Snake1

#include <Windows.h>
#include <string>
#include <time.h>
#include <list>
#include <math.h>
typedef std::list <RECT> snakeList;
snakeList snake;
enum Direction {UP,DOWN,LEFT,RIGHT};
Direction direction;

RECT rect,rnd={0,0,20,20};
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR plCmdLine, int mShowCMD)
{
    srand(time(NULL));
    direction = UP;

    LPTSTR className = L"nazwaKlasy";
    WNDCLASSEX wc;
    HWND hwnd;
    MSG msg;
    wc.cbSize = sizeof(WNDCLASSEX);
    wc.style = CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc = WndProc;
    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.hInstance = hInstance;
    wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wc.hCursor = LoadCursor(NULL,IDC_ARROW);
    wc.hbrBackground = (HBRUSH) (COLOR_WINDOW +1);
    wc.lpszClassName = className;
    wc.lpszMenuName = NULL;
    wc.hIconSm= LoadIcon(NULL, IDI_APPLICATION);

    if(RegisterClassEx(&wc))
    {
        if((hwnd=CreateWindowEx(WS_EX_CLIENTEDGE, className, L"Paint",WS_OVERLAPPEDWINDOW,100, 100,900,900,NULL,NULL,hInstance,NULL))!=NULL)
        {
            RECT rect = {400,400,420,420};
            snake.push_front(rect);
            ShowWindow(hwnd, mShowCMD);
            UpdateWindow(hwnd);
            SetTimer(hwnd,1,100,NULL);
            while(GetMessage(&msg,NULL,0,0))
            {
                TranslateMessage(&msg);
                DispatchMessage(&msg);
            }

        }
        else
            MessageBox(NULL, L"Error", L"Create Window", MB_OK);

    }
    else
        MessageBox(NULL, L"Error", L"Register CLASS", MB_OK);
    KillTimer(hwnd,1);
    DestroyWindow(hwnd);
    return 0;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lparam)
{
    GetClientRect(hwnd,&rect);
    switch(msg)
    {
    case WM_SIZE:
        {
            break;
        }
    case WM_PAINT:
        {
            HDC hdc = GetDC(hwnd);
            HPEN oldPen,p1=CreatePen(PS_SOLID,1,RGB(0,0,0));
            HBRUSH oldBrush,b1=CreateSolidBrush(RGB(0,255,0));
            oldPen = (HPEN) SelectObject(hdc,p1);
            oldBrush = (HBRUSH) SelectObject(hdc,b1);
            FillRect(hdc,&rect,oldBrush);
            for(snakeList::iterator iter=snake.begin();iter!=snake.end();iter++)
            {
                FillRect(hdc,&(*iter),b1);
            }
            FillRect(hdc,&rnd,b1);
            SelectObject(hdc,oldPen);
            SelectObject(hdc,oldBrush);
            DeleteObject(p1);
            DeleteObject(b1);
            ReleaseDC(hwnd,hdc);
            break;
        }
    case WM_TIMER:
        {
            switch(direction)
            {
            case UP:
                {
                    RECT r=*snake.begin();
                    r.top-=20;
                    r.bottom-=20;
                    if(r.bottom<=rect.top)
                    {
                        r.bottom=rect.bottom;
                        r.top=rect.bottom-20;
                    }
                    if(r.left==rnd.left && r.top==rnd.top)
                    {
                        rnd.left=(rand()%rect.right/20)*20;
                        rnd.top=(rand()%rect.bottom/20)*20;
                        rnd.right=rnd.left+20;
                        rnd.bottom=rnd.top+20;
                        snake.push_front(r);
                    }
                    else
                    {
                        snake.push_front(r);
                        snake.pop_back();
                    }
                    break;
                }
            case DOWN:
                {
                    RECT r=*snake.begin();
                    r.top+=20;
                    r.bottom+=20;
                    if(r.top>=rect.bottom)
                    {
                        r.top=rect.top;
                        r.bottom=rect.top+20;
                    }
                    if(r.left==rnd.left && r.top==rnd.top)
                    {
                        rnd.left=(rand()%rect.right/20)*20;
                        rnd.top=(rand()%rect.bottom/20)*20;
                        rnd.right=rnd.left+20;
                        rnd.bottom=rnd.top+20;
                        snake.push_front(r);
                    }
                    else
                    {
                        snake.push_front(r);
                        snake.pop_back();
                    }
                    break;
                }
            case LEFT:
                {
                    RECT r=*snake.begin();
                    r.right-=20;
                    r.left-=20;
                    if(r.right<=rect.left)
                    {
                        r.right=rect.right;
                        r.left=rect.right-20;
                    }
                    if(r.left==rnd.left && r.top==rnd.top)
                    {
                        rnd.left=(rand()%rect.right/20)*20;
                        rnd.top=(rand()%rect.bottom/20)*20;
                        rnd.right=rnd.left+20;
                        rnd.bottom=rnd.top+20;
                        snake.push_front(r);
                    }
                    else
                    {
                        snake.push_front(r);
                        snake.pop_back();
                    }
                    break;
                }
            case RIGHT:
                {
                    RECT r=*snake.begin();
                    r.right+=20;
                    r.left+=20;
                    if(r.left>=rect.right)
                    {
                        r.left=rect.left;
                        r.right=rect.left+20;
                    }
                    if(r.left==rnd.left && r.top==rnd.top)
                    {
                        rnd.left=(rand()%rect.right/20)*20;
                        rnd.top=(rand()%rect.bottom/20)*20;
                        rnd.right=rnd.left+20;
                        rnd.bottom=rnd.top+20;
                        snake.push_front(r);
                    }
                    else
                    {
                        snake.push_front(r);
                        snake.pop_back();
                    }
                    break;
                }
            }
            InvalidateRect(hwnd,&rect,0);
            break;
        }
    case WM_KEYDOWN:
        {
            switch(wParam)
            {
            case VK_UP:
                direction = UP;
                break;
            case VK_DOWN:
                direction = DOWN;
                break;
            case VK_LEFT:
                direction = LEFT;
                break;
            case VK_RIGHT:
                direction = RIGHT;
                break;
            }
            break;
        }
    case WM_DESTROY:
        {
            KillTimer(hwnd,1);
            PostQuitMessage(0);
            break;
        }
    }

    return DefWindowProc(hwnd,msg,wParam,lparam);
}