winapiassemblymasmmasm32
Win32 paint application
I have to write a program like paint in Windows. I'm using MASM32. Everything come normaly but when I move my mouse to draw, it draw a dash line, not a solid line.
Please help me to fix this :( Do we have another idea for this? Thank you and sorry for my bad English
P/S: Look at an image to see my problem!
.386 ; use 80386 instruction
.model flat,stdcall ; uses flat memory addressing model
option casemap:none
include C:\masm32\include\windows.inc ; windows.inc have structures and constants
include C:\masm32\include\user32.inc
includelib C:\masm32\lib\user32.lib ; CreateWindowEx, RegisterClassEx,...
include C:\masm32\include\kernel32.inc
includelib C:\masm32\lib\kernel32.lib ; ExitProcess
include C:\masm32\include\masm32.inc
includelib C:\masm32\lib\masm32.lib
include C:\masm32\include\gdi32.inc
includelib C:\masm32\lib\gdi32.lib
.CONST
DRAWING equ 1
WAITING equ 0
.DATA
ClassName db 'SimpleWinClass',0
AppName db 'Paint',0
labelNoti db 'Notification',0
labelClick db 'Start draw!',0
labelRelease db 'Stop draw!',0
labelDrawing db 'Drawing...',0
labelWaiting db 'Waiting.',0
object db '.',0
fontName db 'myfont',0
StaticClassName db 'static',0
X dw 'x',0
Y dw 'y',0
state db WAITING
.DATA?
; HINSTANCE & LPSTR typedef DWORD in windows.inc
; reserve the space for future use
hInstance HINSTANCE ?
CommandLine LPSTR ?
hitpoint POINT <>
; use for create window
wc WNDCLASSEX <?>
msg MSG <?> ; handle message
hwnd HWND ? ; handle window procedure
hwndX HWND ?
hwndY HWND ?
hwndState HWND ?
hdc HDC ?
ps PAINTSTRUCT <?>
font HGDIOBJ ?
hFont HFONT ?
.CODE
start:
; call GetModuleHandle(null)
; https://msdn.microsoft.com/en-us/library/windows/desktop/ms683199(v=vs.85).aspx
push NULL
call GetModuleHandle ; module handle same as instance handle in Win32
mov hInstance, eax ; return an instance to handle in eax
; call GetCommandLine()
; https://msdn.microsoft.com/en-us/library/windows/desktop/ms683156(v=vs.85).aspx
call GetCommandLine ; no parameters
mov CommandLine, eax ; return a pointer to the command-line for current process
; call WinMain(hInstance, hPrevInstance, CmdLine, CmdShow)
; our main function
push SW_SHOW
push CommandLine
push NULL
push hInstance
call WinMain
; call ExitProcess
push eax
call ExitProcess
; Define WinMain
WinMain proc hInst:HINSTANCE, hPrevInst:HINSTANCE, CmdLine:LPSTR, CmdShow:DWORD
; Structure in msdn, define in windows.inc
; https://msdn.microsoft.com/en-us/library/windows/desktop/ms633577(v=vs.85).aspx
; Load default icon
push IDI_APPLICATION
push NULL
call LoadIcon
mov wc.hIcon, eax
mov wc.hIconSm, eax
; Load default cursor
push IDC_ARROW
push NULL
call LoadCursor
mov wc.hCursor, eax
mov wc.cbSize, SIZEOF WNDCLASSEX ; size of this structure
mov wc.style, CS_HREDRAW or CS_VREDRAW ; style of windows https://msdn.microsoft.com/en-us/library/windows/desktop/ff729176(v=vs.85).aspx
mov wc.lpfnWndProc, OFFSET WndProc ; andress of window procedure
mov wc.cbClsExtra, NULL
mov wc.cbWndExtra, NULL
push hInstance
pop wc.hInstance
mov wc.hbrBackground,COLOR_WINDOW+1 ; background color, require to add 1
mov wc.lpszMenuName, NULL
mov wc.lpszClassName, OFFSET ClassName
; we register our own class, named in ClassName
push offset wc
call RegisterClassEx
; after register ClassName, we use it to create windows compond
; https://msdn.microsoft.com/en-us/library/windows/desktop/ms632680(v=vs.85).aspx
push NULL
push hInstance
push NULL
push NULL
push 600
push 600
push CW_USEDEFAULT
push CW_USEDEFAULT
push WS_OVERLAPPEDWINDOW
push offset AppName
push offset ClassName
push WS_EX_CLIENTEDGE
call CreateWindowEx
mov hwnd, eax ; return windows handle
; display window
; https://msdn.microsoft.com/en-us/library/windows/desktop/ms633548(v=vs.85).aspx
push CmdShow
push hwnd
call ShowWindow
; update window
; https://msdn.microsoft.com/en-us/library/windows/desktop/dd145167(v=vs.85).aspx
push hwnd
call UpdateWindow
; Message Loop
MESSAGE_LOOP:
; get message
; https://msdn.microsoft.com/en-us/library/windows/desktop/ms644936(v=vs.85).aspx
push 0
push 0
push NULL
push offset msg
call GetMessage
; return in eax
; if the function retrieves a message other than WM_QUIT, the return value is nonzero.
; if the function retrieves the WM_QUIT message, the return value is zero.
cmp eax, 0
jle END_LOOP
; translate virtual-key messages into character messages - ASCII in WM_CHAR
; https://msdn.microsoft.com/en-us/library/windows/desktop/ms644955(v=vs.85).aspx
push offset msg
call TranslateMessage
; sends the message data to the window procedure responsible for the specific window the message is for.
; https://msdn.microsoft.com/en-us/library/windows/desktop/ms644934(v=vs.85).aspx
push offset msg
call DispatchMessage
jmp MESSAGE_LOOP
END_LOOP:
mov eax, msg.wParam
ret
WinMain endp
; Handle message with switch(notification)
; https://msdn.microsoft.com/en-us/library/windows/desktop/ms633573(v=vs.85).aspx
WndProc proc hWnd:HWND, uMsg:UINT, wParam:WPARAM, lParam:LPARAM
; close app
cmp uMsg, WM_DESTROY
je ON_WM_DESTROY
cmp uMsg, WM_CREATE
je ON_WM_CREATE
cmp uMsg, WM_PAINT
je ON_WM_PAINT
cmp uMsg, WM_LBUTTONDOWN
je ON_WM_LBUTTONDOWN
cmp uMsg, WM_LBUTTONUP
je ON_WM_LBUTTONUP
cmp uMsg, WM_MOUSEMOVE
je ON_WM_MOUSEMOVE
jmp ON_DEFAULT
; user close program
ON_WM_DESTROY:
push NULL
call PostQuitMessage
jmp EXIT
ON_WM_CREATE:
; create static text
push NULL
push hInstance
push 1
push hWnd
push 25
push 50
push 20
push 20
push WS_CHILD or WS_VISIBLE or WS_BORDER or ES_LEFT
push offset X
push offset StaticClassName
push WS_EX_CLIENTEDGE
call CreateWindowEx
mov hwndX, eax
; create static text
push NULL
push hInstance
push 1
push hWnd
push 25
push 50
push 20
push 90
push WS_CHILD or WS_VISIBLE or WS_BORDER or ES_LEFT
push offset Y
push offset StaticClassName
push WS_EX_CLIENTEDGE
call CreateWindowEx
mov hwndY, eax
; create static text
push NULL
push hInstance
push 1
push hWnd
push 25
push 80
push 60
push 20
push WS_CHILD or WS_VISIBLE or WS_BORDER or ES_LEFT
push offset labelWaiting
push offset StaticClassName
push WS_EX_CLIENTEDGE
call CreateWindowEx
mov hwndState, eax
push offset fontName
push DEFAULT_PITCH or FF_DONTCARE
push DEFAULT_QUALITY
push CLIP_DEFAULT_PRECIS
push CLIP_DEFAULT_PRECIS
push DEFAULT_CHARSET
push FALSE
push FALSE
push FALSE
push 700
push 0
push 0
push 16
push 24
call CreateFont
mov font, eax
jmp EXIT
ON_WM_LBUTTONDOWN:
mov [state], DRAWING
push offset labelDrawing
push hwndState
call SetWindowText
jmp EXIT
ON_WM_LBUTTONUP:
mov [state], WAITING
push offset labelWaiting
push hwndState
call SetWindowText
jmp EXIT
ON_WM_MOUSEMOVE:
push lParam
call updateXY
cmp [state], DRAWING
je DRAW
jne EXIT
DRAW:
push FALSE
push NULL
push hWnd
call InvalidateRect
jmp EXIT
ON_WM_PAINT:
push offset ps
push hWnd
call BeginPaint
mov hdc, eax
push font
push hdc
call SelectObject
mov hFont, eax
push 1
push offset object
push hitpoint.y
push hitpoint.x
push hdc
call TextOut
push hFont
push hWnd
call SelectObject
push offset ps
push hWnd
call EndPaint
jmp EXIT
ON_DEFAULT:
; handle any message that program don't handle
; https://msdn.microsoft.com/en-us/library/windows/desktop/ms633572(v=vs.85).aspx
push lParam
push wParam
push uMsg ; message
push hWnd ; windows
call DefWindowProc
jmp EXIT
EXIT:
ret
WndProc endp
updateXY proc lParam:LPARAM
mov eax, lParam
xor ebx, ebx
mov bx, ax
mov hitpoint.x, ebx
push offset X
push ebx
call dwtoa
push offset X
push hwndX
call SetWindowText
mov eax, lParam
shr eax, 16
mov hitpoint.y, eax
push offset Y
push eax
call dwtoa
push offset Y
push hwndY
call SetWindowText
ret
updateXY endp
end start
Solution
You're using the string output function TextOut to output a dot ('.') as a point. This character has more (white) background than (black) data points. So moving the mouse overwrites the points at the current position with background. You can see the effect when you cross the lines.
You need a character with more black data. Let's choose the space (' ') and invert the background:
object db ' ',0
...
ON_WM_PAINT:
...
mov hFont, eax
invoke SetBkColor, hdc, 00FF0000h
push 1
push offset object
push hitpoint.y
push hitpoint.x
push hdc
call TextOut
...
INVOKE is a built-in MASM macro that do the appropriate pushes, pops and calls for you according to the calling convention declared in a preceding PROTO or PROC directive or the default calling convention. For example, you can change
push 1
push offset object
push hitpoint.y
push hitpoint.x
push hdc
call TextOut
to
invoke TextOut, hdc, hitpoint.x, hitpoint.y, offset object, 1
A dashed line is also caused by the mouse acceleration if you quickly move the mouse. I've found no easy way to turn off that acceleration. An appropriate size of the inverted space reduces the chance for a dash line if you slowly move the mouse. Change width and height of the font:
push offset fontName
push DEFAULT_PITCH or FF_DONTCARE
push DEFAULT_QUALITY
push CLIP_DEFAULT_PRECIS
push CLIP_DEFAULT_PRECIS
push DEFAULT_CHARSET
push FALSE
push FALSE
push FALSE
push 700
push 0
push 0
push 18 ; Width
push 12 ; Height
call CreateFont
mov font, eax
Better is to use MoveToEx and LineTo to paint a line from the last mouse position to the current mouse position. To set the thickness of the line you can use CreatePen and SelectObject.
Example for LineTo:
.386 ; use 80386 instruction
.model flat,stdcall ; uses flat memory addressing model % STDCALL as default calling convention
option casemap:none
include C:\masm32\include\windows.inc
include C:\masm32\include\kernel32.inc
include C:\masm32\include\user32.inc
include C:\masm32\include\gdi32.inc
include C:\masm32\include\masm32.inc
includelib C:\masm32\lib\kernel32.lib ; ExitProcess, GetCommandLineA, GetModuleHandleA
includelib C:\masm32\lib\user32.lib ; BeginPaint, CreateWindowExA@, DefWindowProcA, DispatchMessageA, EndPaint, GetMessageA, InvalidateRect, LoadCursorA, LoadIconA, PostQuitMessage, RegisterClassExA, SetWindowTextA, ShowWindow, TranslateMessage, UpdateWindow
includelib C:\masm32\lib\gdi32.lib ; CreatePen, LineTo, MoveToEx, SelectObject
includelib C:\masm32\lib\masm32.lib ; dwtoa
.CONST
DRAWING equ 1
WAITING equ 0
.DATA
ClassName db 'SimpleWinClass',0
AppName db 'Paint',0
labelDrawing db 'Drawing...',0
labelWaiting db 'Waiting.',0
StaticClassName db 'static',0
X dw 'x',0
Y dw 'y',0
state db WAITING
.DATA?
hInstance HINSTANCE ?
CommandLine LPSTR ?
hitpoint POINT <>
lastpoint POINT <>
wc WNDCLASSEX <?>
msg MSG <?> ; handle message
hwnd HWND ? ; handle window procedure
hwndX HWND ?
hwndY HWND ?
hwndState HWND ?
hdc HDC ?
ps PAINTSTRUCT <?>
hPen HPEN ?
.CODE
updateXY PROC lParam:LPARAM
movzx eax, WORD PTR lParam
mov hitpoint.x, eax
invoke dwtoa, eax, offset X
invoke SetWindowText, hwndX, offset X
mov eax, lParam
shr eax, 16
mov hitpoint.y, eax
invoke dwtoa, eax, offset Y
invoke SetWindowText, hwndY, offset Y
ret
updateXY ENDP
; https://msdn.microsoft.com/library/windows/desktop/ms633573.aspx
WndProc PROC hWnd:HWND, uMsg:UINT, wParam:WPARAM, lParam:LPARAM
cmp uMsg, WM_MOUSEMOVE
je ON_WM_MOUSEMOVE
cmp uMsg, WM_PAINT
je ON_WM_PAINT
cmp uMsg, WM_CREATE
je ON_WM_CREATE
cmp uMsg, WM_LBUTTONDOWN
je ON_WM_LBUTTONDOWN
cmp uMsg, WM_LBUTTONUP
je ON_WM_LBUTTONUP
cmp uMsg, WM_DESTROY
je ON_WM_DESTROY
jmp ON_DEFAULT
ON_WM_DESTROY: ; User closes program
invoke PostQuitMessage, NULL
jmp EXIT
ON_WM_CREATE:
; Create windows for text
invoke CreateWindowEx, WS_EX_CLIENTEDGE, offset StaticClassName, offset X, WS_CHILD or WS_VISIBLE or WS_BORDER or ES_LEFT, 20, 20, 50, 25, hWnd, 1, hInstance, NULL
mov hwndX, eax
invoke CreateWindowEx, WS_EX_CLIENTEDGE, offset StaticClassName, offset Y, WS_CHILD or WS_VISIBLE or WS_BORDER or ES_LEFT, 90, 20, 50, 25, hWnd, 1, hInstance, NULL
mov hwndY, eax
invoke CreateWindowEx, WS_EX_CLIENTEDGE, offset StaticClassName, offset labelWaiting, WS_CHILD or WS_VISIBLE or WS_BORDER or ES_LEFT, 20, 60, 80, 23, hWnd, 1, hInstance, NULL
mov hwndState, eax
; Create pen for LineTo
invoke CreatePen, PS_SOLID, 10, 00FF0000h
mov hPen, eax
jmp EXIT
ON_WM_LBUTTONDOWN:
; last mouse position = current mouse position
mov eax, hitpoint.x
mov lastpoint.x, eax
mov eax, hitpoint.y
mov lastpoint.y, eax
mov [state], DRAWING
invoke SetWindowText, hwndState, offset labelDrawing
jmp EXIT
ON_WM_LBUTTONUP:
mov [state], WAITING
invoke SetWindowText, hwndState, offset labelWaiting
jmp EXIT
ON_WM_MOUSEMOVE:
invoke updateXY, lParam ; PROC above
cmp [state], DRAWING
jne EXIT
invoke InvalidateRect, hWnd, NULL, FALSE ; https://msdn.microsoft.com/library/dd145002.aspx
jmp EXIT
ON_WM_PAINT:
invoke BeginPaint, hWnd, offset ps
invoke MoveToEx, ps.hdc, lastpoint.x, lastpoint.y, NULL
invoke SelectObject, ps.hdc, hPen;
invoke LineTo, ps.hdc, hitpoint.x, hitpoint.y
mov eax, hitpoint.x ; last mouse position = current mouse position
mov lastpoint.x, eax
mov eax, hitpoint.y
mov lastpoint.y, eax
invoke EndPaint, hWnd, offset ps
jmp EXIT
ON_DEFAULT: ; handle any message that program don't handle
invoke DefWindowProc, hWnd, uMsg, wParam, lParam ; https://msdn.microsoft.com/library/windows/desktop/ms633572.aspx
jmp EXIT
EXIT:
ret
WndProc ENDP
WinMain PROC hInst:HINSTANCE, hPrevInst:HINSTANCE, CmdLine:LPSTR, CmdShow:DWORD
; WNDCLASSEX structure in MSDN, declaration in windows.inc
; https://msdn.microsoft.com/library/windows/desktop/ms633577.aspx
invoke LoadIcon, NULL, IDI_APPLICATION ; Load default icon
mov wc.hIcon, eax
mov wc.hIconSm, eax
invoke LoadCursor, NULL, IDC_ARROW ; Load default cursor
mov wc.hCursor, eax
mov wc.cbSize, SIZEOF WNDCLASSEX ; size of this structure
mov wc.style, CS_HREDRAW or CS_VREDRAW ; style of windows https://msdn.microsoft.com/library/windows/desktop/ff729176.aspx
mov wc.lpfnWndProc, OFFSET WndProc ; andress of window procedure
mov wc.cbClsExtra, NULL
mov wc.cbWndExtra, NULL
push hInstance
pop wc.hInstance
mov wc.hbrBackground,COLOR_WINDOW+1 ; background color, require to add 1
mov wc.lpszMenuName, NULL
mov wc.lpszClassName, OFFSET ClassName
invoke RegisterClassEx, offset wc ; https://msdn.microsoft.com/library/windows/desktop/ms633587.aspx
; https://msdn.microsoft.com/library/windows/desktop/ms632680.aspx
invoke CreateWindowEx, WS_EX_CLIENTEDGE, offset ClassName, offset AppName, WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, 600, 600, NULL, NULL, hInstance, NULL
mov hwnd, eax ; Store windows handle
invoke ShowWindow, hwnd, CmdShow ; https://msdn.microsoft.com/library/windows/desktop/ms633548.aspx
invoke UpdateWindow, hwnd ; https://msdn.microsoft.com/library/windows/desktop/dd145167.aspx
; Message Loop
MESSAGE_LOOP: ; https://msdn.microsoft.com/library/windows/desktop/ms644936.aspx
invoke GetMessage, offset msg, NULL, 0, 0
test eax, eax
jle END_LOOP
invoke TranslateMessage, offset msg
invoke DispatchMessage, offset msg
jmp MESSAGE_LOOP
END_LOOP:
mov eax, msg.wParam
ret
WinMain ENDP
main PROC
invoke GetModuleHandle, NULL ; https://msdn.microsoft.com/library/windows/desktop/ms683199.aspx
mov hInstance, eax ; return an instance to handle in eax
invoke GetCommandLine ; https://msdn.microsoft.com/library/windows/desktop/ms683156.aspx
mov CommandLine, eax ; return a pointer to the command-line for current process
invoke WinMain, hInstance, NULL, CommandLine, SW_SHOW
invoke ExitProcess, eax
main ENDP
END main