From 2af6a1000a1d065a75b6312c4e24a92b79e3f0ac Mon Sep 17 00:00:00 2001
From: lisyarus <lisyarus@gmail.com>
Date: Sat, 30 Dec 2023 22:57:45 +0300
Subject: [PATCH] WebGPU wrapper wip: add buffer object

---
 libs/wgpu/include/psemek/wgpu/buffer.hpp | 91 ++++++++++++++++++++++++
 libs/wgpu/objects-todo                   |  2 +-
 libs/wgpu/source/buffer.cpp              | 72 +++++++++++++++++++
 3 files changed, 164 insertions(+), 1 deletion(-)
 create mode 100644 libs/wgpu/include/psemek/wgpu/buffer.hpp
 create mode 100644 libs/wgpu/source/buffer.cpp

diff --git a/libs/wgpu/include/psemek/wgpu/buffer.hpp b/libs/wgpu/include/psemek/wgpu/buffer.hpp
new file mode 100644
index 00000000..7d3bce98
--- /dev/null
+++ b/libs/wgpu/include/psemek/wgpu/buffer.hpp
@@ -0,0 +1,91 @@
+#pragma once
+
+#include <psemek/wgpu/chained_struct.hpp>
+#include <psemek/wgpu/detail/object.hpp>
+
+#include <cstdint>
+#include <string>
+#include <functional>
+
+namespace psemek::wgpu
+{
+
+	struct buffer
+		: detail::object<buffer>
+	{
+		using detail::object<buffer>::object;
+
+		enum usage : std::uint32_t
+		{
+			none = 0x00000000,
+			map_read = 0x00000001,
+			map_write = 0x00000002,
+			copy_src = 0x00000004,
+			copy_dst = 0x00000008,
+			index = 0x00000010,
+			vertex = 0x00000020,
+			uniform = 0x00000040,
+			storage = 0x00000080,
+			indirect = 0x00000100,
+			query_resolve = 0x00000200,
+		};
+
+		enum class map_mode : std::uint32_t
+		{
+			none = 0x00000000,
+			read = 0x00000001,
+			write = 0x00000002,
+		};
+
+		enum class map_state : std::uint32_t
+		{
+			unmapped = 0x00000000,
+			pending = 0x00000001,
+			mapped = 0x00000002,
+		};
+
+		enum class map_async_status : std::uint32_t
+		{
+			success = 0x00000000,
+			validation_error = 0x00000001,
+			unknown = 0x00000002,
+			device_lost = 0x00000003,
+			destroyed_before_callback = 0x00000004,
+			unmapped_before_callback = 0x00000005,
+			mapping_already_pending = 0x00000006,
+			offset_out_of_range = 0x00000007,
+			size_out_of_range = 0x00000008,
+		};
+
+		struct descriptor {
+			std::vector<chained_struct> chain = {};
+			std::string label = {};
+			enum usage usage;
+			uint64_t size;
+			bool mapped_at_creation = false;
+		};
+
+		using map_callback = std::function<void(map_async_status)>;
+
+		void destroy();
+		std::uint64_t get_size();
+		usage get_usage();
+		map_state get_map_state();
+		void const * get_const_mapped_range(std::size_t offset, std::size_t size);
+		void * get_mapped_range(std::size_t offset, std::size_t size);
+		void map_async(map_mode flags, std::size_t offset, std::size_t size, map_callback const & callback);
+		void unmap();
+		void set_label(std::string const & label);
+
+		static void reference(void * ptr);
+		static void release(void * ptr);
+
+	private:
+		explicit buffer(void * ptr)
+			: detail::object<buffer>(ptr)
+		{}
+
+		friend struct device;
+	};
+
+}
diff --git a/libs/wgpu/objects-todo b/libs/wgpu/objects-todo
index b13145bd..e275df3d 100644
--- a/libs/wgpu/objects-todo
+++ b/libs/wgpu/objects-todo
@@ -1,7 +1,7 @@
 + WGPUAdapter
   WGPUBindGroup
   WGPUBindGroupLayout
-  WGPUBuffer
++ WGPUBuffer
   WGPUCommandBuffer
   WGPUCommandEncoder
   WGPUComputePassEncoder
diff --git a/libs/wgpu/source/buffer.cpp b/libs/wgpu/source/buffer.cpp
new file mode 100644
index 00000000..f0bab4e1
--- /dev/null
+++ b/libs/wgpu/source/buffer.cpp
@@ -0,0 +1,72 @@
+#include <psemek/wgpu/buffer.hpp>
+#include <psemek/wgpu/external/webgpu.h>
+
+#include <memory>
+
+namespace psemek::wgpu
+{
+
+	void buffer::destroy()
+	{
+		wgpuBufferDestroy((WGPUBuffer)get());
+	}
+
+	std::uint64_t buffer::get_size()
+	{
+		return wgpuBufferGetSize((WGPUBuffer)get());
+	}
+
+	buffer::usage buffer::get_usage()
+	{
+		return (usage)wgpuBufferGetUsage((WGPUBuffer)get());
+	}
+
+	buffer::map_state buffer::get_map_state()
+	{
+		return (map_state)wgpuBufferGetMapState((WGPUBuffer)get());
+	}
+
+	void const * buffer::get_const_mapped_range(std::size_t offset, std::size_t size)
+	{
+		return wgpuBufferGetConstMappedRange((WGPUBuffer)get(), offset, size);
+	}
+
+	void * buffer::get_mapped_range(std::size_t offset, std::size_t size)
+	{
+		return wgpuBufferGetMappedRange((WGPUBuffer)get(), offset, size);
+	}
+
+	void buffer::map_async(map_mode flags, std::size_t offset, std::size_t size, map_callback const & callback)
+	{
+		auto userdata = new map_callback(callback);
+
+		auto real_callback = [](WGPUBufferMapAsyncStatus status, void * userdata)
+		{
+			std::unique_ptr<map_callback> callback((map_callback *)userdata);
+			if (*callback) (*callback)((map_async_status)status);
+		};
+
+		wgpuBufferMapAsync((WGPUBuffer)get(), (WGPUMapModeFlags)flags, offset, size, real_callback, userdata);
+	}
+
+	void buffer::unmap()
+	{
+		wgpuBufferUnmap((WGPUBuffer)get());
+	}
+
+	void buffer::set_label(std::string const & label)
+	{
+		wgpuBufferSetLabel((WGPUBuffer)get(), label.data());
+	}
+
+	void buffer::reference(void * ptr)
+	{
+		wgpuBufferReference((WGPUBuffer)ptr);
+	}
+
+	void buffer::release(void * ptr)
+	{
+		wgpuBufferRelease((WGPUBuffer)ptr);
+	}
+
+}