C++: Display Color Pinstripe

The task is to create 1 pixel wide colored vertical pinstripes with a sufficient number of pinstripes to span the entire width of the graphics display. The pinstripes should either follow the system palette sequence or a sequence that includes Black, Red, Green, Blue, Magenta, Cyan, Yellow, White.

After filling the top quarter of the display, we switch to a wider 2 pixel wide vertical pinstripe pattern. Halfway down the display we switch to 3 pixel wide vertical pinstripe and then finally to a 4 pixels wide vertical pinstripe for the last quarter of the display.

#include <windows.h>

//--------------------------------------------------------------------------------------------------
class pinstripe
{
public:
	pinstripe()                        { createColors(); }
	void setDimensions( int x, int y ) { _mw = x; _mh = y; }
	void createColors()
	{
		colors[0] = 0; colors[1] = 255; colors[2] = RGB( 0, 255, 0 );
		colors[3] = RGB( 0, 0, 255 ); colors[4] = RGB( 255, 0, 255 ); 
		colors[5] = RGB( 0, 255, 255 ); colors[6] = RGB( 255, 255, 0 ); 
		colors[7] = RGB( 255, 255, 255 );
	}

	void draw( HDC dc )
	{
		HPEN pen;
		int lh = _mh / 4, row, cp;
		for( int lw = 1; lw < 5; lw++ )
		{
			cp = 0;
			row = ( lw - 1 ) * lh;
			for( int x = 0 + lw > 1 ? lw > 3 ? 2 : 1 : 0; x < _mw; x += lw )
			{
				pen = CreatePen( PS_SOLID, lw, colors[cp] );
				++cp %= 8;

				SelectObject( dc, pen );
				MoveToEx( dc, x, row, NULL );
				LineTo( dc, x, row + lh );
				DeleteObject( pen );
			}
		}
	}

private:
	int _mw, _mh;
	DWORD colors[8];
};
//--------------------------------------------------------------------------------------------------
pinstripe pin;

//--------------------------------------------------------------------------------------------------
void PaintWnd( HWND hWnd )
{
	PAINTSTRUCT ps;
	HDC hdc = BeginPaint( hWnd, &ps );
	pin.draw( hdc );
	EndPaint( hWnd, &ps );
}
//--------------------------------------------------------------------------------------------------
LRESULT CALLBACK WndProc( HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam )
{
	switch( msg )
	{
	case WM_DESTROY: PostQuitMessage( 0 ); break;
	case WM_PAINT: PaintWnd( hWnd ); break;
	default:
		return DefWindowProc( hWnd, msg, wParam, lParam );
	}
	return 0;
}
//--------------------------------------------------------------------------------------------------
HWND InitAll( HINSTANCE hInstance )
{
	WNDCLASSEX wcex;
	ZeroMemory( &wcex, sizeof( wcex ) );

	wcex.cbSize	       = sizeof( WNDCLASSEX );
	wcex.style	       = CS_HREDRAW | CS_VREDRAW;
	wcex.lpfnWndProc   = WndProc;
	wcex.hInstance     = hInstance;
	wcex.hCursor       = LoadCursor( NULL, IDC_ARROW );
	wcex.hbrBackground = ( HBRUSH )( COLOR_WINDOW + 1 );
	wcex.lpszClassName = "_CLR_PS_";

	RegisterClassEx( &wcex ); 
	return CreateWindow( "_CLR_PS_", ".: Clr Pinstripe -- PJorente :.", WS_POPUP, CW_USEDEFAULT, 0, 200, 200, NULL, NULL, hInstance, NULL );
}
//--------------------------------------------------------------------------------------------------
int APIENTRY _tWinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nCmdShow )
{
	srand( GetTickCount() );

	HWND hwnd = InitAll( hInstance );
	if( !hwnd ) return -1;

	int mw = GetSystemMetrics( SM_CXSCREEN ),
	mh = GetSystemMetrics( SM_CYSCREEN );

	pin.setDimensions( mw, mh );

	RECT rc = { 0, 0, mw, mh };

	AdjustWindowRectEx( &rc, WS_POPUP, FALSE, 0 );
	int w = rc.right  - rc.left, 
	h = rc.bottom - rc.top;

	int posX = ( GetSystemMetrics( SM_CXSCREEN ) >> 1 ) - ( w >> 1 ),
	posY = ( GetSystemMetrics( SM_CYSCREEN ) >> 1 ) - ( h >> 1 );

	SetWindowPos( hwnd, HWND_TOP, posX, posY, w, h, SWP_NOZORDER );
	ShowWindow( hwnd, nCmdShow );
	UpdateWindow( hwnd );

	MSG msg;
	ZeroMemory( &msg, sizeof( msg ) );
	while( msg.message != WM_QUIT )
	{
		if( PeekMessage( &msg, NULL, 0, 0, PM_REMOVE ) != 0 )
		{
			TranslateMessage( &msg );
			DispatchMessage( &msg );
		}
	}
	return UnregisterClass( "_CLR_PS_", hInstance );
}
//--------------------------------------------------------------------------------------------------