Complete Guide of the Assembly Language To Handle Character Display Using 32 bit System Call in Graphics mode

1. Handling Character Display
in graphics mode Using
32 bit system call
ASJAD ALI
(p14-6100)

2. LIST OF TOICS
 Write Console
 GetStdHandle
 GetConsoleCursorInfo
 SetConsoleCursorInfo
 ConsoleScreenBufferInfo
 GetConsoleScreenBufferInfo
 SetConsoleScreenBufferSize
 SetConsoleTitle
 WriteConsoleOutputAttribute

3.  TYPE OF BUFFER:
 INPUT BUFFER:
 Input Buffer contain queue of inputs record
 E.g Mouse Click , Keyboard etc
 SECREEN BUFFER:
 2D array of Character and color data affecting
appearance of text

4.  INVOKE WriteConsole,
 eax, ; console output handle
 edx, ; string pointer
 ecx, ; string length
 ADDR bytesWritten,
 WriteConsole
(
_In_ HANDLE hConsoleOutput,
_In_ VOID *lpBuffer,
_In_ DWORD nNumberOfCharsToWrite,
_Out_ LPDWORD lpNumberOfCharsWritten,
);

5.  GetStdHandle
 GET the Control of the Screen Buffer
INVOKE GetStdHandle, STD_OUTPUT_HANDLE
mov outHandle,eax

6.  ;INVOKE GetConsoleCursorInfo, outHandle,
 ; ADDR cursorInfo
 ;mov eax, cursorInfo.dwSize
 typedef struct _CONSOLE_CURSOR_INFO
 {
 DWORD dwSize;
 BOOL bVisible;
 }

7.  ;mov cursorInfo.bVisible,1
 ;mov cursorInfo.dwSize,100
 ;INVOKE SetConsoleCursorInfo, outHandle,
 ; ADDR cursorInfo
 SetConsoleCursorInfo
 (
 HANDLE hConsoleOutput,
 CONSOLE_CURSOR_INFO *lpConsoleCursorInfo
 );

8.  CONSOLE_SCREEN_BUFFER_INFO
 {
 COORD dwSize;
COORD dwCursorPosition;
WORD wAttributes; SMALL_RECT
srWindow;
COORD dwMaximumWindowSize;
 }

9.  INVOKE GetConsoleScreenBufferInfo,
outHandle,
 ADDR consoleInfo
 GetConsoleScreenBufferInfo
 (
 HANDLE hConsoleOutput, (input)
 PCONSOLE_SCREEN_BUFFER_INFO
*lpConsoleScreenBufferInfo (Output)
 );

10.  mov scrSize.x, 80
 mov scrSize.y, 25
 INVOKE SetConsoleScreenBufferSize,
 outHandle,scrSize

11. INVOKE SetConsoleTitle,
ADDR titleStr

12.  INVOKE WriteConsoleOutputAttribute,
 outHandle, ADDR attributes,
 BufSize, xyPos,
 ADDR cellsWritten
 WriteConsoleOutputAttribute
 (
 _In_ HANDLE hConsoleOutput,
 _In_ WORD *lpAttribute,
 _In_ DWORD nLength,
 _In_ COORD dwWriteCoord,
 _Out_ LPDWORD lpNumberOfAttrsWritten
 );