver thread)
+     *
+     * @param nativeStream The native stream, this parameter depends on the concrete implementation.
+     * @return A new Stream object.
+     */
+    virtual Stream* createStream(void* nativeStream) noexcept;
+
+    /**
+     * Destroys a Stream.
+     * @param stream Stream to destroy.
+     */
+    virtual void destroyStream(Stream* stream) noexcept;
+
+    /**
+     * The specified stream takes ownership of the texture (tname) object
+     * Once attached, the texture is automatically updated with the Stream's content, which
+     * could be a video stream for instance.
+     *
+     * @param stream Stream to take ownership of the texture
+     * @param tname  GL texture id to "bind" to the Stream.
+     */
+    virtual void attach(Stream* stream, intptr_t tname) noexcept;
+
+    /**
+     * Destroys the texture associated to the stream
+     * @param stream Stream to detach from its texture
+     */
+    virtual void detach(Stream* stream) noexcept;
+
+    /**
+     * Updates the content of the texture attached to the stream.
+     * @param stream Stream to update
+     * @param timestamp Output parameter: Timestamp of the image bound to the texture.
+     */
+    virtual void updateTexImage(Stream* stream, int64_t* timestamp) noexcept;
+
+
+    // --------------------------------------------------------------------------------------------
+    // External Image support
+
+    /**
+     * Creates an external texture handle. External textures don't have any parameters because
+     * these are undefined until setExternalImage() is called.
+     * @return a pointer to an ExternalTexture structure filled with valid token. However, the
+     *         implementation could just return { 0, GL_TEXTURE_2D } at this point. The actual
+     *         values can be delayed until setExternalImage.
+     */
+    virtual ExternalTexture *createExternalImageTexture() noexcept;
+
+    /**
+     * Destroys an external texture handle and associated data.
+     * @param texture a pointer to the handle to destroy.
+     */
+    virtual void destroyExternalImage(ExternalTexture* texture) noexcept;
+
+    // called on the application thread to allow Filament to take ownership of the image
+
+    /**
+     * Takes ownership of the externalImage. The externalImage parameter depends on the Platform's
+     * concrete implementation. Ownership is released when destroyExternalImage() is called.
+     *
+     * WARNING: This is called synchronously from the application thread (NOT the Driver thread)
+     *
+     * @param externalImage A token representing the platform's external image.
+     * @see destroyExternalImage
+     */
+    virtual void retainExternalImage(void* externalImage) noexcept;
+
+    /**
+     * Called to bind the platform-specific externalImage to an ExternalTexture.
+     * ExternalTexture::id is guaranteed to be bound when this method is called and ExternalTexture
+     * is updated with new values for id/target if necessary.
+     *
+     * WARNING: this method is not allowed to change the bound texture, or must restore the previous
+     * binding upon return. This is to avoid problem with a backend doing state caching.
+     *
+     * @param externalImage The platform-specific external image.
+     * @param texture an in/out pointer to ExternalTexture, id and target can be updated if necessary.
+     * @return true on success, false on error.
+     */
+    virtual bool setExternalImage(void* externalImage, ExternalTexture* texture) noexcept;
+
+    /**
+     * The method allows platforms to convert a user-supplied external image object into a new type
+     * (e.g. HardwareBuffer => EGLImage). The default implementation returns source.
+     * @param source Image to transform.
+     * @return Transformed image.
+     */
+    virtual AcquiredImage transformAcquiredImage(AcquiredImage source) noexcept;
+
+    // --------------------------------------------------------------------------------------------
+
+    /**
+     * Returns true if additional OpenGL contexts can be created. Default: false.
+     * @return true if additional OpenGL contexts can be created.
+     * @see createContext
+     */
+    virtual bool isExtraContextSupported() const noexcept;
+
+    /**
+     * Creates an OpenGL context with the same configuration than the main context and makes it
+     * current to the current thread. Must not be called from the main driver thread.
+     * createContext() is only supported if isExtraContextSupported() returns true.
+     * These additional contexts will be automatically terminated in terminate.
+     *
+     * @param shared whether the new context is shared with the main context.
+     * @see isExtraContextSupported()
+     * @see terminate()
+     */
+    virtual void createContext(bool shared);
+};
+
+} // namespace filament
+
+#endif // TNT_FILAMENT_BACKEND_PRIVATE_OPENGLPLATFORM_H

macos/include/backend/platforms/PlatformCocoaGL.h

@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_COCOA_GL_H
+#define TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_COCOA_GL_H
+
+#include <stdint.h>
+
+#include <backend/platforms/OpenGLPlatform.h>
+
+#include <backend/DriverEnums.h>
+
+namespace filament::backend {
+
+struct PlatformCocoaGLImpl;
+
+/**
+ * A concrete implementation of OpenGLPlatform that supports macOS's Cocoa.
+ */
+class PlatformCocoaGL : public OpenGLPlatform {
+public:
+    PlatformCocoaGL();
+    ~PlatformCocoaGL() noexcept override;
+
+protected:
+    // --------------------------------------------------------------------------------------------
+    // Platform Interface
+
+    Driver* createDriver(void* sharedContext,
+            const Platform::DriverConfig& driverConfig) noexcept override;
+
+    // Currently returns 0
+    int getOSVersion() const noexcept override;
+
+    bool pumpEvents() noexcept override;
+
+    // --------------------------------------------------------------------------------------------
+    // OpenGLPlatform Interface
+
+    bool isExtraContextSupported() const noexcept override;
+    void createContext(bool shared) override;
+
+    void terminate() noexcept override;
+
+    SwapChain* createSwapChain(void* nativewindow, uint64_t flags) noexcept override;
+    SwapChain* createSwapChain(uint32_t width, uint32_t height, uint64_t flags) noexcept override;
+    void destroySwapChain(SwapChain* swapChain) noexcept override;
+    void makeCurrent(SwapChain* drawSwapChain, SwapChain* readSwapChain) noexcept override;
+    void commit(SwapChain* swapChain) noexcept override;
+    OpenGLPlatform::ExternalTexture* createExternalImageTexture() noexcept override;
+    void destroyExternalImage(ExternalTexture* texture) noexcept override;
+    void retainExternalImage(void* externalImage) noexcept override;
+    bool setExternalImage(void* externalImage, ExternalTexture* texture) noexcept override;
+
+private:
+    PlatformCocoaGLImpl* pImpl = nullptr;
+};
+
+} // namespace filament::backend
+
+#endif // TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_COCOA_GL_H

macos/include/backend/platforms/PlatformCocoaTouchGL.h

@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_COCOA_TOUCH_GL_H
+#define TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_COCOA_TOUCH_GL_H
+
+#include <stdint.h>
+
+#include <backend/platforms/OpenGLPlatform.h>
+
+#include <backend/DriverEnums.h>
+
+namespace filament::backend {
+
+struct PlatformCocoaTouchGLImpl;
+
+class PlatformCocoaTouchGL : public OpenGLPlatform {
+public:
+    PlatformCocoaTouchGL();
+    ~PlatformCocoaTouchGL() noexcept;
+
+    // --------------------------------------------------------------------------------------------
+    // Platform Interface
+
+    Driver* createDriver(void* sharedGLContext,
+            const Platform::DriverConfig& driverConfig) noexcept override;
+
+    int getOSVersion() const noexcept final { return 0; }
+
+    // --------------------------------------------------------------------------------------------
+    // OpenGLPlatform Interface
+
+    void terminate() noexcept override;
+
+    uint32_t createDefaultRenderTarget() noexcept override;
+
+    bool isExtraContextSupported() const noexcept override;
+    void createContext(bool shared) override;
+
+    SwapChain* createSwapChain(void* nativewindow, uint64_t flags) noexcept override;
+    SwapChain* createSwapChain(uint32_t width, uint32_t height, uint64_t flags) noexcept override;
+    void destroySwapChain(SwapChain* swapChain) noexcept override;
+    void makeCurrent(SwapChain* drawSwapChain, SwapChain* readSwapChain) noexcept override;
+    void commit(SwapChain* swapChain) noexcept override;
+
+    OpenGLPlatform::ExternalTexture* createExternalImageTexture() noexcept override;
+    void destroyExternalImage(ExternalTexture* texture) noexcept override;
+    void retainExternalImage(void* externalImage) noexcept override;
+    bool setExternalImage(void* externalImage, ExternalTexture* texture) noexcept override;
+
+private:
+    PlatformCocoaTouchGLImpl* pImpl = nullptr;
+};
+
+using ContextManager = PlatformCocoaTouchGL;
+
+} // namespace filament::backend
+
+#endif // TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_COCOA_TOUCH_GL_H

macos/include/backend/platforms/PlatformEGL.h

@@ -0,0 +1,153 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_EGL_H
+#define TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_EGL_H
+
+#include <stdint.h>
+
+#include <EGL/egl.h>
+#include <EGL/eglext.h>
+
+#include <backend/platforms/OpenGLPlatform.h>
+
+#include <backend/DriverEnums.h>
+
+#include <utility>
+#include <vector>
+
+namespace filament::backend {
+
+/**
+ * A concrete implementation of OpenGLPlatform that supports EGL.
+ */
+class PlatformEGL : public OpenGLPlatform {
+public:
+
+    PlatformEGL() noexcept;
+    bool isExtraContextSupported() const noexcept override;
+    void createContext(bool shared) override;
+
+protected:
+
+    // --------------------------------------------------------------------------------------------
+    // Helper for EGL configs and attributes parameters
+
+    class Config {
+    public:
+        Config();
+        Config(std::initializer_list<std::pair<EGLint, EGLint>> list);
+        EGLint& operator[](EGLint name);
+        EGLint operator[](EGLint name) const;
+        void erase(EGLint name) noexcept;
+        EGLint const* data() const noexcept {
+            return reinterpret_cast<EGLint const*>(mConfig.data());
+        }
+        size_t size() const noexcept {
+            return mConfig.size();
+        }
+    private:
+        std::vector<std::pair<EGLint, EGLint>> mConfig = {{ EGL_NONE, EGL_NONE }};
+    };
+
+    // --------------------------------------------------------------------------------------------
+    // Platform Interface
+
+    /**
+     * Initializes EGL, creates the OpenGL context and returns a concrete Driver implementation
+     * that supports OpenGL/OpenGL ES.
+     */
+    Driver* createDriver(void* sharedContext,
+            const Platform::DriverConfig& driverConfig) noexcept override;
+
+    /**
+     * This returns zero. This method can be overridden to return something more useful.
+     * @return zero
+     */
+    int getOSVersion() const noexcept override;
+
+    // --------------------------------------------------------------------------------------------
+    // OpenGLPlatform Interface
+
+    void terminate() noexcept override;
+
+    bool isSRGBSwapChainSupported() const noexcept override;
+    SwapChain* createSwapChain(void* nativewindow, uint64_t flags) noexcept override;
+    SwapChain* createSwapChain(uint32_t width, uint32_t height, uint64_t flags) noexcept override;
+    void destroySwapChain(SwapChain* swapChain) noexcept override;
+    void makeCurrent(SwapChain* drawSwapChain, SwapChain* readSwapChain) noexcept override;
+    void commit(SwapChain* swapChain) noexcept override;
+
+    bool canCreateFence() noexcept override;
+    Fence* createFence() noexcept override;
+    void destroyFence(Fence* fence) noexcept override;
+    FenceStatus waitFence(Fence* fence, uint64_t timeout) noexcept override;
+
+    OpenGLPlatform::ExternalTexture* createExternalImageTexture() noexcept override;
+    void destroyExternalImage(ExternalTexture* texture) noexcept override;
+    bool setExternalImage(void* externalImage, ExternalTexture* texture) noexcept override;
+
+    /**
+     * Logs glGetError() to slog.e
+     * @param name a string giving some context on the error. Typically __func__.
+     */
+    static void logEglError(const char* name) noexcept;
+    static void logEglError(const char* name, EGLint error) noexcept;
+    static const char* getEglErrorName(EGLint error) noexcept;
+
+    /**
+     * Calls glGetError() to clear the current error flags. logs a warning to log.w if
+     * an error was pending.
+     */
+    static void clearGlError() noexcept;
+
+    /**
+     * Always use this instead of eglMakeCurrent().
+     */
+    EGLBoolean makeCurrent(EGLSurface drawSurface, EGLSurface readSurface) noexcept;
+
+    // TODO: this should probably use getters instead.
+    EGLDisplay mEGLDisplay = EGL_NO_DISPLAY;
+    EGLContext mEGLContext = EGL_NO_CONTEXT;
+    EGLSurface mCurrentDrawSurface = EGL_NO_SURFACE;
+    EGLSurface mCurrentReadSurface = EGL_NO_SURFACE;
+    EGLSurface mEGLDummySurface = EGL_NO_SURFACE;
+    EGLConfig mEGLConfig = EGL_NO_CONFIG_KHR;
+    Config mContextAttribs;
+    std::vector<EGLContext> mAdditionalContexts;
+
+    // supported extensions detected at runtime
+    struct {
+        struct {
+            bool OES_EGL_image_external_essl3 = false;
+        } gl;
+        struct {
+            bool ANDROID_recordable = false;
+            bool KHR_create_context = false;
+            bool KHR_gl_colorspace = false;
+            bool KHR_no_config_context = false;
+        } egl;
+    } ext;
+
+    void initializeGlExtensions() noexcept;
+
+private:
+    EGLConfig findSwapChainConfig(uint64_t flags) const;
+};
+
+} // namespace filament::backend
+
+#endif // TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_EGL_H

macos/include/backend/platforms/PlatformEGLAndroid.h

@@ -0,0 +1,82 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_EGL_ANDROID_H
+#define TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_EGL_ANDROID_H
+
+#include <backend/platforms/PlatformEGL.h>
+
+namespace filament::backend {
+
+class ExternalStreamManagerAndroid;
+
+/**
+ * A concrete implementation of OpenGLPlatform and subclass of PlatformEGL that supports
+ * EGL on Android. It adds Android streaming functionality to PlatformEGL.
+ */
+class PlatformEGLAndroid : public PlatformEGL {
+public:
+
+    PlatformEGLAndroid() noexcept;
+    ~PlatformEGLAndroid() noexcept override;
+
+protected:
+
+    // --------------------------------------------------------------------------------------------
+    // Platform Interface
+
+    /**
+     * Returns the Android SDK version.
+     * @return Android SDK version.
+     */
+    int getOSVersion() const noexcept override;
+
+    Driver* createDriver(void* sharedContext,
+            const Platform::DriverConfig& driverConfig) noexcept override;
+
+    // --------------------------------------------------------------------------------------------
+    // OpenGLPlatform Interface
+
+    void terminate() noexcept override;
+
+    /**
+     * Set the presentation time using `eglPresentationTimeANDROID`
+     * @param presentationTimeInNanosecond
+     */
+    void setPresentationTime(int64_t presentationTimeInNanosecond) noexcept override;
+
+
+    Stream* createStream(void* nativeStream) noexcept override;
+    void destroyStream(Stream* stream) noexcept override;
+    void attach(Stream* stream, intptr_t tname) noexcept override;
+    void detach(Stream* stream) noexcept override;
+    void updateTexImage(Stream* stream, int64_t* timestamp) noexcept override;
+
+    /**
+     * Converts a AHardwareBuffer to EGLImage
+     * @param source source.image is a AHardwareBuffer
+     * @return source.image contains an EGLImage
+     */
+    AcquiredImage transformAcquiredImage(AcquiredImage source) noexcept override;
+
+private:
+    int mOSVersion;
+    ExternalStreamManagerAndroid& mExternalStreamManager;
+};
+
+} // namespace filament::backend
+
+#endif // TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_EGL_ANDROID_H

macos/include/backend/platforms/PlatformEGLHeadless.h

@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TNT_FILAMENT_DRIVER_OPENGL_PLATFORM_EGL_HEADLESS_H
+#define TNT_FILAMENT_DRIVER_OPENGL_PLATFORM_EGL_HEADLESS_H
+
+#include "PlatformEGL.h"
+
+namespace filament::backend {
+
+/**
+ * A concrete implementation of OpenGLPlatform that supports EGL with only headless swapchains.
+ */
+class PlatformEGLHeadless : public PlatformEGL {
+public:
+    PlatformEGLHeadless() noexcept;
+
+    Driver* createDriver(void* sharedContext,
+            const Platform::DriverConfig& driverConfig) noexcept override;
+};
+
+} // namespace filament
+
+#endif // TNT_FILAMENT_DRIVER_OPENGL_PLATFORM_EGL_HEADLESS_H

macos/include/backend/platforms/PlatformGLX.h

@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_GLX_H
+#define TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_GLX_H
+
+#include <stdint.h>
+
+#include "bluegl/BlueGL.h"
+#include <GL/glx.h>
+
+#include <backend/platforms/OpenGLPlatform.h>
+
+#include <backend/DriverEnums.h>
+
+#include <vector>
+
+namespace filament::backend {
+
+/**
+ * A concrete implementation of OpenGLPlatform that supports GLX.
+ */
+class PlatformGLX : public OpenGLPlatform {
+protected:
+    // --------------------------------------------------------------------------------------------
+    // Platform Interface
+
+    Driver* createDriver(void* sharedGLContext,
+            const DriverConfig& driverConfig) noexcept override;
+
+    int getOSVersion() const noexcept final override { return 0; }
+
+    // --------------------------------------------------------------------------------------------
+    // OpenGLPlatform Interface
+
+    void terminate() noexcept override;
+
+    SwapChain* createSwapChain(void* nativewindow, uint64_t flags) noexcept override;
+    SwapChain* createSwapChain(uint32_t width, uint32_t height, uint64_t flags) noexcept override;
+    void destroySwapChain(SwapChain* swapChain) noexcept override;
+    void makeCurrent(SwapChain* drawSwapChain, SwapChain* readSwapChain) noexcept override;
+    void commit(SwapChain* swapChain) noexcept override;
+
+private:
+    Display *mGLXDisplay;
+    GLXContext mGLXContext;
+    GLXFBConfig* mGLXConfig;
+    GLXPbuffer mDummySurface;
+    std::vector<GLXPbuffer> mPBuffers;
+};
+
+} // namespace filament::backend
+
+#endif // TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_GLX_H

macos/include/backend/platforms/PlatformWGL.h

@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_WGL_H
+#define TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_WGL_H
+
+#include <stdint.h>
+
+#include <windows.h>
+#include "utils/unwindows.h"
+
+#include <backend/platforms/OpenGLPlatform.h>
+#include <backend/DriverEnums.h>
+
+#include <vector>
+
+namespace filament::backend {
+
+/**
+ * A concrete implementation of OpenGLPlatform that supports WGL.
+ */
+class PlatformWGL : public OpenGLPlatform {
+protected:
+    // --------------------------------------------------------------------------------------------
+    // Platform Interface
+
+    Driver* createDriver(void* sharedGLContext,
+            const Platform::DriverConfig& driverConfig) noexcept override;
+
+    int getOSVersion() const noexcept final override { return 0; }
+
+    // --------------------------------------------------------------------------------------------
+    // OpenGLPlatform Interface
+
+    void terminate() noexcept override;
+
+    bool isExtraContextSupported() const noexcept override;
+    void createContext(bool shared) override;
+
+    SwapChain* createSwapChain(void* nativewindow, uint64_t flags) noexcept override;
+    SwapChain* createSwapChain(uint32_t width, uint32_t height, uint64_t flags) noexcept override;
+    void destroySwapChain(SwapChain* swapChain) noexcept override;
+    void makeCurrent(SwapChain* drawSwapChain, SwapChain* readSwapChain) noexcept override;
+    void commit(SwapChain* swapChain) noexcept override;
+
+protected:
+    HGLRC mContext = NULL;
+    HWND mHWnd = NULL;
+    HDC mWhdc = NULL;
+    PIXELFORMATDESCRIPTOR mPfd = {};
+    std::vector<HGLRC> mAdditionalContexts;
+    std::vector<int> mAttribs;
+};
+
+} // namespace filament::backend
+
+#endif // TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_GLX_H

macos/include/backend/platforms/PlatformWebGL.h

@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_WEBGL_H
+#define TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_WEBGL_H
+
+#include <stdint.h>
+
+#include <backend/platforms/OpenGLPlatform.h>
+
+#include <backend/DriverEnums.h>
+
+namespace filament::backend {
+
+/**
+ * A concrete implementation of OpenGLPlatform that supports WebGL.
+ */
+class PlatformWebGL : public OpenGLPlatform {
+protected:
+    // --------------------------------------------------------------------------------------------
+    // Platform Interface
+
+    Driver* createDriver(void* sharedGLContext,
+            const Platform::DriverConfig& driverConfig) noexcept override;
+
+    int getOSVersion() const noexcept override;
+
+    // --------------------------------------------------------------------------------------------
+    // OpenGLPlatform Interface
+
+    void terminate() noexcept override;
+
+    SwapChain* createSwapChain(void* nativewindow, uint64_t flags) noexcept override;
+    SwapChain* createSwapChain(uint32_t width, uint32_t height, uint64_t flags) noexcept override;
+    void destroySwapChain(SwapChain* swapChain) noexcept override;
+    void makeCurrent(SwapChain* drawSwapChain, SwapChain* readSwapChain) noexcept override;
+    void commit(SwapChain* swapChain) noexcept override;
+};
+
+} // namespace filament::backend
+
+#endif // TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_WEBGL_H

macos/include/backend/platforms/VulkanPlatform.h

@@ -0,0 +1,238 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TNT_FILAMENT_BACKEND_PLATFORMS_VULKANPLATFORM_H
+#define TNT_FILAMENT_BACKEND_PLATFORMS_VULKANPLATFORM_H
+
+#include <backend/Platform.h>
+
+#include <bluevk/BlueVK.h>
+#include <utils/FixedCapacityVector.h>
+#include <utils/PrivateImplementation.h>
+
+#include <tuple>
+#include <unordered_set>
+
+namespace filament::backend {
+
+using SwapChain = Platform::SwapChain;
+
+/**
+ * Private implementation details for the provided vulkan platform.
+ */
+struct VulkanPlatformPrivate;
+
+/**
+ * A Platform interface that creates a Vulkan backend.
+ */
+class VulkanPlatform : public Platform, utils::PrivateImplementation<VulkanPlatformPrivate> {
+public:
+
+    /**
+     * A collection of handles to objects and metadata that comprises a Vulkan context. The client
+     * can instantiate this struct and pass to Engine::Builder::sharedContext if they wishes to
+     * share their vulkan context. This is specifically necessary if the client wishes to override
+     * the swapchain API.
+     */
+    struct VulkanSharedContext {
+        VkInstance instance = VK_NULL_HANDLE;
+        VkPhysicalDevice physicalDevice = VK_NULL_HANDLE;
+        VkDevice logicalDevice = VK_NULL_HANDLE;
+        uint32_t graphicsQueueFamilyIndex = 0xFFFFFFFF;
+        // In the usual case, the client needs to allocate at least one more graphics queue
+        // for Filament, and this index is the param to pass into vkGetDeviceQueue. In the case
+        // where the gpu only has one graphics queue. Then the client needs to ensure that no
+        // concurrent access can occur.
+        uint32_t graphicsQueueIndex = 0xFFFFFFFF;
+    };
+
+    /**
+     * Shorthand for the pointer to the Platform SwapChain struct, we use it also as a handle (i.e.
+     * identifier for the swapchain).
+     */
+    using SwapChainPtr = Platform::SwapChain*;
+
+    /**
+     * Collection of images, formats, and extent (width/height) that defines the swapchain.
+     */
+    struct SwapChainBundle {
+        utils::FixedCapacityVector<VkImage> colors;
+        VkImage depth = VK_NULL_HANDLE;
+        VkFormat colorFormat = VK_FORMAT_UNDEFINED;
+        VkFormat depthFormat = VK_FORMAT_UNDEFINED;
+        VkExtent2D extent = {0, 0};
+    };
+
+    VulkanPlatform();
+
+    ~VulkanPlatform() override;
+
+    Driver* createDriver(void* sharedContext,
+            Platform::DriverConfig const& driverConfig) noexcept override;
+
+    int getOSVersion() const noexcept override {
+        return 0;
+    }
+
+    // ----------------------------------------------------
+    // ---------- Platform Customization options ----------
+    /**
+     * The client preference can be stored within the struct.  We allow for two specification of
+     * preference:
+     *     1) A substring to match against `VkPhysicalDeviceProperties.deviceName`.
+     *     2) Index of the device in the list as returned by vkEnumeratePhysicalDevices.
+     */
+    struct GPUPreference {
+        std::string deviceName;
+        int8_t index = -1;
+    };
+
+    /**
+     * Client can provide a preference over the GPU to use in the vulkan instance
+     * @return            `GPUPreference` struct that indicates the client's preference
+     */
+    virtual GPUPreference getPreferredGPU() noexcept {
+        return {};
+    }
+    // -------- End platform customization options --------
+    // ----------------------------------------------------
+
+    /**
+     * Returns whether the platform supports sRGB swapchain. This is true by default, and the client
+     * needs to override this method to specify otherwise.
+     * @return            Whether the platform supports sRGB swapchain.
+     */
+    virtual bool isSRGBSwapChainSupported() const {
+        return true;
+    }
+
+    /**
+     * Get the images handles and format of the memory backing the swapchain. This should be called
+     * after createSwapChain() or after recreateIfResized().
+     * @param swapchain   The handle returned by createSwapChain()
+     * @return            An array of VkImages
+     */
+    virtual SwapChainBundle getSwapChainBundle(SwapChainPtr handle);
+
+    /**
+     * Acquire the next image for rendering. The `index` will be written with an non-negative
+     * integer that the backend can use to index into the `SwapChainBundle.colors` array. The
+     * corresponding VkImage will be used as the output color attachment. The client should signal
+     * the `clientSignal` semaphore when the image is ready to be used by the backend.
+     * @param handle         The handle returned by createSwapChain()
+     * @param clientSignal   The semaphore that the client will signal to indicate that the backend
+     *                       may render into the image.
+     * @param index          Pointer to memory that will be filled with the index that corresponding
+     *                       to an image in the `SwapChainBundle.colors` array.
+     * @return               Result of acquire
+     */
+    virtual VkResult acquire(SwapChainPtr handle, VkSemaphore clientSignal, uint32_t* index);
+
+    /**
+     * Present the image corresponding to `index` to the display. The client should wait on
+     * `finishedDrawing` before presenting.
+     * @param handle             The handle returned by createSwapChain()
+     * @param index              Index that corresponding to an image in the
+     *                           `SwapChainBundle.colors` array.
+     * @param finishedDrawing    Backend passes in a semaphore that the client will signal to
+     *                           indicate that the client may render into the image.
+     * @return                   Result of present
+     */
+    virtual VkResult present(SwapChainPtr handle, uint32_t index, VkSemaphore finishedDrawing);
+
+    /**
+     * Check if the surface size has changed.
+     * @param handle             The handle returned by createSwapChain()
+     * @return                   Whether the swapchain has been resized
+     */
+    virtual bool hasResized(SwapChainPtr handle);
+
+    /**
+     * Carry out a recreation of the swapchain.
+     * @param handle             The handle returned by createSwapChain()
+     * @return                   Result of the recreation
+     */
+    virtual VkResult recreate(SwapChainPtr handle);
+
+    /**
+     * Create a swapchain given a platform window, or if given a null `nativeWindow`, then we
+     * try to create a headless swapchain with the given `extent`.
+     * @param flags     Optional parameters passed to the client as defined in
+     *                  Filament::SwapChain.h.
+     * @param extent    Optional width and height that indicates the size of the headless swapchain.
+     * @return          Result of the operation
+     */
+    virtual SwapChainPtr createSwapChain(void* nativeWindow, uint64_t flags = 0,
+            VkExtent2D extent = {0, 0});
+
+    /**
+     * Destroy the swapchain.
+     * @param handle    The handle returned by createSwapChain()
+     */
+    virtual void destroy(SwapChainPtr handle);
+
+    /**
+     * Clean up any resources owned by the Platform. For example, if the Vulkan instance handle was
+     * generated by the platform, we need to clean it up in this method.
+     */
+    virtual void terminate();
+
+    /**
+     * @return The instance (VkInstance) for the Vulkan backend.
+     */
+    VkInstance getInstance() const noexcept;
+
+    /**
+     * @return The logical device (VkDevice) that was selected as the backend device.
+     */
+    VkDevice getDevice() const noexcept;
+
+    /**
+     * @return The physical device (i.e gpu) that was selected as the backend physical device.
+     */
+    VkPhysicalDevice getPhysicalDevice() const noexcept;
+
+    /**
+     * @return The family index of the graphics queue selected for the Vulkan backend.
+     */
+    uint32_t getGraphicsQueueFamilyIndex() const noexcept;
+
+    /**
+     * @return The index of the graphics queue (if there are multiple graphics queues)
+     *         selected for the Vulkan backend.
+     */
+    uint32_t getGraphicsQueueIndex() const noexcept;
+
+    /**
+     * @return The queue that was selected for the Vulkan backend.
+     */
+    VkQueue getGraphicsQueue() const noexcept;
+
+private:
+    // Platform dependent helper methods
+    using ExtensionSet = std::unordered_set<std::string_view>;
+    static ExtensionSet getRequiredInstanceExtensions();
+
+    using SurfaceBundle = std::tuple<VkSurfaceKHR, VkExtent2D>;
+    static SurfaceBundle createVkSurfaceKHR(void* nativeWindow, VkInstance instance,
+            uint64_t flags) noexcept;
+
+    friend struct VulkanPlatformPrivate;
+};
+
+}// namespace filament::backend
+
+#endif// TNT_FILAMENT_BACKEND_PLATFORMS_VULKANPLATFORM_H