помогите с программой

 BUFFER(x,y) = ' ';

#include <windows.h>
#include <stdlib.h>
#define BUFFER(x,y) *(pBuffer + y * cxBuffer + x)
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow)
{
static TCHAR szAppName[] = L"Typer";
HWND hwnd;
MSG msg;
WNDCLASSEX wndclass;
wndclass.cbSize = sizeof(wndclass);
wndclass.style = CS_HREDRAW | CS_VREDRAW;
wndclass.lpfnWndProc = WndProc;
wndclass.cbClsExtra = 0;
wndclass.cbWndExtra = 0;
wndclass.hInstance = hInstance;
wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
wndclass.hbrBackground =(HBRUSH) GetStockObject(WHITE_BRUSH);
wndclass.lpszMenuName = NULL;
wndclass.lpszClassName = szAppName;
wndclass.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
RegisterClassEx(&wndclass);
hwnd = CreateWindow(szAppName,L"Typing Program",
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, CW_USEDEFAULT,
CW_USEDEFAULT, CW_USEDEFAULT,
NULL, NULL, hInstance, NULL);
ShowWindow(hwnd, iCmdShow);
UpdateWindow(hwnd);
while(GetMessage(&msg, NULL, 0, 0))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return msg.wParam;
}
LRESULT CALLBACK WndProc(HWND hwnd, UINT iMsg, WPARAM wParam, LPARAM lParam)
{
static TCHAR *pBuffer = NULL;
static int cxChar, cyChar, cxClient, cyClient, cxBuffer, cyBuffer,
xCaret, yCaret;
HDC hdc;
int x, y, i;
PAINTSTRUCT ps;
TEXTMETRIC tm;
switch(iMsg)
{
case WM_CREATE :
hdc = GetDC(hwnd);
SelectObject(hdc, GetStockObject(SYSTEM_FIXED_FONT));
GetTextMetrics(hdc, &tm);
cxChar = tm.tmAveCharWidth;
cyChar = tm.tmHeight;
ReleaseDC(hwnd, hdc);
return 0;
case WM_SIZE :
// obtain window size in pixels
cxClient = LOWORD(lParam);
cyClient = HIWORD(lParam);
// calculate window size in characters
cxBuffer = max(1, cxClient / cxChar);
cyBuffer = max(1, cyClient / cyChar);
// allocate memory for buffer and clear it
if(pBuffer != NULL)
free(pBuffer);
if((pBuffer =(TCHAR *) malloc(cxBuffer * cyBuffer)) == NULL)
MessageBox(hwnd, L"Window too large.Cannot allocate enough memory.", L"Typer",
MB_ICONEXCLAMATION | MB_OK);
else
for(y = 0; y < cyBuffer; y++)
for(x = 0; x < cxBuffer; x++)
BUFFER(x,y) = ' ';
// set caret to upper left corner
xCaret = 0;
yCaret = 0;
if(hwnd == GetFocus())
SetCaretPos(xCaret * cxChar, yCaret * cyChar);
return 0;
case WM_SETFOCUS :
// create and show the caret
CreateCaret(hwnd, NULL, cxChar, cyChar);
SetCaretPos(xCaret * cxChar, yCaret * cyChar);
ShowCaret(hwnd);
return 0;
case WM_KILLFOCUS :
// hide and destroy the caret
HideCaret(hwnd);
DestroyCaret();
return 0;
case WM_KEYDOWN :
switch(wParam)
{
case VK_HOME :
xCaret = 0;
break;
case VK_END :
xCaret = cxBuffer - 1;
break;
case VK_PRIOR :
yCaret = 0;
break;
case VK_NEXT :
yCaret = cyBuffer - 1;
break;
case VK_LEFT :
xCaret = max(xCaret - 1, 0);
break;
case VK_RIGHT :
xCaret = min(xCaret + 1, cxBuffer - 1);
break;
case VK_UP :
yCaret = max(yCaret - 1, 0);
break;
case VK_DOWN :
yCaret = min(yCaret + 1, cyBuffer - 1);
break;
case VK_DELETE :
for(x = xCaret; x < cxBuffer - 1; x++)
BUFFER(x, yCaret) = BUFFER(x + 1, yCaret);
BUFFER(cxBuffer - 1, yCaret) = ' ';
HideCaret(hwnd);
hdc = GetDC(hwnd);
SelectObject(hdc,
GetStockObject(SYSTEM_FIXED_FONT));
TextOut(hdc, xCaret * cxChar, yCaret * cyChar,
& BUFFER(xCaret, yCaret),
cxBuffer - xCaret);
ShowCaret(hwnd);
ReleaseDC(hwnd, hdc);
break;
}
SetCaretPos(xCaret * cxChar, yCaret * cyChar);
return 0;
case WM_CHAR :
for(i = 0; i <(int) LOWORD(lParam); i++)
{
switch(wParam)
{
case '\b' : // backspace
if(xCaret > 0)
{
xCaret--;
SendMessage(hwnd, WM_KEYDOWN,
VK_DELETE, 1L);
}
break;
case '\t' : // tab
do
{
SendMessage(hwnd, WM_CHAR, ' ', 1L);
}
while(xCaret % 8 != 0);
break;
case '\n' : // line feed
if(++yCaret == cyBuffer)
yCaret = 0;
break;
case '\r' : // carriage return
xCaret = 0;
if(++yCaret == cyBuffer)
yCaret = 0;
break;
case '\x1B' : // escape
for(y = 0; y < cyBuffer; y++)
for(x = 0; x < cxBuffer; x++)
BUFFER(x, y) = ' ';
xCaret = 0;
yCaret = 0;
InvalidateRect(hwnd, NULL, FALSE);
break;
default : // character codes
BUFFER(xCaret, yCaret) =(char) wParam;
HideCaret(hwnd);
hdc = GetDC(hwnd);
SelectObject(hdc,
GetStockObject(SYSTEM_FIXED_FONT));
TextOut(hdc, xCaret * cxChar, yCaret * cyChar,
& BUFFER(xCaret, yCaret), 1);
ShowCaret(hwnd);
ReleaseDC(hwnd, hdc);
if(++xCaret == cxBuffer)
{
xCaret = 0;
if(++yCaret == cyBuffer)
yCaret = 0;
}
break;
}
}
SetCaretPos(xCaret * cxChar, yCaret * cyChar);
return 0;
case WM_PAINT :
hdc = BeginPaint(hwnd, &ps);
SelectObject(hdc, GetStockObject(SYSTEM_FIXED_FONT));
for(y = 0; y < cyBuffer; y++)
TextOut(hdc, 0, y * cyChar, & BUFFER(0,y), cxBuffer);
EndPaint(hwnd, &ps);
return 0;
case WM_DESTROY :
PostQuitMessage(0);
return 0;
}
return DefWindowProc(hwnd, iMsg, wParam, lParam);
}

*(pBuffer - 1)