screen.asm

这是DOS系统的源代码,汇编写的,值得看看,对开发操作系统的人员有价值

;*	available registers :
;*		BX = work register
;*		AL, AH = work
;*	exit : n/a
;*	* NOTE: for overlapping windows, check that psOverlap:DI is pointing to
;*	*  our window (pwndDraw).

DRAW_ROUTINES	PROC NEAR

;*	* TextOut Variants
TO_dmTFB:	;* Text + attributes
	lodsb
	CheckWnd TO_dmTFB_next
	mov	bx,bp				;* set bh = attribute
	mov	bl,al				;* set bl = character
ifdef	BUILTIN_SNOW
	mov	dx,3DAh			;* CGA video status port
	StartDrawCrit
endif	;BUILTIN_SNOW
	mov	ax,bx
	stosw					;* only time for 1 store
ifdef	BUILTIN_SNOW
	EndDrawCrit
endif	;BUILTIN_SNOW
TO_dmTFB_next:
	loop	TO_dmTFB
	ret

TO_dmT:		;* Text only
	lodsb					;* get byte
	CheckWnd TO_dmT_next
	mov	bl,al
ifdef	BUILTIN_SNOW
	mov	dx,3DAh
	StartDrawCrit
endif	;BUILTIN_SNOW
	mov	al,bl
	stosb
ifdef	BUILTIN_SNOW
	EndDrawCrit
endif	;BUILTIN_SNOW
	inc	di
TO_dmT_next:
	loop	TO_dmT
	ret

ifndef	DRAW_MODE_MINIMIZE

TO_dmTF:	;* leave background alone
	mov	bh,ah
l1_tf:	lodsb
	CheckWnd TO_dmTF_next
	mov	bx,bp				;* bh = attribute
	mov	bl,al
ifdef	BUILTIN_SNOW
	mov	dx,3DAh
	StartDrawCrit
endif	;BUILTIN_SNOW
	mov	ah,es:[di+1]
ifdef	BUILTIN_SNOW
	EndDrawCrit
endif	;BUILTIN_SNOW
	and	ah,0F0H
	or	bh,ah
ifdef	BUILTIN_SNOW
	StartDrawCrit
endif	;BUILTIN_SNOW
	mov	ax,bx
	stosw
ifdef	BUILTIN_SNOW
	EndDrawCrit
endif	;BUILTIN_SNOW
TO_dmTF_next:
	loop	l1_tf
	ret

TO_dmB:		;* background only
	CheckWnd TO_dmB_next
	mov	bx,bp				; bh has new bg in hi nybble
	and	bh,0F0H				; change background only
	inc	di
ifdef	BUILTIN_SNOW
	mov	dx,3DAh
	StartDrawCrit
endif	;BUILTIN_SNOW
	mov	al,es:[di]			; al = old attribute
	and	al,0Fh				; al = old foreground only
	or	al,bh				; al = old fore & new back
	stosb					;* only time for 1 store
ifdef	BUILTIN_SNOW
	EndDrawCrit
endif	;BUILTIN_SNOW
TO_dmB_next:
	loop	TO_dmB
	ret

TO_dmTMb:	;* character + map background
	CheckWnd TO_dmTMb_next
ifdef	BUILTIN_SNOW
	mov	dx,3DAh
	StartDrawCrit
endif	;BUILTIN_SNOW
	mov	bl,es:[di+1]
ifdef	BUILTIN_SNOW
	EndDrawCrit
endif	;BUILTIN_SNOW
	lodsb					;* get character in AL
	and	bx,00F0H
	shr	bx,1
	shr	bx,1
	shr	bx,1
	shr	bx,1
	add	bx,bp
	mov	ah,ds:[bx]			;* look up new attribute
	mov	bx,ax
ifdef	BUILTIN_SNOW
	StartDrawCrit
endif	;BUILTIN_SNOW
	mov	ax,bx
	stosw
ifdef	BUILTIN_SNOW
	EndDrawCrit
endif	;BUILTIN_SNOW
TO_dmTMb_next:
	loop	TO_dmTMb
	ret

FR_dmMf:
TO_dmMf:		;* map foreground
	CheckWnd FR_dmMf_next
	inc	di
ifdef	BUILTIN_SNOW
	mov	dx,3DAh
	StartDrawCrit
endif	;BUILTIN_SNOW
	mov	bl,es:[di]
ifdef	BUILTIN_SNOW
	EndDrawCrit
endif	;BUILTIN_SNOW
	and	bx,000FH
	add	bx,bp
	mov	bl,ds:[bx]			;* look up new attribute
ifdef	BUILTIN_SNOW
	StartDrawCrit
endif	;BUILTIN_SNOW
	mov	al,bl
	stosb
ifdef	BUILTIN_SNOW
	EndDrawCrit
endif	;BUILTIN_SNOW
FR_dmMf_next:
	loop	TO_dmMf
	ret


TO_dmMfb:	;* Map attribute: old background maps to new background, 
		;                 old foreground maps to new foreground.
		;  Note: the tables for these guys are 16 + 16 bytes each.

	inc	di
ifdef	BUILTIN_SNOW
	mov	dx,3DAh
	StartDrawCrit
endif	;BUILTIN_SNOW
	mov	bl,es:[di]			;* get old attribute
ifdef	BUILTIN_SNOW
	EndDrawCrit
endif	;BUILTIN_SNOW
	and	bx,000FH			;* mask to foreground
	add	bx,bp
	mov	bl,ds:[bx]			;* look up new foreground
	push	bx				;* save BL = new foreground

ifdef	BUILTIN_SNOW
	StartDrawCrit
endif	;BUILTIN_SNOW
	mov	bl,es:[di]			;* get old attribute
ifdef	BUILTIN_SNOW
	EndDrawCrit
endif	;BUILTIN_SNOW
	and	bx,00F0H			;* mask to background
	shr	bx,1
	shr	bx,1
	shr	bx,1
	shr	bx,1
	add	bx,bp				;* bx = &rgca[background]
	add	bx,16				;* bg's follow fg's in array.

ifdef	BUILTIN_SNOW
	StartDrawCrit
endif	;BUILTIN_SNOW
	pop	ax				;* restore AL = new fground
	or	al,ds:[bx]			;* Merge in new background
	stosb
ifdef	BUILTIN_SNOW
	EndDrawCrit
	dec	cx
	or	cx,cx
	jz	@F
	jmp	TO_dmMfb
@@:
ELSE	;NOT DEFINED BUILTIN_SNOW
	loop	TO_dmMfb
endif	;BUILTIN_SNOW
	ret

TO_dmMAttr:	;* Map entire attribute: old attr maps to new attr.
		;  Note that the tables for these guys are 256 bytes each.

	inc	di
ifdef	BUILTIN_SNOW
	mov	dx,3DAh
	StartDrawCrit
endif	;BUILTIN_SNOW
	xor	bx,bx				; BH = 0 for indexing.
	mov	bl,es:[di]			;* get old attribute
	add	bx,bp
	mov	al,ds:[bx]			;* look up new attribute
	stosb
ifdef	BUILTIN_SNOW
	EndDrawCrit
endif	;BUILTIN_SNOW
	loop	TO_dmMAttr
	ret

endif	; !DRAW_MODE_MINIMIZE


;*****************************************************************************
;*	* Fill Rectangle Variants
FR_dmTFB:	;* normal
	mov	ax,si				;* al = character
	mov	bx,bp				;* bh = attribute
	mov	bl,al				;* bx = ca:ch
FR_dmTFB_1:
	CheckWnd FR_dmTFB_next
ifdef	BUILTIN_SNOW
	mov	dx,3DAh
	StartDrawCrit
endif	;BUILTIN_SNOW
	mov	ax,bx
	stosw					;* store one
ifdef	BUILTIN_SNOW
	EndDrawCrit
endif	;BUILTIN_SNOW
FR_dmTFB_next:
	loop	FR_dmTFB_1
	ret

ifndef	DRAW_MODE_MINIMIZE

FR_dmT:		;* text only
	mov	bx,si				;* bl = character
	jmp	short FR_dmFB_1

endif	; !DRAW_MODE_MINIMIZE

FR_dmFB:	;* ca only
	mov	bx,bp				;* bh = attribute
	mov	bl,bh				;* bl = value to store
	inc	di				;* point to ca
;*	* this breaks the window test!!!!

FR_dmFB_1:
	CheckWnd FR_dmFB_next
ifdef	BUILTIN_SNOW
	mov	dx,3DAh
	StartDrawCrit
endif	;BUILTIN_SNOW
	mov	al,bl
	stosb					;* store one
ifdef	BUILTIN_SNOW
	EndDrawCrit
endif	;BUILTIN_SNOW
	inc	di				;* to next ca
FR_dmFB_next:
	loop	FR_dmFB_1
	ret

ifndef	DRAW_MODE_MINIMIZE

FR_dmB:	;* fill background only
	mov	bx,bp				;* bh = attribute
	and	bh,0F0H				;* change background only
	mov	bl,00FH				;* keep mask
	jmp	short FR_dmF_1

FR_dmF:	;* fill foreground only
	mov	bx,bp				;* bh = attribute
	and	bh,00FH				;* change foreground only
	mov	bl,0F0H				;* keep mask
FR_dmF_1:
	inc	di				;* point to ca
;*	* this breaks the window test!!!!
	push	bp				;* bp used for temp
FR_dmF_2:
	CheckWnd FR_dmF_next
ifdef	BUILTIN_SNOW
	mov	dx,3DAh
	StartDrawCrit
endif	;BUILTIN_SNOW
	mov	al,es:[di]			;* get old background
ifdef	BUILTIN_SNOW
	EndDrawCrit
endif	;BUILTIN_SNOW
	and	al,bl				;* keep half
	or	al,bh				;* replace half
	mov	bp,ax
ifdef	BUILTIN_SNOW
	StartDrawCrit
endif	;BUILTIN_SNOW
	mov	ax,bp
	stosb
ifdef	BUILTIN_SNOW
	EndDrawCrit
endif	;BUILTIN_SNOW
	inc	di
FR_dmF_next:
	loop	FR_dmF_2
	pop	bp				;* restored trashed bp
	ret

FR_dmTMb:	;* character + map background
	CheckWnd FR_dmTMb_next
ifdef	BUILTIN_SNOW
	mov	dx,3DAh
	StartDrawCrit
endif	;BUILTIN_SNOW
	mov	bl,es:[di+1]			;* get old attribute
ifdef	BUILTIN_SNOW
	EndDrawCrit
endif	;BUILTIN_SNOW
	and	bx,00F0H			;* mask background
	shr	bx,1
	shr	bx,1
	shr	bx,1
	shr	bx,1
	add	bx,bp				;* bx = &rgca[background]
	mov	ax,si				;* load character (into al)
	mov	ah,ds:[bx]			;* look up new attribute
	mov	bx,ax
ifdef	BUILTIN_SNOW
	StartDrawCrit
endif	;BUILTIN_SNOW
	mov	ax,bx
	stosw
ifdef	BUILTIN_SNOW
	EndDrawCrit
endif	;BUILTIN_SNOW
FR_dmTMb_next:
	loop	FR_dmTMb
	ret


FR_dmMb:	;* map background only
	CheckWnd FR_dmMb_next
	inc	di				;* point to attribute
ifdef	BUILTIN_SNOW
	mov	dx,3DAh
	StartDrawCrit
endif	;BUILTIN_SNOW
	mov	bl,es:[di]			;* get old attribute
ifdef	BUILTIN_SNOW
	EndDrawCrit
endif	;BUILTIN_SNOW
	and	bx,00F0H			;* mask background
	shr	bx,1
	shr	bx,1
	shr	bx,1
	shr	bx,1
	add	bx,bp				;* bx = &rgca[background]
	mov	bl,ds:[bx]			;* look up new attribute
ifdef	BUILTIN_SNOW
	StartDrawCrit
endif	;BUILTIN_SNOW
	mov	al,bl
	stosb
ifdef	BUILTIN_SNOW
	EndDrawCrit
endif	;BUILTIN_SNOW
FR_dmMb_next:
	loop	FR_dmMb
	ret

endif	; !DRAW_MODE_MINIMIZE


;*****************************************************************************
;*	* DBCS Fill Rectangle Variants (text modify only)
;*	* all entry points should start with "shr cx,1"

ifdef	KANJI

FR_dmTFB_DBCS:	;* normal
	shr	cx,1
	mov	dx,si				;* dx = DB character (dl first)
	mov	bx,bp				;* bh = attribute
	mov	bl,dl				;* BX = first ca:ch
	mov	dl,dh
	mov	dh,bh				;* DX = second ca:ch
FR_dmTFB_1_DBCS:
	CheckWnd FR_dmTFB_next_DBCS
ifdef	BUILTIN_SNOW
	push	cx
	mov	cx,dx
	mov	dx,3DAh
	StartDrawCrit
	mov	ax,bx
	stosw					;* store first character
	mov	ax,cx
	stosw					;* store second character
	EndDrawCrit
	pop	cx
ELSE	; !BUILTIN_SNOW
	mov	ax,bx
	stosw					;* store first character
	mov	ax,dx
	stosw					;* store second character
endif	;BUILTIN_SNOW

FR_dmTFB_next_DBCS:
	loop	FR_dmTFB_1_DBCS
	ret

ifndef	DRAW_MODE_MINIMIZE

FR_dmT_DBCS:		;* text only
	shr	cx,1
	mov	bx,si				;* bl = 1st, bh = 2nd
FR_dmFB_1_DBCS:
	CheckWnd FR_dmFB_next_DBCS
ifdef	BUILTIN_SNOW
	mov	dx,3DAh
	StartDrawCrit
endif	;BUILTIN_SNOW
	mov	al,bl
	stosb					;* store one
	inc	di				;* to next ca
	mov	al,bh
	stosb					;* store one
ifdef	BUILTIN_SNOW
	EndDrawCrit
endif	;BUILTIN_SNOW
	inc	di				;* to next ca
FR_dmFB_next_DBCS:
	loop	FR_dmFB_1_DBCS
	ret

endif	; !DRAW_MODE_MINIMIZE

endif	;KANJI

;*****************************************************************************

ifndef	DRAW_MODE_MINIMIZE

;*	???? UNIMPLEMENTED !!!!!!
TO_dmF:
TO_dmTB:
TO_dmTMf:
TO_dmMb:
FR_dmTF:
FR_dmTB:
FR_dmTMf:
FR_dmMfb:
FR_dmMAttr:
ifdef	KANJI
FR_dmTF_DBCS:
FR_dmTB_DBCS:
FR_dmTMf_DBCS:
FR_dmTMb_DBCS:
endif	;KANJI

;??????

endif	; !DRAW_MODE_MINIMIZE

InvalidMode:
ifdef	DEBUG
	cCall	CowAssertFailed
	DB	"Invalid draw mode $"
endif	;DEBUG
	ret

DRAW_ROUTINES	ENDP		;* all near

;*****************************************************************************

;********** EndScreen **********
;*	entry:	fClear => clear screen
;*	* Exit procedure - clear the screen
;*	exit:	n/a

cPublic	EndScreen,<PUBLIC, ATOMIC>
	parmW fClear
cBegin	EndScreen

	StartPublic

	mov	cx,fClear
	jcxz	dont_clear

ifdef	REVIEW
	mov	al,caOld
ELSE
	mov	al,7
endif	;!REVIEW
	mov	ah,al				;* duplicate for MONO
	xchg	ax,[rgsa]			;* change isa == 0
	push	ax				;* save old

	xor	ax,ax
	mov	bx,' '
	xor	cx,cx
	xor	dx,dx
	mov	cl,axMac
	mov	dl,ayMac
ifdef	WINDOW_OVERLAP
	xor	ax,ax
	mov	pwndCur,ax
endif	;WINDOW_OVERLAP
	cCall	FillArc,<ax,ax,cx,dx,bx,ax>	;* fill all with ' ' isaDefault

	pop	word ptr [rgsa]			;* restore old isaDefault

	xor	ax,ax
	cCall	insj.lpfnMoveHwCursCsdInsj,<ax,ax,sp>	;* top of screen & on

dont_clear:
;*	* kill the screen driver
	cCall	insj.lpfnTermCsdInsj		;* ()

	StopPublic

cEnd	EndScreen

;*****************************************************************************


;********** ImodeGuessCurrent **********
;*	entry: n/a
;*	* call driver to guess current mode
;*	exit:	AX = imode (or -1 (imodeUnkown) if not known)

labelFP	<PUBLIC, ImodeGuessCurrent>
	jmp	insj.lpfnImodeGuessCurrentCsdInsj



;********** FQueryInst **********
;*	entry:
;*		pinst : pointer to INST structure to fill
;*		imode : index of mode to test
;*	* Get information about modes available
;*	* just call the INSJ procedure
;*	exit:	AX != 0 => ok (*pinst filled in)
;*		== 0 => error (imode too high or can't query)

IFDEF	DEBUG

cPublic	FQueryInst,<PUBLIC>
	parmW pinst
	parmW imode
cBegin	FQueryInst

	cCall	insj.lpfnFQueryInstCsdInsj,<pinst,imode>

	or	ax,ax					; If bogus mode, 
	jz	fqi_done				;   can't check inst.

	mov	bx,pinst

	test	[bx].finstInst,finstExtendedMono	; If ExtendedMono,
	jz	@F					;   then must have
	test	[bx].finstInst,finstAttrFont		;   AttrFont.
	jz	bust
@@:
	test	[bx].finstInst,finstAttrFont
	jz	fqi_done
	test	[bx].finstInst,finstMonochrome		; If AttrFont, then
	jz	bust					;   must have Mono
	test	[bx].finstInst,finstText		;   and Text.
	jnz	fqi_done
bust:	
	cCall	CowAssertFailed
	DB	"FQueryInst fInst bits not in sync.$"

fqi_done:

cEnd	FQueryInst

ELSE	;!DEBUG

labelFP	<PUBLIC, FQueryInst>
	jmp	insj.lpfnFQueryInstCsdInsj

ENDIF	;!DEBUG



;********** FGetColorPalette **********
;*	entry:	co	color
;*		pcoi	color combination index (returned)
;*		rgcov	RGB palette info (returned)
;*	* get current palette setting for co
;*	exit:	AX = 0 => no color palette available, pcoi, rgcov

labelFP	<PUBLIC, FGetColorPalette>
	jmp	insj.lpfnFGetColorPaletteCsdInsj



;********** SetColorPalette **********
;*	entry:	co	color
;*		coi	color combination index
;*		rgcov	RGB palette info
;*	* set current palette setting for co, does nothing if no color palette
;*	exit:	n/a

labelFP	<PUBLIC, SetColorPalette>
	jmp	insj.lpfnSetColorPaletteCsdInsj



;********** MoveHardwareCursor **********
;*	entry:	axCurs, ayCurs = new absolute cursor position
;*		fOn => whether on or off