RAČUNARSKA ELEKTRONIKA VEŽBE 4

Transcription

1 RAČUNARSKA ELEKTRONIKA VEŽBE 4 Aleksandra Lekić lekic.aleksandra@etf.bg.ac.rs Elektrotehnički fakultet, Univerzitet u Beogradu 2016/2017 ETF Beograd RE VEŽBE / / 47

2 MS-Windows Programianje Radi kao 16-bitno MS-DOS u tekstualnom modu. Biblioteka Irvine32.inc sadrži podršku za standardne MS-Windows funkcije. Postoji podrška za: čitanje sa standardnog ulaza ispis na standardni izlaz ispis teksta u boji Radi sa 8-bitnim ASCII i 16-bitnim Unicode setom karaktera. Objašnjenje biblioteke Irvine 2Fabout.htm ETF Beograd RE VEŽBE / / 47

3 Console Handle procedure Function GetStdHandle ReadConsole WriteConsole Description Retrieves a handle for the standard input, standard output, or standard error device. Reads character input from the console input buffer and removes it from the buffer. Writes a character string to a console screen buffer beginning at the current cursor location. ETF Beograd RE VEŽBE / / 47

4 Console Handle procedure Write Message Write Message MessageBoxA PROTO, hwnd:dword, ; handle to window (can be null) lptext:ptr BYTE, ; string, inside of box lpcaption:ptr BYTE, ; string, dialog box title utype:dword ; contents and behavior Write Message utype - MB_OK, MB_OKCANCEL, MB_YESNO, MB_YESNOCANCEL, MB_RETRYCANCEL, MB_ABORTRETRYIGNORE i MB_CANCELTRYCONTINUE. ETF Beograd RE VEŽBE / / 47

5 Console Handle procedure 1 ; Demonstrate MessageBoxA (MessageBox.asm) 2 INCLUDE Irvine32.inc 3 4.data 5 captionw BYTE "Warning",0 6 warningmsg BYTE "The current operation may take years to complete.",0 7 captionq BYTE "Question",0 8 questionmsg BYTE "A matching user account was not found." 9 BYTE 0dh,0ah,"Do you wish to continue?",0 10 captionc BYTE "Information",0 11 infomsg BYTE "Select Yes to save a backup file before continuing,",0dh,0ah 12 BYTE "or click Cancel to stop the operation",0 13 captionh BYTE "Cannot View User List",0 14 haltmsg BYTE "This operation not supported by your user account.", code 17 main PROC 18 ; Display Exclamation icon with OK button 19 INVOKE MessageBox, NULL, ADDR warningmsg, ADDR captionw, 20 MB_OK + MB_ICONEXCLAMATION 21 ; Display Question icon with Yes/No buttons 22 INVOKE MessageBox, NULL, ADDR questionmsg, 23 ADDR captionq, MB_YESNO + MB_ICONQUESTION 24 ; interpret the button clicked by the user 25 cmp eax,idyes ; YES button clicked? 26 ; Display Information icon with Yes/No/Cancel buttons 27 INVOKE MessageBox, NULL, ADDR infomsg, 28 ADDR captionc, MB_YESNOCANCEL + MB_ICONINFORMATION + MB_DEFBUTTON2 29 ; Display stop icon with OK button 30 INVOKE MessageBox, NULL, ADDR haltmsg, ADDR captionh, MB_OK + MB_ICONSTOP 31 exit 32 main ENDP 33 END main ETF Beograd RE VEŽBE / / 47

6 Console Input Console Input Read Console ReadConsole PROTO, hconsoleinput:handle, ; input handle lpbuffer:ptr BYTE, ; pointer to buffer nnumberofcharstoread:dword, ; number of chars to read lpnumberofcharsread:ptr DWORD, ; ptr to num bytes read lpreserved:dword ; (not used) Read Console Čita podatak sa standardnog ulaza i stavlja ga u bafer. ETF Beograd RE VEŽBE / / 47

7 Console Input 1 ; Read From the Console (ReadConsole.asm) 2 3 ; Read a line of input from standard input. 4 5 INCLUDE Irvine32.inc 6 7 BufSize = data 10 buffer BYTE BufSize DUP(?) 11 stdinhandle HANDLE? 12 bytesread DWORD? code 15 main PROC 16 ; Get handle to standard input 17 INVOKE GetStdHandle, STD_INPUT_HANDLE 18 mov stdinhandle,eax ; Wait for user input 21 INVOKE ReadConsole, stdinhandle, ADDR buffer, 22 BufSize, ADDR bytesread, ; Display the buffer 25 mov esi,offset buffer 26 mov ecx,bytesread 27 mov ebx,type buffer 28 call DumpMem exit 31 main ENDP 32 END main ETF Beograd RE VEŽBE / / 47

8 Console Input Keyboard procedure ReadChar - čeka se da se ukuca karakter u ASCII kodu na tastaturi i upisuje se u AL registar. ReadKey - ne čeka na karakter. Ako nema karaktera setuje se zero flag, a ako postoji karakter zero flag nije setovan. U tom se slučaju upisuje u registar AL karakter ili nula. Gornje polovine registara EAX i EDX su prepisane. ETF Beograd RE VEŽBE / / 47

9 Console Input 1 ; Testing ReadKey (TestReadkey.asm) INCLUDE Irvine32.inc 5 INCLUDE Macros.inc 6 7.code 8 main PROC 9 10 L1: mov eax,10 ; delay for msg processing 11 call Delay 12 call ReadKey ; wait for a keypress 13 jz L test ebx,capslock_on 16 jz L2 17 mwrite <"CapsLock is ON",0dh,0ah> 18 jmp L L2: mwrite <"CapsLock is OFF",0dh,0ah> L3: exit 23 main ENDP 24 END main ETF Beograd RE VEŽBE / / 47

10 Console Input Čitanje stanja tastature Program testira vrednost registra EAX prema tabeli: ETF Beograd RE VEŽBE / / 47

11 Console Input 1 ; Keyboard Toggle Keys (Keybd.asm) 2 3 ; This program shows how to detect the states of various 4 ; keyboard toggle keys. Before you run the program, hold 5 ; down a selected key. 6 7 INCLUDE Irvine32.inc 8 INCLUDE Macros.inc 9 10 ; GetKeyState sets bit 0 in EAX if a toggle key is 11 ; currently on (CapsLock, NumLock, ScrollLock). 12 ; It sets the high bit of EAX if the specified key is 13 ; currently down code 16 main PROC INVOKE GetKeyState, VK_NUMLOCK 19 test al,1 20.IF!Zero? 21 mwrite <"The NumLock key is ON",0dh,0ah> 22.ENDIF INVOKE GetKeyState, VK_LSHIFT 25 call DumpRegs 26 test eax, h 27.IF!Zero? 28 mwrite <"The Left Shift key is currently DOWN",0dh,0ah> 29.ENDIF exit 32 main ENDP 33 END main ETF Beograd RE VEŽBE / / 47

12 Console Output Console Output WriteConsole WriteConsole PROTO, hconsoleoutput:handle, lpbuffer:ptr BYTE, nnumberofcharstowrite:dword, lpnumberofcharswritten:ptr DWORD, lpreserved:dword ETF Beograd RE VEŽBE / / 47

13 Console Output 1 ; Win32 Console Example #1 (Console1.asm) 2 ; This program calls the following Win32 Console functions: 3 ; GetStdHandle, ExitProcess, WriteConsole 4 INCLUDE Irvine32.inc 5 6.data 7 endl EQU <0dh,0ah> ; end of line sequence 8 9 message LABEL BYTE 10 BYTE "This program is a simple demonstration of " 11 BYTE "console mode output, using the GetStdHandle " 12 BYTE "and WriteConsole functions.", endl 13 messagesize DWORD ($ message) consolehandle HANDLE 0 ; handle to standard output device 16 byteswritten DWORD? ; number of bytes written code 19 main PROC 20 ; Get the console output handle: 21 INVOKE GetStdHandle, STD_OUTPUT_HANDLE 22 mov consolehandle,eax ; Write a string to the console: 25 INVOKE WriteConsole, 26 consolehandle, ; console output handle 27 ADDR message, ; string pointer 28 messagesize, ; string length 29 ADDR byteswritten, ; returns num bytes written 30 0 ; not used INVOKE ExitProcess,0 33 main ENDP 34 END main ETF Beograd RE VEŽBE / / 47

14 Console Output Console Output WriteConsoleOutputCharacter WriteConsoleOutputCharacter PROTO, hconsoleoutput:handle, ; console output handle lpcharacter:ptr BYTE, ; pointer to buffer nlength:dword, ; size of buffer dwwritecoord:coord, ; first cell coordinates lpnumberofcharswritten:ptr DWORD ; output count Ako tekst dođe do kraja reda, prelomi se u novi. Ako funkcija ne može da ispiše karaktere (npr. tab), vraća nulu. ETF Beograd RE VEŽBE / / 47

15 Čitanje i upis u fajlove Kreiranje fajla Create File CreateFile PROTO, ; create new file lpfilename:ptr BYTE, ; ptr to filename dwdesiredaccess:dword, ; access mode dwsharemode:dword, ; share mode lpsecurityattributes:dword, ; ptr security attrib dwcreationdisposition:dword, ; file creation options dwflagsandattributes:dword, ; file attributes htemplatefile:dword ; handle to template file ETF Beograd RE VEŽBE / / 47

16 Čitanje i upis u fajlove Parametri prilikom kreiranja fajla ETF Beograd RE VEŽBE / / 47

17 Čitanje i upis u fajlove Parametri prilikom kreiranja fajla dwdesiredaccess Specificira pristup čitanja fajla i upisa u fajl. Može imati vrednosti: 0 - za proveru da li fajl postoji ili prosleđivanje osobina bez pristupa fajlu, GENERIC_READ - fajl namenjen čitanju, GENERIC_WRITE - fajl namenjen upisu. Za upis/čitanje se koristi GENERIC_READ kombinovano sa GENERIC_WRITE. dwcreationdisposition Podrazumeva akciju koju treba sprovesti nad fajlom: CREATE_NEW, CREATE_ALWAYS, OPEN_EXISTING, OPEN_ALWAYS, TRUNCATE_EXISTING. ETF Beograd RE VEŽBE / / 47

18 Čitanje i upis u fajlove Parametri prilikom kreiranja fajla dwflagsandattributes ETF Beograd RE VEŽBE / / 47

19 Čitanje i upis u fajlove File procedure CloseHandle CloseHandle PROTO, hobject:handle ; handle to object ReadFile ReadFile PROTO, hfile:handle, ; input handle lpbuffer:ptr BYTE, ; ptr to buffer nnumberofbytestoread:dword, ; num bytes to read lpnumberofbytesread:ptr DWORD, ; bytes actually read lpoverlapped:ptr DWORD ; ptr to asynch info ETF Beograd RE VEŽBE / / 47

20 Čitanje i upis u fajlove File procedure WriteFile WriteFile PROTO, hfile:handle, ; output handle lpbuffer:ptr BYTE, ; pointer to buffer nnumberofbytestowrite:dword, ; size of buffer lpnumberofbyteswritten:ptr DWORD, ; num bytes written lpoverlapped:ptr DWORD ; ptr to asynch info SetFilePointer SetFilePointer PROTO, hfile:handle, ; file handle ldistancetomove:sdword, ; bytes to move pointer lpdistancetomovehigh:ptr SDWORD, ; ptr bytes to move, high dwmovemethod:dword ; starting point ETF Beograd RE VEŽBE / / 47

21 Čitanje i upis u fajlove 1 ; Creating a File (CreateFile.asm) 2 3 ; Inputs text from the user, writes the text to an output file. 4 5 INCLUDE Irvine32.inc 6 7 BUFFER_SIZE = data 9 buffer BYTE BUFFER_SIZE DUP(?) 10 filename BYTE "output.txt",0 11 filehandle HANDLE? 12 stringlength DWORD? 13 byteswritten DWORD? 14 str1 BYTE "Cannot create file",0dh,0ah,0 15 str2 BYTE "Bytes written to file [output.txt]: ",0 16 str3 BYTE "Enter up to 500 characters and press " 17 BYTE "[Enter]: ",0dh,0ah, code 20 main PROC 21 ; Create a new text file. 22 mov edx,offset filename 23 call CreateOutputFile 24 mov filehandle,eax ; Check for errors. 27 cmp eax, INVALID_HANDLE_VALUE ; error found? 28 jne file_ok ; no: skip 29 mov edx,offset str1 ; display error 30 call WriteString 31 call WriteString 32 jmp quit 33 file_ok: ; Ask the user to input a string. 36 mov edx,offset str3 ; "Enter up to..." 37 call WriteString 38 mov ecx,buffer_size ; Input a string 39 mov edx,offset buffer 40 call ReadString 41 mov stringlength,eax ; counts chars entered ; Write the buffer to the output file. 44 mov eax,filehandle 45 mov edx,offset buffer 46 mov ecx,stringlength 47 call WriteToFile 48 mov byteswritten,eax ; save return value 49 call CloseFile ; Display the return value. 52 mov edx,offset str2 ; "Bytes written" 53 call WriteString 54 mov eax,byteswritten 55 call WriteDec 56 call Crlf quit: 59 exit 60 main ENDP 61 END main ETF Beograd RE VEŽBE / / 47

22 Čitanje i upis u fajlove 1 ; Reading a File (ReadFile.asm) 2 ; Opens, reads, and displays a text file using 3 ; procedures from Irvine32.lib. 4 INCLUDE Irvine32.inc 5 INCLUDE macros.inc 6 7 BUFFER_SIZE = data 10 buffer BYTE BUFFER_SIZE DUP(?) 11 filename BYTE 80 DUP(0) 12 filehandle HANDLE? code 15 main PROC ; Let user input a filename. 18 mwrite "Enter an input filename: " 19 mov edx,offset filename 20 mov ecx,sizeof filename 21 call ReadString ; Open the file for input. 24 mov edx,offset filename 25 call OpenInputFile 26 mov filehandle,eax ; Check for errors. 29 cmp eax,invalid_handle_value ; error opening file? 30 jne file_ok ; no: skip 31 mwrite <"Cannot open file",0dh,0ah> 32 jmp quit ; and quit 33 file_ok: 34 ; Read the file into a buffer. 35 mov edx,offset buffer 36 mov ecx,buffer_size 37 call ReadFromFile 38 jnc check_buffer_size ; error reading? 39 mwrite "Error reading file. " ; yes: show error message 40 call WriteWindowsMsg 41 jmp close_file check_buffer_size: 44 cmp eax,buffer_size ; buffer large enough? 45 jb buf_size_ok ; yes 46 mwrite <"Error: Buffer too small for the file",0dh,0ah> 47 jmp quit ; and quit 48 buf_size_ok: 49 mov buffer[eax],0 ; insert null terminator 50 mwrite "File size: " 51 call WriteDec ; display file size 52 call Crlf 53 ; Display the buffer. 54 mwrite <"Buffer:",0dh,0ah,0dh,0ah> 55 mov edx,offset buffer ; display the buffer 56 call WriteString 57 call Crlf close_file: 60 mov eax,filehandle 61 call CloseFile 62 quit: 63 exit 64 main ENDP 65 END main ETF Beograd RE VEŽBE / / 47

23 Manipulacija prozora konzole Manipulacija prozora konzole Win32 API omogućava da se kontroliše veličina prozora konzole i veličina bafera prozora. Prozor konzole prikazuje deo bafera kao što se vidi na slici: ETF Beograd RE VEŽBE / / 47

24 Screen buffer Funkcija SetConsoleWindowInfo GetConsoleScreenBufferInfo SetConsoleCursorPosition ScrollConsoleScreenBuffer Značenje podešava veličinu i poziciju prozora konzole relativno u odnosu na screen buffer vraća koordinate pravougaonika konzolnog prozora relativnog u odnosu na screen buffer postavlja kursor na željenu lokaciju na ekranu; ako nije ta pozicija vidljiva, pomera prozor konzole pomera deo teksta kroz bafer kako ne bi uticao na prikazan tekst u prozoru konzole ETF Beograd RE VEŽBE / / 47

25 Screen buffer SetConsoleTitle Menja se naziv prozora konzole..data titlestr BYTE Console title,0.code INVOKE SetConsoleTitle, ADDR titlestr ETF Beograd RE VEŽBE / / 47

26 Screen buffer GetConsoleScreenBufferInfo Vraća informaciju o tekućem stanju prozora konzole. Ima dva parametra - HANDLE na prozor konzole i pokazivač na strukturu screen buffer-a. GetConsoleScreenBufferInfo PROTO, hconsoleoutput:handle, lpconsolescreenbufferinfo:ptr CONSOLE_SCREEN_BUFFER_INFO ETF Beograd RE VEŽBE / / 47

27 Screen buffer GetConsoleScreenBufferInfo CONSOLE_SCREEN_BUFFER_INFO struktura: CONSOLE_SCREEN_BUFFER_INFO STRUCT dwsize COORD <> dwcursorposition COORD <> wattributes WORD? srwindow SMALL_RECT <> dwmaximumwindowsize COORD <> CONSOLE_SCREEN_BUFFER_INFO ENDS COORD je struktura od dva elementa veličine WORD, u fajlu SmallWin.inc. RECT je struktura od četiri elementa veličine WORD, u fajlu SmallWin.inc. ETF Beograd RE VEŽBE / / 47

28 Screen buffer GetConsoleScreenBufferInfo dwsize - veličina screen buffer-a dwcursorposition - lokacija kursora wattributes - boja karaktera u konzolnom baferu srwindow - koordinate konzolnog prozora relativnih u donosu na screen buffer dwmaximumwindowsize - maksimalna veličina prozora konzole Primer.data consoleinfo CONSOLE_SCREEN_BUFFER_INFO <> outhandle HANDLE?.code INVOKE GetConsoleScreenBufferInfo, outhandle, ADDR consoleinfo ETF Beograd RE VEŽBE / / 47

29 Screen buffer SetConsoleWindowInfo podešava veličinu i lokaciju prozora konzole relativno u odnosu na screen buffer. SetConsoleWindowInfo PROTO, hconsoleoutput:handle, ; screen buffer handle babsolute:dword, ; coordinate type lpconsolewindow:ptr SMALL_RECT ; ptr to window rectangle ETF Beograd RE VEŽBE / / 47

30 Screen buffer SetConsoleScreenBufferSize podešava se veličina screen buffer-a kao broj redova i broj kolona. SetConsoleScreenBufferSize PROTO, hconsoleoutput:handle, ; handle to screen buffer dwsize:coord ; new screen buffer size ETF Beograd RE VEŽBE / / 47

31 Screen buffer 1 ; Scrolling the Console Window (Scroll.asm) 2 3 ; This program writes 50 lines of text to the console buffer, 4 ; resizes, and scrolls the console window back to line 0. 5 ; Demonstrates the SetConsoleWindowInfo function. 6 7 INCLUDE Irvine32.inc 8 9.data 10 message BYTE ": This line of text was written " 11 BYTE "to the screen buffer",0dh,0ah 12 messagesize DWORD ($ message) outhandle HANDLE 0 ; standard output handle 15 byteswritten DWORD? ; number of bytes written 16 linenum DWORD 0 17 windowrect SMALL_RECT <0,0,60,11> ; left,top,right,bottom code 20 main PROC 21 INVOKE GetStdHandle, STD_OUTPUT_HANDLE 22 mov outhandle,eax 23.REPEAT 24 mov eax,linenum 25 call WriteDec ; display each line number 26 INVOKE WriteConsole, 27 outhandle, ; console output handle 28 ADDR message, ; string pointer 29 messagesize, ; string length 30 ADDR byteswritten, ; returns num bytes written 31 0 ; not used 32 inc linenum ; next line number 33.UNTIL linenum > ; Resize and reposition the console window relative to the 36 ; screen buffer. 37 INVOKE SetConsoleWindowInfo, 38 outhandle, 39 TRUE, 40 ADDR windowrect call Readchar ; wait for a key 43 call Clrscr ; clear the screen buffer 44 call Readchar ; wait for a second key INVOKE ExitProcess,0 47 main ENDP 48 END main ETF Beograd RE VEŽBE / / 47

32 Kontrola kursora Funkcija Značenje GetConsoleCursorInf vraća veličinu i vidljivost kursora SetConsoleCursorInfo podešava veličinu i vidljivost kursora SetConsoleCursorPosition podešava X, Y poziciju kursora ETF Beograd RE VEŽBE / / 47

33 Kontrola kursora Struktura kursora CONSOLE_CURSOR_INFO STRUCT dwsize DWORD? bvisible DWORD? CONSOLE_CURSOR_INFO ENDS dwsize - veličina kursora, obično 25 bvisible - vidljivost kursora - TRUE ako je vidljiv ETF Beograd RE VEŽBE / / 47

34 Kontrola kursora GetConsoleCursorInfo/SetConsoleCursorInfo GetConsoleCursorInfo GetConsoleCursorInfo PROTO, hconsoleoutput:handle, lpconsolecursorinfo:ptr CONSOLE_CURSOR_INFO SetConsoleCursorInfo SetConsoleCursorInfo PROTO, hconsoleoutput:handle, lpconsolecursorinfo:ptr CONSOLE_CURSOR_INFO ETF Beograd RE VEŽBE / / 47

35 Kontrola kursora SetConsoleCursorPosition SetConsoleCursorPosition PROTO, hconsoleoutput:dword, ; input mode handle dwcursorposition:coord ; screen X,Y coordinates ETF Beograd RE VEŽBE / / 47

36 Kontrola kursora 1 ; Console Demo #2 (Console2.asm) 2 3 ; Demonstration of SetConsoleCursorPosition, 4 ; GetConsoleCursorInfo, SetConsoleCursorInfo, 5 ; SetConsoleScreenBufferSize, SetConsoleCursorPosition, 6 ; SetConsoleTitle, and GetConsoleScreenBufferInfo. 7 8 INCLUDE SmallWin.inc 9 10.data 11 outhandle DWORD? 12 scrsize COORD <120,50> 13 xypos COORD <20,5> 14 consoleinfo CONSOLE_SCREEN_BUFFER_INFO <> 15 cursorinfo CONSOLE_CURSOR_INFO <> 16 titlestr BYTE "Console2 Demo Program", code 19 main PROC 20 ; Get Console output handle. 21 INVOKE GetStdHandle, STD_OUTPUT_HANDLE 22 mov outhandle,eax ; Get console cursor information. 25 INVOKE GetConsoleCursorInfo, outhandle, 26 ADDR cursorinfo 27 ; Set console cursor size to 75% 28 mov cursorinfo.dwsize,75 29 INVOKE SetConsoleCursorInfo, outhandle, 30 ADDR cursorinfo ; Set the screen buffer size. 33 INVOKE SetConsoleScreenBufferSize, 34 outhandle,scrsize ; Set the cursor position to (20,5). 37 INVOKE SetConsoleCursorPosition, outhandle, xypos ; Set the console window s title. 40 INVOKE SetConsoleTitle, ADDR titlestr ; Get screen buffer & window size information. 43 INVOKE GetConsoleScreenBufferInfo, outhandle, 44 ADDR consoleinfo INVOKE ExitProcess,0 47 main ENDP 48 END main ETF Beograd RE VEŽBE / / 47

37 Promena boje teksta Promena boje teksta SetConsoleTextAttribute Podešava foreground i background boju teksta. SetConsoleTextAttribute PROTO, hconsoleoutput:handle, ; console output handle wattributes:word ; color attribute WriteConsoleOutputAttribute Kopira niz vrednosti atributa u uzastopne registre screen buffer-a počevši na specificiranoj lokaciji. WriteConsoleOutputAttribute PROTO, hconsoleoutput:dword, ; output handle lpattribute:ptr WORD, ; write attributes nlength:dword, ; number of cells dwwritecoord:coord, ; first cell coordinates lpnumberofattrswritten:ptr DWORD ; output count ETF Beograd RE VEŽBE / / 47

38 Promena boje teksta 1 ; Writing Text Colors (WriteColors.asm) 2 3 ; Demonstration of WriteConsoleOutputCharacter, 4 ; and WriteConsoleOutputAttribute functions. 5 6 INCLUDE Irvine32.inc 7.data 8 outhandle HANDLE? 9 cellswritten DWORD? 10 xypos COORD <10,2> ; Array of character codes: 13 buffer BYTE 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 14 BYTE 16,17,18, BufSize DWORD ($ buffer) 16 ; Array of attributes: 17 attributes WORD 0Fh,0Eh,0Dh,0Ch,0Bh,0Ah,9,8,7,6 18 WORD 5,4,3,2,1,0F0h,0E0h,0D0h,0C0h,0B0h code 21 main PROC ; Get the Console standard output handle: 24 INVOKE GetStdHandle, STD_OUTPUT_HANDLE 25 mov outhandle,eax ; Set the colors from (10,2) to (30,2): 28 INVOKE WriteConsoleOutputAttribute, 29 outhandle, ADDR attributes, 30 BufSize, xypos, 31 ADDR cellswritten 32 ; Write character codes 1 to 20: 33 INVOKE WriteConsoleOutputCharacter, 34 outhandle, ADDR buffer, BufSize, 35 xypos, ADDR cellswritten call ReadChar 38 exit 39 main ENDP 40 END main ETF Beograd RE VEŽBE / / 47

39 Time/Date funkcije Time/Date funkcije Funkcije i strukture su: GetLocalTime, SetLocalTime GetTickCount, Sleep GetDateTime SYSTEMTIME struktura ETF Beograd RE VEŽBE / / 47

40 Time/Date funkcije SYSTEMTIME struktura SYSTEMTIME se koristi sa time/date Win32 API funkcijama. SYSTEMTIME STRUCT wyear WORD? ; year (4 digits) wmonth WORD? ; month (1-12) wdayofweek WORD? ; day of week (0-6) wday WORD? ; day (1-31) whour WORD? ; hours (0-23) wminute WORD? ; minutes (0-59) wsecond WORD? ; seconds (0-59) wmilliseconds WORD? ; milliseconds (0-999) SYSTEMTIME ENDS ETF Beograd RE VEŽBE / / 47

41 Time/Date funkcije GetLocalTime/SetLocalTime GetLocalTime vraća vreme i datum tekućeg dana na osnovu sistemskog sata. GetLocalTime PROTO, lpsystemtime:ptr SYSTEMTIME SetLocalTime podešava sistemsko vreme i datum. SetLocalTime PROTO, lpsystemtime:ptr SYSTEMTIME ETF Beograd RE VEŽBE / / 47

42 Time/Date funkcije GetTickCount, Sleep GetTickCount vraća broj ms proteklih od startovanja sistema. Sleep GetTickCount PROTO ; return value in EAX pauzira tekući program na specificirani broj ms. Sleep PROTO, dwmilliseconds:dword ETF Beograd RE VEŽBE / / 47

43 Time/Date funkcije 1 ; Calculate Elapsed Time (Timer.asm) 2 3 ; Demonstrate a simple stopwatch timer, using 4 ; the Win32 GetTickCount function. 5 6 INCLUDE Irvine32.inc 7 INCLUDE macros.inc 8 9.data 10 starttime DWORD? code 13 main PROC 14 INVOKE GetTickCount ; get starting tick count 15 mov starttime,eax ; save it ; Create a useless calculation loop. 18 mov ecx, h 19 L1: imul ebx 20 imul ebx 21 imul ebx 22 loop L1 23 INVOKE GetTickCount ; get new tick count 24 cmp eax,starttime ; lower than starting one? 25 jb error ; it wrapped around sub eax,starttime ; get elapsed milliseconds 28 call WriteDec ; display it 29 mwrite <" milliseconds have elapsed",0dh,0ah > 30 jmp quit error: 33 mwrite "Error: GetTickCount invalid--system has " 34 mwrite <"been active for more than 49.7 days ",0dh,0ah> 35 quit: 36 exit 37 main ENDP END main ETF Beograd RE VEŽBE / / 47

44 Time/Date funkcije 1 ; Calculate Elapsed Time (TimingLoop.asm) 2 3 ; This program uses GetTickCount to calculate the number 4 ; of milliseconds that have elapsed since the program 5 ; started. 6 7 INCLUDE Irvine32.inc 8 9 TIME_LIMIT = data 11 starttime DWORD? 12 dot BYTE ".", code 15 main PROC 16 INVOKE GetTickCount 17 mov starttime,eax L1: 20 mov edx,offset dot ; display a dot 21 call WriteString INVOKE Sleep,100 ; sleep for 100ms INVOKE GetTickCount 26 sub eax,starttime ; check the elapsed time 27 cmp eax,time_limit 28 jb L L2: exit 31 main ENDP 32 END main ETF Beograd RE VEŽBE / / 47

45 Primer programa Bouncing Ball Bouncing Ball Write a program that simulates a ball bouncing within a rectangle. Your rectangle will be the size of the standard MS-DOS screen: 25 rows by 80 columns (X = 0-79 and Y = 0-24). The rectangle should contain an internal vertical wall consisting of a single column of block characters (ASCII code 0DBh) starting at row 5, column 40, extending down to row 19, column 40. The background should be blue, and the wall and ball should be white. The ball travels at a constant speed, determined by a delay value of 20 ms inside the loop that displays, erases, and moves the ball. The following sequence of actions will be in the loop: display, delay, erase, move. The ball is just a single character, drawn with the ASCII code 2. To move the ball, you write over it with a blank, move the cursor position to a new location, and redraw the ball. The ball can only move 1 row and 1 column during each loop cycle. You will need to call the following library procedures: Clrscr, Delay, SetTextColor, WriteChar and Gotoxy. You will (probably) need to use the high-level.if,.else and.endif directives explained at the end of Chapter 6. ETF Beograd RE VEŽBE / / 47

46 Primer programa Bouncing Ball Suggested Algorithm: Suppose you have a current location (X, Y), and two direction values, dx, and dy. The latter control the ball s movement. For example, if dx = 1 and dy = 1, the ball is moving downward and to the right. Evaluate the potential new X and Y location: 1 If the new location is outside the rectangle s X and Y coordinates, reverse the ball s direction by negating dx or dy, whichever is appropriate. 2 If the new location is in the middle of the vertical wall, negate dx. 3 If the new location is either the top or the bottom of the vertical wall, negate dy. Next, add dx and dy to your current X and Y coordinates, generating the ball s new location. Redraw the ball at this new location. ETF Beograd RE VEŽBE / / 47

47 KRAJ! ETF Beograd RE VEŽBE / / 47