source: xtideuniversalbios/trunk/Assembly_Library/Src/Display/DisplayContext.asm@ 56

Last change on this file since 56 was 52, checked in by Tomi Tilli, 14 years ago

Changes to Assembly Library:
Completely rewritten line splitting (slower but no need to modify string).
Some changes to string processing functions.
Saved few bytes from CGA detection.
File size: 9.0 KB
Line 
1; File name : DisplayContext.asm
2; Project name : Assembly Library
3; Created date : 25.6.2010
4; Last update : 11.10.2010
5; Author : Tomi Tilli
6; Description : Functions for managing display context.
7
8; Section containing code
9SECTION .text
10
11;--------------------------------------------------------------------
12; DisplayContext_Initialize
13; Parameters:
14; DS: BDA segment (zero)
15; Returns:
16; Nothing
17; Corrupts registers:
18; AX, DX, DI
19;--------------------------------------------------------------------
20ALIGN JUMP_ALIGN
21DisplayContext_Initialize:
22 call .DetectAndSetDisplaySegment ; and .InitializeFlags
23 mov WORD [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fnCharOut], DEFAULT_CHARACTER_OUTPUT
24 mov WORD [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCursorShape], CURSOR_NORMAL
25 mov BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bAttribute], SCREEN_BACKGROUND_ATTRIBUTE
26 xor ax, ax
27 call DisplayCursor_SetCoordinatesFromAX
28 jmp DisplayContext_SynchronizeToHardware
29
30;--------------------------------------------------------------------
31; .DetectAndSetDisplaySegment
32; Parameters:
33; DS: BDA segment (zero)
34; Returns:
35; Nothing
36; Corrupts registers:
37; AX, DX
38;--------------------------------------------------------------------
39.DetectAndSetDisplaySegment:
40 mov ax, COLOR_TEXT_SEGMENT
41 cmp BYTE [VIDEO_BDA.bMode], MDA_TEXT_MODE
42 jne SHORT .StoreSegmentToDisplayContext
43 mov ax, MONO_TEXT_SEGMENT
44.StoreSegmentToDisplayContext:
45 mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition+2], ax
46 ; Fall to InitializeFlags
47
48;--------------------------------------------------------------------
49; .InitializeFlags
50; Parameters:
51; DS: BDA segment (zero)
52; Returns:
53; Nothing
54; Corrupts registers:
55; AX, DX
56;--------------------------------------------------------------------
57.InitializeFlags:
58 mov dl, FLG_CONTEXT_ATTRIBUTES
59 call CgaSnow_IsCgaPresent
60 jnc SHORT .DoNotSetCgaFlag
61 or dl, FLG_CONTEXT_CGA
62.DoNotSetCgaFlag:
63 mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], dl
64 ret
65
66
67;--------------------------------------------------------------------
68; DisplayContext_Push
69; Parameters:
70; Nothing
71; Returns:
72; Nothing
73; Corrupts registers:
74; AX, DI
75;--------------------------------------------------------------------
76ALIGN JUMP_ALIGN
77DisplayContext_Push:
78 mov di, ds ; Backup DS
79 LOAD_BDA_SEGMENT_TO ds, ax
80 pop ax ; Pop return address
81
82 %assign i 0
83 %rep DISPLAY_CONTEXT_size / 2
84 push WORD [VIDEO_BDA.displayContext + i]
85 %assign i i+2
86 %endrep
87
88 mov ds, di ; Restore DS
89 jmp ax
90
91;--------------------------------------------------------------------
92; DisplayContext_Pop
93; Parameters:
94; Nothing
95; Returns:
96; Nothing
97; Corrupts registers:
98; AX, DI
99;--------------------------------------------------------------------
100ALIGN JUMP_ALIGN
101DisplayContext_Pop:
102 mov di, ds ; Backup DS
103 LOAD_BDA_SEGMENT_TO ds, ax
104 pop ax ; Pop return address
105
106 %assign i DISPLAY_CONTEXT_size-2
107 %rep DISPLAY_CONTEXT_size / 2
108 pop WORD [VIDEO_BDA.displayContext + i]
109 %assign i i-2
110 %endrep
111
112 push ax ; Push return address
113 push dx
114 call DisplayContext_SynchronizeToHardware
115 pop dx
116 mov ds, di ; Restore DS
117 ret
118
119
120;--------------------------------------------------------------------
121; DisplayContext_PrepareOffScreenBufferInESBXwithLengthInCX
122; Parameters:
123; CX: Off screen buffer length in characters
124; ES:BX: Ptr to off screen buffer
125; Returns:
126; Nothing
127; Corrupts registers:
128; AX, DI
129;--------------------------------------------------------------------
130ALIGN JUMP_ALIGN
131DisplayContext_PrepareOffScreenBufferInESBXwithLengthInCX:
132 push ds
133
134 LOAD_BDA_SEGMENT_TO ds, di
135 xchg ax, bx
136 mov bx, es
137 call DisplayContext_SetCharacterPointerFromBXAX ; ES:DI now has the pointer
138
139 mov bl, ATTRIBUTES_NOT_USED
140 mov ax, BUFFER_OUTPUT_WITH_CHAR_ONLY
141 call DisplayContext_SetCharOutputFunctionFromAXwithAttribFlagInBL
142 mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCharOutParam], cx
143
144 mov bx, di
145 pop ds
146 ret
147
148
149;--------------------------------------------------------------------
150; DisplayContext_SynchronizeToHardware
151; Parameters:
152; DS: BDA segment (zero)
153; Returns:
154; Nothing
155; Corrupts registers:
156; AX, DX
157;--------------------------------------------------------------------
158ALIGN JUMP_ALIGN
159DisplayContext_SynchronizeToHardware:
160 call DisplayPage_SynchronizeToHardware
161 call DisplayCursor_SynchronizeShapeToHardware
162 jmp DisplayCursor_SynchronizeCoordinatesToHardware
163
164
165;--------------------------------------------------------------------
166; DisplayContext_SetCharacterPointerFromBXAX
167; Parameters:
168; BX:AX: Ptr to destination for next character to output
169; DS: BDA segment (zero)
170; Returns:
171; ES:DI: Pointer that was in BX:AX
172; Corrupts registers:
173; AX
174;--------------------------------------------------------------------
175ALIGN JUMP_ALIGN
176DisplayContext_SetCharacterPointerFromBXAX:
177 mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition], ax
178 mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition+2], bx
179 xchg di, ax
180 mov es, bx
181 ret
182
183
184;--------------------------------------------------------------------
185; DisplayContext_GetCharacterPointerToBXAX
186; Parameters:
187; DS: BDA segment (zero)
188; Returns:
189; BX:AX: Ptr to destination for next character to output
190; Corrupts registers:
191; Nothing
192;--------------------------------------------------------------------
193ALIGN JUMP_ALIGN
194DisplayContext_GetCharacterPointerToBXAX:
195 mov ax, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition]
196 mov bx, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition+2]
197 ret
198
199
200;--------------------------------------------------------------------
201; DisplayContext_SetCharOutputFunctionFromAXwithAttribFlagInBL
202; Parameters:
203; AX: Offset to character output function
204; BL: Attribute Flag
205; DS: BDA segment (zero)
206; Returns:
207; Nothing
208; Corrupts registers:
209; BL
210;--------------------------------------------------------------------
211ALIGN JUMP_ALIGN
212DisplayContext_SetCharOutputFunctionFromAXwithAttribFlagInBL:
213 and bl, FLG_CONTEXT_ATTRIBUTES
214 and BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], ~FLG_CONTEXT_ATTRIBUTES
215 or [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], bl
216 mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fnCharOut], ax
217 ret
218
219
220;--------------------------------------------------------------------
221; DisplayContext_SetCharacterAttributeFromAL
222; Parameters:
223; AL: Character attribute
224; DS: BDA segment (zero)
225; Returns:
226; Nothing
227; Corrupts registers:
228; Nothing
229;--------------------------------------------------------------------
230ALIGN JUMP_ALIGN
231DisplayContext_SetCharacterAttributeFromAL:
232 mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bAttribute], al
233 ret
234
235
236;--------------------------------------------------------------------
237; DisplayContext_SetCharacterOutputParameterFromAX
238; Parameters:
239; AX: Parameter for Character Output function
240; DS: BDA segment (zero)
241; Returns:
242; Nothing
243; Corrupts registers:
244; Nothing
245;--------------------------------------------------------------------
246ALIGN JUMP_ALIGN
247DisplayContext_SetCharacterOutputParameterFromAX:
248 mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCharOutParam], ax
249 ret
250
251;--------------------------------------------------------------------
252; DisplayContext_GetCharacterOutputParameterToDX
253; Parameters:
254; DS: BDA segment (zero)
255; Returns:
256; DX: User parameter for Character Output function
257; Corrupts registers:
258; Nothing
259;--------------------------------------------------------------------
260ALIGN JUMP_ALIGN
261DisplayContext_GetCharacterOutputParameterToDX:
262 mov dx, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCharOutParam]
263 ret
264
265
266;--------------------------------------------------------------------
267; DisplayContext_GetCharacterOffsetToAXfromByteOffsetInAX
268; Parameters:
269; AX: Offset in bytes from some character to another
270; DS: BDA segment (zero)
271; Returns:
272; AX: Offset in characters from some character to another
273; Corrupts registers:
274; Nothing
275;--------------------------------------------------------------------
276ALIGN JUMP_ALIGN
277DisplayContext_GetCharacterOffsetToAXfromByteOffsetInAX:
278 test BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], FLG_CONTEXT_ATTRIBUTES
279 jz SHORT ReturnOffsetInAX
280 sar ax, 1 ; BYTE count to WORD count
281 ret
282
283;--------------------------------------------------------------------
284; DisplayContext_GetByteOffsetToAXfromCharacterOffsetInAX
285; Parameters:
286; AX: Offset in characters from some character to another
287; DS: BDA segment (zero)
288; Returns:
289; AX: Offset in bytes from some character to another
290; Corrupts registers:
291; Nothing
292;--------------------------------------------------------------------
293ALIGN JUMP_ALIGN
294DisplayContext_GetByteOffsetToAXfromCharacterOffsetInAX:
295 test BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], FLG_CONTEXT_ATTRIBUTES
296 jz SHORT ReturnOffsetInAX
297 sal ax, 1 ; WORD count to BYTE count
298ALIGN JUMP_ALIGN, ret
299ReturnOffsetInAX:
300 ret
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