Changeset 47 in xtideuniversalbios for trunk/Assembly_Library/Src/Display/DisplayFormat.asm

Timestamp:

Oct 4, 2010, 7:22:40 PM (15 years ago)

Author:

Tomi Tilli

google:author:

aitotat

Message:

Assembly Library:
CGA snow prevention now works when copying strings on formatted printing.

File:

• trunk/Assembly_Library/Src/Display/DisplayFormat.asm (modified) (2 diffs)

trunk/Assembly_Library/Src/Display/DisplayFormat.asm

@@ -2 +2 @@
 ; Project name  :   Assembly Library
 ; Created date  :   29.6.2010
-; Last update   :   26.9.2010
+; Last update   :   4.10.2010
 ; Author        :   Tomi Tilli
 ; Description   :   Functions for displaying formatted strings.
@@ -212 +212 @@
     jle     SHORT .NothingToAppendOrPrepend
 
-    mov     bx, di
-    add     bx, ax              ; BX = DI after prepending
-
+    std
     push    si
-    dec     di                  ; DI = Offset to last byte formatted
-    mov     si, di
-    add     di, ax              ; DI = Offset to new location for last byte
-    std
+
+    lea     si, [di-1]          ; SI = Offset to last byte formatted
+    add     di, ax              ; DI = Cursor location after preceeding completed
+    push    di
+    dec     di                  ; DI = Offset where to move last byte formatted
+    xchg    bx, ax              ; BX = BYTEs to prepend
+    call    .ReverseMoveCXbytesFromESSItoESDI
+    xchg    ax, bx
+    call    .ReversePrintAXspacesStartingFromESDI
+
+    pop     di
+    pop     si
+    cld                         ; Restore DF
+.NothingToAppendOrPrepend:
+    ret
+
+;--------------------------------------------------------------------
+; .ReverseMoveCXbytesFromESSItoESDI
+;   Parameters:
+;       CX:     Number of bytes to move
+;       DS:     BDA segment (zero)
+;       ES:SI:  Ptr to source in video RAM
+;       ES:DI:  Ptr to destination in video RAM
+;   Returns:
+;       DI:     Offset to character preceeding string just moved
+;   Corrupts registers:
+;       AX, CX, DX, SI
+;--------------------------------------------------------------------
+ALIGN JUMP_ALIGN
+.ReverseMoveCXbytesFromESSItoESDI:
+%ifdef ELIMINATE_CGA_SNOW
+    call    DisplayCharOut_LoadAndVerifyStatusRegisterFromBDA
+    je      SHORT .WaitUntilReadyToMoveNextByte
+%endif
+
     eSEG_STR rep, es, movsb
 
-    mov     dl, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags]
-    and     dx, BYTE FLG_CONTEXT_ATTRIBUTES
-    not     dx
-    and     di, dx              ; WORD alignment when using attributes
-
+%ifdef ELIMINATE_CGA_SNOW
+    jmp     SHORT .AlignDIforFirstPreceedingSpace
+.WaitUntilReadyToMoveNextByte:
+    cli             ; Interrupt request would mess up timing
+    WAIT_UNTIL_SAFE_CGA_WRITE
+.MovsbWithoutWaitSinceUnknownPort:
+    eSEG    es
+    movsb
+    sti
+    loop    .WaitUntilReadyToMoveNextByte
+%endif
+    ; Fall to .AlignDIforFirstPreceedingSpace
+
+;--------------------------------------------------------------------
+; .AlignDIforFirstPreceedingSpace
+;   Parameters:
+;       DS:     BDA segment (zero)
+;       ES:DI:  Byte offset before last byte moved
+;   Returns:
+;       DI:     Offset to space preceeding moved string
+;   Corrupts registers:
+;       AX
+;--------------------------------------------------------------------
+ALIGN JUMP_ALIGN
+.AlignDIforFirstPreceedingSpace:
+    mov     al, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags]
+    and     ax, BYTE FLG_CONTEXT_ATTRIBUTES
+    not     ax
+    and     di, ax
+    ret
+
+;--------------------------------------------------------------------
+; .ReversePrintAXspacesStartingFromESDI
+;   Parameters:
+;       AX:     Number of spaces to print
+;       DS:     BDA segment (zero)
+;       ES:DI:  Ptr to destination in video RAM
+;   Returns:
+;       DI:     Updated
+;   Corrupts registers:
+;       AX, CX, DX
+ALIGN JUMP_ALIGN
+.ReversePrintAXspacesStartingFromESDI:
     call    DisplayContext_GetCharacterOffsetToAXfromByteOffsetInAX
     xchg    cx, ax              ; CX = Spaces to prepend
     mov     al, ' '
-    call    DisplayPrint_RepeatCharacterFromALwithCountInCX
-    cld                         ; Restore DF
-
-    mov     di, bx
-    pop     si
-.NothingToAppendOrPrepend:
-    ret
+    jmp     DisplayPrint_RepeatCharacterFromALwithCountInCX
+