// Copyright (C) 2003 Dolphin Project.

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 2.0.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License 2.0 for more details.

// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/

// Official SVN repository and contact information can be found at
// http://code.google.com/p/dolphin-emu/

#include "StringUtil.h"
#include "VideoConfig.h"

#include "D3DBase.h"
#include "D3DTexture.h"
#include "GfxState.h"

namespace DX11
{

HINSTANCE hD3DCompilerDll = NULL;
D3DREFLECT PD3DReflect = NULL;
int d3dcompiler_dll_ref = 0;

HINSTANCE hD3DXDll = NULL;
D3DX11COMPILEFROMMEMORYTYPE PD3DX11CompileFromMemory = NULL;
D3DX11FILTERTEXTURETYPE PD3DX11FilterTexture = NULL;
D3DX11SAVETEXTURETOFILEATYPE PD3DX11SaveTextureToFileA = NULL;
D3DX11SAVETEXTURETOFILEWTYPE PD3DX11SaveTextureToFileW = NULL;
int d3dx_dll_ref = 0;

CREATEDXGIFACTORY PCreateDXGIFactory = NULL;
HINSTANCE hDXGIDll = NULL;
int dxgi_dll_ref = 0;

typedef HRESULT (WINAPI* D3D11CREATEDEVICEANDSWAPCHAIN)(IDXGIAdapter*, D3D_DRIVER_TYPE, HMODULE, UINT, CONST D3D_FEATURE_LEVEL*, UINT, UINT, CONST DXGI_SWAP_CHAIN_DESC*, IDXGISwapChain**, ID3D11Device**, D3D_FEATURE_LEVEL*, ID3D11DeviceContext**);
D3D11CREATEDEVICE PD3D11CreateDevice = NULL;
D3D11CREATEDEVICEANDSWAPCHAIN PD3D11CreateDeviceAndSwapChain = NULL;
D3D10CREATEBLOB PD3D10CreateBlob = NULL;

HINSTANCE hD3DDll_10 = NULL;
HINSTANCE hD3DDll_11 = NULL;

int d3d_dll_ref = 0;

// SharedPtr funcs
HRESULT D3D11CreateDeviceShared(IDXGIAdapter *pAdapter, D3D_DRIVER_TYPE DriverType,
	HMODULE Software, UINT Flags, const D3D_FEATURE_LEVEL *pFeatureLevels,
	UINT FeatureLevels, UINT SDKVersion, SharedPtr<ID3D11Device>* _Device,
	D3D_FEATURE_LEVEL *pFeatureLevel, SharedPtr<ID3D11DeviceContext>* _ImmediateContext)
{
	ID3D11Device* device = nullptr;
	ID3D11DeviceContext* context = nullptr;

	const HRESULT hr = PD3D11CreateDevice(pAdapter, DriverType, Software, Flags, pFeatureLevels,
		FeatureLevels, SDKVersion, &device, pFeatureLevel, &context);

	if (_Device)
		*_Device = SharedPtr<ID3D11Device>::FromPtr(device);

	if (_ImmediateContext)
		*_ImmediateContext = SharedPtr<ID3D11DeviceContext>::FromPtr(context);

	return hr;
}

HRESULT D3D11CreateDeviceAndSwapChainShared(IDXGIAdapter *pAdapter,
	D3D_DRIVER_TYPE DriverType, HMODULE Software, UINT Flags, const D3D_FEATURE_LEVEL *pFeatureLevels,
	UINT FeatureLevels, UINT SDKVersion, const DXGI_SWAP_CHAIN_DESC *pSwapChainDesc,
	SharedPtr<IDXGISwapChain>* _SwapChain, SharedPtr<ID3D11Device>* _Device,
	D3D_FEATURE_LEVEL *pFeatureLevel, SharedPtr<ID3D11DeviceContext>* _ImmediateContext)
{
	ID3D11Device* device = nullptr;
	IDXGISwapChain* chain = nullptr;
	ID3D11DeviceContext* context = nullptr;

	const HRESULT hr = PD3D11CreateDeviceAndSwapChain(pAdapter, DriverType, Software, Flags,
		pFeatureLevels, FeatureLevels, SDKVersion, pSwapChainDesc, &chain, &device, pFeatureLevel, &context); 

	if (_Device)
		*_Device = SharedPtr<ID3D11Device>::FromPtr(device);

	if (_SwapChain)
		*_SwapChain = SharedPtr<IDXGISwapChain>::FromPtr(chain);

	if (_ImmediateContext)
		*_ImmediateContext = SharedPtr<ID3D11DeviceContext>::FromPtr(context);

	return hr;
}

SharedPtr<ID3D11Texture2D> CreateTexture2DShared(
	const D3D11_TEXTURE2D_DESC* pDesc, const D3D11_SUBRESOURCE_DATA* pInitialData)
{
	ID3D11Texture2D* texture = nullptr;

	D3D::g_device->CreateTexture2D(pDesc, pInitialData, &texture);

	return SharedPtr<ID3D11Texture2D>::FromPtr(texture);
}

SharedPtr<ID3D11Texture2D> SwapChainGetBufferTexture2DShared(IDXGISwapChain* swapchain, UINT buffer)
{
	ID3D11Texture2D* buf = nullptr;

	swapchain->GetBuffer(0, IID_ID3D11Texture2D, (void**)&buf);

	return SharedPtr<ID3D11Texture2D>::FromPtr(buf);
}

SharedPtr<ID3D11BlendState> CreateBlendStateShared(const D3D11_BLEND_DESC *pBlendStateDesc)
{
	ID3D11BlendState* state = nullptr;

	D3D::g_device->CreateBlendState(pBlendStateDesc, &state);

	return SharedPtr<ID3D11BlendState>::FromPtr(state);
}

SharedPtr<ID3D11InputLayout> CreateInputLayoutShared(const D3D11_INPUT_ELEMENT_DESC *pInputElementDescs,
	UINT NumElements, const void *pShaderBytecodeWithInputSignature, SIZE_T BytecodeLength)
{
	ID3D11InputLayout* layout = nullptr;

	D3D::g_device->CreateInputLayout(pInputElementDescs, NumElements,
		pShaderBytecodeWithInputSignature, BytecodeLength, &layout);

	return SharedPtr<ID3D11InputLayout>::FromPtr(layout);
}

SharedPtr<ID3D11Buffer> CreateBufferShared(const D3D11_BUFFER_DESC *pDesc,
	const D3D11_SUBRESOURCE_DATA *pInitialData)
{
	ID3D11Buffer* buffer = nullptr;

	D3D::g_device->CreateBuffer(pDesc, pInitialData, &buffer);

	return SharedPtr<ID3D11Buffer>::FromPtr(buffer);
}

namespace D3D
{

SharedPtr<ID3D11Device> g_device;
SharedPtr<ID3D11DeviceContext> g_context;
SharedPtr<IDXGISwapChain> g_swapchain;

D3D_FEATURE_LEVEL featlevel;
std::unique_ptr<D3DTexture2D> backbuf;
HWND hWnd;

std::vector<DXGI_SAMPLE_DESC> g_aa_modes; // supported AA modes of the current adapter

bool bgra_textures_supported;

#define NUM_SUPPORTED_FEATURE_LEVELS 3
const D3D_FEATURE_LEVEL supported_feature_levels[NUM_SUPPORTED_FEATURE_LEVELS] = {
	D3D_FEATURE_LEVEL_11_0,
	D3D_FEATURE_LEVEL_10_1,
	D3D_FEATURE_LEVEL_10_0
};

unsigned int xres, yres;

bool bFrameInProgress = false;

HRESULT LoadDXGI()
{
	if (dxgi_dll_ref++ > 0) return S_OK;

	if (hDXGIDll) return S_OK;
	hDXGIDll = LoadLibraryA("dxgi.dll");
	if (!hDXGIDll)
	{
		MessageBoxA(NULL, "Failed to load dxgi.dll", "Critical error", MB_OK | MB_ICONERROR);
		--dxgi_dll_ref;
		return E_FAIL;
	}
	PCreateDXGIFactory = (CREATEDXGIFACTORY)GetProcAddress(hDXGIDll, "CreateDXGIFactory");
	if (PCreateDXGIFactory == NULL) MessageBoxA(NULL, "GetProcAddress failed for CreateDXGIFactory!", "Critical error", MB_OK | MB_ICONERROR);

	return S_OK;
}

HRESULT LoadD3D()
{
	if (d3d_dll_ref++ > 0)
		return S_OK;

	hD3DDll_10 = LoadLibraryA("d3d10.dll");
	if (!hD3DDll_10)
	{
		MessageBoxA(NULL, "Failed to load d3d10.dll", "Critical error", MB_OK | MB_ICONERROR);
		--d3d_dll_ref;
		return E_FAIL;
	}

	hD3DDll_11 = LoadLibraryA("d3d11.dll");
	if (!hD3DDll_11)
	{
		MessageBoxA(NULL, "Failed to load d3d11.dll", "Critical error", MB_OK | MB_ICONERROR);
		--d3d_dll_ref;
		return E_FAIL;
	}

	PD3D11CreateDevice = (D3D11CREATEDEVICE)GetProcAddress(hD3DDll_11, "D3D11CreateDevice");
	if (PD3D11CreateDevice == NULL)
		MessageBoxA(NULL, "GetProcAddress failed for D3D11CreateDevice!", "Critical error", MB_OK | MB_ICONERROR);

	PD3D11CreateDeviceAndSwapChain = (D3D11CREATEDEVICEANDSWAPCHAIN)GetProcAddress(hD3DDll_11, "D3D11CreateDeviceAndSwapChain");
	if (PD3D11CreateDeviceAndSwapChain == NULL)
		MessageBoxA(NULL, "GetProcAddress failed for D3D11CreateDeviceAndSwapChain!", "Critical error", MB_OK | MB_ICONERROR);

	PD3D10CreateBlob = (D3D10CREATEBLOB)GetProcAddress(hD3DDll_10, "D3D10CreateBlob");
	if (PD3D10CreateBlob == NULL)
		MessageBoxA(NULL, "GetProcAddress failed for D3D10CreateBlob!", "Critical error", MB_OK | MB_ICONERROR);

	return S_OK;
}

HRESULT LoadD3DX()
{
	if (d3dx_dll_ref++ > 0) return S_OK;
	if (hD3DXDll) return S_OK;

	// try to load D3DX11 first to check whether we have proper runtime support
	// try to use the dll the backend was compiled against first - don't bother about debug runtimes
	hD3DXDll = LoadLibraryA(D3DX11_DLL_A);
	if (!hD3DXDll)
	{
		// if that fails, use the dll which should be available in every SDK which officially supports DX11.
		hD3DXDll = LoadLibraryA("d3dx11_42.dll");
		if (!hD3DXDll)
		{
			MessageBoxA(NULL, "Failed to load d3dx11_42.dll, update your DX11 runtime, please", "Critical error", MB_OK | MB_ICONERROR);
			return E_FAIL;
		}
		else
		{
			NOTICE_LOG(VIDEO, "Successfully loaded d3dx11_42.dll. If you're having trouble, try updating your DX runtime first.");
		}
	}

	PD3DX11CompileFromMemory = (D3DX11COMPILEFROMMEMORYTYPE)GetProcAddress(hD3DXDll, "D3DX11CompileFromMemory");
	if (PD3DX11CompileFromMemory == NULL) MessageBoxA(NULL, "GetProcAddress failed for D3DX11CompileFromMemory!", "Critical error", MB_OK | MB_ICONERROR);

	PD3DX11FilterTexture = (D3DX11FILTERTEXTURETYPE)GetProcAddress(hD3DXDll, "D3DX11FilterTexture");
	if (PD3DX11FilterTexture == NULL) MessageBoxA(NULL, "GetProcAddress failed for D3DX11FilterTexture!", "Critical error", MB_OK | MB_ICONERROR);

	PD3DX11SaveTextureToFileA = (D3DX11SAVETEXTURETOFILEATYPE)GetProcAddress(hD3DXDll, "D3DX11SaveTextureToFileA");
	if (PD3DX11SaveTextureToFileA == NULL) MessageBoxA(NULL, "GetProcAddress failed for D3DX11SaveTextureToFileA!", "Critical error", MB_OK | MB_ICONERROR);

	PD3DX11SaveTextureToFileW = (D3DX11SAVETEXTURETOFILEWTYPE)GetProcAddress(hD3DXDll, "D3DX11SaveTextureToFileW");
	if (PD3DX11SaveTextureToFileW == NULL) MessageBoxA(NULL, "GetProcAddress failed for D3DX11SaveTextureToFileW!", "Critical error", MB_OK | MB_ICONERROR);

	return S_OK;
}

HRESULT LoadD3DCompiler()
{
	if (d3dcompiler_dll_ref++ > 0) return S_OK;
	if (hD3DCompilerDll) return S_OK;

	// try to load D3DCompiler first to check whether we have proper runtime support
	// try to use the dll the backend was compiled against first - don't bother about debug runtimes
	hD3DCompilerDll = LoadLibraryA(D3DCOMPILER_DLL_A);
	if (!hD3DCompilerDll)
	{
		// if that fails, use the dll which should be available in every SDK which officially supports DX11.
		hD3DCompilerDll = LoadLibraryA("D3DCompiler_42.dll");
		if (!hD3DCompilerDll)
		{
			MessageBoxA(NULL, "Failed to load D3DCompiler_42.dll, update your DX11 runtime, please", "Critical error", MB_OK | MB_ICONERROR);
			return E_FAIL;
		}
		else
		{
			NOTICE_LOG(VIDEO, "Successfully loaded D3DCompiler_42.dll. If you're having trouble, try updating your DX runtime first.");
		}
	}

	PD3DReflect = (D3DREFLECT)GetProcAddress(hD3DCompilerDll, "D3DReflect");
	if (PD3DReflect == NULL) MessageBoxA(NULL, "GetProcAddress failed for D3DReflect!", "Critical error", MB_OK | MB_ICONERROR);

	return S_OK;
}

void UnloadDXGI()
{
	if (!dxgi_dll_ref) return;
	if (--dxgi_dll_ref != 0) return;

	if(hDXGIDll) FreeLibrary(hDXGIDll);
	hDXGIDll = NULL;
	PCreateDXGIFactory = NULL;
}

void UnloadD3DX()
{
	if (!d3dx_dll_ref) return;
	if (--d3dx_dll_ref != 0) return;

	if(hD3DXDll) FreeLibrary(hD3DXDll);
	hD3DXDll = NULL;
	PD3DX11FilterTexture = NULL;
	PD3DX11SaveTextureToFileA = NULL;
	PD3DX11SaveTextureToFileW = NULL;
}

void UnloadD3D()
{
	if (!d3d_dll_ref || --d3d_dll_ref != 0)
		return;

	FreeLibrary(hD3DDll_10);
	FreeLibrary(hD3DDll_11);

	hD3DDll_10 = hD3DDll_11 = NULL;

	PD3D11CreateDevice = NULL;
	PD3D11CreateDeviceAndSwapChain = NULL;
	PD3D10CreateBlob = NULL;
}

void UnloadD3DCompiler()
{
	if (!d3dcompiler_dll_ref) return;
	if (--d3dcompiler_dll_ref != 0) return;

	if (hD3DCompilerDll) FreeLibrary(hD3DCompilerDll);
	hD3DCompilerDll = NULL;
	PD3DReflect = NULL;
}

std::vector<DXGI_SAMPLE_DESC> EnumAAModes(IDXGIAdapter* adapter)
{
	// NOTE: D3D 10.0 doesn't support multisampled resources which are bound as depth buffers AND shader resources.
	// Thus, we can't have MSAA with 10.0 level hardware.
	D3D_FEATURE_LEVEL feat_level;

	SharedPtr<ID3D11Device> device;
	SharedPtr<ID3D11DeviceContext> context;

	const HRESULT hr = D3D11CreateDeviceShared(adapter, D3D_DRIVER_TYPE_UNKNOWN, NULL,
		D3D11_CREATE_DEVICE_SINGLETHREADED, supported_feature_levels,
		NUM_SUPPORTED_FEATURE_LEVELS, D3D11_SDK_VERSION, std::addressof(device), &feat_level, std::addressof(context));

	std::vector<DXGI_SAMPLE_DESC> aa_modes;

	if (FAILED(hr) || feat_level == D3D_FEATURE_LEVEL_10_0)
	{
		DXGI_SAMPLE_DESC desc;
		desc.Count = 1;
		desc.Quality = 0;
		aa_modes.push_back(desc);
	}
	else
	{
		for (UINT samples = 0; samples != D3D11_MAX_MULTISAMPLE_SAMPLE_COUNT; ++samples)
		{
			UINT quality_levels = 0;
			device->CheckMultisampleQualityLevels(DXGI_FORMAT_R8G8B8A8_UNORM, samples, &quality_levels);
			if (quality_levels > 0)
			{
				DXGI_SAMPLE_DESC desc;
				desc.Count = samples;
				for (desc.Quality = 0; desc.Quality != quality_levels; ++desc.Quality)
					aa_modes.push_back(desc);
			}
		}
	}

	return aa_modes;
}

DXGI_SAMPLE_DESC GetAAMode(int index)
{
	return g_aa_modes[index];
}

HRESULT Create(HWND wnd)
{
	hWnd = wnd;
	HRESULT hr;

	RECT client;
	GetClientRect(hWnd, &client);
	xres = client.right - client.left;
	yres = client.bottom - client.top;

	hr = LoadDXGI();
	if (SUCCEEDED(hr)) hr = LoadD3D();
	if (SUCCEEDED(hr)) hr = LoadD3DX();
	if (SUCCEEDED(hr)) hr = LoadD3DCompiler();
	if (FAILED(hr))
	{
		UnloadDXGI();
		UnloadD3D();
		UnloadD3DX();
		UnloadD3DCompiler();
		return hr;
	}

	IDXGIFactory* factory;
	hr = PCreateDXGIFactory(__uuidof(IDXGIFactory), (void**)&factory);
	if (FAILED(hr))
		MessageBox(wnd, _T("Failed to create IDXGIFactory object"),
			_T("Dolphin Direct3D 11 backend"), MB_OK | MB_ICONERROR);

	IDXGIAdapter* adapter;
	hr = factory->EnumAdapters(g_ActiveConfig.iAdapter, &adapter);
	if (FAILED(hr))
	{
		// try using the first one
		hr = factory->EnumAdapters(0, &adapter);
		if (FAILED(hr))
			MessageBox(wnd, _T("Failed to enumerate adapters"),
				_T("Dolphin Direct3D 11 backend"), MB_OK | MB_ICONERROR);
	}

	// TODO: Make this configurable
	IDXGIOutput* output;
	hr = adapter->EnumOutputs(0, &output);
	if (FAILED(hr))
	{
		// try using the first one
		hr = adapter->EnumOutputs(0, &output);
		if (FAILED(hr))
			MessageBox(wnd, _T("Failed to enumerate outputs"),
				_T("Dolphin Direct3D 11 backend"), MB_OK | MB_ICONERROR);
	}

	// get supported AA modes
	g_aa_modes = EnumAAModes(adapter);
	if (g_Config.iMultisampleMode >= (int)g_aa_modes.size())
	{
		g_Config.iMultisampleMode = 0;
		UpdateActiveConfig();
	}

	DXGI_SWAP_CHAIN_DESC swap_chain_desc;
	memset(&swap_chain_desc, 0, sizeof(swap_chain_desc));
	swap_chain_desc.BufferCount = 1;
	swap_chain_desc.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
	swap_chain_desc.OutputWindow = wnd;
	swap_chain_desc.SampleDesc.Count = 1;
	swap_chain_desc.SampleDesc.Quality = 0;
	swap_chain_desc.Windowed = TRUE;

	DXGI_MODE_DESC mode_desc;
	memset(&mode_desc, 0, sizeof(mode_desc));
	mode_desc.Width = xres;
	mode_desc.Height = yres;
	mode_desc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
	mode_desc.Scaling = DXGI_MODE_SCALING_UNSPECIFIED;
	hr = output->FindClosestMatchingMode(&mode_desc, &swap_chain_desc.BufferDesc, NULL);
	if (FAILED(hr))
		MessageBox(wnd, _T("Failed to find a supported video mode"),
			_T("Dolphin Direct3D 11 backend"), MB_OK | MB_ICONERROR);

	// forcing buffer resolution to xres and yres.. TODO: The new video mode might not actually be supported!
	swap_chain_desc.BufferDesc.Width = xres;
	swap_chain_desc.BufferDesc.Height = yres;

#if defined(_DEBUG) || defined(DEBUGFAST)
	const D3D11_CREATE_DEVICE_FLAG device_flags = (D3D11_CREATE_DEVICE_FLAG)(D3D11_CREATE_DEVICE_DEBUG
		| D3D11_CREATE_DEVICE_SINGLETHREADED);
#else
	const D3D11_CREATE_DEVICE_FLAG device_flags = D3D11_CREATE_DEVICE_SINGLETHREADED;
#endif

	SharedPtr<ID3D11Device> device;
	SharedPtr<IDXGISwapChain> swapchain;
	SharedPtr<ID3D11DeviceContext> context;

	hr = D3D11CreateDeviceAndSwapChainShared(adapter, D3D_DRIVER_TYPE_UNKNOWN, NULL, device_flags,
		supported_feature_levels, NUM_SUPPORTED_FEATURE_LEVELS, D3D11_SDK_VERSION,
		&swap_chain_desc, std::addressof(swapchain), std::addressof(device), &featlevel, std::addressof(context));

	if (FAILED(hr) || !device || !swapchain || !context)
	{
		MessageBox(wnd, _T("Failed to initialize Direct3D.\nMake sure your video card supports at least D3D 10.0"),
			_T("Dolphin Direct3D 11 backend"), MB_OK | MB_ICONERROR);
		return E_FAIL;
	}

	SetDebugObjectName(context, "device context");
	
	SAFE_RELEASE(factory);
	SAFE_RELEASE(output);
	SAFE_RELEASE(adapter);

	auto const buf = SwapChainGetBufferTexture2DShared(swapchain, 0);
	if (!buf)
	{
		MessageBox(wnd, _T("Failed to get swapchain buffer"), _T("Dolphin Direct3D 11 backend"), MB_OK | MB_ICONERROR);
		return E_FAIL;
	}

	g_device = device;
	g_context = context;
	g_swapchain = swapchain;

	backbuf.reset(new D3DTexture2D(buf, D3D11_BIND_RENDER_TARGET));

	CHECK(backbuf!=NULL, "Create back buffer texture");
	SetDebugObjectName(backbuf->GetTex(), "backbuffer texture");
	SetDebugObjectName(backbuf->GetRTV(), "backbuffer render target view");

	context->OMSetRenderTargets(1, &backbuf->GetRTV(), NULL);

	// BGRA textures are easier to deal with in TextureCache, but might not be supported by the hardware
	UINT format_support;
	device->CheckFormatSupport(DXGI_FORMAT_B8G8R8A8_UNORM, &format_support);
	bgra_textures_supported = (format_support & D3D11_FORMAT_SUPPORT_TEXTURE2D) != 0;

	stateman.reset(new StateManager);

	return S_OK;
}

void Close()
{
	// release all bound resources
	g_context->ClearState();
	backbuf.reset();
	g_swapchain.reset();
	stateman.reset();
	g_context->Flush();  // immediately destroy device objects

	g_context.reset();
	g_device.reset();

	// unload DLLs
	UnloadD3DX();
	UnloadD3D();
	UnloadDXGI();
}

const char* VertexShaderVersionString()
{
	if(featlevel == D3D_FEATURE_LEVEL_11_0) return "vs_5_0";
	else if(featlevel == D3D_FEATURE_LEVEL_10_1) return "vs_4_1";
	else /*if(featlevel == D3D_FEATURE_LEVEL_10_0)*/ return "vs_4_0";
}

const char* GeometryShaderVersionString()
{
	if(featlevel == D3D_FEATURE_LEVEL_11_0) return "gs_5_0";
	else if(featlevel == D3D_FEATURE_LEVEL_10_1) return "gs_4_1";
	else /*if(featlevel == D3D_FEATURE_LEVEL_10_0)*/ return "gs_4_0";
}

const char* PixelShaderVersionString()
{
	if(featlevel == D3D_FEATURE_LEVEL_11_0) return "ps_5_0";
	else if(featlevel == D3D_FEATURE_LEVEL_10_1) return "ps_4_1";
	else /*if(featlevel == D3D_FEATURE_LEVEL_10_0)*/ return "ps_4_0";
}

D3DTexture2D* GetBackBuffer() { return backbuf.get(); }
unsigned int GetBackBufferWidth() { return xres; }
unsigned int GetBackBufferHeight() { return yres; }

bool BGRATexturesSupported() { return bgra_textures_supported; }

// Returns the maximum width/height of a texture. This value only depends upon the feature level in DX11
unsigned int GetMaxTextureSize()
{
	switch (featlevel)
	{
		case D3D_FEATURE_LEVEL_11_0:
			return D3D11_REQ_TEXTURE2D_U_OR_V_DIMENSION;

		case D3D_FEATURE_LEVEL_10_1:
		case D3D_FEATURE_LEVEL_10_0:
			return D3D10_REQ_TEXTURE2D_U_OR_V_DIMENSION;

		case D3D_FEATURE_LEVEL_9_3:
			return 4096;

		case D3D_FEATURE_LEVEL_9_2:
		case D3D_FEATURE_LEVEL_9_1:
			return 2048;

		default:
			return 0;
	}
}

void Reset()
{
	// release all back buffer references
	backbuf.reset();

	// resize swapchain buffers
	RECT client;
	GetClientRect(hWnd, &client);
	xres = client.right - client.left;
	yres = client.bottom - client.top;
	D3D::g_swapchain->ResizeBuffers(1, xres, yres, DXGI_FORMAT_R8G8B8A8_UNORM, 0);

	// recreate back buffer texture
	auto const buf = SwapChainGetBufferTexture2DShared(g_swapchain, 0);
	if (!buf)
	{
		MessageBox(hWnd, _T("Failed to get swapchain buffer"), _T("Dolphin Direct3D 11 backend"), MB_OK | MB_ICONERROR);
		return;
	}

	backbuf.reset(new D3DTexture2D(buf, D3D11_BIND_RENDER_TARGET));
	CHECK(backbuf!=NULL, "Create back buffer texture");
	SetDebugObjectName(backbuf->GetTex(), "backbuffer texture");
	SetDebugObjectName(backbuf->GetRTV(), "backbuffer render target view");
}

bool BeginFrame()
{
	if (bFrameInProgress)
	{
		PanicAlert("BeginFrame called although a frame is already in progress");
		return false;
	}

	bFrameInProgress = true;
	return (g_device != NULL);
}

void EndFrame()
{
	if (!bFrameInProgress)
	{
		PanicAlert("EndFrame called although no frame is in progress");
		return;
	}
	bFrameInProgress = false;
}

void Present()
{
	// TODO: Is 1 the correct value for vsyncing?
	g_swapchain->Present((UINT)g_ActiveConfig.bVSync, 0);
}

}  // namespace D3D

}  // namespace DX11