circle cpp Defines the entry point for the application include stdafx

// circle.cpp : Defines the entry point for the application.
//

#include "stdafx.h"
#include "circle.h"
#include <windows.h>
#include <cmath>  
#define PI 3.14159

//структура "шарик"
struct mol{double x,y,vx,vy,m; int r, color;};
//объект структуры "шарик"
struct mol ball={500,200,30,30,2,20,3};
double dt= 0.5; //шаг интегрирования по времени (громко сказано - интегрирование :) )


void StepBack(mol* s)  //вернуть шарику координаты предыдущего временного шага
{
	//double z,u,w;
				//for(z = 0; z<6.28;z=z+0.1){
            //u = cos(z);
            //w = sin(z);
			s->x = s->x - s->vx*dt; s->y = s->y - s->vy*dt;}
//}

#define MAX_LOADSTRING 100

// Global Variables:
HINSTANCE hInst;								// current instance
TCHAR szTitle[MAX_LOADSTRING];					// The title bar text
TCHAR szWindowClass[MAX_LOADSTRING];			// the main window class name

// Forward declarations of functions included in this code module:
ATOM				MyRegisterClass(HINSTANCE hInstance);
BOOL				InitInstance(HINSTANCE, int);
LRESULT CALLBACK	WndProc(HWND, UINT, WPARAM, LPARAM);
INT_PTR CALLBACK	About(HWND, UINT, WPARAM, LPARAM);

int APIENTRY _tWinMain(HINSTANCE hInstance,
                     HINSTANCE hPrevInstance,
                     LPTSTR    lpCmdLine,
                     int       nCmdShow)
{
	UNREFERENCED_PARAMETER(hPrevInstance);
	UNREFERENCED_PARAMETER(lpCmdLine);

 	// TODO: Place code here.
	MSG msg;
	HACCEL hAccelTable;

	// Initialize global strings
	LoadString(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
	LoadString(hInstance, IDC_CIRCLE, szWindowClass, MAX_LOADSTRING);
	MyRegisterClass(hInstance);

	// Perform application initialization:
	if (!InitInstance (hInstance, nCmdShow))
	{
		return FALSE;
	}

	hAccelTable = LoadAccelerators(hInstance, MAKEINTRESOURCE(IDC_CIRCLE));

	// Main message loop:
	while (GetMessage(&msg, NULL, 0, 0))
	{
		if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
		{
			TranslateMessage(&msg);
			DispatchMessage(&msg);
		}
	}

	return (int) msg.wParam;
}



//
//  FUNCTION: MyRegisterClass()
//
//  PURPOSE: Registers the window class.
//
//  COMMENTS:
//
//    This function and its usage are only necessary if you want this code
//    to be compatible with Win32 systems prior to the 'RegisterClassEx'
//    function that was added to Windows 95. It is important to call this function
//    so that the application will get 'well formed' small icons associated
//    with it.
//
ATOM MyRegisterClass(HINSTANCE hInstance)
{
	WNDCLASSEX wcex;

	wcex.cbSize = sizeof(WNDCLASSEX);

	wcex.style			= CS_HREDRAW | CS_VREDRAW;
	wcex.lpfnWndProc	= WndProc;
	wcex.cbClsExtra		= 0;
	wcex.cbWndExtra		= 0;
	wcex.hInstance		= hInstance;
	wcex.hIcon			= LoadIcon(hInstance, MAKEINTRESOURCE(IDI_CIRCLE));
	wcex.hCursor		= LoadCursor(NULL, IDC_ARROW);
	wcex.hbrBackground	= (HBRUSH)(COLOR_WINDOW+1);
	wcex.lpszMenuName	= MAKEINTRESOURCE(IDC_CIRCLE);
	wcex.lpszClassName	= szWindowClass;
	wcex.hIconSm		= LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_SMALL));

	return RegisterClassEx(&wcex);
}

//
//   FUNCTION: InitInstance(HINSTANCE, int)
//
//   PURPOSE: Saves instance handle and creates main window
//
//   COMMENTS:
//
//        In this function, we save the instance handle in a global variable and
//        create and display the main program window.
//
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
   HWND hWnd;

   hInst = hInstance; // Store instance handle in our global variable

   hWnd = CreateWindow(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW,
      CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL);

   if (!hWnd)
   {
      return FALSE;
   }

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

   return TRUE;
}

//
//  FUNCTION: WndProc(HWND, UINT, WPARAM, LPARAM)
//
//  PURPOSE:  Processes messages for the main window.
//
//  WM_COMMAND	- process the application menu
//  WM_PAINT	- Paint the main window
//  WM_DESTROY	- post a quit message and return
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	int wmId, wmEvent;
	PAINTSTRUCT ps;
	HDC hdc;
	HBRUSH brush;

	switch (message)
	{
		case WM_CREATE: //create timer (0.01 sec)
			SetTimer(hWnd, 1, 100, NULL);
			break;
			case WM_TIMER: //when the timer snaps into action

			hdc = GetDC(hWnd); //получаем контекст устройств
			brush = (HBRUSH)SelectObject(hdc, GetStockObject(WHITE_BRUSH)); //выбираем белую кисть

			RECT tempRect; //прямоугольник, который покроет (закрасит, сотрёт) весь шарик
			tempRect.left = ball.x - ball.r;
			tempRect.top = ball.y - ball.r ;
			tempRect.right = ball.x + ball.r;
			tempRect.bottom = ball.y + ball.r ;

			FillRect(hdc, &tempRect, brush); //стереть шарик
			//double z,u,w;
			//	for(z = 0; z<6.28;z=z+0.1){
            //u = cos(z);
            //w = sin(z);
			ball.x = ball.x + ball.vx*100*cos(phy); //вычислить новое положение шарика
			ball.y = ball.y + ball.vy*100*sin(phy);
			phy+= PI/18;
			
			RECT rect;
			GetClientRect(hWnd, &rect); //получить прямоугольник клиентской области окна

			 //если произошло отражение от стенки, то обработать это особым образом
			if(ball.x - ball.r < 0 || ball.x + ball.r > rect.right) 
				{StepBack(&ball); ball.vx = -ball.vx;}
			if(ball.y - ball.r < 0 || ball.y + ball.r > rect.bottom)
				{StepBack(&ball); ball.vy = -ball.vy;}
	
			brush = (HBRUSH) SelectObject(hdc, GetStockObject(ball.color));//выбрать кисть для рисования
			Ellipse(hdc, ball.x - ball.r, ball.y - ball.r, ball.x + ball.r, ball.y + ball.r); //нарисовать шарик

			SelectObject(hdc, brush); //выбрать старую кисть
			ReleaseDC(hWnd, hdc); //освободить контекст устройства
			break;
			
			case WM_DESTROY:
			KillTimer(hWnd, 1);
			PostQuitMessage(0);
			break;
	case WM_COMMAND:
		wmId    = LOWORD(wParam);
		wmEvent = HIWORD(wParam);
		// Parse the menu selections:
		switch (wmId)
		{
		case IDM_ABOUT:
			DialogBox(hInst, MAKEINTRESOURCE(IDD_ABOUTBOX), hWnd, About);
			break;
		case IDM_EXIT:
			DestroyWindow(hWnd);
			break;
		default:
			return DefWindowProc(hWnd, message, wParam, lParam);
		}
		break;
	case WM_PAINT:
		hdc = BeginPaint(hWnd, &ps);
		// TODO: Add any drawing code here...
		EndPaint(hWnd, &ps);
		break;

	
	default:
		return DefWindowProc(hWnd, message, wParam, lParam);
	}
	return 0;
}

// Message handler for about box.
INT_PTR CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
	UNREFERENCED_PARAMETER(lParam);
	switch (message)
	{
	case WM_INITDIALOG:
		return (INT_PTR)TRUE;

	case WM_COMMAND:
		if (LOWORD(wParam) == IDOK || LOWORD(wParam) == IDCANCEL)
		{
			EndDialog(hDlg, LOWORD(wParam));
			return (INT_PTR)TRUE;
		}
		break;
	}
	return (INT_PTR)FALSE;
}