TIMER ET DEGRADE (WIN32)

//************************************************************
#include <windows.h>
#include <commctrl.h>
#include <string.h>
#include <stdio.h>
//************************************************************
LRESULT CALLBACK WndProc(HWND,UINT,WPARAM,LPARAM);
//************************************************************

int WINAPI WinMain(
                  HINSTANCE hInstance,
                  HINSTANCE hPrevInstance,
                  PSTR      szCmdLine,
                  int       iCmdShow
                  )
{
static char   szAppName[] = "TIMER et DEGRADE";
HWND          hwnd;
MSG           msg;
WNDCLASSEX    wndclass;

wndclass.cbSize        = sizeof(wndclass);
wndclass.style         = 0;
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       = NULL;

RegisterClassEx(&wndclass);
    
hwnd = CreateWindow ( szAppName,               // nom de la classe
                      szAppName,                  // titre de la fenetre
                      WS_OVERLAPPEDWINDOW,     // style de la fenetre
                      CW_USEDEFAULT,           // position initiale en x
                      CW_USEDEFAULT,           // position initiale en y
                      CW_USEDEFAULT,           // largeur initiale
                      CW_USEDEFAULT,           // hauteur initiale
                      NULL,                    // handle de la fenetre mere
                      NULL,                    // handle du menu de la fenetre
                      hInstance,               // handle de l'instance
                      NULL) ;                  // parametres de creation

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 int colorRed,colorGreen,colorBlue;

switch (iMsg)
  {
  case WM_CREATE:
    {
    colorRed    = 0;
    colorGreen  = 0;
    colorBlue   = 0;
    SetTimer(hwnd,1001,100,NULL);
	  return 0;
    }
	case WM_PAINT:
    {
    HDC     		  hdc;
    PAINTSTRUCT   ps;
    RECT          rc;
    HGDIOBJ       oldBrush;

    hdc = BeginPaint(hwnd,&ps);
    GetClientRect(hwnd,&rc);

    oldBrush = SelectObject(hdc,CreateSolidBrush(RGB(colorRed,colorGreen,colorBlue)));

    Rectangle(hdc,rc.left,rc.top,rc.right,rc.bottom);

    DeleteObject(SelectObject(hdc,oldBrush));
 		EndPaint(hwnd,&ps);
  	return 0;
    }  
  case WM_TIMER:
    {
    switch(wParam)
      {
      case 1001:
        {
        colorBlue    = (colorBlue  + 3) & 255;
        colorGreen   = (colorGreen + 5) & 255;
        colorBlue    = (colorBlue  + 7) & 255;
        InvalidateRect(hwnd,NULL,FALSE);
        return 0;
        }
      }
    break;
    }
  // -------------------------------------
  case WM_DESTROY:
    {
    KillTimer(hwnd,1001);
    PostQuitMessage(0);
    return 0;
    }    
  }
return DefWindowProc(hwnd,iMsg,wParam,lParam);
}