[핵심 API로 배우는 윈도우프로그래밍(강경우, 한빛아카데미)] 10장 4번 풀이

#include <Windows.h>
#include<tchar.h>
#include<string.h>
#include<winres.h>
#include<process.h>
#include<time.h>
#include<stdio.h>
#include<stdlib.h>
#pragma comment(linker,"/entry:WinMainCRTStartup /subsystem:console")
 
LRESULT CALLBACK WndProc(HWND hwnd, UINT iMsg, WPARAM wParam, LPARAM lParam);
void ThreadProc(void *);
HINSTANCE hInst;
HWND hwnd;
 
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpszCmdLine, int nCmdShow)
{
    MSG msg;
    WNDCLASS WndClass;
 
    hInst = hInstance;
    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 = _T("Window Class Name");
 
    RegisterClass(&WndClass);
 
    hwnd = CreateWindow(
        _T("Window Class Name"),
        _T("박정호"),
        WS_OVERLAPPEDWINDOW,
        50,
        50,
        1000,
        700,
        NULL,
        NULL,
        hInstance,
        NULL);
 
    ShowWindow(hwnd, nCmdShow);
    UpdateWindow(hwnd);
 
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return (int)msg.wParam;
}
 
#define THREAD_NUM 10
static RECT rt;
HANDLE hEvent;
BOOL directionX[THREAD_NUM] = { TRUE, };
BOOL directionY[THREAD_NUM] = { TRUE, };
int xPos[THREAD_NUM], yPos[THREAD_NUM];
static int r[THREAD_NUM], g[THREAD_NUM], b[THREAD_NUM];
LRESULT CALLBACK WndProc(HWND hwnd, UINT iMsg, WPARAM wParam, LPARAM lParam)
{
    HDC hdc;
    PAINTSTRUCT ps;
    static HANDLE hThread[THREAD_NUM];
    static int count = 0;
    static BOOL GO = FALSE;
    static BOOL init = TRUE;
    int thread_num = 0;
    switch (iMsg)
    {
    case WM_CREATE:
        GetClientRect(hwnd, &rt);
        hEvent = CreateEvent(NULL, TRUE, TRUE, NULL);
        for (int i = 0; i < THREAD_NUM; i++)
        {
            xPos[i] = rand() % (rt.right - 200) + 100;
            yPos[i] = rand() % (rt.bottom - 200) + 100;
            r[i] = rand() % 256;
            g[i] = rand() % 256;
            b[i] = rand() % 256;
        }
        break;
 
    case WM_LBUTTONDOWN:
        for (int i = 0; i < THREAD_NUM; i++)
        {
            hThread[i] = (HANDLE)_beginthreadex(NULL, 0, (unsigned int(__stdcall *)(void *))ThreadProc, (void*)&i, 0, NULL);
            Sleep(50);
        }
        break;
    case WM_PAINT:
        hdc = BeginPaint(hwnd, &ps);
        for (int i = 0; i < THREAD_NUM; i++)
        {
            //SelectObject(hdc, CreateSolidBrush(RGB(r[i], g[i], b[i])));
            Ellipse(hdc, xPos[i] - 20, yPos[i] - 20, xPos[i] + 20, yPos[i] + 20);
        }
        EndPaint(hwnd, &ps);
        break;
    case WM_DESTROY:
        CloseHandle(hThread);
        PostQuitMessage(0);
        break;
 
    }
    return DefWindowProc(hwnd, iMsg, wParam, lParam);
}
void ThreadProc(void *arg)
{
    HDC hdc;
    int index = *((int *)arg);
    hdc = GetDC(hwnd);
    while (1)
    {
        //WaitForSingleObject(hEvent, INFINITE);
 
        if (xPos[index] < 20 || xPos[index]>rt.right - 20)
            directionX[index] = directionX[index] ? FALSE : TRUE;
        if (yPos[index] < 20 || yPos[index]>rt.bottom - 20)
            directionY[index] = directionY[index] ? FALSE : TRUE;
 
        if (directionX[index])
            xPos[index] ++;
        else
            xPos[index] --;
 
        if (directionY[index])
            yPos[index] ++;
        else
            yPos[index] --;
 
        for (int i = 0; i < THREAD_NUM; i++)
        {
            if (sqrt(pow(xPos[index] - xPos[i], 2) + pow(yPos[index] - yPos[i], 2)) < 40 && i != index)    //충돌
            {
                xPos[index] = yPos[index] = -30;
                xPos[i] = yPos[i] = -30;
                InvalidateRgn(hwnd, NULL, TRUE);
                return;
            }
            //printf("%lf\n", sqrt(pow(xPos[index] - xPos[i], 2) + pow(yPos[index] - yPos[i], 2)));
        }
        Sleep(10);
        InvalidateRgn(hwnd, NULL, TRUE);
    }
    ReleaseDC(hwnd, hdc);
    return;
}