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source: xtideuniversalbios/trunk/Assembly_Library/Src/Display/DisplayContext.asm@ 178

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Last change on this file since 178 was 162, checked in by krille_n_@…, 13 years ago

Changes to all parts of the project:

Size optimizations, mostly by excluding code from the BIOS.
Cleaned the source a bit, fixed spelling and grammar mistakes.

File size: 9.5 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	;--------------------------------------------------------------------
[133]	150	%ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS
[48]	151	ALIGN JUMP_ALIGN
[52]	152	DisplayContext_PrepareOffScreenBufferInESBXwithLengthInCX:
[48]	153	push ds
	154
	155	LOAD_BDA_SEGMENT_TO ds, di
	156	xchg ax, bx
	157	mov bx, es
	158	call DisplayContext_SetCharacterPointerFromBXAX ; ES:DI now has the pointer
	159
	160	mov bl, ATTRIBUTES_NOT_USED
	161	mov ax, BUFFER_OUTPUT_WITH_CHAR_ONLY
	162	call DisplayContext_SetCharOutputFunctionFromAXwithAttribFlagInBL
[52]	163	mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCharOutParam], cx
[48]	164
	165	mov bx, di
	166	pop ds
	167	ret
[133]	168	%endif
[48]	169
	170
	171	;--------------------------------------------------------------------
[41]	172	; DisplayContext_SetCharacterPointerFromBXAX
	173	; Parameters:
	174	; BX:AX: Ptr to destination for next character to output
	175	; DS: BDA segment (zero)
	176	; Returns:
[48]	177	; ES:DI: Pointer that was in BX:AX
[41]	178	; Corrupts registers:
	179	; AX
	180	;--------------------------------------------------------------------
[133]	181	%ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS
[41]	182	ALIGN JUMP_ALIGN
	183	DisplayContext_SetCharacterPointerFromBXAX:
	184	mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition], ax
	185	mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition+2], bx
	186	xchg di, ax
	187	mov es, bx
	188	ret
[133]	189	%endif
[41]	190
	191
	192	;--------------------------------------------------------------------
	193	; DisplayContext_GetCharacterPointerToBXAX
	194	; Parameters:
	195	; DS: BDA segment (zero)
	196	; Returns:
	197	; BX:AX: Ptr to destination for next character to output
	198	; Corrupts registers:
	199	; Nothing
	200	;--------------------------------------------------------------------
[133]	201	%ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS
[41]	202	ALIGN JUMP_ALIGN
	203	DisplayContext_GetCharacterPointerToBXAX:
	204	mov ax, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition]
	205	mov bx, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition+2]
	206	ret
[133]	207	%endif
[41]	208
	209
	210	;--------------------------------------------------------------------
[45]	211	; DisplayContext_SetCharOutputFunctionFromAXwithAttribFlagInBL
[41]	212	; Parameters:
	213	; AX: Offset to character output function
[45]	214	; BL: Attribute Flag
[41]	215	; DS: BDA segment (zero)
	216	; Returns:
	217	; Nothing
	218	; Corrupts registers:
[50]	219	; BL
[41]	220	;--------------------------------------------------------------------
	221	ALIGN JUMP_ALIGN
[45]	222	DisplayContext_SetCharOutputFunctionFromAXwithAttribFlagInBL:
[50]	223	and bl, FLG_CONTEXT_ATTRIBUTES
	224	and BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], ~FLG_CONTEXT_ATTRIBUTES
	225	or [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], bl
[41]	226	mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fnCharOut], ax
	227	ret
	228
	229
	230	;--------------------------------------------------------------------
	231	; DisplayContext_SetCharacterAttributeFromAL
	232	; Parameters:
	233	; AL: Character attribute
	234	; DS: BDA segment (zero)
	235	; Returns:
	236	; Nothing
	237	; Corrupts registers:
	238	; Nothing
	239	;--------------------------------------------------------------------
	240	ALIGN JUMP_ALIGN
	241	DisplayContext_SetCharacterAttributeFromAL:
	242	mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bAttribute], al
	243	ret
	244
	245
	246	;--------------------------------------------------------------------
	247	; DisplayContext_SetCharacterOutputParameterFromAX
	248	; Parameters:
	249	; AX: Parameter for Character Output function
	250	; DS: BDA segment (zero)
	251	; Returns:
	252	; Nothing
	253	; Corrupts registers:
	254	; Nothing
	255	;--------------------------------------------------------------------
	256	ALIGN JUMP_ALIGN
	257	DisplayContext_SetCharacterOutputParameterFromAX:
	258	mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCharOutParam], ax
	259	ret
	260
	261	;--------------------------------------------------------------------
	262	; DisplayContext_GetCharacterOutputParameterToDX
	263	; Parameters:
	264	; DS: BDA segment (zero)
	265	; Returns:
	266	; DX: User parameter for Character Output function
	267	; Corrupts registers:
	268	; Nothing
[133]	269	;--------------------------------------------------------------------
[162]	270	;%ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS ; This appears to be completely unused
	271	;ALIGN JUMP_ALIGN
	272	;DisplayContext_GetCharacterOutputParameterToDX:
	273	; mov dx, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCharOutParam]
	274	; ret
	275	;%endif
[44]	276
	277
	278	;--------------------------------------------------------------------
	279	; DisplayContext_GetCharacterOffsetToAXfromByteOffsetInAX
	280	; Parameters:
	281	; AX: Offset in bytes from some character to another
	282	; DS: BDA segment (zero)
	283	; Returns:
	284	; AX: Offset in characters from some character to another
	285	; Corrupts registers:
	286	; Nothing
[133]	287	;--------------------------------------------------------------------
[44]	288	ALIGN JUMP_ALIGN
	289	DisplayContext_GetCharacterOffsetToAXfromByteOffsetInAX:
	290	test BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], FLG_CONTEXT_ATTRIBUTES
	291	jz SHORT ReturnOffsetInAX
	292	sar ax, 1 ; BYTE count to WORD count
	293	ret
	294
	295	;--------------------------------------------------------------------
	296	; DisplayContext_GetByteOffsetToAXfromCharacterOffsetInAX
	297	; Parameters:
	298	; AX: Offset in characters from some character to another
	299	; DS: BDA segment (zero)
	300	; Returns:
	301	; AX: Offset in bytes from some character to another
	302	; Corrupts registers:
	303	; Nothing
[133]	304	;--------------------------------------------------------------------
[44]	305	ALIGN JUMP_ALIGN
	306	DisplayContext_GetByteOffsetToAXfromCharacterOffsetInAX:
	307	test BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], FLG_CONTEXT_ATTRIBUTES
	308	jz SHORT ReturnOffsetInAX
	309	sal ax, 1 ; WORD count to BYTE count
	310	ALIGN JUMP_ALIGN, ret
	311	ReturnOffsetInAX:
	312	ret

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