Changeset 42 in xtideuniversalbios for trunk/Assembly_Library/Src/Display/DisplayPrint.asm

Timestamp:

Sep 18, 2010, 6:04:31 PM (14 years ago)

Author:

aitotat

google:author:

aitotat

Message:

Display Library no more produces CGA snow.

File:

• trunk/Assembly_Library/Src/Display/DisplayPrint.asm (modified) (4 diffs)

trunk/Assembly_Library/Src/Display/DisplayPrint.asm

@@ -2 +2 @@
 ; Project name  :   Assembly Library
 ; Created date  :   26.6.2010
-; Last update   :   10.8.2010
+; Last update   :   18.9.2010
 ; Author        :   Tomi Tilli
 ; Description   :   Functions for display output.
@@ -250 +250 @@
 
 ;--------------------------------------------------------------------
-; DisplayPrint_RepeatCharacterFromALwithCountInCX
-;   Parameters:
-;       AL:     Character to display
-;       CX:     Repeat count
-;       DS:     BDA segment (zero)
-;       ES:DI:  Ptr to cursor location in video RAM
-;   Returns:
-;       DI:     Updated offset to video RAM
-;   Corrupts registers:
-;       AX, DX
-;--------------------------------------------------------------------
-ALIGN JUMP_ALIGN
-DisplayPrint_RepeatCharacterFromALwithCountInCX:
-    push    ax
-    call    DisplayPrint_CharacterFromAL
-    pop     ax
-    loop    DisplayPrint_RepeatCharacterFromALwithCountInCX
-    ret
-
-
-;--------------------------------------------------------------------
-; DisplayPrint_CharacterFromAL
-;   Parameters:
-;       AL:     Character to display
-;       DS:     BDA segment (zero)
-;       ES:DI:  Ptr to cursor location in video RAM
-;   Returns:
-;       DI:     Updated offset to video RAM
-;   Corrupts registers:
-;       AX, DX
-;--------------------------------------------------------------------
-ALIGN JUMP_ALIGN
-DisplayPrint_CharacterFromAL:
-    mov     ah, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bAttribute]
-    jmp     [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fnCharOut]
-
-
-;--------------------------------------------------------------------
 ; DisplayPrint_ClearScreen
 ;   Parameters:
@@ -317 +279 @@
 ;       ES:DI:  Ptr to cursor location in video RAM
 ;   Returns:
-;       Nothing
+;       DI:     Updated offset to video RAM
 ;   Corrupts registers:
 ;       AX, DX
@@ -323 +285 @@
 ALIGN JUMP_ALIGN
 DisplayPrint_ClearAreaWithHeightInAHandWidthInAL:
+    push    si
     push    cx
     push    bx
-    push    di
-
-    xchg    bx, ax                          ; Move parameters to BX
+
+    xchg    bx, ax                          ; Area size to BX
     call    DisplayCursor_GetSoftwareCoordinatesToAX
-    xchg    dx, ax                          ; Coordinates now in DX
-    xor     cx, cx                          ; Zero CX
-
-ALIGN JUMP_ALIGN
-.ClearRowFromArea:
+    xchg    si, ax                          ; Software (Y,X) coordinates now in SI
+    xor     cx, cx
+
+ALIGN JUMP_ALIGN
+.ClearRowLoop:
+    mov     cl, bl                          ; Area width now in CX
     mov     al, ' '                         ; Clear with space
-    mov     ah, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bAttribute]
-    mov     cl, bl                          ; Area width = WORDs to clear
-    rep stosw
-    dec     bh
-    jz      SHORT .AreaCleared
-
-    inc     dh                              ; Increment row
-    push    dx
-    xchg    ax, dx
+    call    DisplayPrint_RepeatCharacterFromALwithCountInCX
+
+    xchg    ax, si                          ; Coordinates to AX
+    inc     ah                              ; Increment row
+    mov     si, ax
     call    DisplayCursor_SetCoordinatesFromAX
-    pop     dx
-    jmp     SHORT .ClearRowFromArea
-
-ALIGN JUMP_ALIGN
-.AreaCleared:
-    pop     di
-    mov     [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition], di
+    dec     bh                              ; Decrement rows left
+    jnz     SHORT .ClearRowLoop
+
     pop     bx
     pop     cx
-    ret
+    pop     si
+    ret
+
+
+;--------------------------------------------------------------------
+; DisplayPrint_RepeatCharacterFromALwithCountInCX
+;   Parameters:
+;       AL:     Character to display
+;       CX:     Repeat count
+;       DS:     BDA segment (zero)
+;       ES:DI:  Ptr to cursor location in video RAM
+;   Returns:
+;       DI:     Updated offset to video RAM
+;   Corrupts registers:
+;       AX, DX
+;--------------------------------------------------------------------
+ALIGN JUMP_ALIGN
+DisplayPrint_RepeatCharacterFromALwithCountInCX:
+    push    ax
+    call    DisplayPrint_CharacterFromAL
+    pop     ax
+    loop    DisplayPrint_RepeatCharacterFromALwithCountInCX
+    ret
+
+
+;--------------------------------------------------------------------
+; DisplayPrint_CharacterFromAL
+;   Parameters:
+;       AL:     Character to display
+;       DS:     BDA segment (zero)
+;       ES:DI:  Ptr to cursor location in video RAM
+;   Returns:
+;       DI:     Updated offset to video RAM
+;   Corrupts registers:
+;       AX, DX
+;--------------------------------------------------------------------
+ALIGN JUMP_ALIGN
+DisplayPrint_CharacterFromAL:
+    mov     ah, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bAttribute]
+    jmp     [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fnCharOut]