Rewrite host GPU abstraction

- Don't have to repeat the same thing for 4 renderers.
 - Add native Metal renderer.

src/util/d3d12_pipeline.h

@@ -0,0 +1,65 @@
+// SPDX-FileCopyrightText: 2019-2023 Connor McLaughlin <stenzek@gmail.com>
+// SPDX-License-Identifier: (GPL-3.0 OR CC-BY-NC-ND-4.0)
+
+#include "gpu_device.h"
+
+#include "common/windows_headers.h"
+
+#include <d3d12.h>
+#include <vector>
+#include <wrl/client.h>
+
+class D3D12Device;
+
+class D3D12Shader final : public GPUShader
+{
+  friend D3D12Device;
+
+public:
+  using Bytecode = std::vector<u8>;
+
+  ~D3D12Shader() override;
+
+  ALWAYS_INLINE const Bytecode& GetBytecode() const { return m_bytecode; }
+  ALWAYS_INLINE D3D12_SHADER_BYTECODE GetD3DBytecode() const { return {m_bytecode.data(), m_bytecode.size()}; }
+  ALWAYS_INLINE const u8* GetBytecodeData() const { return m_bytecode.data(); }
+  ALWAYS_INLINE u32 GetBytecodeSize() const { return static_cast<u32>(m_bytecode.size()); }
+
+  void SetDebugName(const std::string_view& name) override;
+
+private:
+  D3D12Shader(GPUShaderStage stage, Bytecode bytecode);
+
+  Bytecode m_bytecode;
+};
+
+class D3D12Pipeline final : public GPUPipeline
+{
+  friend D3D12Device;
+
+public:
+  ~D3D12Pipeline() override;
+
+  ALWAYS_INLINE ID3D12PipelineState* GetPipeline() const { return m_pipeline.Get(); }
+  ALWAYS_INLINE Layout GetLayout() const { return m_layout; }
+  ALWAYS_INLINE D3D12_PRIMITIVE_TOPOLOGY GetTopology() const { return m_topology; }
+  ALWAYS_INLINE u32 GetVertexStride() const { return m_vertex_stride; }
+  ALWAYS_INLINE u32 GetBlendConstants() const { return m_blend_constants; }
+  ALWAYS_INLINE const std::array<float, 4>& GetBlendConstantsF() const { return m_blend_constants_f; }
+  ALWAYS_INLINE bool HasVertexStride() const { return (m_vertex_stride > 0); }
+
+  void SetDebugName(const std::string_view& name) override;
+
+  static std::string GetPipelineName(const GraphicsConfig& config);
+
+private:
+  D3D12Pipeline(Microsoft::WRL::ComPtr<ID3D12PipelineState> pipeline, Layout layout, D3D12_PRIMITIVE_TOPOLOGY topology,
+                u32 vertex_stride, u32 blend_constants);
+
+  Microsoft::WRL::ComPtr<ID3D12PipelineState> m_pipeline;
+  Layout m_layout;
+  D3D12_PRIMITIVE_TOPOLOGY m_topology;
+  u32 m_vertex_stride;
+  u32 m_blend_constants;
+  std::array<float, 4> m_blend_constants_f;
+};