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source: xtideuniversalbios/trunk/Assembly_Library/Src/Display/DisplayFormat.asm@ 182

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Last change on this file since 182 was 181, checked in by krille_n_@…, 13 years ago

Changes to all parts of the project:

Size optimizations.
Added a define (EXCLUDE_FROM_XTIDECFG) to exclude unused library code from XTIDECFG.
Tried to minimize time spent with interrupts disabled.
Some minor attempts to improve speed (reordering instructions etc).
Tried to improve readability, did some cleanup and fixed some errors in comments.

File size: 10.9 KB

Rev	Line
[41]	1	; Project name : Assembly Library
	2	; Description : Functions for displaying formatted strings.
	3
	4	; Section containing code
	5	SECTION .text
	6
	7	;--------------------------------------------------------------------
	8	; DisplayFormat_ParseCharacters
	9	; Parameters:
	10	; DS: BDA segment (zero)
[44]	11	; SS:BP: Pointer to first format parameter (-=2 updates to next parameter)
[41]	12	; CS:SI: Pointer to string to format
	13	; ES:DI: Ptr to cursor location in video RAM
	14	; Returns:
[44]	15	; CS:SI: Ptr to end of format string (ptr to one past NULL)
[41]	16	; DI: Updated offset to video RAM
	17	; Corrupts registers:
[44]	18	; AX, BX, CX, DX, BP
[41]	19	;--------------------------------------------------------------------
	20	ALIGN JUMP_ALIGN
	21	DisplayFormat_ParseCharacters:
[44]	22	call ReadCharacterAndTestForNull
[101]	23	jz SHORT ReturnFromFormat
[44]	24
	25	ePUSH_T cx, DisplayFormat_ParseCharacters ; Return address
	26	xor cx, cx ; Initial placeholder size
	27	cmp al, '%' ; Format specifier?
[101]	28	jne SHORT DisplayPrint_CharacterFromAL
	29	; Fall to ParseFormatSpecifier
[44]	30
[41]	31	;--------------------------------------------------------------------
[44]	32	; ParseFormatSpecifier
[41]	33	; Parameters:
[44]	34	; CX: Placeholder size
	35	; DS: BDA segment (zero)
	36	; SS:BP: Pointer to first format parameter (-=2 for next parameter)
	37	; CS:SI: Pointer to string to format
	38	; ES:DI: Ptr to cursor location in video RAM
	39	; Returns:
	40	; SI: Updated to first unparsed character
	41	; DI: Updated offset to video RAM
	42	; BP: Updated to next format parameter
	43	; Corrupts registers:
	44	; AX, BX, CX, DX
	45	;--------------------------------------------------------------------
	46	ParseFormatSpecifier:
	47	call ReadCharacterAndTestForNull
	48	call Char_IsDecimalDigitInAL
[101]	49	jc SHORT ParsePlaceholderSizeDigitFromALtoCX
[44]	50	call GetFormatSpecifierParserToAX
	51	call ax ; Parser function
	52	dec bp
	53	dec bp ; SS:BP now points to next parameter
[181]	54	inc cx
	55	loop PrependOrAppendSpaces
[101]	56	ReturnFromFormat:
[44]	57	ret
	58
	59	;--------------------------------------------------------------------
[101]	60	; ParsePlaceholderSizeDigitFromALtoCX
[44]	61	; Parameters:
	62	; AL: Digit character from format string
	63	; CX: Current placeholder size
	64	; DS: BDA segment (zero)
	65	; Returns:
	66	; CX: Current placeholder size
	67	; Jumps back to ParseFormatSpecifier
	68	; Corrupts registers:
	69	; AX
	70	;--------------------------------------------------------------------
	71	ALIGN JUMP_ALIGN
[101]	72	ParsePlaceholderSizeDigitFromALtoCX:
[44]	73	mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition], di
	74	sub al, '0' ; Digit '0'...'9' to integer 0...9
	75	mov ah, cl ; Previous number parameter to AH
	76	aad ; AL += (AH * 10)
	77	mov cl, al ; Updated number parameter now in CX
	78	jmp SHORT ParseFormatSpecifier
	79
	80
	81	;--------------------------------------------------------------------
	82	; ReadCharacterAndTestForNull
	83	; Parameters:
[41]	84	; CS:SI: Pointer next character from string
	85	; Returns:
	86	; AL: Character from string
	87	; SI: Incremented to next character
	88	; ZF: Set if NULL, cleared if valid character
	89	; Corrupts registers:
	90	; Nothing
	91	;--------------------------------------------------------------------
	92	ALIGN JUMP_ALIGN
[44]	93	ReadCharacterAndTestForNull:
[41]	94	eSEG cs
	95	lodsb ; Load from CS:SI to AL
	96	test al, al ; NULL to end string?
	97	ret
	98
	99
	100	;--------------------------------------------------------------------
[44]	101	; GetFormatSpecifierParserToAX
[41]	102	; Parameters:
[44]	103	; AL: Format specifier character
[41]	104	; Returns:
[44]	105	; AX: Offset to parser function
[41]	106	; Corrupts registers:
[44]	107	; AX, BX
[41]	108	;--------------------------------------------------------------------
	109	ALIGN JUMP_ALIGN
[44]	110	GetFormatSpecifierParserToAX:
	111	mov bx, .rgcFormatCharToLookupIndex
	112	ALIGN JUMP_ALIGN
	113	.CheckForNextSpecifierParser:
	114	cmp al, [cs:bx]
	115	je SHORT .ConvertIndexToFunctionOffset
	116	inc bx
	117	cmp bx, .rgcFormatCharToLookupIndexEnd
	118	jb SHORT .CheckForNextSpecifierParser
	119	mov ax, c_FormatCharacter
	120	ret
	121	ALIGN JUMP_ALIGN
	122	.ConvertIndexToFunctionOffset:
	123	sub bx, .rgcFormatCharToLookupIndex
	124	shl bx, 1 ; Shift for WORD lookup
	125	mov ax, [cs:bx+.rgfnFormatSpecifierParser]
	126	ret
[41]	127
[44]	128	.rgcFormatCharToLookupIndex:
[134]	129	%ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS
[44]	130	db "aAduxsSct-+%"
[134]	131	%else
	132	db "Auxsc-" ; Required by XTIDE Universal BIOS
	133	%endif
[44]	134	.rgcFormatCharToLookupIndexEnd:
	135	ALIGN WORD_ALIGN
	136	.rgfnFormatSpecifierParser:
[134]	137	%ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS
[44]	138	dw a_FormatAttributeForNextCharacter
[134]	139	%endif
[44]	140	dw A_FormatAttributeForRemainingString
[134]	141	%ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS
[44]	142	dw d_FormatSignedDecimalWord
[134]	143	%endif
[44]	144	dw u_FormatUnsignedDecimalWord
	145	dw x_FormatHexadecimalWord
	146	dw s_FormatStringFromSegmentCS
[134]	147	%ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS
[44]	148	dw S_FormatStringFromFarPointer
[134]	149	%endif
[44]	150	dw c_FormatCharacter
[134]	151	%ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS
[44]	152	dw t_FormatRepeatCharacter
[134]	153	%endif
[44]	154	dw PrepareToPrependParameterWithSpaces
[134]	155	%ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS
[44]	156	dw PrepareToAppendSpacesAfterParameter
	157	dw percent_FormatPercent
[134]	158	%endif
[41]	159
[44]	160
[41]	161	;--------------------------------------------------------------------
[44]	162	; PrependOrAppendSpaces
[41]	163	; Parameters:
[44]	164	; CX: Minimum length for format specifier in characters
[41]	165	; DS: BDA segment (zero)
	166	; ES:DI: Ptr to cursor location in video RAM
	167	; Returns:
[44]	168	; Nothing
[41]	169	; Corrupts registers:
	170	; AX, BX, CX, DX
	171	;--------------------------------------------------------------------
	172	ALIGN JUMP_ALIGN
[44]	173	PrependOrAppendSpaces:
	174	mov ax, di
	175	sub ax, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition]
	176	test cx, cx
	177	js SHORT .PrependWithSpaces
	178	; Fall to .AppendSpaces
[41]	179
	180	;--------------------------------------------------------------------
[44]	181	; .AppendSpaces
[41]	182	; Parameters:
[44]	183	; AX: Number of format parameter BYTEs printed
	184	; CX: Minimum length for format specifier in characters
[41]	185	; DS: BDA segment (zero)
	186	; ES:DI: Ptr to cursor location in video RAM
	187	; Returns:
[44]	188	; Nothing
[41]	189	; Corrupts registers:
[44]	190	; AX, CX, DX
[41]	191	;--------------------------------------------------------------------
[44]	192	.AppendSpaces:
	193	call DisplayContext_GetCharacterOffsetToAXfromByteOffsetInAX
	194	sub cx, ax
	195	jle SHORT .NothingToAppendOrPrepend
[41]	196	mov al, ' '
[44]	197	jmp DisplayPrint_RepeatCharacterFromALwithCountInCX
[41]	198
	199	;--------------------------------------------------------------------
[44]	200	; .PrependWithSpaces
[41]	201	; Parameters:
[44]	202	; AX: Number of format parameter BYTEs printed
	203	; CX: Negative minimum length for format specifier in characters
[41]	204	; DS: BDA segment (zero)
	205	; ES:DI: Ptr to cursor location in video RAM
	206	; Returns:
[44]	207	; Nothing
[41]	208	; Corrupts registers:
[44]	209	; AX, BX, CX, DX
[41]	210	;--------------------------------------------------------------------
	211	ALIGN JUMP_ALIGN
[44]	212	.PrependWithSpaces:
	213	xchg ax, cx
	214	neg ax
	215	call DisplayContext_GetByteOffsetToAXfromCharacterOffsetInAX
	216	sub ax, cx ; AX = BYTEs to prepend, CX = BYTEs to move
	217	jle SHORT .NothingToAppendOrPrepend
[41]	218
[47]	219	std
	220	push si
[41]	221
[47]	222	lea si, [di-1] ; SI = Offset to last byte formatted
	223	add di, ax ; DI = Cursor location after preceeding completed
	224	push di
	225	dec di ; DI = Offset where to move last byte formatted
	226	xchg bx, ax ; BX = BYTEs to prepend
[48]	227	call .ReverseCopyCXbytesFromESSItoESDI
[47]	228	xchg ax, bx
	229	call .ReversePrintAXspacesStartingFromESDI
	230
	231	pop di
	232	pop si
	233	cld ; Restore DF
	234	.NothingToAppendOrPrepend:
	235	ret
	236
	237	;--------------------------------------------------------------------
[48]	238	; .ReverseCopyCXbytesFromESSItoESDI
[47]	239	; Parameters:
[48]	240	; CX: Number of bytes to copy
[47]	241	; DS: BDA segment (zero)
[48]	242	; ES:SI: Ptr to old location
	243	; ES:DI: Ptr to new location
[47]	244	; Returns:
[48]	245	; DI: Updated to before last character copied
[47]	246	; Corrupts registers:
	247	; AX, CX, DX, SI
	248	;--------------------------------------------------------------------
	249	ALIGN JUMP_ALIGN
[48]	250	.ReverseCopyCXbytesFromESSItoESDI:
	251	test BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], FLG_CONTEXT_ATTRIBUTES
	252	jz SHORT .CopyWithoutDisplayProcessing
[47]	253
[48]	254	WAIT_RETRACE_IF_NECESSARY_THEN rep movsb
	255	dec di ; Point to preceeding character instead of attribute
	256	ret
	257	ALIGN JUMP_ALIGN
	258	.CopyWithoutDisplayProcessing:
[44]	259	eSEG_STR rep, es, movsb
[47]	260	ret
	261
	262	;--------------------------------------------------------------------
	263	; .ReversePrintAXspacesStartingFromESDI
	264	; Parameters:
	265	; AX: Number of spaces to print
	266	; DS: BDA segment (zero)
	267	; ES:DI: Ptr to destination in video RAM
	268	; Returns:
	269	; DI: Updated
	270	; Corrupts registers:
	271	; AX, CX, DX
	272	ALIGN JUMP_ALIGN
	273	.ReversePrintAXspacesStartingFromESDI:
[44]	274	call DisplayContext_GetCharacterOffsetToAXfromByteOffsetInAX
	275	xchg cx, ax ; CX = Spaces to prepend
	276	mov al, ' '
[47]	277	jmp DisplayPrint_RepeatCharacterFromALwithCountInCX
[44]	278
	279
	280
	281	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
	282	; Formatting functions
[41]	283	; Parameters:
	284	; DS: BDA segment (zero)
[44]	285	; SS:BP: Pointer to next format parameter (-=2 updates to next parameter)
[41]	286	; ES:DI: Ptr to cursor location in video RAM
	287	; Returns:
[44]	288	; SS:BP: Points to last WORD parameter used
[41]	289	; Corrupts registers:
	290	; AX, BX, DX
[44]	291	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
[134]	292	%ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS
[41]	293	ALIGN JUMP_ALIGN
[44]	294	a_FormatAttributeForNextCharacter:
[41]	295	mov bl, [bp]
	296	xchg bl, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bAttribute]
[44]	297	push bx
	298	push cx
	299	push di
	300	call DisplayFormat_ParseCharacters ; Recursive call
	301	pop WORD [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition]
	302	pop cx
	303	pop bx
[41]	304	mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bAttribute], bl
[44]	305	ret
[134]	306	%endif
[41]	307
	308	ALIGN JUMP_ALIGN
[44]	309	A_FormatAttributeForRemainingString:
[41]	310	mov al, [bp]
	311	mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bAttribute], al
[44]	312	ret
[41]	313
[134]	314	%ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS
[41]	315	ALIGN JUMP_ALIGN
[44]	316	d_FormatSignedDecimalWord:
[41]	317	mov ax, [bp]
[44]	318	mov bx, 10
	319	jmp DisplayPrint_SignedWordFromAXWithBaseInBX
[134]	320	%endif
[41]	321
	322	ALIGN JUMP_ALIGN
[44]	323	u_FormatUnsignedDecimalWord:
[41]	324	mov ax, [bp]
	325	mov bx, 10
[44]	326	jmp DisplayPrint_WordFromAXWithBaseInBX
[41]	327
	328	ALIGN JUMP_ALIGN
[44]	329	x_FormatHexadecimalWord:
[41]	330	mov ax, [bp]
	331	mov bx, 16
	332	call DisplayPrint_WordFromAXWithBaseInBX
	333	mov al, 'h'
[44]	334	jmp DisplayPrint_CharacterFromAL
[41]	335
	336	ALIGN JUMP_ALIGN
[44]	337	s_FormatStringFromSegmentCS:
[41]	338	xchg si, [bp]
	339	call DisplayPrint_NullTerminatedStringFromCSSI
[44]	340	mov si, [bp]
	341	ret
[41]	342
[134]	343	%ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS
[41]	344	ALIGN JUMP_ALIGN
[44]	345	S_FormatStringFromFarPointer:
	346	mov bx, [bp-2]
[41]	347	xchg si, [bp]
	348	call DisplayPrint_NullTerminatedStringFromBXSI
[44]	349	mov si, [bp]
	350	dec bp
	351	dec bp
	352	ret
[134]	353	%endif
[41]	354
	355	ALIGN JUMP_ALIGN
[44]	356	c_FormatCharacter:
[41]	357	mov al, [bp]
[44]	358	jmp DisplayPrint_CharacterFromAL
[41]	359
[134]	360	%ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS
[41]	361	ALIGN JUMP_ALIGN
[44]	362	t_FormatRepeatCharacter:
	363	push cx
[41]	364	mov cx, [bp-2]
	365	mov al, [bp]
	366	call DisplayPrint_RepeatCharacterFromALwithCountInCX
[44]	367	pop cx
	368	dec bp
	369	dec bp
	370	ret
[41]	371
	372	ALIGN JUMP_ALIGN
[44]	373	percent_FormatPercent:
[41]	374	mov al, '%'
[44]	375	jmp DisplayPrint_CharacterFromAL
[134]	376	%endif
[41]	377
	378	ALIGN JUMP_ALIGN
[44]	379	PrepareToPrependParameterWithSpaces:
	380	neg cx
	381	; Fall to PrepareToAppendSpacesAfterParameter
[41]	382
	383	ALIGN JUMP_ALIGN
[44]	384	PrepareToAppendSpacesAfterParameter:
	385	add sp, BYTE 2 ; Remove return offset
	386	jmp ParseFormatSpecifier

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