#include <windows.h>
#include <winnls32.h>
#include <mmsystem.h>
#include <ddraw.h>

#define FLIP_BLANK (1000/60)
#define SCREEN_WIDTH 640
#define SCREEN_HEIGHT 480
#define COLOR_KEY 2

int screen_width, screen_height;

char key_map[256];
DWORD wait_time;

HWND g_hWnd = NULL;
LPDIRECTDRAW lpDD = NULL;
LPDIRECTDRAWSURFACE lpFront = NULL;
LPDIRECTDRAWSURFACE lpBack = NULL;
LPDIRECTDRAWSURFACE lpWork = NULL;
PALETTEENTRY peEntry[256];
LPDIRECTDRAWPALETTE lpPalette = NULL;

/*
*   DirectDraw
*/
int initDD(HWND hWnd, int w, int h, int ck){
  DDSURFACEDESC ddsd;
  DDSCAPS ddscaps;
  DDCOLORKEY ddck = {ck, ck};

  screen_width = w;
  screen_height = h;
   
  if(DirectDrawCreate(NULL, &lpDD, NULL) != DD_OK){
    return 0;
  }

  if(lpDD->SetCooperativeLevel(hWnd, DDSCL_FULLSCREEN | DDSCL_EXCLUSIVE) != DD_OK){
    return 0;
  }

  if(lpDD->SetDisplayMode(w, h, 8) != DD_OK){
    return 0;
  }

  ZeroMemory(&ddsd, sizeof(ddsd));
  ddsd.dwSize = sizeof(ddsd);
  ddsd.dwFlags = DDSD_CAPS | DDSD_BACKBUFFERCOUNT;
  ddsd.ddsCaps.dwCaps = DDSCAPS_PRIMARYSURFACE | DDSCAPS_FLIP | DDSCAPS_COMPLEX;
  ddsd.dwBackBufferCount = 1;
  if(lpDD->CreateSurface(&ddsd, &lpFront, NULL) != DD_OK){
    return 0;
  }

  ddscaps.dwCaps = DDSCAPS_BACKBUFFER;   
  if(lpFront->GetAttachedSurface(&ddscaps, &lpBack) != DD_OK){
    return 0;
  }

  ZeroMemory(&ddsd, sizeof(ddsd));
  ddsd.dwSize = sizeof(ddsd);
  ddsd.dwFlags = DDSD_CAPS | DDSD_WIDTH | DDSD_HEIGHT;
  ddsd.ddsCaps.dwCaps = DDSCAPS_OFFSCREENPLAIN; // | DDSCAPS_SYSTEMMEMORY;
  ddsd.dwWidth = w;
  ddsd.dwHeight = h;
  if((lpDD->CreateSurface(&ddsd, &lpWork, NULL)) != DD_OK){
    return 0;
  }

  if(lpDD->CreatePalette(DDPCAPS_8BIT, peEntry, &lpPalette, NULL) != DD_OK){
    return 0;
  }
  lpFront->SetPalette(lpPalette);

  lpWork->SetColorKey(DDCKEY_SRCBLT, &ddck);

  peEntry[1].peRed = 255;
  peEntry[1].peGreen = 0;
  peEntry[1].peBlue = 0;
  peEntry[1].peFlags = 1;

  lpPalette->SetEntries(0, 1, 1, &peEntry[1]);

  return 1;
}

#define RELEASE(i) if(i){i->Release();i=NULL;}
void deinitDD(void){
  RELEASE(lpPalette);
  RELEASE(lpFront);
  lpBack = NULL;
  RELEASE(lpWork);
  RELEASE(lpDD);
}

void fillBackSurface(unsigned char c){
  DDBLTFX ddbltfx;
  ZeroMemory(&ddbltfx, sizeof(DDBLTFX));
  ddbltfx.dwSize=sizeof(DDBLTFX);
  ddbltfx.dwFillColor = c;
  lpBack->Blt(NULL, NULL, NULL, DDBLT_COLORFILL | DDBLT_WAIT, &ddbltfx);
}

void drawPoint(LPDIRECTDRAWSURFACE lpsf, int x, int y, int c){
  unsigned char *p;
  DDSURFACEDESC desc;

  ZeroMemory(&desc, sizeof(DDSURFACEDESC));
  desc.dwSize = sizeof(DDSURFACEDESC);
  lpsf->Lock(NULL, &desc, DDLOCK_WAIT | DDLOCK_SURFACEMEMORYPTR, NULL);
  p = (unsigned char *)desc.lpSurface;

  p[x + y * desc.lPitch] = c;

  lpsf->Unlock(desc.lpSurface);
}

HRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam){
  switch(message){
  case WM_KEYDOWN:
    if(wParam == VK_ESCAPE){
      PostMessage(hWnd, WM_CLOSE, 0, 0);
      return 0;
    }
    key_map[wParam] = 1;
    return 0;
  case WM_KEYUP:
    key_map[wParam] = 0;
    return 0;
  case WM_DESTROY:
    PostQuitMessage(0);
    return 0;
  }

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

int APIENTRY WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, LPSTR, int nCmdShow){
  MSG msg;
  WNDCLASS wc;
  int cx = 0;
  int cy = 0;
  DWORD color_key[2] = {DDBLTFAST_NOCOLORKEY, DDBLTFAST_SRCCOLORKEY};

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

  HWND hWnd = CreateWindow(
    "DirectDraw", "DirectDraw Test", WS_POPUPWINDOW,
    CW_USEDEFAULT, CW_USEDEFAULT, SCREEN_WIDTH, SCREEN_HEIGHT,
    NULL, NULL, hInst, NULL);
  
  if(hWnd == NULL){
    return 0;
  }

  g_hWnd = hWnd;

  ShowWindow(hWnd, nCmdShow);
  UpdateWindow(hWnd);

  if(!(initDD(hWnd, SCREEN_WIDTH, SCREEN_HEIGHT, COLOR_KEY))){
    return 0;
  }

  RECT rect = {0, 0, 64, 64};

  for(int i = 0; i < 64 * 64; i++){
    int x = i % 64;
    int y = i / 64;

    // ロックとアンロックを繰り返すので本当は良くない
    if(x < 4 || x >= 60 || y < 4 || y >= 60){
      drawPoint(lpWork, x, y, 1);
    }
    else{
      drawPoint(lpWork, x, y, COLOR_KEY);
    }
  }

  // カーソル非表示
  ShowCursor(FALSE);

  // IMEバーを非表示
  WINNLSEnableIME(NULL, FALSE);

  while(1){
    wait_time = timeGetTime();
    fillBackSurface(255);

    if(key_map[VK_UP]){
      cy -= 3;
    }
    else if(key_map[VK_DOWN]){
      cy += 1;
    }

    if(key_map[VK_LEFT]){
      cx -= 4;
    }
    else if(key_map[VK_RIGHT]){
      cx += 2;
    }

    if(cx < 0)cx = 0;
    if(cy < 0)cy = 0;

    lpBack->BltFast(cx, cy, lpWork, &rect, color_key[1] | DDBLTFAST_WAIT);

    lpFront->Flip(NULL, DDFLIP_WAIT);

    do{
      while(PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)){
        if(msg.message == WM_QUIT){
          goto fin;
        }
        TranslateMessage(&msg);
        DispatchMessage(&msg);
      }
    }while(timeGetTime() < wait_time + FLIP_BLANK);
  }
  
fin:

  deinitDD();

  ShowCursor(TRUE);

  return msg.wParam;
}