#include <windows.h>
#include <d3d9.h>
#include <d3dx9.h>

#define RELEASE(x) if(x){x->Release();x=NULL;}

#define SCREEN_FPS 60
#define SCREEN_WIDTH 640
#define SCREEN_HEIGHT 480

HINSTANCE g_Inst;
HWND g_hWnd;
LPCSTR szAppName = "Direct3D";

LRESULT CALLBACK WndProc(HWND hWnd,UINT msg,UINT wParam,LONG lParam);

static int bActive = 0;
static int bFullScreen = 0;

D3DPRESENT_PARAMETERS d3dpp;
D3DFORMAT dspfmt;
LPDIRECT3D9 pD3D = NULL;
LPDIRECT3DDEVICE9 pDevice = NULL;
LPDIRECT3DTEXTURE9 pTexture = NULL;

// 頂点情報の構造体
typedef struct _D3DLVERTEX_{
  float x, y, z;
  float nx, ny, nz;
  D3DCOLOR c;
  float tu0, tv0;
}LVERTEX;

// 最奥いっぱいに描かれる赤い四角
LVERTEX ver1[4] ={
  {-2.0f,  1.5f, 0.5f, 0.0f,  0.0f, -1.0f, 0xFFFF0000, 0.0f, 0.0f},
  {-2.0f, -1.5f, 0.5f, 0.0f,  0.0f, -1.0f, 0xFFFF0000, 0.0f, 1.0f},
  { 2.0f, -1.5f, 0.5f, 0.0f,  0.0f, -1.0f, 0xFFFF0000, 1.0f, 1.0f},
  { 2.0f,  1.5f, 0.5f, 0.0f,  0.0f, -1.0f, 0xFFFF0000, 1.0f, 0.0f}
};

// 手前に描かれる緑のテクスチャを貼った四角
LVERTEX ver2[4] ={
  {-0.3f,  0.3f, 0.0f, 0.0f,  0.0f, -1.0f, 0xFFFFFFFF, 0.0f, 0.0f},
  {-0.3f, -0.3f, 0.0f, 0.0f,  0.0f, -1.0f, 0xFFFFFFFF, 0.0f, 1.0f},
  {0.3f, -0.3f, 0.0f, 0.0f,  0.0f, -1.0f, 0xFFFFFFFF, 1.0f, 1.0f},
  {0.3f,  0.3f, 0.0f, 0.0f,  0.0f, -1.0f, 0xFFFFFFFF, 1.0f, 0.0f}
};

// テクスチャの初期設定
int initTexture(void){
  int i, t;
  D3DLOCKED_RECT pLockedRect;

  if(FAILED(D3DXCreateTexture(pDevice, 2, 2, 1, 0, D3DFMT_A8R8G8B8, D3DPOOL_MANAGED, &pTexture))){ // or D3DPOOL_SYSTEMMEM 
    return 0;
  }

  pTexture->LockRect(0, &pLockedRect, NULL, 0);

  for(t = 0; t < 2; t++){
    for(i = 0; i < 2; i++){
      unsigned char *p = (unsigned char *)pLockedRect.pBits + pLockedRect.Pitch * t + i * 4;

      p[0] = (unsigned char)0;   // b
      p[1] = (unsigned char)255; // g
      p[2] = (unsigned char)0;   // r
      p[3] = (unsigned char)255; // a
    }
  }

  pTexture->UnlockRect(0);

  return 1;
}

// Direct3D の初期化
int initD3D(void){
  D3DDISPLAYMODE dsp;

  pD3D = Direct3DCreate9(D3D_SDK_VERSION);

  if(pD3D == NULL){
    return 0;
  }

  // 現在のディスプレイモードを得る
  if(FAILED(pD3D->GetAdapterDisplayMode(D3DADAPTER_DEFAULT, &dsp))){
    return 0;
  }

  dspfmt = dsp.Format;

  ZeroMemory(&d3dpp, sizeof(d3dpp));

  d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;   //垂直同期でフリップ

  // フルスクリーン or ウィンドウ
  if(bFullScreen == 1){
    d3dpp.BackBufferFormat = D3DFMT_R5G6B5;
    d3dpp.Windowed = 0;
  }
  else{
    d3dpp.BackBufferFormat = dsp.Format;
    d3dpp.Windowed = 1;
  }

  d3dpp.BackBufferCount = 1;
  d3dpp.BackBufferWidth = SCREEN_WIDTH;
  d3dpp.BackBufferHeight = SCREEN_HEIGHT;
  d3dpp.EnableAutoDepthStencil = TRUE;
  d3dpp.AutoDepthStencilFormat = D3DFMT_D16;
  
  // Ｔ＆Ｌ ＨＡＬ
  if(FAILED(pD3D->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, g_hWnd, D3DCREATE_HARDWARE_VERTEXPROCESSING, &d3dpp, &pDevice))){
    // ＨＡＬ
    if(FAILED(pD3D->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL,g_hWnd, D3DCREATE_SOFTWARE_VERTEXPROCESSING, &d3dpp, &pDevice))){
      // ＨＥＬ
      if(FAILED(pD3D->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_REF, g_hWnd,D3DCREATE_SOFTWARE_VERTEXPROCESSING, &d3dpp, &pDevice))){
        return 0;
      }
    }
  }

  if(initTexture() == 0){
    return 0;
  }

  return 1;
}

// Direct3D の後片付け
void deinitD3d(void){
  RELEASE(pTexture);
  RELEASE(pDevice);
  RELEASE(pD3D);
}

// 視野の初期設定
int initView(void){
  float fAspect;
  D3DVIEWPORT9 vp;
  D3DXMATRIX mat;

  pDevice->GetViewport(&vp);
  fAspect = (float)vp.Width / (float)vp.Height;

  // Ｚ方向(視点 -1.0 手前 -0.5 中心 0.0 奥 0.5) Ｙ方向の視野角 90度
  D3DXMatrixPerspectiveFovLH(&mat, D3DXToRadian(90.0f), fAspect, 0.5f, 1.5f);
  pDevice->SetTransform(D3DTS_PROJECTION, &mat);
  D3DXMatrixLookAtLH(&mat, &D3DXVECTOR3(0.0f, 0.0f, -1.0f), &D3DXVECTOR3(0, 0, 0), &D3DXVECTOR3(0, 1, 0));
  pDevice->SetTransform(D3DTS_VIEW, &mat);

  return 1;
}

// 光源の初期設定
int initLighting(void){
  D3DMATERIAL9 mtrl;

  ZeroMemory(&mtrl, sizeof(D3DMATERIAL9));
  mtrl.Diffuse.r = 1.0f;
  mtrl.Diffuse.g = 1.0f;
  mtrl.Diffuse.b = 1.0f;
  mtrl.Diffuse.a = 1.0f;
  mtrl.Ambient.r = 1.0f;
  mtrl.Ambient.g = 1.0f;
  mtrl.Ambient.b = 1.0f;
  mtrl.Ambient.a = 1.0f;
  pDevice->SetMaterial(&mtrl);

  D3DLIGHT9 light;
 
  ZeroMemory(&light, sizeof(D3DLIGHT9));
  light.Type = D3DLIGHT_DIRECTIONAL;
  light.Diffuse.r = 1.0f;
  light.Diffuse.g = 1.0f;
  light.Diffuse.b = 1.0f;
  D3DXVECTOR3 vecDir(0.0f, 0.0f, 1.0f);
  D3DXVec3Normalize(static_cast<D3DXVECTOR3*>(&light.Direction), &vecDir);
  light.Range = 1000.0f;

  pDevice->SetLight( 0, &light );
  pDevice->LightEnable( 0, TRUE );

  pDevice->SetRenderState(D3DRS_AMBIENT, 0x00000000);
  pDevice->SetRenderState(D3DRS_LIGHTING, TRUE);

  return 1;
}

// レンダリングに関する初期設定
int initRender(void){
  // 視野の初期設定
  initView();
  // 光源の初期設定
  initLighting();
  // カリングの設定
  pDevice->SetRenderState(D3DRS_CULLMODE, D3DCULL_CW);  // NONE or CW or CCW
  // Z バッファの設定
  pDevice->SetRenderState(D3DRS_ZENABLE, TRUE);
  pDevice->SetRenderState(D3DRS_ZWRITEENABLE, TRUE);
  pDevice->SetRenderState(D3DRS_ZFUNC, D3DCMP_LESSEQUAL );
  // テクスチャの設定
  pDevice->SetSamplerState(0, D3DSAMP_MAGFILTER, D3DTEXF_NONE);
  pDevice->SetSamplerState(0, D3DSAMP_MIPFILTER, D3DTEXF_NONE);
  // αブレンドの設定
  pDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, TRUE);
  pDevice->SetRenderState(D3DRS_SRCBLEND, D3DBLEND_SRCALPHA);
  pDevice->SetRenderState(D3DRS_DESTBLEND, D3DBLEND_INVSRCALPHA);

  return 1;
}

// 描画本体
int drawIdle(void){

  // 画面を白で塗りつぶし、Ｚバッファをクリア
  pDevice->Clear(0, NULL, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER , D3DCOLOR_XRGB(255,255,255), 1.0, 0);

  //頂点フォーマットの設定
  pDevice->SetFVF(D3DFVF_XYZ | D3DFVF_NORMAL | D3DFVF_DIFFUSE | D3DFVF_TEX1);  

  if(SUCCEEDED(pDevice->BeginScene())){
    D3DXMATRIX mat;
    D3DXMatrixIdentity(&mat);
    //D3DXMatrixTranslation(&mat, 1.0f, 0.0f, 0.0f);
    //D3DXMatrixRotationX(&mat, D3DXToRadian(45.0f));
    //D3DXMatrixRotationY(&mat, D3DXToRadian(45.0f));
    //D3DXMatrixRotationZ(&mat, D3DXToRadian(45.0f));
    //D3DXMatrixScaling(&mat, 1.5f, 1.5f, 1.0f);
    pDevice->SetTransform(D3DTS_WORLD, &mat);
    pDevice->DrawPrimitiveUP(D3DPT_TRIANGLEFAN, 2, ver1, sizeof(LVERTEX));
    pDevice->SetTexture(0, pTexture);
    pDevice->DrawPrimitiveUP(D3DPT_TRIANGLEFAN, 2, ver2, sizeof(LVERTEX));
    pDevice->SetTexture(0, NULL);

    pDevice->EndScene();

    if(FAILED(pDevice->Present(NULL, NULL, NULL, NULL))){
      if(FAILED(pDevice->Reset(&d3dpp))){
        return 0;
      }
    }
  }

  return 1;
}

// ウィンドウプロシージャ
LRESULT CALLBACK WndProc(HWND hWnd, UINT msg, UINT wParam, LONG lParam){
  switch(msg){
  case WM_ACTIVATE:
    bActive = HIWORD(wParam)?0:1;
    break;
  case WM_KEYDOWN:
    switch(wParam){
    case VK_F3:  // F3 キーでウィンドウとフルスクリーンを入れ替え
      bFullScreen = !bFullScreen;
      if(bFullScreen == 1){
        d3dpp.BackBufferFormat = D3DFMT_R5G6B5;
        d3dpp.Windowed = 0;
      }else{
        d3dpp.BackBufferFormat = dspfmt;
        d3dpp.Windowed = 1;
      }
      if(FAILED(pDevice->Reset(&d3dpp))){
        PostMessage(hWnd, WM_CLOSE, 0, 0);
        return 0L;
      }
      initRender();
      if(bFullScreen != 1){
      DrawMenuBar(g_hWnd);
    }
      break;
    case VK_ESCAPE:
      PostMessage(hWnd, WM_CLOSE, 0, 0);
      break;
    default:
      break;
    }
    break;
  case WM_DESTROY:
    PostQuitMessage(0);
    break;
    case WM_IME_NOTIFY:
    // ＩＭＥのツールバーを非表示に
    break;
  default:
    return DefWindowProc(hWnd, msg, wParam, lParam);
  }
  return 0L;
}

// メイン
int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, LPSTR lpCmdLine, int nCmdShow){
  int result;
  int cx, cy;
  WNDCLASS wc;
  MSG msg;
  DWORD waittime;

  // 256色以下のモードで起動不可
  HDC dc = GetDC(0);
  int iBit = GetDeviceCaps(dc, BITSPIXEL);
  ReleaseDC(0, dc);
  if(iBit < 15){
    MessageBox(0, "256色以下では実行できません", szAppName, MB_ICONSTOP|MB_OK);
    return 0;
  }

  g_Inst=hInst;

  if(!hPrevInst){
    wc.lpszClassName = "Direct3D";
    wc.lpfnWndProc = WndProc;
    wc.style = CS_HREDRAW | CS_VREDRAW;
    wc.hInstance = hInst;
    wc.hIcon = NULL;
    wc.hCursor = LoadCursor(NULL,IDC_ARROW);
    wc.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
    wc.lpszMenuName = NULL;
    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    if(!RegisterClass(&wc)){
      return 0;
    }
  }

  cx = SCREEN_WIDTH + GetSystemMetrics(SM_CXDLGFRAME) * 2;
  cy = SCREEN_HEIGHT + GetSystemMetrics(SM_CYDLGFRAME) * 2 + GetSystemMetrics(SM_CYCAPTION);

  g_hWnd = CreateWindowEx(0, szAppName, szAppName,
             WS_OVERLAPPED | WS_SYSMENU | WS_MINIMIZEBOX,
             CW_USEDEFAULT, CW_USEDEFAULT, cx, cy,
             (HWND)NULL, (HMENU)NULL,
             hInst, (LPSTR)NULL);

  ShowWindow(g_hWnd, nCmdShow);
  UpdateWindow(g_hWnd);

  result = initD3D();

  if(result == 0){
    goto fin;
  }

  result = initRender();

  if(result == 0){
    goto fin;
  }

  msg.wParam = 0;

  while(1){
    waittime = GetTickCount();
    if(bActive){
      if(!drawIdle()){
        goto fin;
      }
    }
    else{
      WaitMessage();
    }
    do{
      while(PeekMessage(&msg, NULL, 0, 0, PM_NOREMOVE)){
        if(!GetMessage(&msg, NULL, 0, 0)){
          goto fin;
        }
        TranslateMessage(&msg);
        DispatchMessage(&msg);
      }
    }while(GetTickCount() < waittime + SCREEN_FPS);
  }

fin:

  deinitD3d();

  return msg.wParam;
}