#pragma once
// CPU-memory vertex/index buffers behind the D3D8 buffer handles. 40250 fills its buffers through
// Lock/Unlock (CGrannyModel::__LoadVertices, CGrannyModelInstance deform) and the renderer later reads
// them back, so the platform keeps the bytes in memory instead of creating device objects.
#include "EterLib/StdAfx.h"

#include <cstdint>
#include <atomic>
#include <vector>

inline std::atomic<std::uint64_t> mt_next_cpu_buffer_id{1};

struct MtCpuVertexBuffer : IDirect3DVertexBuffer8
{
	const std::uint64_t id = mt_next_cpu_buffer_id.fetch_add(1, std::memory_order_relaxed);
	std::uint64_t revision = 0;
	std::vector<uint8_t> bytes;
	DWORD fvf = 0;

	HRESULT Lock(UINT offset, UINT size, BYTE** data, DWORD) override
	{
		if (size_t(offset) + size > bytes.size())
			return E_FAIL;
		*data = bytes.data() + offset;
		return S_OK;
	}
	HRESULT Unlock() override { ++revision; return S_OK; }
};

struct MtCpuIndexBuffer : IDirect3DIndexBuffer8
{
	const std::uint64_t id = mt_next_cpu_buffer_id.fetch_add(1, std::memory_order_relaxed);
	std::uint64_t revision = 0;
	std::vector<uint8_t> bytes;
	D3DFORMAT format = D3DFMT_INDEX16;

	HRESULT Lock(UINT offset, UINT size, BYTE** data, DWORD) override
	{
		if (size_t(offset) + size > bytes.size())
			return E_FAIL;
		*data = bytes.data() + offset;
		return S_OK;
	}
	HRESULT Unlock() override { ++revision; return S_OK; }
};

// D3DXGetFVFVertexSize.
inline unsigned mt_fvf_vertex_size(DWORD fvf)
{
	unsigned size = 0;
	switch (fvf & D3DFVF_POSITION_MASK)
	{
		case D3DFVF_XYZ: size += 12; break;
		case D3DFVF_XYZRHW: size += 16; break;
		case D3DFVF_XYZB1: size += 16; break;
		case D3DFVF_XYZB2: size += 20; break;
		case D3DFVF_XYZB3: size += 24; break;
		case D3DFVF_XYZB4: size += 28; break;
		case D3DFVF_XYZB5: size += 32; break;
	}
	if (fvf & D3DFVF_NORMAL) size += 12;
	if (fvf & D3DFVF_PSIZE) size += 4;
	if (fvf & D3DFVF_DIFFUSE) size += 4;
	if (fvf & D3DFVF_SPECULAR) size += 4;
	const unsigned texCount = (fvf & D3DFVF_TEXCOUNT_MASK) >> D3DFVF_TEXCOUNT_SHIFT;
	for (unsigned i = 0; i < texCount; ++i)
	{
		static const unsigned coordSize[4] = { 8, 12, 16, 4 };
		size += coordSize[(fvf >> (16 + i * 2)) & 3];
	}
	return size;
}