Windows programming: Draw lines, simple collision detection, simple frame rate locking

#defineWin32_lean_and_mean#include<windows.h>#include<windowsx.h>#include<mmsystem.h>#include<stdio.h>#include<stdlib.h>#include<math.h>#defineWindow_class_name "WINCLASS1"#defineWindow_width 640#defineWindow_height 480#defineKEYDOWN (Vk_code) ((Getasynckeystate (vk_code) & 0x8000)? 1:0)#defineKEYUP (Vk_code) ((Getasynckeystate (vk_code) & 0x8000)? 0:1)//Global VariablesHWND Main_window_handle =NULL; HINSTANCE Hinstance_app=NULL;Charbuffer[ the];//window processing FunctionsLRESULT CALLBACK WindowProc (HWND hwnd, UINT MSG, WPARAM WPARAM, LPARAM lpram) {paintstruct ps;    HDC hdc;    Rect rect; Charbuffer[ the]; Switch(msg) { Casewm_create: {return 0; } Break;  Casewm_paint: {hdc=GetDC (HWND);                     ReleaseDC (hwnd, HDC); GetClientRect (hwnd,&rect); ValidateRect (hwnd,&rect); return 0; } Break;  Casewm_close: {if(Idyes! = MessageBox (hwnd,"Are you sure you want to exit the application? ","Exit", Mb_yesno |mb_iconexclamation)) {                         return 0; }                     Else{postquitmessage (0); }    } Break;  Casewm_size: {} Break;  CaseWm_destroy: {postquitmessage (0); return 0; } Break; default: Break; }    returnDefWindowProc (hwnd, MSG, WParam, Lpram);}voidGamemain () {return;}intWINAPI WinMain (hinstance hinstance, hinstance hprevinstance, LPSTR lpCmdLine,intncmdshow) {    //Defining window ClassesWndclassex Winclass;    HWND hwnd;    MSG msg; Hpen Pen=NULL; intColor_change_count = -; //populate the members of the window classWinclass.cbsize =sizeof(Wndclassex); Winclass.style= Cs_dblclks | CS_OWNDC | Cs_hredraw |Cs_vredraw; Winclass.lpfnwndproc= WindowProc;//window Message handler functionWinclass.cbclsextra =0; Winclass.cbwndextra=0; Winclass.hinstance=hinstance; Winclass.hicon=LoadIcon (NULL, idi_application); Winclass.hcursor=loadcursor (NULL, Idc_arrow); Winclass.hbrbackground=(Hbrush) getstockobject (Black_brush); Winclass.lpszmenuname=NULL; Winclass.lpszclassname= Window_class_name;//window class nameWINCLASS.HICONSM =LoadIcon (NULL, idi_application); //saving an instance handle to a global variableHinstance_app =hinstance; //Register window class    if(! RegisterClassEx (&Winclass)) {        return 0; }    //create a member of a window class    if(! (HWnd =CreateWindowEx (NULL, Window_class_name,"time-locked screen Saver", Ws_overlappedwindow|ws_visible, $, $, window_width, window_height, NULL, NULL, HINSTANCE, NULL))) {        return 0; }    //Save the form handle to a global variableMain_window_handle =hWnd; //Get device contextHDC HDC =GetDC (HWND); //set the seed of the random number generatorSrand (GetTickCount ()); //segment End coordinates    intx1 = rand ()%window_width; inty1 = rand ()%window_height; intx2 = rand ()%window_width; inty2 = rand ()%window_height; //the speed of the end of the segment    intX1V =-4+ rand ()%8; intY1V =-4+ rand ()%8; intX2V =-4+ rand ()%8; intY2V =-4+ rand ()%8; //message Loops     while(TRUE) {DWORD start_time=GetTickCount (); if(PeekMessage (&msg, HWnd,0,0, Pm_remove)) {            if(Msg.message = =wm_quit) {                 Break; } translatemessage (&msg); DispatchMessage (&msg); }        //100 times The color change        if(++color_change_count >= -) {Color_change_count=0; if(pen) {DeleteObject (pen); } Pen= CreatePen (Ps_solid,1, RGB (rand ()% the, rand ()% the, rand ()% the));        SelectObject (hdc, pen); }        //Move end of segmentX1 + =x1v; Y1+=y1v; X2+=x2v; Y2+=y2v; //collision detection to see if the boundary of the form is encountered        if(x1<0|| X1>window_width) {x1v= -x1v; X1+=x1v; }        if(y1<0|| Y1>window_height) {y1v= -y1v; Y1+=y1v; }        if(x2<0|| X2>window_width) {x2v= -x2v; X2+=x2v; }        if(y2<0|| Y2>window_height) {y2v= -y2v; Y2+=y2v;        } movetoex (hdc, X1, y1,null);        LineTo (hdc, x2, y2); //The lock frame rate is 30fps,1/30 seconds, approximately equal to 33 milliseconds.          while(GetTickCount ()-Start_time < -); //If the user presses ESC, the WM_CLOSE message is sent. Exits the program.         if(KEYDOWN (Vk_escape)) SendMessage (HWnd, Wm_close,0,0);    } ReleaseDC (HWnd, HDC); returnMsg.wparam;}

Windows programming: Draw lines, simple collision detection, simple frame rate locking