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source: xtideuniversalbios/trunk/Assembly_Library/Src/Display/DisplayContext.asm@ 125

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Last change on this file since 125 was 115, checked in by Tomi Tilli, 13 years ago

Changes to Assembly Library:

Current cursor coordinates won't no longer be reset when initializing Display Library.

File size: 9.2 KB

Rev	Line
[41]	1	; Project name : Assembly Library
	2	; Description : Functions for managing display context.
	3
	4	; Section containing code
	5	SECTION .text
	6
	7	;--------------------------------------------------------------------
	8	; DisplayContext_Initialize
	9	; Parameters:
	10	; DS: BDA segment (zero)
	11	; Returns:
	12	; Nothing
	13	; Corrupts registers:
	14	; AX, DX, DI
	15	;--------------------------------------------------------------------
	16	ALIGN JUMP_ALIGN
	17	DisplayContext_Initialize:
	18	mov WORD [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fnCharOut], DEFAULT_CHARACTER_OUTPUT
	19	mov WORD [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCursorShape], CURSOR_NORMAL
[44]	20	mov BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bAttribute], SCREEN_BACKGROUND_ATTRIBUTE
[101]	21	; Fall to .DetectAndSetDisplaySegment
[41]	22
	23	;--------------------------------------------------------------------
	24	; .DetectAndSetDisplaySegment
	25	; Parameters:
	26	; DS: BDA segment (zero)
	27	; Returns:
	28	; Nothing
	29	; Corrupts registers:
[50]	30	; AX, DX
[41]	31	;--------------------------------------------------------------------
	32	.DetectAndSetDisplaySegment:
[50]	33	mov ax, COLOR_TEXT_SEGMENT
[41]	34	cmp BYTE [VIDEO_BDA.bMode], MDA_TEXT_MODE
[101]	35	eCMOVE ah, MONO_TEXT_SEGMENT >> 8
[50]	36	mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition+2], ax
[101]	37	; Fall to .InitializeFlags
[50]	38
	39	;--------------------------------------------------------------------
	40	; .InitializeFlags
	41	; Parameters:
	42	; DS: BDA segment (zero)
	43	; Returns:
	44	; Nothing
	45	; Corrupts registers:
	46	; AX, DX
	47	;--------------------------------------------------------------------
	48	.InitializeFlags:
	49	mov dl, FLG_CONTEXT_ATTRIBUTES
	50	call CgaSnow_IsCgaPresent
	51	jnc SHORT .DoNotSetCgaFlag
	52	or dl, FLG_CONTEXT_CGA
	53	.DoNotSetCgaFlag:
	54	mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], dl
[101]	55	; Fall to .InitializeCursor
[41]	56
[101]	57	;--------------------------------------------------------------------
	58	; .InitializeCursor
	59	; Parameters:
	60	; DS: BDA segment (zero)
	61	; Returns:
	62	; Nothing
	63	; Corrupts registers:
	64	; AX, DX
	65	;--------------------------------------------------------------------
	66	.InitializeCursor:
[115]	67	call DisplayCursor_GetHardwareCoordinatesToAX ; Coordinates before init
	68	call DisplayCursor_SetCoordinatesFromAX ; Cursor to Display Context
[101]	69	; Fall to DisplayContext_SynchronizeToHardware
[41]	70
	71	;--------------------------------------------------------------------
[101]	72	; DisplayContext_SynchronizeToHardware
	73	; Parameters:
	74	; DS: BDA segment (zero)
	75	; Returns:
	76	; Nothing
	77	; Corrupts registers:
	78	; AX, DX
	79	;--------------------------------------------------------------------
	80	ALIGN JUMP_ALIGN
	81	DisplayContext_SynchronizeToHardware:
	82	call DisplayPage_SynchronizeToHardware
	83	call DisplayCursor_SynchronizeShapeToHardware
	84	jmp DisplayCursor_SynchronizeCoordinatesToHardware
	85
	86
	87	;--------------------------------------------------------------------
[41]	88	; DisplayContext_Push
	89	; Parameters:
	90	; Nothing
	91	; Returns:
	92	; Nothing
	93	; Corrupts registers:
	94	; AX, DI
	95	;--------------------------------------------------------------------
	96	ALIGN JUMP_ALIGN
	97	DisplayContext_Push:
	98	mov di, ds ; Backup DS
	99	LOAD_BDA_SEGMENT_TO ds, ax
	100	pop ax ; Pop return address
	101
	102	%assign i 0
	103	%rep DISPLAY_CONTEXT_size / 2
	104	push WORD [VIDEO_BDA.displayContext + i]
	105	%assign i i+2
	106	%endrep
	107
	108	mov ds, di ; Restore DS
	109	jmp ax
	110
	111	;--------------------------------------------------------------------
	112	; DisplayContext_Pop
	113	; Parameters:
	114	; Nothing
	115	; Returns:
	116	; Nothing
	117	; Corrupts registers:
	118	; AX, DI
	119	;--------------------------------------------------------------------
	120	ALIGN JUMP_ALIGN
	121	DisplayContext_Pop:
	122	mov di, ds ; Backup DS
	123	LOAD_BDA_SEGMENT_TO ds, ax
	124	pop ax ; Pop return address
	125
	126	%assign i DISPLAY_CONTEXT_size-2
	127	%rep DISPLAY_CONTEXT_size / 2
	128	pop WORD [VIDEO_BDA.displayContext + i]
	129	%assign i i-2
	130	%endrep
	131
	132	push ax ; Push return address
	133	push dx
	134	call DisplayContext_SynchronizeToHardware
	135	pop dx
	136	mov ds, di ; Restore DS
	137	ret
	138
	139
	140	;--------------------------------------------------------------------
[52]	141	; DisplayContext_PrepareOffScreenBufferInESBXwithLengthInCX
[48]	142	; Parameters:
[52]	143	; CX: Off screen buffer length in characters
	144	; ES:BX: Ptr to off screen buffer
[48]	145	; Returns:
	146	; Nothing
	147	; Corrupts registers:
[52]	148	; AX, DI
[48]	149	;--------------------------------------------------------------------
	150	ALIGN JUMP_ALIGN
[52]	151	DisplayContext_PrepareOffScreenBufferInESBXwithLengthInCX:
[48]	152	push ds
	153
	154	LOAD_BDA_SEGMENT_TO ds, di
	155	xchg ax, bx
	156	mov bx, es
	157	call DisplayContext_SetCharacterPointerFromBXAX ; ES:DI now has the pointer
	158
	159	mov bl, ATTRIBUTES_NOT_USED
	160	mov ax, BUFFER_OUTPUT_WITH_CHAR_ONLY
	161	call DisplayContext_SetCharOutputFunctionFromAXwithAttribFlagInBL
[52]	162	mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCharOutParam], cx
[48]	163
	164	mov bx, di
	165	pop ds
	166	ret
	167
	168
	169	;--------------------------------------------------------------------
[41]	170	; DisplayContext_SetCharacterPointerFromBXAX
	171	; Parameters:
	172	; BX:AX: Ptr to destination for next character to output
	173	; DS: BDA segment (zero)
	174	; Returns:
[48]	175	; ES:DI: Pointer that was in BX:AX
[41]	176	; Corrupts registers:
	177	; AX
	178	;--------------------------------------------------------------------
	179	ALIGN JUMP_ALIGN
	180	DisplayContext_SetCharacterPointerFromBXAX:
	181	mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition], ax
	182	mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition+2], bx
	183	xchg di, ax
	184	mov es, bx
	185	ret
	186
	187
	188	;--------------------------------------------------------------------
	189	; DisplayContext_GetCharacterPointerToBXAX
	190	; Parameters:
	191	; DS: BDA segment (zero)
	192	; Returns:
	193	; BX:AX: Ptr to destination for next character to output
	194	; Corrupts registers:
	195	; Nothing
	196	;--------------------------------------------------------------------
	197	ALIGN JUMP_ALIGN
	198	DisplayContext_GetCharacterPointerToBXAX:
	199	mov ax, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition]
	200	mov bx, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition+2]
	201	ret
	202
	203
	204	;--------------------------------------------------------------------
[45]	205	; DisplayContext_SetCharOutputFunctionFromAXwithAttribFlagInBL
[41]	206	; Parameters:
	207	; AX: Offset to character output function
[45]	208	; BL: Attribute Flag
[41]	209	; DS: BDA segment (zero)
	210	; Returns:
	211	; Nothing
	212	; Corrupts registers:
[50]	213	; BL
[41]	214	;--------------------------------------------------------------------
	215	ALIGN JUMP_ALIGN
[45]	216	DisplayContext_SetCharOutputFunctionFromAXwithAttribFlagInBL:
[50]	217	and bl, FLG_CONTEXT_ATTRIBUTES
	218	and BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], ~FLG_CONTEXT_ATTRIBUTES
	219	or [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], bl
[41]	220	mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fnCharOut], ax
	221	ret
	222
	223
	224	;--------------------------------------------------------------------
	225	; DisplayContext_SetCharacterAttributeFromAL
	226	; Parameters:
	227	; AL: Character attribute
	228	; DS: BDA segment (zero)
	229	; Returns:
	230	; Nothing
	231	; Corrupts registers:
	232	; Nothing
	233	;--------------------------------------------------------------------
	234	ALIGN JUMP_ALIGN
	235	DisplayContext_SetCharacterAttributeFromAL:
	236	mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bAttribute], al
	237	ret
	238
	239
	240	;--------------------------------------------------------------------
	241	; DisplayContext_SetCharacterOutputParameterFromAX
	242	; Parameters:
	243	; AX: Parameter for Character Output function
	244	; DS: BDA segment (zero)
	245	; Returns:
	246	; Nothing
	247	; Corrupts registers:
	248	; Nothing
	249	;--------------------------------------------------------------------
	250	ALIGN JUMP_ALIGN
	251	DisplayContext_SetCharacterOutputParameterFromAX:
	252	mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCharOutParam], ax
	253	ret
	254
	255	;--------------------------------------------------------------------
	256	; DisplayContext_GetCharacterOutputParameterToDX
	257	; Parameters:
	258	; DS: BDA segment (zero)
	259	; Returns:
	260	; DX: User parameter for Character Output function
	261	; Corrupts registers:
	262	; Nothing
	263	;--------------------------------------------------------------------
	264	ALIGN JUMP_ALIGN
	265	DisplayContext_GetCharacterOutputParameterToDX:
	266	mov dx, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCharOutParam]
	267	ret
[44]	268
	269
	270	;--------------------------------------------------------------------
	271	; DisplayContext_GetCharacterOffsetToAXfromByteOffsetInAX
	272	; Parameters:
	273	; AX: Offset in bytes from some character to another
	274	; DS: BDA segment (zero)
	275	; Returns:
	276	; AX: Offset in characters from some character to another
	277	; Corrupts registers:
	278	; Nothing
	279	;--------------------------------------------------------------------
	280	ALIGN JUMP_ALIGN
	281	DisplayContext_GetCharacterOffsetToAXfromByteOffsetInAX:
	282	test BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], FLG_CONTEXT_ATTRIBUTES
	283	jz SHORT ReturnOffsetInAX
	284	sar ax, 1 ; BYTE count to WORD count
	285	ret
	286
	287	;--------------------------------------------------------------------
	288	; DisplayContext_GetByteOffsetToAXfromCharacterOffsetInAX
	289	; Parameters:
	290	; AX: Offset in characters from some character to another
	291	; DS: BDA segment (zero)
	292	; Returns:
	293	; AX: Offset in bytes from some character to another
	294	; Corrupts registers:
	295	; Nothing
	296	;--------------------------------------------------------------------
	297	ALIGN JUMP_ALIGN
	298	DisplayContext_GetByteOffsetToAXfromCharacterOffsetInAX:
	299	test BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], FLG_CONTEXT_ATTRIBUTES
	300	jz SHORT ReturnOffsetInAX
	301	sal ax, 1 ; WORD count to BYTE count
	302	ALIGN JUMP_ALIGN, ret
	303	ReturnOffsetInAX:
	304	ret

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