?? xpbitmap.asm
字號:
mov al,ah
out dx,al
@@RowLoop:
mov cl,bh
shr cl,1
rep movsw ; Copy a complete row for curr plane
adc cl,0
rep movsb
add di,[LineInc] ; Move to next row
dec bl ; decrement row counter
jnz @@RowLoop ; Jump if more rows left
pop di ; Restore bitmaps start dest byte
rol ah,1 ; Shift mask for next plane
adc di,0 ; If wrapped increment dest address
dec [Plane] ; Decrement plane counter
jnz @@PlaneLoop ; Jump if more planes left
pop ds ; restore data segment
pop di ; restore registers
pop si
mov sp,bp ; dealloc local variables
pop bp
ret
_x_put_pbm endp
;----------------------------------------------------------------------
; x_flip_pbm - Write a planar bitmap from system ram to video ram
; If "Orientation" is set then the bitmap is flipped from left to right as
; it is drawn
;
; Source Bitmap structure:
;
; Width:byte, Height:byte, Bitmap data (plane 0)...Bitmap data (plane 1)..,
; Bitmap data (plane 2)..,Bitmap data (plane 3)..
;
; note width is in bytes ie lots of 4 pixels
;
; x_flip_pbm(X,Y,ScrnOffs,char far * Bitmap, WORD orientation)
;
;
; LIMITATIONS: No clipping is supported
; Only supports bitmaps with widths which are a multiple of
; 4 pixels
;
; NOTES: The flipped put function is slower than the standard put function
;
; Written by Themie Gouthas
;----------------------------------------------------------------------
_x_flip_pbm proc
ARG X:word,Y:word,ScrnOffs:word,Bitmap:dword,Orientation:word
LOCAL Plane:byte,BMHeight:byte,LineInc:word=LocalStk
push bp
mov bp,sp
sub sp,LocalStk ; Create space for local variables
push si
push di
push ds
cld
mov ax,SCREEN_SEG
mov es,ax
mov ax,[Y] ; Calculate dest screen row
mov bx,[_ScrnLogicalByteWidth] ; by mult. dest Y coord by Screen
mul bx ; width then adding screen offset
mov di,[ScrnOffs] ; store result in DI
add di,ax
mov cx,[X] ; Load X coord into CX and make a
mov dx,cx ; copy in DX
shr dx,2 ; Find starting byte in dest row
add di,dx ; add to DI giving screen offset of
; first pixel's byte
lds si,[Bitmap] ; DS:SI -> Bitmap data
lodsw ; Al = B.M. width (bytes) AH = B.M.
; height
cmp Orientation,0
jz UnFlipped
mov [BMHeight],ah ; Save source bitmap dimensions
xor ah,ah ; LineInc = bytes to the begin.
add bx,ax ; of bitmaps next row on screen
mov [LineInc],bx
mov bh,al ; Use bh as column loop count
and cx,0003h ; mask X coord giving plane of 1st
; bitmap pixel(zero CH coincidentally)
mov ah,11h ; Init. mask for VGA plane selection
shl ah,cl ; Shift for starting pixel plane
mov dx,SC_INDEX ; Prepare VGA for cpu to video writes
mov al,MAP_MASK
out dx,al
inc dx
mov [Plane],4 ; Set plane counter to 4
@@PlaneLoop:
push di ; Save bitmap's start dest. offset
mov bl,[BMHeight] ; Reset row counter (BL)
mov al,ah
out dx,al ; set vga write plane
@@RowLoop:
mov cl,bh ; Reset Column counter cl
@@ColLoop:
lodsb
mov es:[di],al
dec di
sub di,2
loop @@ColLoop ; loop if more columns left
@@DoneCol:
add di,[LineInc] ; Move to next row
dec bl ; decrement row counter
jnz @@RowLoop ; Jump if more rows left
pop di ; Restore bitmaps start dest byte
ror ah,1 ; Shift mask for next plane
sbb di,0 ; If wrapped increment dest address
dec [Plane] ; Decrement plane counter
jnz @@PlaneLoop ; Jump if more planes left
pop ds ; restore data segment
pop di ; restore registers
pop si
mov sp,bp ; dealloc local variables
pop bp
ret
_x_flip_pbm endp
;----------------------------------------------------------------------
; x_get_pbm - Read a planar bitmap to system ram from video ram
;
; Source Bitmap structure:
;
; Width:byte, Height:byte, Bitmap data (plane 0)...Bitmap data (plane 1)..,
; Bitmap data (plane 2)..,Bitmap data (plane 3)..
;
; note width is in bytes ie lots of 4 pixels
;
; x_get_pbm(X,Y,BMwidth,BMheight,ScrnOffs,char far * Bitmap)
;
;
; LIMITATIONS: No clipping is supported
; Only supports bitmaps with widths which are a multiple of
; 4 pixels
; FEATURES : Automatically selects REP MOVSB or REP MOVSW depending on
; source bitmap width, by modifying opcode ;-).
;
; Written by Themie Gouthas
;----------------------------------------------------------------------
_x_get_pbm proc
ARG X:word,Y:word,SrcWidth:byte,SrcHeight:byte,ScrnOffs:word,Bitmap:dword
LOCAL Plane:byte,LineInc:word=LocalStk
push bp
mov bp,sp
sub sp,LocalStk ; Create space for local variables
push si
push di
push ds
cld
mov ax,[Y] ; Calculate screen row
mov bx,[_ScrnLogicalByteWidth] ; by mult. Y coord by Screen
mul bx ; width then adding screen offset
mov si,[ScrnOffs] ; store result in SI
add si,ax
mov cx,[X] ; Load X coord into CX and make a
mov dx,cx ; copy in DX
shr dx,2 ; Find starting byte in screen row
add si,dx ; add to SI giving screen offset of
; first pixel's byte
mov ax,SCREEN_SEG
mov ds,ax
les di,[Bitmap] ; ES:DI -> Bitmap data
mov al,[SrcWidth]
mov ah,[SrcHeight]
stosw ; Al = B.M. width (bytes) AH = B.M.
; height
xor ah,ah ; LineInc = bytes to the begin.
sub bx,ax ; of bitmaps next row on screen
mov [LineInc],bx
mov bh,al
; Self Modifying, Shame, shame shame..
and cx,0003h ; mask X coord giving plane of 1st
; bitmap pixel(zero CH coincidentally)
mov ah,11h ; Init. mask for VGA plane selection
shl ah,cl ; Shift for starting pixel plane
mov dx,GC_INDEX ; Prepare VGA for cpu to video reads
mov al,READ_MAP
out dx,al
inc dx
mov [Plane],4 ; Set plane counter (BH) to 4
mov al,cl
@@PlaneLoop:
push si
mov bl,[SrcHeight]
out dx,al
@@RowLoop:
mov cl,bh
shr cl,1
rep movsw ; Copy a complete row for curr plane
adc cl,0
rep movsb
add si,[LineInc] ; Move to next row
dec bl ; decrement row counter
jnz @@RowLoop ; Jump if more rows left
pop si ; Restore bitmaps start dest byte
inc al ; Select next plane to read from
and al,3 ;
rol ah,1 ; Shift mask for next plane
adc si,0 ; If wrapped increment dest address
dec [Plane] ; Decrement plane counter
jnz @@PlaneLoop ; Jump if more planes left
pop ds ; restore data segment
pop di ; restore registers
pop si
mov sp,bp ; dealloc local variables
pop bp
ret
_x_get_pbm endp
end
ARG X:word,Y:word,ScrnOffs:word,Bitmap:dword,Orientation:word
LOCAL Plane:byte,BMHeight:byte,LineInc:word,Columns:byte=LocalStk
push bp
mov bp,sp
sub sp,LocalStk ; Create space for local variables
push si
push di
push ds
cld
mov ax,SCREEN_SEG
mov es,ax
mov ax,[Y] ; Calculate dest screen row
mov bx,[_ScrnLogicalByteWidth] ; by mult. dest Y coord by Screen
mul bx ; width then adding screen offset
mov di,[ScrnOffs] ; store result in DI
add di,ax
mov cx,[X] ; Load X coord into CX and make a
mov dx,cx ; copy in DX
shr dx,2 ; Find starting byte in dest row
add di,dx ; add to DI giving screen offset of
; first pixel's byte
lds si,[Bitmap] ; DS:SI -> Bitmap data
lodsw ; Al = B.M. width (bytes) AH = B.M.
; height
cmp Orientation,0
jz UnFlipped
mov [BMHeight],ah ; Save source bitmap dimensions
xor ah,ah ; LineInc = bytes to the begin.
add bx,ax ; of bitmaps next row on screen
mov [LineInc],bx
mov [Columns],al ; Use bh as column loop count
and cx,0003h ; mask X coord giving plane of 1st
; bitmap pixel(zero CH coincidentally)
mov ah,11h ; Init. mask for VGA plane selection
shl ah,cl ; Shift for starting pixel plane
mov bh,ah
mov dx,SC_INDEX ; Prepare VGA for cpu to video writes
mov al,MAP_MASK
out dx,al
inc dx
mov [Plane],4 ; Set plane counter to 4
@@PlaneLoop:
push di ; Save bitmap's start dest. offset
mov bl,[BMHeight] ; Reset row counter (BL)
mov al,bh
out dx,al ; set vga write plane
@@RowLoop:
mov cl,[Columns] ; Reset Column counter cl
shr cx,1
jnc @@ColLoop
lodsb
mov es:[di],al
dec di
@@ColLoop:
lodsw ; Get next source bitmap byte
xchg al,ah
mov es:[di],ax
sub di,2
loop @@ColLoop ; loop if more columns left
add di,[LineInc] ; Move to next row
dec bl ; decrement row counter
jnz @@RowLoop ; Jump if more rows left
pop di ; Restore bitmaps start dest byte
ror bh,1 ; Shift mask for next plane
sbb di,0 ; If wrapped increment dest address
dec [Plane] ; Decrement plane counter
jnz @@PlaneLoop ; Jump if more planes left
pop ds ; restore data segment
pop di ; restore registers
pop si
mov sp,bp ; dealloc local variables
pop bp
ret?? 快捷鍵說明
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