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Okay, before I even begin, I will offer a warning: You might regard the code you are about to read crazy. In it, I use ESP to reference params and locals, I SUBtract from ESP and MOVe params, rather than PUSHing and POPping, and you won't find a PROC...ENDP, STRUCT, or WM_* anywhere.

It is this way because I was trying to learn what all those luxuries do for me, and then binrapt on #win32asm said I might as well use ESP for speed or write it in C. Naturally, being a n00b not to be outdone, I did just that. And, for the most part, it works. I even figured out how to shortcircuit DefWindowProc to return to WndProc's caller. However, I have goofed something where I handle the WM_PAINT message, and after WM_PAINT is handled, WndProc RETurns and then crashes. But, only on that message do thing go wrong...

It is commented, however, it is probably painful to look at. I have also attached the file, which retains my indentation, making it slightly easier to read than what is below.

; Assemble with "GoAsm <file.asm>"

; Link with "GoLink <file.asm> kernel32.dll user32.dll"
; Append "-debug coff" to GoLine command to link with symbols

data section

	szClsNm		db "FastererWin", 0x0
	szAppNm		db "Attempt at a ", 0x22, "Fasterer", 0x22, " Window Implementation", 0x0
	szText		db "This is my attempt at a ", 0x22, "fasterer", 0x22, " window ", \
			   "implementation. Rather than managing a ", \
			   "static stack frame manually through EBP, ", \
			   "I manage a dynamic stack frame through ESP.", \
			   0xA, 0xA, \
			   "To alleviate the headache that ensues from ", \
			   "trying to keep track of params and locals ", \
			   "on the stack, especially between intervening ", \
			   "PUSHes and POPs, I did away with them all ", \
			   "together. Instead, I SUBtract from ESP the ", \
			   "number of bytes I need for passing params. ", \
			   "This allows me to deal with a fixed number ", \
			   "of intervening bytes throughout the entire ", \
			   "process of putting params on the stack, as ", \
			   "opposed to the number changing with each ", \
			   "PUSH. An ideal side effect of using this ", \
			   "method is that now I can place params on the ", \
			   "stack in left-to-right order, at increasing ", \
			   "offsets from ESP, instead of right-to-left, ", \
			   "at decreasing offsets from EBP.", \
			   0xA, 0xA, \
			   "Well, any speed advantage will surely not be ", \
			   "human-perceptible, but at least I have the ", \
			   "satisfaction of know that this implementation ", \
			   "is ", 0x22, "fasterer", 0x22, " than my last one. Also, I have ", \
			   "discovered an opportunity for additional speed ", \
			   "gain. About 99.999% of windows messages, at ", \
			   "least in this program, are sent to DefWindowProc. ", \
			   "Instead of WndProc coping its params on the stack ", \
			   "before calling DefWindowProc, it just discards ", \
			   "its local storage and JuMPs to it instead. ", \
			   "This eliminates two copies of the same data ", \
			   "on the stack and one whole procedure RETurn."
			   0x0

	hInst		dd 0x0

code section

Start:

	; Get hInst

	sub esp, 0x4			; Prep 1 Arg
	mov d, 0x0			; Calling App hInst
	call GetModuleHandleA		; Get hInst
	mov , eax		; Save hInst

	; Call FastererWin

	sub esp, 0x10			; Prep 4 Args
	mov , eax			; hInst
	mov d, 0x0		; No Prev Inst
	mov d, 0x0		; No Cmd Ln
	mov d, 0xA		; Show Def
	call WinMain			; FastererWin

	; Exit to Win

	ret 				; Ret Val in EAX

WinMain:

	; Reserve Auto Store

	sub esp, 0x4C			; 0x30+0x18+0x4

	; No Crit Regs on Stack

	; Auto Store on Stack

	; WndClsEx:	esp		; 0x0
	; cbSize	+0x0
	; style		+0x4
	; lpfnWndProc	+0x8
	; cbClsEx	+0xC
	; cbWndEx	+0x10
	; hInst		+0x14
	; hIcon		+0x18
	; hCurs		+0x1C
	; hbrBckGrnd	+0x20
	; lpszMnuNm	+0x24
	; lpszClsNm	+0x28
	; hIconSm	+0x2C

	; Msg:		esp+0x30	; 0x0+0x30
        ; hWnd		+0x0
	; msg		+0x4
	; wParam	+0x8
	; lParam	+0xC
	; time		+0x10
	; pt		+0x14

        ; hWnd:		esp+0x48	; 0x30+0x18

	; Ret Addr on Stack

	; Ret EIP:	esp+0x4C	; 0x48+0x4

	; Params on Stack

        ; hInst		esp+0x50	; 0x4C+0x4
        ; hPrevInst	esp+0x54	; 0x50+0x4
	; lpCmdLn	esp+0x58	; 0x54+0x4
	; nCmdShow	esp+0x5C	; 0x58+0x4

	; Do Not Preserve Crit Regs

	; Fill WinClsEx

	mov d, 0x30		; WinClsEx Size
	mov d, 0x1|0x2		; Horiz and Vert Redraw
	mov d, addr WndProc	; FastererWin Wndproc
	mov d, 0x0		; No Extra Cls Bytes
	mov d, 0x0		; No Extra Wnd Bytes
	mov , eax		; EAX Still hInst
	mov d, 0x5		; Window Color
	mov d, 0x0		; No Menu
	mov d, addr szClsNm	; FastererWin Cls Nm

	; Get WinClsEx hIcon and hIconSm

	sub esp, 0x8			; Prep 2 Args
	mov d, 0x0			; Sys hIcon
	mov d, 0x7F00		; Std App hIcon
	call LoadIconA			; Get hIcon
	mov , eax		; Save WinClsEx hIcon
	mov , eax		; Save WinClsEx hIconSm

	; Get WinClsEx hCurs

	sub esp, 0x8			; Prep 2 Args
	; WOW! --->			; Correct Args Still on Stack
	call LoadCursorA		; Get hCurs
	mov , eax		; Save WinClsEx hCurs

	; Register FastererWin WinCls

	lea eax, 			; Load WinClsEx Addr
	sub esp, 0x4			; Prep 1 Arg
	mov , eax			; WinClsEx Addr
	call RegisterClassExA		; Register FastererWin WinCls

	; Create FastererWin Win

	sub esp, 0x30			; Prep 12 Args
	mov d, 0x0			; No Ex Style
	mov , addr szClsNm	; FastererWin
	mov , addr szAppNm
	mov d, 0x0|0x40000|0x80000|0xC00000
					; Overlapped|ThickFrame|SysMnu|Caption
	mov d, 0x80000000	; Def X Coord
	mov d, 0x80000000	; Def Y Coord
	mov d, 0x80000000	; Def Width
	mov d, 0x80000000	; Def Height
	mov d, 0x0		; DeskTop Parent Win
	mov d, 0x0		; No Mnu
	mov eax, 	; Get hInst Param
	mov , eax		; hInst Param
	mov d, 0x0		; No Ex Info
	call CreateWindowExA		; Create FastererWin Win
	mov , eax		; Save FastererWin hWnd

	; Show FastererWin Win

	sub esp, 0x8			; Prep 2 Args
	mov , eax			; FastererWin hWnd
	mov eax, 		; Get nCmdShow
	mov , eax		; nCmdShow
	call ShowWindow			; Show FastererWin Win

	; Update FastererWin Win

	sub esp, 0x4			; Prep 1 Arg
	mov eax, 		; Get FastererWin hWnd
	mov , eax			; FastererWin hWnd
	call UpdateWindow		; Update FastererWin Win

	MsgLp:

		; Get Msg

		lea eax, 		; Get Msg Addr
		sub esp, 0x10			; Prep 4 Args
		mov , eax			; Msg Addr
		mov d, 0x0		; No hWnd for All Msgs
		mov d, 0x0		; No Min Msg Filter
		mov d, 0x0		; No Max Msg Filter
		call GetMessageA		; Get Msg

		; Exit Msg Lp on Null Msg

		or eax, eax			; Check Null Msg
		jz >EndMsgLp			; Exit Msg Lp on Null Msg

		; Do Not Trans Msg

		; Dispatch Msg

		lea eax, 		; Get Msg Addr
		sub esp, 0x4			; Prep 1 Arg
		mov , eax			; Msg Addr
		call DispatchMessageA		; Dispatch Msg

	jmp <MsgLp			; Keep Pumping Msgs

	EndMsgLp:

	mov eax, 		; Ret Msg wParam

	; Do Not Restore Crit Regs

	; Discard Auto Store

	add esp, 0x4C			; 0x30+0x18+0x4

	; Exit to Start

	ret 0x10			; Discard 4 Params

WndProc:

	; Reserve Auto Store

	sub esp, 0x48			; 0x34+0x10+0x4

	; No Crit Regs on Stack

	; Auto Store on Stack

	; PaintStruct:	esp		; 0x0
	; hdc		+0x0
	; fErase	+0x4
	; rcPaint	+0x8
	; fRestore	+0xC
	; fIncUpdate	+0x10
	; rgbReserved	+0x14

	; Rect:		esp+0x34	; 0x0+0x34
	; left		+0x0
	; top		+0x4
	; right		+0x8
	; bottom	+0xC

	; hdc:		esp+0x44	; 0x34+0x10

	; Ret Addr on Stack

	; Ret EIP:	esp+0x48	; 0x44+0x4

	; Params on Stack

        ; hWnd		esp+0x4C	; 0x48+0x4
        ; uMsg		esp+0x50	; 0x4C+0x4
	; wParam	esp+0x54	; 0x50+0x4
	; lParam	esp+0x58	; 0x54+0x4

	; Do Not Preserve Crit Regs

	ProcMsgs:

		; Check for Msgs of Interest

		mov eax, 		; Get Msg Num

		; Something buggy with OnPaint...

		;cmp eax, 0xF			; Paint Msg?
		;jz >OnPaint			; Paint FastererWin Win

		cmp eax, 0x2			; Destroy Msg?
		jz >OnDestroy			; Destroy FastererWin Win
	
		; Discard Auto Store...

		add esp, 0x48			; 0x34+0x10+0x4

		; Fwd Msg to Windows

		jmp DefWindowProcA		; DefWindowProcA Will
						; Ret to WndProc's Caller

	OnPaint:

		; Paint FastererWin Win

		lea eax, 			; Get PaintStruct Addr
		sub esp, 0x8			; Prep 2 Args
		mov , eax		; PaintStruct Addr
		mov eax, 		; Get hWnd
		mov , eax			; hWnd
		call BeginPaint			; Begin Painting
		mov , eax		; Save hdc

		; Get FastererWin Win Rect

		lea eax, 		; Get Rect Addr
		sub esp, 0x8			; Prep 2 Args
		mov , eax		; Rect Addr
		mov eax, 		; Get hWnd
		mov , eax			; hWnd
		call GetClientRect		; Get FastererWin Win Rect

		; Draw Text to FastererWin Win

		mov eax, 		; Get hdc
		sub esp, 0x14			; Prep 5 Args
		mov , eax			; hdc
		mov , addr szText	; szText Addr
		mov d, -1		; Assume szText Zero Terminated
		lea eax, 	; Get Rect Addr
		mov , eax		; Rect Addr
		mov d, 0x10|0x40000	; Word Break and Ellipsis
		call DrawTextA			; Draw Text

		; End Paint FastererWin Win

		lea eax, 			; Get PaintStruct Addr
		sub esp, 0x8			; Prep 2 Args
		mov , eax		; PaintStruct Addr
		mov eax, 		; Get hWnd
		mov , eax			; hWnd
		call EndPaint			; End Painting

		; Set Ret Val

		xor eax, eax			; ???
		
		; Exit ProcMsgs

		jmp >EndProcMsgs

	OnDestroy:

		; Destroy FastererWin Win

		sub esp, 0x4			; Prep 1 Arg
		mov d, 0x0
		call PostQuitMessage		; Destroy FastererWin Win

		; Set Ret Val

		xor eax, eax			; ???

	EndProcMsgs:

	; Do Not Restore Crit Regs

	; Discard Auto Store

	add esp, 0x48			; 0x34+0x10+0x4

	; Exit to Dispatch/SendMessage

	ret 0x10			; Discard 4 Params

If you uncomment this section, listed below for convenience, it crashes after WM_PAINT.

		; Something buggy with OnPaint...

		;cmp eax, 0xF			; Paint Msg?
		;jz >OnPaint			; Paint FastererWin Win

Any masochists out there that can tell me where I goofed, other than the obvious "Why the hell are you coding like that?"?

Thanks to anyone interested in helping.

Sinsi,

Thanks a million!  You sure made quick work of that.

There's one mouse trap with the WM_PAINT message which you must be aware of. That message is sent during the creation of the window. If your procedure is such that it uses data (specially memory addresses) which will be defined only AFTER the creation of the window, it's bound to try accessing illegal memory areas and crash your program right from the start.

To circumvent such a problem, have some kind of a flag in your global data which you have initialized to 0 (or -1 or whatever) and you check it BEFORE running the paint code; you then skip that paint code as long as that flag remains set to its initial value. You modify that flag when you define the required data which would then allow the paint code to be executed as intended.

Raymond