/* Copyright (c) 2021, NVIDIA CORPORATION. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *  * Neither the name of NVIDIA CORPORATION nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/* This example demonstrates how to use the CUDA Direct3D bindings to
 * transfer data between CUDA and DX9 2D, CubeMap, and Volume Textures.
 */

#pragma warning(disable : 4312)

#include <windows.h>
#include <mmsystem.h>

// This header inclues all the necessary D3D11 and CUDA includes
#include <dynlink_d3d11.h>
#include <cuda_runtime_api.h>
#include <cuda_d3d11_interop.h>
#include <d3dcompiler.h>

// includes, project
#include <rendercheck_d3d11.h>
#include <helper_cuda.h>
#include <helper_functions.h>  // includes cuda.h and cuda_runtime_api.h

#define MAX_EPSILON 10

static char *SDK_name = "simpleD3D11Texture";

//-----------------------------------------------------------------------------
// Global variables
//-----------------------------------------------------------------------------
IDXGIAdapter *g_pCudaCapableAdapter = NULL;  // Adapter to use
ID3D11Device *g_pd3dDevice = NULL;           // Our rendering device
ID3D11DeviceContext *g_pd3dDeviceContext = NULL;
IDXGISwapChain *g_pSwapChain = NULL;  // The swap chain of the window
ID3D11RenderTargetView *g_pSwapChainRTV =
    NULL;  // The Render target view on the swap chain ( used for clear)
ID3D11RasterizerState *g_pRasterState = NULL;

ID3D11InputLayout *g_pInputLayout = NULL;

#ifdef USEEFFECT
#pragma message( \
    ">>>> NOTE : Using Effect library (see DXSDK Utility folder for sources)")
#pragma message( \
    ">>>> WARNING : Currently only libs for vc9 are provided with the sample. See DXSDK for more...")
#pragma message( \
    ">>>> WARNING : The effect is currently failing... some strange internal error in Effect lib")
ID3DX11Effect *g_pSimpleEffect = NULL;
ID3DX11EffectTechnique *g_pSimpleTechnique = NULL;
ID3DX11EffectVectorVariable *g_pvQuadRect = NULL;
ID3DX11EffectScalarVariable *g_pUseCase = NULL;
ID3DX11EffectShaderResourceVariable *g_pTexture2D = NULL;
ID3DX11EffectShaderResourceVariable *g_pTexture3D = NULL;
ID3DX11EffectShaderResourceVariable *g_pTextureCube = NULL;

static const char g_simpleEffectSrc[] =
    "float4 g_vQuadRect; \n"
    "int g_UseCase; \n"
    "Texture2D g_Texture2D; \n"
    "Texture3D g_Texture3D; \n"
    "TextureCube g_TextureCube; \n"
    "\n"
    "SamplerState samLinear{ \n"
    "    Filter = MIN_MAG_LINEAR_MIP_POINT; \n"
    "};\n"
    "\n"
    "struct Fragment{ \n"
    "    float4 Pos : SV_POSITION;\n"
    "    float3 Tex : TEXCOORD0; };\n"
    "\n"
    "Fragment VS( uint vertexId : SV_VertexID )\n"
    "{\n"
    "    Fragment f;\n"
    "    f.Tex = float3( 0.f, 0.f, 0.f); \n"
    "    if (vertexId == 1) f.Tex.x = 1.f; \n"
    "    else if (vertexId == 2) f.Tex.y = 1.f; \n"
    "    else if (vertexId == 3) f.Tex.xy = float2(1.f, 1.f); \n"
    "    \n"
    "    f.Pos = float4( g_vQuadRect.xy + f.Tex * g_vQuadRect.zw, 0, 1);\n"
    "    \n"
    "    if (g_UseCase == 1) { \n"
    "        if (vertexId == 1) f.Tex.z = 0.5f; \n"
    "        else if (vertexId == 2) f.Tex.z = 0.5f; \n"
    "        else if (vertexId == 3) f.Tex.z = 1.f; \n"
    "    } \n"
    "    else if (g_UseCase >= 2) { \n"
    "        f.Tex.xy = f.Tex.xy * 2.f - 1.f; \n"
    "    } \n"
    "    return f;\n"
    "}\n"
    "\n"
    "float4 PS( Fragment f ) : SV_Target\n"
    "{\n"
    "    if (g_UseCase == 0) return g_Texture2D.Sample( samLinear, f.Tex.xy ); "
    "\n"
    "    else if (g_UseCase == 1) return g_Texture3D.Sample( samLinear, f.Tex "
    "); \n"
    "    else if (g_UseCase == 2) return g_TextureCube.Sample( samLinear, "
    "float3(f.Tex.xy, 1.0) ); \n"
    "    else if (g_UseCase == 3) return g_TextureCube.Sample( samLinear, "
    "float3(f.Tex.xy, -1.0) ); \n"
    "    else if (g_UseCase == 4) return g_TextureCube.Sample( samLinear, "
    "float3(1.0, f.Tex.xy) ); \n"
    "    else if (g_UseCase == 5) return g_TextureCube.Sample( samLinear, "
    "float3(-1.0, f.Tex.xy) ); \n"
    "    else if (g_UseCase == 6) return g_TextureCube.Sample( samLinear, "
    "float3(f.Tex.x, 1.0, f.Tex.y) ); \n"
    "    else if (g_UseCase == 7) return g_TextureCube.Sample( samLinear, "
    "float3(f.Tex.x, -1.0, f.Tex.y) ); \n"
    "    else return float4(f.Tex, 1);\n"
    "}\n"
    "\n"
    "technique11 Render\n"
    "{\n"
    "    pass P0\n"
    "    {\n"
    "        SetVertexShader( CompileShader( vs_5_0, VS() ) );\n"
    "        SetGeometryShader( NULL );\n"
    "        SetPixelShader( CompileShader( ps_5_0, PS() ) );\n"
    "    }\n"
    "}\n"
    "\n";
#else
//
// Vertex and Pixel shaders here : VS() & PS()
//
static const char g_simpleShaders[] =
    "cbuffer cbuf \n"
    "{ \n"
    "  float4 g_vQuadRect; \n"
    "  int g_UseCase; \n"
    "} \n"
    "Texture2D g_Texture2D; \n"
    "Texture3D g_Texture3D; \n"
    "TextureCube g_TextureCube; \n"
    "\n"
    "SamplerState samLinear{ \n"
    "    Filter = MIN_MAG_LINEAR_MIP_POINT; \n"
    "};\n"
    "\n"
    "struct Fragment{ \n"
    "    float4 Pos : SV_POSITION;\n"
    "    float3 Tex : TEXCOORD0; };\n"
    "\n"
    "Fragment VS( uint vertexId : SV_VertexID )\n"
    "{\n"
    "    Fragment f;\n"
    "    f.Tex = float3( 0.f, 0.f, 0.f); \n"
    "    if (vertexId == 1) f.Tex.x = 1.f; \n"
    "    else if (vertexId == 2) f.Tex.y = 1.f; \n"
    "    else if (vertexId == 3) f.Tex.xy = float2(1.f, 1.f); \n"
    "    \n"
    "    f.Pos = float4( g_vQuadRect.xy + f.Tex * g_vQuadRect.zw, 0, 1);\n"
    "    \n"
    "    if (g_UseCase == 1) { \n"
    "        if (vertexId == 1) f.Tex.z = 0.5f; \n"
    "        else if (vertexId == 2) f.Tex.z = 0.5f; \n"
    "        else if (vertexId == 3) f.Tex.z = 1.f; \n"
    "    } \n"
    "    else if (g_UseCase >= 2) { \n"
    "        f.Tex.xy = f.Tex.xy * 2.f - 1.f; \n"
    "    } \n"
    "    return f;\n"
    "}\n"
    "\n"
    "float4 PS( Fragment f ) : SV_Target\n"
    "{\n"
    "    if (g_UseCase == 0) return g_Texture2D.Sample( samLinear, f.Tex.xy ); "
    "\n"
    "    else if (g_UseCase == 1) return g_Texture3D.Sample( samLinear, f.Tex "
    "); \n"
    "    else if (g_UseCase == 2) return g_TextureCube.Sample( samLinear, "
    "float3(f.Tex.xy, 1.0) ); \n"
    "    else if (g_UseCase == 3) return g_TextureCube.Sample( samLinear, "
    "float3(f.Tex.xy, -1.0) ); \n"
    "    else if (g_UseCase == 4) return g_TextureCube.Sample( samLinear, "
    "float3(1.0, f.Tex.xy) ); \n"
    "    else if (g_UseCase == 5) return g_TextureCube.Sample( samLinear, "
    "float3(-1.0, f.Tex.xy) ); \n"
    "    else if (g_UseCase == 6) return g_TextureCube.Sample( samLinear, "
    "float3(f.Tex.x, 1.0, f.Tex.y) ); \n"
    "    else if (g_UseCase == 7) return g_TextureCube.Sample( samLinear, "
    "float3(f.Tex.x, -1.0, f.Tex.y) ); \n"
    "    else return float4(f.Tex, 1);\n"
    "}\n"
    "\n";

struct ConstantBuffer {
  float vQuadRect[4];
  int UseCase;
};

ID3D11VertexShader *g_pVertexShader;
ID3D11PixelShader *g_pPixelShader;
ID3D11Buffer *g_pConstantBuffer;
ID3D11SamplerState *g_pSamplerState;

#endif
// testing/tracing function used pervasively in tests.  if the condition is
// unsatisfied
// then spew and fail the function immediately (doing no cleanup)
#define AssertOrQuit(x)                                                  \
  if (!(x)) {                                                            \
    fprintf(stdout, "Assert unsatisfied in %s at %s:%d\n", __FUNCTION__, \
            __FILE__, __LINE__);                                         \
    return 1;                                                            \
  }

bool g_bDone = false;
bool g_bPassed = true;

int *pArgc = NULL;
char **pArgv = NULL;

const unsigned int g_WindowWidth = 720;
const unsigned int g_WindowHeight = 720;

int g_iFrameToCompare = 10;

// Data structure for 2D texture shared between DX10 and CUDA
struct {
  ID3D11Texture2D *pTexture;
  ID3D11ShaderResourceView *pSRView;
  cudaGraphicsResource *cudaResource;
  void *cudaLinearMemory;
  size_t pitch;
  int width;
  int height;
#ifndef USEEFFECT
  int offsetInShader;
#endif
} g_texture_2d;

// Data structure for volume textures shared between DX10 and CUDA
struct {
  ID3D11Texture3D *pTexture;
  ID3D11ShaderResourceView *pSRView;
  cudaGraphicsResource *cudaResource;
  void *cudaLinearMemory;
  size_t pitch;
  int width;
  int height;
  int depth;
#ifndef USEEFFECT
  int offsetInShader;
#endif
} g_texture_3d;

// Data structure for cube texture shared between DX10 and CUDA
struct {
  ID3D11Texture2D *pTexture;
  ID3D11ShaderResourceView *pSRView;
  cudaGraphicsResource *cudaResource;
  void *cudaLinearMemory;
  size_t pitch;
  int size;
#ifndef USEEFFECT
  int offsetInShader;
#endif
} g_texture_cube;

// The CUDA kernel launchers that get called
extern "C" {
bool cuda_texture_2d(void *surface, size_t width, size_t height, size_t pitch,
                     float t);
bool cuda_texture_3d(void *surface, int width, int height, int depth,
                     size_t pitch, size_t pitchslice, float t);
bool cuda_texture_cube(void *surface, int width, int height, size_t pitch,
                       int face, float t);
}

//-----------------------------------------------------------------------------
// Forward declarations
//-----------------------------------------------------------------------------
HRESULT InitD3D(HWND hWnd);
HRESULT InitTextures();

void RunKernels();
bool DrawScene();
void Cleanup();
void Render();

LRESULT WINAPI MsgProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);

#define NAME_LEN 512

bool findCUDADevice() {
  int nGraphicsGPU = 0;
  int deviceCount = 0;
  bool bFoundGraphics = false;
  char devname[NAME_LEN];

  // This function call returns 0 if there are no CUDA capable devices.
  cudaError_t error_id = cudaGetDeviceCount(&deviceCount);

  if (error_id != cudaSuccess) {
    printf("cudaGetDeviceCount returned %d\n-> %s\n", (int)error_id,
           cudaGetErrorString(error_id));
    exit(EXIT_FAILURE);
  }

  if (deviceCount == 0) {
    printf("> There are no device(s) supporting CUDA\n");
    return false;
  } else {
    printf("> Found %d CUDA Capable Device(s)\n", deviceCount);
  }

  // Get CUDA device properties
  cudaDeviceProp deviceProp;

  for (int dev = 0; dev < deviceCount; ++dev) {
    cudaGetDeviceProperties(&deviceProp, dev);
    STRCPY(devname, NAME_LEN, deviceProp.name);
    printf("> GPU %d: %s\n", dev, devname);
  }

  return true;
}

bool findDXDevice(char *dev_name) {
  HRESULT hr = S_OK;
  cudaError cuStatus;

  // Iterate through the candidate adapters
  IDXGIFactory *pFactory;
  hr = sFnPtr_CreateDXGIFactory(__uuidof(IDXGIFactory), (void **)(&pFactory));

  if (!SUCCEEDED(hr)) {
    printf("> No DXGI Factory created.\n");
    return false;
  }

  UINT adapter = 0;

  for (; !g_pCudaCapableAdapter; ++adapter) {
    // Get a candidate DXGI adapter
    IDXGIAdapter *pAdapter = NULL;
    hr = pFactory->EnumAdapters(adapter, &pAdapter);

    if (FAILED(hr)) {
      break;  // no compatible adapters found
    }

    // Query to see if there exists a corresponding compute device
    int cuDevice;
    cuStatus = cudaD3D11GetDevice(&cuDevice, pAdapter);
    printLastCudaError("cudaD3D11GetDevice failed");  // This prints and resets
                                                      // the cudaError to
                                                      // cudaSuccess

    if (cudaSuccess == cuStatus) {
      // If so, mark it as the one against which to create our d3d10 device
      g_pCudaCapableAdapter = pAdapter;
      g_pCudaCapableAdapter->AddRef();
    }

    pAdapter->Release();
  }

  printf("> Found %d D3D11 Adapater(s).\n", (int)adapter);

  pFactory->Release();

  if (!g_pCudaCapableAdapter) {
    printf("> Found 0 D3D11 Adapater(s) /w Compute capability.\n");
    return false;
  }

  DXGI_ADAPTER_DESC adapterDesc;
  g_pCudaCapableAdapter->GetDesc(&adapterDesc);
  wcstombs(dev_name, adapterDesc.Description, 128);

  printf("> Found 1 D3D11 Adapater(s) /w Compute capability.\n");
  printf("> %s\n", dev_name);

  return true;
}

////////////////////////////////////////////////////////////////////////////////
// Program main
////////////////////////////////////////////////////////////////////////////////
int main(int argc, char *argv[]) {
  char device_name[256];
  char *ref_file = NULL;

  pArgc = &argc;
  pArgv = argv;

  printf("[%s] - Starting...\n", SDK_name);

  if (!findCUDADevice())  // Search for CUDA GPU
  {
    printf("> CUDA Device NOT found on \"%s\".. Exiting.\n", device_name);
    exit(EXIT_SUCCESS);
  }

  if (!dynlinkLoadD3D11API())  // Search for D3D API (locate drivers, does not
                               // mean device is found)
  {
    printf("> D3D11 API libraries NOT found on.. Exiting.\n");
    dynlinkUnloadD3D11API();
    exit(EXIT_SUCCESS);
  }

  if (!findDXDevice(device_name))  // Search for D3D Hardware Device
  {
    printf("> D3D11 Graphics Device NOT found.. Exiting.\n");
    dynlinkUnloadD3D11API();
    exit(EXIT_SUCCESS);
  }

  // command line options
  if (argc > 1) {
    // automatied build testing harness
    if (checkCmdLineFlag(argc, (const char **)argv, "file"))
      getCmdLineArgumentString(argc, (const char **)argv, "file", &ref_file);
  }

//
// create window
//
// Register the window class
#if 1
  WNDCLASSEX wc = {sizeof(WNDCLASSEX),
                   CS_CLASSDC,
                   MsgProc,
                   0L,
                   0L,
                   GetModuleHandle(NULL),
                   NULL,
                   NULL,
                   NULL,
                   NULL,
                   "CUDA SDK",
                   NULL};
  RegisterClassEx(&wc);

  // Create the application's window
  int xBorder = ::GetSystemMetrics(SM_CXSIZEFRAME);
  int yMenu = ::GetSystemMetrics(SM_CYMENU);
  int yBorder = ::GetSystemMetrics(SM_CYSIZEFRAME);
  HWND hWnd = CreateWindow(
      wc.lpszClassName, "CUDA/D3D11 Texture InterOP", WS_OVERLAPPEDWINDOW, 0, 0,
      g_WindowWidth + 2 * xBorder, g_WindowHeight + 2 * yBorder + yMenu, NULL,
      NULL, wc.hInstance, NULL);
#else
  static WNDCLASSEX wc = {
      sizeof(WNDCLASSEX),    CS_CLASSDC, MsgProc, 0L,   0L,
      GetModuleHandle(NULL), NULL,       NULL,    NULL, NULL,
      "CudaD3D9Tex",         NULL};
  RegisterClassEx(&wc);
  HWND hWnd = CreateWindow("CudaD3D9Tex", "CUDA D3D9 Texture Interop",
                           WS_OVERLAPPEDWINDOW, 0, 0, 800, 320,
                           GetDesktopWindow(), NULL, wc.hInstance, NULL);
#endif

  ShowWindow(hWnd, SW_SHOWDEFAULT);
  UpdateWindow(hWnd);

  // Initialize Direct3D
  if (SUCCEEDED(InitD3D(hWnd)) && SUCCEEDED(InitTextures())) {
    // 2D
    // register the Direct3D resources that we'll use
    // we'll read to and write from g_texture_2d, so don't set any special map
    // flags for it
    cudaGraphicsD3D11RegisterResource(&g_texture_2d.cudaResource,
                                      g_texture_2d.pTexture,
                                      cudaGraphicsRegisterFlagsNone);
    getLastCudaError("cudaGraphicsD3D11RegisterResource (g_texture_2d) failed");
    // cuda cannot write into the texture directly : the texture is seen as a
    // cudaArray and can only be mapped as a texture
    // Create a buffer so that cuda can write into it
    // pixel fmt is DXGI_FORMAT_R32G32B32A32_FLOAT
    cudaMallocPitch(&g_texture_2d.cudaLinearMemory, &g_texture_2d.pitch,
                    g_texture_2d.width * sizeof(float) * 4,
                    g_texture_2d.height);
    getLastCudaError("cudaMallocPitch (g_texture_2d) failed");
    cudaMemset(g_texture_2d.cudaLinearMemory, 1,
               g_texture_2d.pitch * g_texture_2d.height);

    // CUBE
    cudaGraphicsD3D11RegisterResource(&g_texture_cube.cudaResource,
                                      g_texture_cube.pTexture,
                                      cudaGraphicsRegisterFlagsNone);
    getLastCudaError(
        "cudaGraphicsD3D11RegisterResource (g_texture_cube) failed");
    // create the buffer. pixel fmt is DXGI_FORMAT_R8G8B8A8_SNORM
    cudaMallocPitch(&g_texture_cube.cudaLinearMemory, &g_texture_cube.pitch,
                    g_texture_cube.size * 4, g_texture_cube.size);
    getLastCudaError("cudaMallocPitch (g_texture_cube) failed");
    cudaMemset(g_texture_cube.cudaLinearMemory, 1,
               g_texture_cube.pitch * g_texture_cube.size);
    getLastCudaError("cudaMemset (g_texture_cube) failed");

    // 3D
    cudaGraphicsD3D11RegisterResource(&g_texture_3d.cudaResource,
                                      g_texture_3d.pTexture,
                                      cudaGraphicsRegisterFlagsNone);
    getLastCudaError("cudaGraphicsD3D11RegisterResource (g_texture_3d) failed");
    // create the buffer. pixel fmt is DXGI_FORMAT_R8G8B8A8_SNORM
    // cudaMallocPitch(&g_texture_3d.cudaLinearMemory, &g_texture_3d.pitch,
    // g_texture_3d.width * 4, g_texture_3d.height * g_texture_3d.depth);
    cudaMalloc(
        &g_texture_3d.cudaLinearMemory,
        g_texture_3d.width * 4 * g_texture_3d.height * g_texture_3d.depth);
    g_texture_3d.pitch = g_texture_3d.width * 4;
    getLastCudaError("cudaMallocPitch (g_texture_3d) failed");
    cudaMemset(g_texture_3d.cudaLinearMemory, 1,
               g_texture_3d.pitch * g_texture_3d.height * g_texture_3d.depth);
    getLastCudaError("cudaMemset (g_texture_3d) failed");
  }

  //
  // the main loop
  //
  while (false == g_bDone) {
    Render();

    //
    // handle I/O
    //
    MSG msg;
    ZeroMemory(&msg, sizeof(msg));

    while (msg.message != WM_QUIT) {
      if (PeekMessage(&msg, NULL, 0U, 0U, PM_REMOVE)) {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
      } else {
        Render();

        if (ref_file) {
          for (int count = 0; count < g_iFrameToCompare; count++) {
            Render();
          }

          const char *cur_image_path = "simpleD3D11Texture.ppm";

          // Save a reference of our current test run image
          CheckRenderD3D11::ActiveRenderTargetToPPM(g_pd3dDevice,
                                                    cur_image_path);

          // compare to offical reference image, printing PASS or FAIL.
          g_bPassed = CheckRenderD3D11::PPMvsPPM(cur_image_path, ref_file,
                                                 argv[0], MAX_EPSILON, 0.15f);

          g_bDone = true;

          Cleanup();

          PostQuitMessage(0);
        } else {
          g_bPassed = true;
        }
      }
    }
  };

  // Release D3D Library (after message loop)
  dynlinkUnloadD3D11API();

  // Unregister windows class
  UnregisterClass(wc.lpszClassName, wc.hInstance);

  //
  // and exit
  //
  printf("> %s running on %s exiting...\n", SDK_name, device_name);

  exit(g_bPassed ? EXIT_SUCCESS : EXIT_FAILURE);
}

//-----------------------------------------------------------------------------
// Name: InitD3D()
// Desc: Initializes Direct3D
//-----------------------------------------------------------------------------
HRESULT InitD3D(HWND hWnd) {
  HRESULT hr = S_OK;

  // Set up the structure used to create the device and swapchain
  DXGI_SWAP_CHAIN_DESC sd;
  ZeroMemory(&sd, sizeof(sd));
  sd.BufferCount = 1;
  sd.BufferDesc.Width = g_WindowWidth;
  sd.BufferDesc.Height = g_WindowHeight;
  sd.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
  sd.BufferDesc.RefreshRate.Numerator = 60;
  sd.BufferDesc.RefreshRate.Denominator = 1;
  sd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
  sd.OutputWindow = hWnd;
  sd.SampleDesc.Count = 1;
  sd.SampleDesc.Quality = 0;
  sd.Windowed = TRUE;

  D3D_FEATURE_LEVEL tour_fl[] = {D3D_FEATURE_LEVEL_11_0, D3D_FEATURE_LEVEL_10_1,
                                 D3D_FEATURE_LEVEL_10_0};
  D3D_FEATURE_LEVEL flRes;
  // Create device and swapchain
  hr = sFnPtr_D3D11CreateDeviceAndSwapChain(
      g_pCudaCapableAdapter,
      D3D_DRIVER_TYPE_UNKNOWN,  // D3D_DRIVER_TYPE_HARDWARE,
      NULL,  // HMODULE Software
      0,  // UINT Flags
      tour_fl,  // D3D_FEATURE_LEVEL* pFeatureLevels
      3,  // FeatureLevels
      D3D11_SDK_VERSION,  // UINT SDKVersion
      &sd,  // DXGI_SWAP_CHAIN_DESC* pSwapChainDesc
      &g_pSwapChain,  // IDXGISwapChain** ppSwapChain
      &g_pd3dDevice,  // ID3D11Device** ppDevice
      &flRes,  // D3D_FEATURE_LEVEL* pFeatureLevel
      &g_pd3dDeviceContext  // ID3D11DeviceContext** ppImmediateContext
      );
  AssertOrQuit(SUCCEEDED(hr));

  g_pCudaCapableAdapter->Release();

  // Get the immediate DeviceContext
  g_pd3dDevice->GetImmediateContext(&g_pd3dDeviceContext);

  // Create a render target view of the swapchain
  ID3D11Texture2D *pBuffer;
  hr =
      g_pSwapChain->GetBuffer(0, __uuidof(ID3D11Texture2D), (LPVOID *)&pBuffer);
  AssertOrQuit(SUCCEEDED(hr));

  hr = g_pd3dDevice->CreateRenderTargetView(pBuffer, NULL, &g_pSwapChainRTV);
  AssertOrQuit(SUCCEEDED(hr));
  pBuffer->Release();

  g_pd3dDeviceContext->OMSetRenderTargets(1, &g_pSwapChainRTV, NULL);

  // Setup the viewport
  D3D11_VIEWPORT vp;
  vp.Width = g_WindowWidth;
  vp.Height = g_WindowHeight;
  vp.MinDepth = 0.0f;
  vp.MaxDepth = 1.0f;
  vp.TopLeftX = 0;
  vp.TopLeftY = 0;
  g_pd3dDeviceContext->RSSetViewports(1, &vp);

#ifdef USEEFFECT
  // Setup the effect
  {
    ID3D10Blob *effectCode, *effectErrors;
    hr = D3DX11CompileFromMemory(
        g_simpleEffectSrc, sizeof(g_simpleEffectSrc), "NoFile", NULL, NULL, "",
        "fx_5_0",
        D3D10_SHADER_OPTIMIZATION_LEVEL0 |
            D3D10_SHADER_ENABLE_BACKWARDS_COMPATIBILITY | D3D10_SHADER_DEBUG,
        0, 0, &effectCode, &effectErrors, 0);

    if (FAILED(hr)) {
      const char *pStr = (const char *)effectErrors->GetBufferPointer();
      printf(pStr);
      assert(1);
    }

    hr = D3DX11CreateEffectFromMemory(
        effectCode->GetBufferPointer(), effectCode->GetBufferSize(),
        0 /*FXFlags*/, g_pd3dDevice, &g_pSimpleEffect);
    AssertOrQuit(SUCCEEDED(hr));
    g_pSimpleTechnique = g_pSimpleEffect->GetTechniqueByName("Render");

    g_pvQuadRect =
        g_pSimpleEffect->GetVariableByName("g_vQuadRect")->AsVector();
    g_pUseCase = g_pSimpleEffect->GetVariableByName("g_UseCase")->AsScalar();

    g_pTexture2D =
        g_pSimpleEffect->GetVariableByName("g_Texture2D")->AsShaderResource();
    g_pTexture3D =
        g_pSimpleEffect->GetVariableByName("g_Texture3D")->AsShaderResource();
    g_pTextureCube =
        g_pSimpleEffect->GetVariableByName("g_TextureCube")->AsShaderResource();
  }
#else
  ID3DBlob *pShader;
  ID3DBlob *pErrorMsgs;
  // Vertex shader
  {
    hr = D3DCompile(g_simpleShaders, strlen(g_simpleShaders), "Memory", NULL,
                    NULL, "VS", "vs_4_0", 0 /*Flags1*/, 0 /*Flags2*/, &pShader,
                    &pErrorMsgs);

    if (FAILED(hr)) {
      const char *pStr = (const char *)pErrorMsgs->GetBufferPointer();
      printf(pStr);
    }

    AssertOrQuit(SUCCEEDED(hr));
    hr = g_pd3dDevice->CreateVertexShader(pShader->GetBufferPointer(),
                                          pShader->GetBufferSize(), NULL,
                                          &g_pVertexShader);
    AssertOrQuit(SUCCEEDED(hr));
    // Let's bind it now : no other vtx shader will replace it...
    g_pd3dDeviceContext->VSSetShader(g_pVertexShader, NULL, 0);
    // hr = g_pd3dDevice->CreateInputLayout(...pShader used for signature...) No
    // need
  }
  // Pixel shader
  {
    hr = D3DCompile(g_simpleShaders, strlen(g_simpleShaders), "Memory", NULL,
                    NULL, "PS", "ps_4_0", 0 /*Flags1*/, 0 /*Flags2*/, &pShader,
                    &pErrorMsgs);

    AssertOrQuit(SUCCEEDED(hr));
    hr = g_pd3dDevice->CreatePixelShader(pShader->GetBufferPointer(),
                                         pShader->GetBufferSize(), NULL,
                                         &g_pPixelShader);
    AssertOrQuit(SUCCEEDED(hr));
    // Let's bind it now : no other pix shader will replace it...
    g_pd3dDeviceContext->PSSetShader(g_pPixelShader, NULL, 0);
  }
  // Create the constant buffer
  {
    D3D11_BUFFER_DESC cbDesc;
    cbDesc.Usage = D3D11_USAGE_DYNAMIC;
    cbDesc.BindFlags =
        D3D11_BIND_CONSTANT_BUFFER;  // D3D11_BIND_SHADER_RESOURCE;
    cbDesc.CPUAccessFlags = D3D11_CPU_ACCESS_WRITE;
    cbDesc.MiscFlags = 0;
    cbDesc.ByteWidth = 16 * ((sizeof(ConstantBuffer) + 16) / 16);
    // cbDesc.StructureByteStride = 0;
    hr = g_pd3dDevice->CreateBuffer(&cbDesc, NULL, &g_pConstantBuffer);
    AssertOrQuit(SUCCEEDED(hr));
    // Assign the buffer now : nothing in the code will interfere with this
    // (very simple sample)
    g_pd3dDeviceContext->VSSetConstantBuffers(0, 1, &g_pConstantBuffer);
    g_pd3dDeviceContext->PSSetConstantBuffers(0, 1, &g_pConstantBuffer);
  }
  // SamplerState
  {
    D3D11_SAMPLER_DESC sDesc;
    sDesc.Filter = D3D11_FILTER_MIN_MAG_MIP_LINEAR;
    sDesc.AddressU = D3D11_TEXTURE_ADDRESS_CLAMP;
    sDesc.AddressV = D3D11_TEXTURE_ADDRESS_CLAMP;
    sDesc.AddressW = D3D11_TEXTURE_ADDRESS_CLAMP;
    sDesc.MinLOD = 0;
    sDesc.MaxLOD = 8;
    sDesc.MipLODBias = 0;
    sDesc.MaxAnisotropy = 1;
    hr = g_pd3dDevice->CreateSamplerState(&sDesc, &g_pSamplerState);
    AssertOrQuit(SUCCEEDED(hr));
    g_pd3dDeviceContext->PSSetSamplers(0, 1, &g_pSamplerState);
  }
#endif
  // Setup  no Input Layout
  g_pd3dDeviceContext->IASetInputLayout(0);
  g_pd3dDeviceContext->IASetPrimitiveTopology(
      D3D11_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP);

  D3D11_RASTERIZER_DESC rasterizerState;
  rasterizerState.FillMode = D3D11_FILL_SOLID;
  rasterizerState.CullMode = D3D11_CULL_FRONT;
  rasterizerState.FrontCounterClockwise = false;
  rasterizerState.DepthBias = false;
  rasterizerState.DepthBiasClamp = 0;
  rasterizerState.SlopeScaledDepthBias = 0;
  rasterizerState.DepthClipEnable = false;
  rasterizerState.ScissorEnable = false;
  rasterizerState.MultisampleEnable = false;
  rasterizerState.AntialiasedLineEnable = false;
  g_pd3dDevice->CreateRasterizerState(&rasterizerState, &g_pRasterState);
  g_pd3dDeviceContext->RSSetState(g_pRasterState);

  return S_OK;
}

//-----------------------------------------------------------------------------
// Name: InitTextures()
// Desc: Initializes Direct3D Textures (allocation and initialization)
//-----------------------------------------------------------------------------
HRESULT InitTextures() {
  //
  // create the D3D resources we'll be using
  //
  // 2D texture
  {
    g_texture_2d.width = 256;
    g_texture_2d.height = 256;

    D3D11_TEXTURE2D_DESC desc;
    ZeroMemory(&desc, sizeof(D3D11_TEXTURE2D_DESC));
    desc.Width = g_texture_2d.width;
    desc.Height = g_texture_2d.height;
    desc.MipLevels = 1;
    desc.ArraySize = 1;
    desc.Format = DXGI_FORMAT_R32G32B32A32_FLOAT;
    desc.SampleDesc.Count = 1;
    desc.Usage = D3D11_USAGE_DEFAULT;
    desc.BindFlags = D3D11_BIND_SHADER_RESOURCE;

    if (FAILED(g_pd3dDevice->CreateTexture2D(&desc, NULL,
                                             &g_texture_2d.pTexture))) {
      return E_FAIL;
    }

    if (FAILED(g_pd3dDevice->CreateShaderResourceView(
            g_texture_2d.pTexture, NULL, &g_texture_2d.pSRView))) {
      return E_FAIL;
    }

#ifdef USEEFFECT
    g_pTexture2D->SetResource(g_texture_2d.pSRView);
#else
    g_texture_2d.offsetInShader =
        0;  // to be clean we should look for the offset from the shader code
    g_pd3dDeviceContext->PSSetShaderResources(g_texture_2d.offsetInShader, 1,
                                              &g_texture_2d.pSRView);
#endif
  }

  // 3D texture
  {
    g_texture_3d.width = 64;
    g_texture_3d.height = 64;
    g_texture_3d.depth = 64;

    D3D11_TEXTURE3D_DESC desc;
    ZeroMemory(&desc, sizeof(D3D11_TEXTURE3D_DESC));
    desc.Width = g_texture_3d.width;
    desc.Height = g_texture_3d.height;
    desc.Depth = g_texture_3d.depth;
    desc.MipLevels = 1;
    desc.Format = DXGI_FORMAT_R8G8B8A8_SNORM;
    desc.Usage = D3D11_USAGE_DEFAULT;
    desc.BindFlags = D3D11_BIND_SHADER_RESOURCE;

    if (FAILED(g_pd3dDevice->CreateTexture3D(&desc, NULL,
                                             &g_texture_3d.pTexture))) {
      return E_FAIL;
    }

    if (FAILED(g_pd3dDevice->CreateShaderResourceView(
            g_texture_3d.pTexture, NULL, &g_texture_3d.pSRView))) {
      return E_FAIL;
    }

#ifdef USEEFFECT
    g_pTexture3D->SetResource(g_texture_3d.pSRView);
#else
    g_texture_3d.offsetInShader =
        1;  // to be clean we should look for the offset from the shader code
    g_pd3dDeviceContext->PSSetShaderResources(g_texture_3d.offsetInShader, 1,
                                              &g_texture_3d.pSRView);
#endif
  }

  // cube texture
  {
    g_texture_cube.size = 64;

    D3D11_TEXTURE2D_DESC desc;
    ZeroMemory(&desc, sizeof(D3D11_TEXTURE2D_DESC));
    desc.Width = g_texture_cube.size;
    desc.Height = g_texture_cube.size;
    desc.MipLevels = 1;
    desc.ArraySize = 6;
    desc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
    desc.SampleDesc.Count = 1;
    desc.Usage = D3D11_USAGE_DEFAULT;
    desc.BindFlags = D3D11_BIND_SHADER_RESOURCE;
    desc.MiscFlags = D3D11_RESOURCE_MISC_TEXTURECUBE;

    if (FAILED(g_pd3dDevice->CreateTexture2D(&desc, NULL,
                                             &g_texture_cube.pTexture))) {
      return E_FAIL;
    }

    D3D11_SHADER_RESOURCE_VIEW_DESC SRVDesc;
    ZeroMemory(&SRVDesc, sizeof(SRVDesc));
    SRVDesc.Format = desc.Format;
    SRVDesc.ViewDimension = D3D11_SRV_DIMENSION_TEXTURECUBE;
    SRVDesc.TextureCube.MipLevels = desc.MipLevels;
    SRVDesc.TextureCube.MostDetailedMip = 0;

    if (FAILED(g_pd3dDevice->CreateShaderResourceView(
            g_texture_cube.pTexture, &SRVDesc, &g_texture_cube.pSRView))) {
      return E_FAIL;
    }

#ifdef USEEFFECT
    g_pTextureCube->SetResource(g_texture_cube.pSRView);
#else
    g_texture_cube.offsetInShader =
        2;  // to be clean we should look for the offset from the shader code
    g_pd3dDeviceContext->PSSetShaderResources(g_texture_cube.offsetInShader, 1,
                                              &g_texture_cube.pSRView);
#endif
  }

  return S_OK;
}

////////////////////////////////////////////////////////////////////////////////
//! Run the Cuda part of the computation
////////////////////////////////////////////////////////////////////////////////
void RunKernels() {
  static float t = 0.0f;

  // populate the 2d texture
  {
    cudaArray *cuArray;
    cudaGraphicsSubResourceGetMappedArray(&cuArray, g_texture_2d.cudaResource,
                                          0, 0);
    getLastCudaError(
        "cudaGraphicsSubResourceGetMappedArray (cuda_texture_2d) failed");

    // kick off the kernel and send the staging buffer cudaLinearMemory as an
    // argument to allow the kernel to write to it
    cuda_texture_2d(g_texture_2d.cudaLinearMemory, g_texture_2d.width,
                    g_texture_2d.height, g_texture_2d.pitch, t);
    getLastCudaError("cuda_texture_2d failed");

    // then we want to copy cudaLinearMemory to the D3D texture, via its mapped
    // form : cudaArray
    cudaMemcpy2DToArray(
        cuArray,                                            // dst array
        0, 0,                                               // offset
        g_texture_2d.cudaLinearMemory, g_texture_2d.pitch,  // src
        g_texture_2d.width * 4 * sizeof(float), g_texture_2d.height,  // extent
        cudaMemcpyDeviceToDevice);                                    // kind
    getLastCudaError("cudaMemcpy2DToArray failed");
  }
  // populate the volume texture
  {
    size_t pitchSlice = g_texture_3d.pitch * g_texture_3d.height;
    cudaArray *cuArray;
    cudaGraphicsSubResourceGetMappedArray(&cuArray, g_texture_3d.cudaResource,
                                          0, 0);
    getLastCudaError(
        "cudaGraphicsSubResourceGetMappedArray (cuda_texture_3d) failed");

    // kick off the kernel and send the staging buffer cudaLinearMemory as an
    // argument to allow the kernel to write to it
    cuda_texture_3d(g_texture_3d.cudaLinearMemory, g_texture_3d.width,
                    g_texture_3d.height, g_texture_3d.depth, g_texture_3d.pitch,
                    pitchSlice, t);
    getLastCudaError("cuda_texture_3d failed");

    // then we want to copy cudaLinearMemory to the D3D texture, via its mapped
    // form : cudaArray
    struct cudaMemcpy3DParms memcpyParams = {0};
    memcpyParams.dstArray = cuArray;
    memcpyParams.srcPtr.ptr = g_texture_3d.cudaLinearMemory;
    memcpyParams.srcPtr.pitch = g_texture_3d.pitch;
    memcpyParams.srcPtr.xsize = g_texture_3d.width;
    memcpyParams.srcPtr.ysize = g_texture_3d.height;
    memcpyParams.extent.width = g_texture_3d.width;
    memcpyParams.extent.height = g_texture_3d.height;
    memcpyParams.extent.depth = g_texture_3d.depth;
    memcpyParams.kind = cudaMemcpyDeviceToDevice;
    cudaMemcpy3D(&memcpyParams);
    getLastCudaError("cudaMemcpy3D failed");
  }

  // populate the faces of the cube map
  for (int face = 0; face < 6; ++face) {
    cudaArray *cuArray;
    cudaGraphicsSubResourceGetMappedArray(&cuArray, g_texture_cube.cudaResource,
                                          face, 0);
    getLastCudaError(
        "cudaGraphicsSubResourceGetMappedArray (cuda_texture_cube) failed");

    // kick off the kernel and send the staging buffer cudaLinearMemory as an
    // argument to allow the kernel to write to it
    cuda_texture_cube(g_texture_cube.cudaLinearMemory, g_texture_cube.size,
                      g_texture_cube.size, g_texture_cube.pitch, face, t);
    getLastCudaError("cuda_texture_cube failed");

    // then we want to copy cudaLinearMemory to the D3D texture, via its mapped
    // form : cudaArray
    cudaMemcpy2DToArray(cuArray,  // dst array
                        0, 0,     // offset
                        g_texture_cube.cudaLinearMemory,
                        g_texture_cube.pitch,                          // src
                        g_texture_cube.size * 4, g_texture_cube.size,  // extent
                        cudaMemcpyDeviceToDevice);                     // kind
    getLastCudaError("cudaMemcpy2DToArray failed");
  }

  t += 0.1f;
}

////////////////////////////////////////////////////////////////////////////////
//! Draw the final result on the screen
////////////////////////////////////////////////////////////////////////////////
bool DrawScene() {
  // Clear the backbuffer to a black color
  float ClearColor[4] = {0.5f, 0.5f, 0.6f, 1.0f};
  g_pd3dDeviceContext->ClearRenderTargetView(g_pSwapChainRTV, ClearColor);

  float quadRect[4] = {-0.9f, -0.9f, 0.7f, 0.7f};
//
// draw the 2d texture
//
#ifdef USEEFFECT
  g_pUseCase->SetInt(0);
  g_pvQuadRect->SetFloatVector((float *)&quadRect);
  g_pSimpleTechnique->GetPassByIndex(0)->Apply(0, g_pd3dDeviceContext);
#else
  HRESULT hr;
  D3D11_MAPPED_SUBRESOURCE mappedResource;
  ConstantBuffer *pcb;
  hr = g_pd3dDeviceContext->Map(g_pConstantBuffer, 0, D3D11_MAP_WRITE_DISCARD,
                                0, &mappedResource);
  AssertOrQuit(SUCCEEDED(hr));
  pcb = (ConstantBuffer *)mappedResource.pData;
  {
    memcpy(pcb->vQuadRect, quadRect, sizeof(float) * 4);
    pcb->UseCase = 0;
  }
  g_pd3dDeviceContext->Unmap(g_pConstantBuffer, 0);
#endif
  g_pd3dDeviceContext->Draw(4, 0);

  //
  // draw a slice the 3d texture
  //
  quadRect[1] = 0.1f;
#ifdef USEEFFECT
  g_pUseCase->SetInt(1);
  g_pvQuadRect->SetFloatVector((float *)&quadRect);
  g_pSimpleTechnique->GetPassByIndex(0)->Apply(0, g_pd3dDeviceContext);
#else
  hr = g_pd3dDeviceContext->Map(g_pConstantBuffer, 0, D3D11_MAP_WRITE_DISCARD,
                                0, &mappedResource);
  AssertOrQuit(SUCCEEDED(hr));
  pcb = (ConstantBuffer *)mappedResource.pData;
  {
    memcpy(pcb->vQuadRect, quadRect, sizeof(float) * 4);
    pcb->UseCase = 1;
  }
  g_pd3dDeviceContext->Unmap(g_pConstantBuffer, 0);
#endif
  g_pd3dDeviceContext->Draw(4, 0);

  //
  // draw the 6 faces of the cube texture
  //
  float faceRect[4] = {-0.1f, -0.9f, 0.5f, 0.5f};

  for (int f = 0; f < 6; f++) {
    if (f == 3) {
      faceRect[0] += 0.55f;
      faceRect[1] = -0.9f;
    }

#ifdef USEEFFECT
    g_pUseCase->SetInt(2 + f);
    g_pvQuadRect->SetFloatVector((float *)&faceRect);
    g_pSimpleTechnique->GetPassByIndex(0)->Apply(0, g_pd3dDeviceContext);
#else
    hr = g_pd3dDeviceContext->Map(g_pConstantBuffer, 0, D3D11_MAP_WRITE_DISCARD,
                                  0, &mappedResource);
    AssertOrQuit(SUCCEEDED(hr));
    pcb = (ConstantBuffer *)mappedResource.pData;
    {
      memcpy(pcb->vQuadRect, faceRect, sizeof(float) * 4);
      pcb->UseCase = 2 + f;
    }
    g_pd3dDeviceContext->Unmap(g_pConstantBuffer, 0);
#endif
    g_pd3dDeviceContext->Draw(4, 0);
    faceRect[1] += 0.6f;
  }

  // Present the backbuffer contents to the display
  g_pSwapChain->Present(0, 0);
  return true;
}

//-----------------------------------------------------------------------------
// Name: Cleanup()
// Desc: Releases all previously initialized objects
//-----------------------------------------------------------------------------
void Cleanup() {
  // unregister the Cuda resources
  cudaGraphicsUnregisterResource(g_texture_2d.cudaResource);
  getLastCudaError("cudaGraphicsUnregisterResource (g_texture_2d) failed");
  cudaFree(g_texture_2d.cudaLinearMemory);
  getLastCudaError("cudaFree (g_texture_2d) failed");

  cudaGraphicsUnregisterResource(g_texture_cube.cudaResource);
  getLastCudaError("cudaGraphicsUnregisterResource (g_texture_cube) failed");
  cudaFree(g_texture_cube.cudaLinearMemory);
  getLastCudaError("cudaFree (g_texture_2d) failed");

  cudaGraphicsUnregisterResource(g_texture_3d.cudaResource);
  getLastCudaError("cudaGraphicsUnregisterResource (g_texture_3d) failed");
  cudaFree(g_texture_3d.cudaLinearMemory);
  getLastCudaError("cudaFree (g_texture_2d) failed");

  //
  // clean up Direct3D
  //
  {
    // release the resources we created
    g_texture_2d.pSRView->Release();
    g_texture_2d.pTexture->Release();
    g_texture_cube.pSRView->Release();
    g_texture_cube.pTexture->Release();
    g_texture_3d.pSRView->Release();
    g_texture_3d.pTexture->Release();

    if (g_pInputLayout != NULL) {
      g_pInputLayout->Release();
    }

#ifdef USEEFFECT

    if (g_pSimpleEffect != NULL) {
      g_pSimpleEffect->Release();
    }

#else

    if (g_pVertexShader) {
      g_pVertexShader->Release();
    }

    if (g_pPixelShader) {
      g_pPixelShader->Release();
    }

    if (g_pConstantBuffer) {
      g_pConstantBuffer->Release();
    }

    if (g_pSamplerState) {
      g_pSamplerState->Release();
    }

#endif

    if (g_pSwapChainRTV != NULL) {
      g_pSwapChainRTV->Release();
    }

    if (g_pSwapChain != NULL) {
      g_pSwapChain->Release();
    }

    if (g_pd3dDevice != NULL) {
      g_pd3dDevice->Release();
    }
  }
}

//-----------------------------------------------------------------------------
// Name: Render()
// Desc: Launches the CUDA kernels to fill in the texture data
//-----------------------------------------------------------------------------
void Render() {
  //
  // map the resources we've registered so we can access them in Cuda
  // - it is most efficient to map and unmap all resources in a single call,
  //   and to have the map/unmap calls be the boundary between using the GPU
  //   for Direct3D and Cuda
  //
  static bool doit = true;

  if (doit) {
    doit = true;
    cudaStream_t stream = 0;
    const int nbResources = 3;
    cudaGraphicsResource *ppResources[nbResources] = {
        g_texture_2d.cudaResource, g_texture_3d.cudaResource,
        g_texture_cube.cudaResource,
    };
    cudaGraphicsMapResources(nbResources, ppResources, stream);
    getLastCudaError("cudaGraphicsMapResources(3) failed");

    //
    // run kernels which will populate the contents of those textures
    //
    RunKernels();

    //
    // unmap the resources
    //
    cudaGraphicsUnmapResources(nbResources, ppResources, stream);
    getLastCudaError("cudaGraphicsUnmapResources(3) failed");
  }

  //
  // draw the scene using them
  //
  DrawScene();
}

//-----------------------------------------------------------------------------
// Name: MsgProc()
// Desc: The window's message handler
//-----------------------------------------------------------------------------
static LRESULT WINAPI MsgProc(HWND hWnd, UINT msg, WPARAM wParam,
                              LPARAM lParam) {
  switch (msg) {
    case WM_KEYDOWN:
      if (wParam == VK_ESCAPE) {
        g_bDone = true;
        Cleanup();
        PostQuitMessage(0);
        return 0;
      }

      break;

    case WM_DESTROY:
      g_bDone = true;
      Cleanup();
      PostQuitMessage(0);
      return 0;

    case WM_PAINT:
      ValidateRect(hWnd, NULL);
      return 0;
  }

  return DefWindowProc(hWnd, msg, wParam, lParam);
}
