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Assembly Source File | 1994-08-23 | 61.8 KB | 2,206 lines

;**************************************************************************** ;* ;* The SuperVGA Kit ;* ;* Copyright (C) 1994 SciTech Software ;* All rights reserved. ;* ;* Filename: $RCSfile: svga.asm $ ;* Version: $Revision: 1.1 $ ;* ;* Language: 80386 Assembler ;* Environment: IBM PC Real Mode and 16/32 bit Protected Mode. ;* ;* Description: Assembly language support routines for the SuperVGA test ;* library. All the code here assumes that the video memory ;* selector has been cached in the FS selector before the ;* code is called. ;* ;* $Id: svga.asm 1.1 1994/08/22 12:27:00 kjb release $ ;* ;**************************************************************************** IDEAL INCLUDE "model.mac" ; Memory model macros header svga ; Set up memory model CRTC EQU 3D4h ; Port of CRTC registers $EXTRN _maxx,UINT $EXTRN _maxy,UINT $EXTRN _maxcolor,ULONG $EXTRN _maxpage,UINT $EXTRN _bytesperline,USHORT $EXTRN _pagesize,ULONG $EXTRN _curBank,UINT $EXTRN _bankSwitch,ULONG $EXTRN _bankShift,UINT $EXTRN _writeBank,ULONG ; Relocated write bank routine $EXTRN _readBank,ULONG ; Relocated read bank routine $EXTRN _extendedflipping,BOOL begdataseg svga originOffset DW ? ; Offset of current page in buffer bankOffset DW ? ; Bank offset in total video memory enddataseg svga begcodeseg svga ;---------------------------------------------------------------------------- ; int _setFS(unsigned sel) ;---------------------------------------------------------------------------- ; Set the FS register to the specified selector value. This register is ; never changed, so we only ever need to do it once (to save time with ; expensive selector loads in protected mode). ;---------------------------------------------------------------------------- procstart __setFS ARG sel:UINT push _bp mov _bp,_sp mov _ax,[sel] mov cx,fs mov fs,ax mov ax,cx pop _bp ret procend __setFS ;---------------------------------------------------------------------------- ; PixelAddr16 Determine buffer address of pixel in SVGA 16 color modes ;---------------------------------------------------------------------------- ; ; Entry: _AX - y-coordinate ; _BX - x-coordinate ; ; Exit: AH - bit mask ; _BX - byte offset in buffer ; CL - number of bits to shift left ; _SI - 64k bank number of the address ; FS - video buffer segment ; ; Registers: none. ; ;---------------------------------------------------------------------------- PROC PixelAddr16 near push _dx ; Save DX mul [_bytesperline] ; DX:AX := y * BytesPerLine mov cl,bl ; CL := low-order byte of x shr _bx,3 ; _BX := x/8 add bx,ax adc dl,0 ; DL:_BX := y*BytesPerLine + x/8 add bx,[originOffset] ; _BX := byte offset in video buffer adc dl,[BYTE bankOffset]; DL := bank number mov _si,_dx ; _SI := bank number mov ah,1 ; AH := unshifted bit mask and cl,7 ; CL := x & 7 xor cl,7 ; CL := # bits to shift left pop _dx ret ENDP PixelAddr16 ;---------------------------------------------------------------------------- ; PixelAddr256 Determine buffer address of pixel in SVGA 256 color modes ;---------------------------------------------------------------------------- ; ; Entry: _AX - y-coordinate ; _BX - x-coordinate ; ; Exit: _BX - byte offset in buffer ; _DX - 64k bank number of the address ; FS - video buffer segment ; ; Registers: None. ; ;---------------------------------------------------------------------------- PROC PixelAddr256 near mul [_bytesperline] ; DX:AX := y * bytesperline add bx,ax adc dx,0 ; DX:_BX := y * BytesPerLine + x add bx,[originOffset] adc dl,[BYTE bankOffset]; DL := bank number ret ENDP PixelAddr256 ;---------------------------------------------------------------------------- ; PixelAddr32k Determine buffer address of pixel in SVGA 32k color modes ;---------------------------------------------------------------------------- ; ; Entry: _AX - y-coordinate ; _BX - x-coordinate ; ; Exit: _BX - byte offset in buffer ; _DX - 64k bank number of the address ; FS - video buffer segment ; ; Registers: None. ; ;---------------------------------------------------------------------------- PROC PixelAddr32k near mul [_bytesperline] ; DX:AX := y * bytesperline shl _bx,1 add bx,ax adc dx,0 ; DX:BX := y * BytesPerLine + x * 2 add bx,[originOffset] adc dl,[BYTE bankOffset]; DL := bank number ret ENDP PixelAddr32k ;---------------------------------------------------------------------------- ; PixelAddr16m Determine buffer address of pixel in SVGA 16m color modes ;---------------------------------------------------------------------------- ; ; Entry: _AX - y-coordinate ; _BX - x-coordinate ; ; Exit: _BX - byte offset in buffer ; _DX - 64k bank number of the address ; FS - video buffer segment ; ; Registers: None. ; ;---------------------------------------------------------------------------- PROC PixelAddr16m near mul [_bytesperline] ; DX:AX := y * bytesperline add ax,bx shl _bx,1 add bx,ax adc dx,0 ; DX:BX := y * BytesPerLine + x * 3 add bx,[originOffset] adc dl,[BYTE bankOffset]; DL := bank number ret ENDP PixelAddr16m ;---------------------------------------------------------------------------- ; PixelAddr4G Determine buffer address of pixel in SVGA 32k color modes ;---------------------------------------------------------------------------- ; ; Entry: _AX - y-coordinate ; _BX - x-coordinate ; ; Exit: _BX - byte offset in buffer ; _DX - 64k bank number of the address ; FS - video buffer segment ; ; Registers: None. ; ;---------------------------------------------------------------------------- PROC PixelAddr4G near mul [_bytesperline] ; DX:AX := y * bytesperline shl _bx,2 add bx,ax adc dx,0 ; DX:BX := y * BytesPerLine + x * 2 add bx,[originOffset] adc dl,[BYTE bankOffset]; DL := bank number ret ENDP PixelAddr4G ;---------------------------------------------------------------------------- ; void clear16(long color) ;---------------------------------------------------------------------------- ; Routine to clear the screen. Works even if the display contains more than ; one bank, so will work for 1024x768 and 1280x1024 video modes. ;---------------------------------------------------------------------------- procstart __clear16 ARG color:ULONG enter_c 0 push es ; Setup graphics controller mov dx,3CEh ; DX := Graphics Controller I/O port mov ah,[BYTE color] ; AH := Background color xor al,al ; AL := 0 (Set/Reset register number) out dx,ax ; load set/reset register mov ax,0F01h ; AH := 1111b (mask for Enable set/reset) ; AL := 1 (enable Set/reset reg number) out dx,ax ; load enable set/reset reg mov _ax,[_maxy] inc _ax mul [_bytesperline] ; DX:AX := number of bytes to fill mov bx,ax ; BX := bytes in last bank to fill mov dh,dl ; DH := number of full banks to fill mov ax,fs mov es,ax xor _di,_di ; ES:_DI -> video memory add di,[originOffset] mov ax,[bankOffset] ; AX := starting bank number cld ; Moves go up in memory or dh,dh ; More than one bank to fill? jz @@SingleBank ; No, only fill a single bank ; Fill all of the full 64k banks first @@OuterLoop: call setBank mov _cx,4000h ; Need to set 4000h double USHORTs per bank rep stosd xor _di,_di inc al dec dh jnz @@OuterLoop ; Now fill the last partial bank @@SingleBank: call setBank xor _cx,_cx mov cx,bx shr _cx,2 ; _CX := number of double USHORTs to set rep stosd ; Restore graphics controller mov dx,3CEh ; DX := Graphics Controller I/O port xor ax,ax ; AH := 0, AL := 0 out dx,ax ; Restore default Set/Reset register inc ax ; AH := 0, AL := 1 out dx,ax ; Restore enable Set/Reset register pop es leave_c ret procend __clear16 ;---------------------------------------------------------------------------- ; void clear256(long color) ;---------------------------------------------------------------------------- ; Routine to clear the screen. Assumes pages begin on bank boundaries ; for simplicity of coding. ;---------------------------------------------------------------------------- procstart __clear256 ARG color:ULONG enter_c 0 push es xor eax,eax mov al,[BYTE color] mov ebx,eax shl ebx,8 or eax,ebx mov ebx,eax shl ebx,16 or eax,ebx mov [color],eax ; Color = 32 bit color value mov _ax,[_maxy] inc _ax mul [_bytesperline] ; DX:AX := number of bytes to fill mov bx,ax ; BX := bytes in last bank to fill mov dh,dl ; DH := number of full banks to fill mov ax,fs mov es,ax xor _di,_di ; ES:_DI -> start of video memory add di,[originOffset] mov dl,[BYTE bankOffset]; DL := starting bank number cld ; Moves go up in memory or dh,dh ; More than one bank to fill? jz @@SingleBank ; No, only fill a single bank ; Fill all of the full 64k banks first @@OuterLoop: mov al,dl call setBank mov eax,[color] mov _cx,4000h ; Need to set 4000h double USHORTs per bank rep stosd xor _di,_di inc dl dec dh jnz @@OuterLoop ; Now fill the last partial bank @@SingleBank: mov al,dl call setBank mov eax,[color] xor _cx,_cx mov cx,bx shr _cx,2 ; _CX := number of double USHORTs to set rep stosd pop es leave_c ret procend __clear256 ;---------------------------------------------------------------------------- ; void clear32k(long color) ;---------------------------------------------------------------------------- ; Routine to clear the screen. Assumes pages begin on bank boundaries ; for simplicity of coding. ;---------------------------------------------------------------------------- procstart __clear32k ARG color:ULONG enter_c 0 push es xor eax,eax mov ax,[WORD color] mov ebx,eax shl ebx,16 or eax,ebx mov [color],eax ; Color = 32 bit color value mov _ax,[_maxy] inc _ax mul [_bytesperline] ; DX:AX := number of bytes to fill mov bx,ax ; BX := bytes in last bank to fill mov dh,dl ; DH := number of full banks to fill mov ax,fs mov es,ax xor _di,_di ; ES:_DI -> start of video memory add di,[originOffset] mov dl,[BYTE bankOffset]; DL := starting bank number cld ; Moves go up in memory ; Fill all of the full 64k banks first @@OuterLoop: mov al,dl call setBank mov eax,[color] mov _cx,4000h ; Need to set 4000h double USHORTs per bank rep stosd xor _di,_di inc dl dec dh jnz @@OuterLoop ; Now fill the last partial bank mov al,dl call setBank mov eax,[color] xor _cx,_cx mov cx,bx shr _cx,2 ; _CX := number of double USHORTs to set rep stosd pop es leave_c ret procend __clear32k ;---------------------------------------------------------------------------- ; void clear16m(long color) ;---------------------------------------------------------------------------- ; Routine to clear the screen. Assumes pages begin on bank boundaries ; for simplicity of coding. ;---------------------------------------------------------------------------- procstart __clear16m ARG color:ULONG enter_c 0 push _bp xor _bx,_bx ; FS:_BX -> start of video memory add bx,[originOffset] mov dl,[BYTE bankOffset]; DL := starting bank number mov ax,dx call setBank ; Change to starting bank number mov _di,[_maxx] inc _di ; _DI := number of pixels to draw mov _si,[_maxy] inc _si ; _SI := number of lines to process mov ax,[WORD color] ; AX := pixel color mov dh,[BYTE color+2] ; DH := top byte of pixel color mov bp,di shl bp,1 add bp,di ; BP := bytes per physical scanline sub bp,[_bytesperline] neg bp ; BP := scanline adjust factor @@NextScanLine: mov _cx,_di @@LoopSolid: cmp bx,0FFFDh jae @@BankSwitch ; Bank switch occurs! mov [WORD fs:_bx],ax ; Set pixel value in buffer mov [BYTE fs:_bx+2],dh add _bx,3 ; Increment to next pixel loop @@LoopSolid ; Loop across line @@AfterPlot: add bx,bp jc @@BankSwitch2 dec _si jnz @@NextScanLine jmp @@Exit @@BankSwitch: call DrawPixelSlow16m inc dl loop @@LoopSolid ; Loop across line jmp @@AfterPlot @@BankSwitch2: inc dl push _ax mov _ax,_dx call setBank pop _ax dec _si jnz @@NextScanLine @@Exit: pop _bp leave_c ret procend __clear16m ;---------------------------------------------------------------------------- ; void clear4G(long color) ;---------------------------------------------------------------------------- ; Routine to clear the screen. Assumes pages begin on bank boundaries ; for simplicity of coding. ;---------------------------------------------------------------------------- procstart __clear4G ARG color:ULONG enter_c 0 push es mov _ax,[_maxy] inc _ax mul [_bytesperline] ; DX:AX := number of bytes to fill mov bx,ax ; BX := bytes in last bank to fill mov dh,dl ; DH := number of full banks to fill mov ax,fs mov es,ax xor _di,_di ; ES:_DI -> start of video memory add di,[originOffset] mov dl,[BYTE bankOffset]; DL := starting bank number cld ; Moves go up in memory ; Fill all of the full 64k banks first @@OuterLoop: mov al,dl call setBank mov eax,[color] mov _cx,4000h ; Need to set 4000h double USHORTs per bank rep stosd xor _di,_di inc dl dec dh jnz @@OuterLoop ; Now fill the last partial bank mov al,dl call setBank mov eax,[color] xor _cx,_cx mov cx,bx shr _cx,2 ; _CX := number of double USHORTs to set rep stosd pop es leave_c ret procend __clear4G ;---------------------------------------------------------------------------- ; void putPixel16(int x,int y,long color) ;---------------------------------------------------------------------------- ; Routine sets the value of a pixel in native VGA graphics modes. ; ; Entry: x - X coordinate of pixel to draw ; y - Y coordinate of pixel to draw ; color - Color of pixel to draw ; ;---------------------------------------------------------------------------- procstart __putPixel16 ARG x:UINT, y:UINT, color:ULONG enter_c 0 ; Compute the pixel's address in video buffer mov _ax,[y] mov _bx,[x] mul [_bytesperline] ; DX:AX := y * BytesPerLine mov cl,bl ; CL := low-order byte of x shr _bx,3 ; _BX := x/8 add bx,ax adc dx,0 ; DX:BX := y*BytesPerLine + x/8 add bx,[originOffset] ; DX:BX := byte offset in video buffer adc dx,[bankOffset] cmp dl,[BYTE _curBank] je @@NoChange mov al,dl call setBank @@NoChange: mov ah,1 ; AH := unshifted bit mask and cl,7 ; CL := x & 7 xor cl,7 ; CL := # bits to shift left ; set Graphics Controller Bit Mask register shl ah,cl ; AH := bit mask in proper postion mov dx,3CEh ; GC address register port mov al,8 ; AL := Bit Mask Register number out dx,ax ; set Graphics Controller Mode register mov ax,0205h ; AL := Mode register number ; AH := Write mode 2 (bits 0,1) ; Read mode 0 (bit 3) out dx,ax ; set data rotate/Function Select register mov ax,3 ; AL := Data Rotate/Func select reg # out dx,ax ; set the pixel value mov al,[fs:_bx] ; latch one byte from each bit plane mov al,[BYTE color] ; AL := pixel value mov [fs:_bx],al ; update all bit planes ; restore default Graphics Controller registers mov ax,0FF08h ; default bit mask out dx,ax mov ax,0005 ; default mode register out dx,ax mov ax,0003 ; default function select out dx,ax leave_c ret procend __putPixel16 ;---------------------------------------------------------------------------- ; void putPixel256(int x,int y,long color) ;---------------------------------------------------------------------------- ; Routine sets the value of a pixel in native VGA graphics modes. ; ; Entry: x - X coordinate of pixel to draw ; y - Y coordinate of pixel to draw ; color - Color of pixel to draw ; ;---------------------------------------------------------------------------- procstart __putPixel256 ARG x:UINT, y:UINT, color:ULONG enter_c 0 mov _ax,[y] mul [_bytesperline] mov _bx,[x] add ax,bx adc dx,0 ; DX:AX := y * BytesPerLine + x add ax,[originOffset] adc dl,[BYTE bankOffset]; DL := bank number mov bx,ax ; BX := Offset in buffer cmp dl,[BYTE _curBank] je @@NoChange mov al,dl call setBank @@NoChange: mov al,[BYTE color] mov [fs:_bx],al ; Replace the pixel leave_c ret procend __putPixel256 ;---------------------------------------------------------------------------- ; void putPixel32k(int x,int y,long color) ;---------------------------------------------------------------------------- ; Routine sets the value of a pixel in native VGA graphics modes. ; ; Entry: x - X coordinate of pixel to draw ; y - Y coordinate of pixel to draw ; color - Color of pixel to draw ; ;---------------------------------------------------------------------------- procstart __putPixel32k ARG x:UINT, y:UINT, color:ULONG enter_c 0 mov _ax,[y] mul [_bytesperline] mov _bx,[x] shl _bx,1 add ax,bx adc dx,0 ; DX:AX := y * BytesPerLine + x * 2 add ax,[originOffset] adc dl,[BYTE bankOffset]; DL := bank number mov bx,ax ; BX := Offset in buffer cmp dl,[BYTE _curBank] je @@NoChange mov al,dl call setBank @@NoChange: mov ax,[USHORT color] mov [fs:_bx],ax ; Replace the pixel leave_c ret procend __putPixel32k ;---------------------------------------------------------------------------- ; void putPixel16m(int x,int y,long color) ;---------------------------------------------------------------------------- ; Routine sets the value of a pixel in native VGA graphics modes. ; ; Entry: x - X coordinate of pixel to draw ; y - Y coordinate of pixel to draw ; color - Color of pixel to draw ; ;---------------------------------------------------------------------------- procstart __putPixel16m ARG x:UINT, y:UINT, color:ULONG enter_c 0 mov _ax,[y] mul [_bytesperline] mov _bx,[x] add ax,bx adc dx,0 shl bx,1 add ax,bx adc dx,0 ; DX:AX := y * BytesPerLine + x * 3 add ax,[originOffset] adc dl,[BYTE bankOffset]; DL := bank number mov bx,ax ; BX := Offset in buffer cmp dl,[BYTE _curBank] je @@NoChange mov al,dl call setBank @@NoChange: mov ax,[WORD color] mov dh,[BYTE color+2] cmp bx,0FFFEh jae @@SlowVersion ; Bank switch occurs in pixel! mov [fs:_bx],ax ; Replace the first byte mov [fs:_bx+2],dh @@Exit: leave_c ret @@SlowVersion: call DrawPixelSlow16m ; Draw the pixel slowly jmp @@Exit procend __putPixel16m ;---------------------------------------------------------------------------- ; IncBXDL Increment the BX/DL offset bank number combination ;---------------------------------------------------------------------------- ; ; This routine is called in place to increment the value of DL:BX where ; DL is the current bank offset, and BX is the current frame buffer offset. ; The routine also ensures that the bank boundary is correctly crossed. It ; is slow, but only gets called for about less than 10 pixels on the entire ; display page. ; ; Entry: BX - Video buffer offset ; DL - Video bank number ; ; Exit: BX - New buffer offset (+1) ; DL - New bank bumber (carried over from BX) ; ; Registers: None. ; ;---------------------------------------------------------------------------- PROC IncBXDL near add bx,1 adc dl,0 xchg al,dl call setBank xchg al,dl ret ENDP IncBXDL ;---------------------------------------------------------------------------- ; DrawPixelSlow16m Draws a pixel split across a bank boundary correctly ;---------------------------------------------------------------------------- ; ; Draws the pixel taking into account that a bank boundary occurs in the ; middle of the pixel. ; ; Entry: DH:AX - Color of the pixel to plot ; FS:_BX - Address of pixel to plot ; _curBank - Current bank number ; ; Exit: DH:AX - Color of pixel to plot ; FS:_BX - Address of pixel to plot + 3 ; _curBank - Current bank number + 1 ; ; Registers: All preserved. ; ;---------------------------------------------------------------------------- PROC DrawPixelSlow16m near push _dx mov dl,[BYTE _curBank] mov [fs:_bx],al ; Replace the pixel call IncBXDL mov [fs:_bx],ah call IncBXDL mov [fs:_bx],dh call IncBXDL pop _dx ret ENDP DrawPixelSlow16m ;---------------------------------------------------------------------------- ; void putPixel4G(int x,int y,long color) ;---------------------------------------------------------------------------- ; Routine sets the value of a pixel in native VGA graphics modes. ; ; Entry: x - X coordinate of pixel to draw ; y - Y coordinate of pixel to draw ; color - Color of pixel to draw ; ;---------------------------------------------------------------------------- procstart __putPixel4G ARG x:UINT, y:UINT, color:ULONG enter_c 0 mov _ax,[y] mul [_bytesperline] mov _bx,[x] shl _bx,1 shl _bx,1 add ax,bx adc dx,0 ; DX:AX := y * BytesPerLine + x * 4 add ax,[originOffset] adc dl,[BYTE bankOffset]; DL := bank number mov bx,ax ; BX := Offset in buffer cmp dl,[BYTE _curBank] je @@NoChange mov al,dl call setBank @@NoChange: mov eax,[color] mov [fs:_BX],eax ; Replace the pixel leave_c ret procend __putPixel4G ;---------------------------------------------------------------------------- ; void _line16(int x1,int y1,int x2,int y2, long color) ;---------------------------------------------------------------------------- ; Routine draws a line in native VGA graphics modes. ; ; Differentiates between horizontal, vertical and sloping lines. Horizontal ; and vertical lines are special cases and can be drawn extremely quickly. ; The sloping lines are drawn using the Midpoint line algorithm. ; ; Entry: x1 - X1 coordinate of line to draw ; y1 - Y1 coordinate of line to draw ; x2 - X2 coordinate of line to draw ; y2 - Y2 coordinate of line to draw ; color - color to draw the line in ; ;---------------------------------------------------------------------------- procstart __line16 ARG x1:UINT, y1:UINT, x2:UINT, y2:UINT, color:ULONG LOCAL Routine:NCPTR, VertInc:ULONG, EIncr:UINT, \ NEIncr:UINT = LocalSize enter_c LocalSize cld ; Configure the graphics controller (write mode 3) mov dx,3CEh ; DX := Graphics Controller port addr mov ax,0B05h ; AL := Mode register number ; AH := Write mode 3 (bits 0,1) ; Read mode 1 (bit 3) out dx,ax xor ah,ah ; AH := replace mode mov al,3 ; AL := Data Rotate/Func select reg # out dx,ax mov ax,0007h ; AH := 0 (don't care for all maps; ; CPU reads always return 0FFH) ; AL := 7 (Color Don't care reg number) out dx,ax ; Set up Color Don't care reg mov ax,0F01h ; AH := 1111b (bit plane mask for ; enable Set/Reset) out dx,ax ; AL := Enable Set/Reset Register # mov ax,0FF08h ; AH := 11111111b, AL := 8 out dx,ax ; restore bit mask register ; Load the current color mov dx,3CEh ; DX := Graphics Controller port addr mov ah,[BYTE color] ; Get color value into ah xor al,al ; AL := Set/Reset Register number out dx,ax mov si,[_bytesperline] ; Increment for video buffer mov [USHORT VertInc+2],0 ; Zero out sign for vertical increment mov _ax,[x2] sub _ax,[x1] ; _AX := X2 - X1 ; Force X1 < X2 jns @@X2Greater ; Jump if X2 > X1 neg _ax ; _AX := X1 - X2 mov _bx,[x2] ; Exchange X1 and X2 xchg _bx,[x1] mov [x2],_bx mov _bx,[y2] ; Exchange Y1 and Y2 xchg _bx,[y1] mov [y2],_bx ; calcluate dy = ABS(Y2-Y1) @@X2Greater: mov _bx,[y2] sub _bx,[y1] ; _BX := Y2 - Y1 jns @@Y2Greater ; Jump if slope is positive neg _bx ; _BX := Y1 - Y2 neg si ; negative increment for buffer mov [USHORT VertInc+2],0FFFFh ; ensure vert increment is negative ; select appropriate routine for slope of line @@Y2Greater: mov [USHORT VertInc],si ; save increment mov [Routine],offset @@LoSlopeLine cmp _bx,_ax jle @@LoSlope ; Jump if dy <= dx (Slope <= 1) mov [Routine],offset @@HiSlopeLine xchg _bx,_ax ; exchange dy and dx ; calculate initial decision variable and increments @@LoSlope: shl _bx,1 ; _BX := 2 * dy mov [EIncr],_bx ; EIncr := 2 * dy sub _bx,_ax ; d = 2 * dy - dx mov _di,_bx ; DI := initial decision variable sub _bx,_ax mov [NEIncr],_bx ; NEIncr := 2 * (dy - dx) ; calculate first pixel address push _ax ; preserve dx mov _ax,[y1] mov _bx,[x1] call PixelAddr16 ; AH := Bit mask ; FS:_BX -> buffer ; CL := # bits to shift left ; _SI := bank number shl ah,cl ; AH := bit mask in proper position mov al,ah ; AL := bit Mask pop _cx ; Restore dx inc _cx ; _CX := # pixels to draw jmp [Routine] ; jump to appropriate routine ;**************************************************************************** ; ; Routine for dy <= dx (slope <= 1) ; FS:_BX -> video buffer ; AL = bit mask for 1st pixel ; AH = bit mask for 1st pixel ; _CX = # pixels to draw ; DX = Graphics Controller data register port addr ; _SI = bank number ; _DI = Initial decision variable ; EIncr - East pixel increment ; NEIncr - North East pixel increment ; ; The Graphics Controller index register should be set to point to the ; Bit Mask register. ; ;**************************************************************************** @@LoSlopeLine: @@StartLo: mov al,ah ; AL := bit mask for next pixel cmp si,[USHORT _curBank] je @@BitMaskIn push _ax ; Preserve AX mov _ax,_si ; AX := new bank number call setBank ; Program this bank pop _ax @@BitMaskIn: or al,ah ; mask current pixel position ror ah,1 ; Rotate pixel value jc @@BitMaskOut ; Jump if mask rotated to leftmost pixel ; bit mask not shifted out or _di,_di ; test sign of d jns @@InPosDi ; jump if d >= 0 add _di,[EIncr] ; d := d + EIncr loop @@BitMaskIn and [fs:_bx],al ; set remaining pixel(s) jmp @@Exit @@InPosDi: add _di,[NEIncr] ; d := d + NEIncr and [fs:_bx],al ; Update bit planes add bx,[USHORT VertInc] ; increment y adc si,[USHORT VertInc+2] ; Adjust bank number loop @@StartLo jmp @@Exit ; bit mask shifted out @@BitMaskOut: and [fs:_bx],al ; Update bit planes add bx,1 ; increment x adc si,0 ; Adjust bank value or _di,_di ; test sign of d jns @@OutPosDi ; jump if non-negative add _di,[EIncr] ; d := d + EIncr loop @@StartLo jmp @@Exit @@OutPosDi: add _di,[NEIncr] ; d := d + NEIncr add bx,[USHORT VertInc] ; vertical increment adc si,[USHORT VertInc+2] ; Adjust bank number loop @@StartLo jmp @@Exit ;**************************************************************************** ; ; Routine for dy > dx (slope > 1) ; FS:_BX -> video buffer ; AL = bit mask for 1st pixel ; _CX = # pixels to draw ; DX = Graphics Controller data register port addr ; _SI = bank number ; _DI = Initial decision variable ; EIncr - East pixel increment ; NEIncr - North East pixel increment ; ; The Graphics Controller index register should be set to point to the ; Bit Mask register. ; ;**************************************************************************** @@HiSlopeLine: @@StartHi: cmp si,[USHORT _curBank] je @@SetHi push _ax ; Preserve AX mov _ax,_si ; AX := new bank number call setBank ; Program this bank pop _ax @@SetHi: and [fs:_bx],al ; update bit planes add bx,[USHORT VertInc] ; increment y adc si,[USHORT VertInc+2] ; Adjust bank number or _di,_di ; test sign of d jns @@HiPosDi ; jump if d >= 0 add _di,[EIncr] ; d := d + EIncr loop @@StartHi jmp @@Exit @@HiPosDi: add _di,[NEIncr] ; d := d + NEIncr ror al,1 ; rotate bit mask adc bx,0 ; Increment BX when mask rotated to ; leftmost pixel position adc si,0 ; Adjust bank number loop @@StartHi ; Restore graphics controller and return to caller @@Exit: mov dx,3CEh ; DX := Graphics Controller port addr xor ax,ax ; AH := 0, AL := 0 out dx,ax ; Restore Set/Reset Register inc ax ; AH := 0, AL := 1 out dx,ax ; Restore Enable Set/Reset register mov al,3 ; AH := 0, AL := 3 out dx,ax ; Restore Data Rotate/Func select reg mov al,5 ; AH := 0, AL := 5 out dx,ax ; default mode register mov ax,0F07h ; default color compare value out dx,ax mov ax,0FF08h ; AH := 11111111b, AL := 8 out dx,ax ; restore bit mask register leave_c ret procend __line16 ;---------------------------------------------------------------------------- ; void _line256(int x1,int y1,int x2,int y2, long color) ;---------------------------------------------------------------------------- ; Routine draws a line in native VGA graphics modes. ; ; Differentiates between horizontal, vertical and sloping lines. Horizontal ; and vertical lines are special cases and can be drawn extremely quickly. ; The sloping lines are drawn using the Midpoint line algorithm. ; ; Entry: x1 - X1 coordinate of line to draw ; y1 - Y1 coordinate of line to draw ; x2 - X2 coordinate of line to draw ; y2 - Y2 coordinate of line to draw ; color - color to draw the line in ; ;---------------------------------------------------------------------------- procstart __line256 ARG x1:UINT, y1:UINT, x2:UINT, y2:UINT, color:ULONG LOCAL Routine:NCPTR, VertInc:ULONG, EIncr:UINT, \ NEIncr:UINT = LocalSize enter_c LocalSize mov si,[_bytesperline] ; Increment for video buffer mov [USHORT VertInc+2],0 ; Zero out sign for vertical increment mov _ax,[x2] sub _ax,[x1] ; _AX := X2 - X1 ; Force X1 < X2 jns @@X2Greater ; Jump if X2 > X1 neg _ax ; _AX := X1 - X2 mov _bx,[x2] ; Exchange X1 and X2 xchg _bx,[x1] mov [x2],_bx mov _bx,[y2] ; Exchange Y1 and Y2 xchg _bx,[y1] mov [y2],_bx ; calcluate dy = ABS(Y2-Y1) @@X2Greater: mov _bx,[y2] sub _bx,[y1] ; _BX := Y2 - Y1 jns @@Y2Greater ; Jump if slope is positive neg _bx ; _BX := Y1 - Y2 neg si ; negative increment for buffer mov [USHORT VertInc+2],0FFFFh ; ensure vert increment is negative ; select appropriate routine for slope of line @@Y2Greater: mov [USHORT VertInc],si ; save increment mov [Routine],offset @@LoSlopeLine cmp _bx,_ax jle @@LoSlope ; Jump if dy <= dx (Slope <= 1) mov [Routine],offset @@HiSlopeLine xchg _bx,_ax ; exchange dy and dx ; calculate initial decision variable and increments @@LoSlope: shl _bx,1 ; _BX := 2 * dy mov [EIncr],_bx ; EIncr := 2 * dy sub _bx,_ax ; d = 2 * dy - dx mov _di,_bx ; _DI := initial decision variable sub _bx,_ax mov [NEIncr],_bx ; NEIncr := 2 * (dy - dx) ; calculate first pixel address push _ax ; preserve dx mov _ax,[y1] mov _bx,[x1] call PixelAddr256 ; FS:_BX -> buffer pop _cx ; Restore dx inc _cx ; CX := # pixels to draw jmp [Routine] ; jump to appropriate routine ;**************************************************************************** ; ; Routine for dy <= dx (slope <= 1) ; FS:_BX -> video buffer ; _CX = # pixels to draw ; _DX = Bank number for first pixel ; _DI = decision variable ; EIncr - East pixel increment ; NEIncr - North East pixel increment ; ;**************************************************************************** @@LoSlopeLine: mov al,0 call setBank mov al,[BYTE color] ; AL := pixel value to fill mov dh,[BYTE _curBank] ; DH := current bank number @@LoopLo: cmp dl,dh je @@SetLo mov dh,al ; DH := color value mov al,dl ; AL := new bank number call setBank ; Program this bank mov al,dh ; AL := color value mov dh,dl ; DH := current bank number @@SetLo: mov [fs:_bx],al ; Set pixel value in buffer add bx,1 ; Increment x coordinate adc dl,0 ; Adjust bank number or _di,_di ; Test sign of d jns @@LoPosDi ; Jump if d >= 0 add _di,[EIncr] ; d := d + EIncr loop @@LoopLo ; Loop for remaining pixels jmp @@Exit ; We are all done @@LoPosDi: add _di,[NEIncr] ; d := d + NEIncr add bx,[USHORT VertInc] ; increment y adc dl,[BYTE VertInc+2] ; adjust page number loop @@LoopLo ; Loop for remaining pixels jmp @@Exit ; We are all done ;**************************************************************************** ; ; Routine for dy > dx (slope > 1) ; ES:_BX -> video buffer ; _CX = # pixels to draw ; _DX = Bank number for first pixel ; _DI = decision variable ; EIncr - East pixel increment ; NEIncr - North East pixel increment ; ;**************************************************************************** @@HiSlopeLine: mov al,[BYTE color] ; AL := pixel value to fill mov dh,[BYTE _curBank] ; DH := current bank number @@LoopHi: cmp dh,dl je @@SetHi mov dh,al ; DH := color value mov al,dl ; AL := new bank number call setBank ; Program this bank mov al,dh ; AL := color value mov dh,dl ; DH := current bank number @@SetHi: mov [fs:_bx],al ; Set pixel value in buffer add bx,[USHORT VertInc] ; increment y adc dl,[BYTE VertInc+2] ; Adjust bank number or _di,_di ; Test sign of d jns @@HiPosDi ; Jump if d >= 0 add _di,[EIncr] ; d := d + EIncr loop @@LoopHi ; Loop for remaining pixels jmp @@Exit ; We are all done @@HiPosDi: add _di,[NEIncr] ; d := d + NEIncr add bx,1 ; Increment x adc dl,0 ; Adjust bank number loop @@LoopHi ; Loop for remaining pixels @@Exit: leave_c ret procend __line256 ;---------------------------------------------------------------------------- ; void _line32k(int x1,int y1,int x2,int y2, long color) ;---------------------------------------------------------------------------- ; Routine draws a line in native VGA graphics modes. ; ; Differentiates between horizontal, vertical and sloping lines. Horizontal ; and vertical lines are special cases and can be drawn extremely quickly. ; The sloping lines are drawn using the Midpoint line algorithm. ; ; Entry: x1 - X1 coordinate of line to draw ; y1 - Y1 coordinate of line to draw ; x2 - X2 coordinate of line to draw ; y2 - Y2 coordinate of line to draw ; color - color to draw the line in ; ;---------------------------------------------------------------------------- procstart __line32k ARG x1:UINT, y1:UINT, x2:UINT, y2:UINT, color:ULONG LOCAL Routine:NCPTR, VertInc:ULONG, EIncr:UINT, \ NEIncr:UINT = LocalSize enter_c LocalSize cld mov si,[_bytesperline] ; Increment for video buffer mov [USHORT VertInc+2],0 ; Zero out sign for vertical increment mov _ax,[x2] sub _ax,[x1] ; _AX := X2 - X1 ; Force X1 < X2 jns @@X2Greater ; Jump if X2 > X1 neg _ax ; _AX := X1 - X2 mov _bx,[x2] ; Exchange X1 and X2 xchg _bx,[x1] mov [x2],_bx mov _bx,[y2] ; Exchange Y1 and Y2 xchg _bx,[y1] mov [y2],_bx ; calcluate dy = ABS(Y2-Y1) @@X2Greater: mov _bx,[y2] sub _bx,[y1] ; _BX := Y2 - Y1 jns @@Y2Greater ; Jump if slope is positive neg _bx ; _BX := Y1 - Y2 neg si ; negative increment for buffer mov [USHORT VertInc+2],0FFFFh ; ensure vert increment is negative ; select appropriate routine for slope of line @@Y2Greater: mov [USHORT VertInc],si ; save increment mov [Routine],offset @@LoSlopeLine cmp _bx,_ax jle @@LoSlope ; Jump if dy <= dx (Slope <= 1) mov [Routine],offset @@HiSlopeLine xchg _bx,_ax ; exchange dy and dx ; calculate initial decision variable and increments @@LoSlope: shl _bx,1 ; _BX := 2 * dy mov [EIncr],_bx ; EIncr := 2 * dy sub _bx,_ax ; d = 2 * dy - dx mov _di,_bx ; _DI := initial decision variable sub _bx,_ax mov [NEIncr],_bx ; NEIncr := 2 * (dy - dx) ; calculate first pixel address push _ax ; preserve dx mov _ax,[y1] mov _bx,[x1] call PixelAddr32k ; FS:_BX -> buffer pop _cx ; Restore dx inc _cx ; _CX := # pixels to draw jmp [Routine] ; jump to appropriate routine ;**************************************************************************** ; ; Routine for dy <= dx (slope <= 1) ; FS:_BX -> video buffer ; _CX = # pixels to draw ; _DX = Bank number for first pixel ; _DI = decision variable ; EIncr - East pixel increment ; NEIncr - North East pixel increment ; ;**************************************************************************** @@LoSlopeLine: mov ax,[USHORT color] ; AX := pixel value to fill mov dh,[BYTE _curBank] ; DH := current bank number @@LoopLo: cmp dl,dh je @@SetLo push _ax ; Save color value mov al,dl ; AL := new bank number call setBank ; Program this bank mov dh,dl ; DH := current bank number pop _ax ; Restore color value @@SetLo: mov [fs:_bx],ax ; Set pixel value in buffer add bx,2 ; Increment x coordinate adc dl,0 ; Adjust bank number or _di,_di ; Test sign of d jns @@LoPosDi ; Jump if d >= 0 add _di,[EIncr] ; d := d + EIncr loop @@LoopLo ; Loop for remaining pixels jmp @@Exit ; We are all done @@LoPosDi: add _di,[NEIncr] ; d := d + NEIncr add bx,[USHORT VertInc] ; increment y adc dl,[BYTE VertInc+2] ; adjust page number loop @@LoopLo ; Loop for remaining pixels jmp @@Exit ; We are all done ;**************************************************************************** ; ; Routine for dy > dx (slope > 1) ; FS:_BX -> video buffer ; _CX = # pixels to draw ; _DX = Bank number for first pixel ; _DI = decision variable ; EIncr - East pixel increment ; NEIncr - North East pixel increment ; ;**************************************************************************** @@HiSlopeLine: mov ax,[USHORT color] ; AL := pixel value to fill mov dh,[BYTE _curBank] ; DH := current bank number @@LoopHi: cmp dh,dl je @@SetHi push _ax ; Save color value mov al,dl ; AL := new bank number call setBank ; Program this bank mov dh,dl ; DH := current bank number pop _ax ; Restore color value @@SetHi: mov [fs:_bx],ax ; Set pixel value in buffer add bx,[USHORT VertInc] ; increment y adc dl,[BYTE VertInc+2] ; Adjust bank number or _di,_di ; Test sign of d jns @@HiPosDi ; Jump if d >= 0 add _di,[EIncr] ; d := d + EIncr loop @@LoopHi ; Loop for remaining pixels jmp @@Exit ; We are all done @@HiPosDi: add _di,[NEIncr] ; d := d + NEIncr add bx,2 ; Increment x adc dl,0 ; Adjust bank number loop @@LoopHi ; Loop for remaining pixels @@Exit: leave_c ret procend __line32k ;---------------------------------------------------------------------------- ; void _line16m(int x1,int y1,int x2,int y2, long color) ;---------------------------------------------------------------------------- ; Routine draws a line in native VGA graphics modes. ; ; Differentiates between horizontal, vertical and sloping lines. Horizontal ; and vertical lines are special cases and can be drawn extremely quickly. ; The sloping lines are drawn using the Midpoint line algorithm. ; ; Entry: x1 - X1 coordinate of line to draw ; y1 - Y1 coordinate of line to draw ; x2 - X2 coordinate of line to draw ; y2 - Y2 coordinate of line to draw ; color - color to draw the line in ; ;---------------------------------------------------------------------------- procstart __line16m ARG x1:UINT, y1:UINT, x2:UINT, y2:UINT, color:ULONG LOCAL Routine:NCPTR, VertInc:ULONG, EIncr:UINT, \ NEIncr:UINT = LocalSize enter_c LocalSize cld mov si,[_bytesperline] ; Increment for video buffer mov [USHORT VertInc+2],0 ; Zero out sign for vertical increment mov _ax,[x2] sub _ax,[x1] ; _AX := X2 - X1 ; Force X1 < X2 jns @@X2Greater ; Jump if X2 > X1 neg _ax ; _AX := X1 - X2 mov _bx,[x2] ; Exchange X1 and X2 xchg _bx,[x1] mov [x2],_bx mov _bx,[y2] ; Exchange Y1 and Y2 xchg _bx,[y1] mov [y2],_bx ; calcluate dy = ABS(Y2-Y1) @@X2Greater: mov _bx,[y2] sub _bx,[y1] ; _BX := Y2 - Y1 jns @@Y2Greater ; Jump if slope is positive neg _bx ; _BX := Y1 - Y2 neg si ; negative increment for buffer mov [USHORT VertInc+2],0FFFFh ; ensure vert increment is negative ; select appropriate routine for slope of line @@Y2Greater: mov [USHORT VertInc],si ; save increment mov [Routine],offset @@LoSlopeLine cmp _bx,_ax jle @@LoSlope ; Jump if dy <= dx (Slope <= 1) mov [Routine],offset @@HiSlopeLine xchg _bx,_ax ; exchange dy and dx ; calculate initial decision variable and increments @@LoSlope: shl _bx,1 ; _BX := 2 * dy mov [EIncr],_bx ; EIncr := 2 * dy sub _bx,_ax ; d = 2 * dy - dx mov _di,_bx ; _DI := initial decision variable sub _bx,_ax mov [NEIncr],_bx ; NEIncr := 2 * (dy - dx) ; calculate first pixel address push _ax ; preserve dx mov _ax,[y1] mov _bx,[x1] call PixelAddr16m ; FS:_BX -> buffer pop _cx ; Restore dx inc _cx ; CX := # pixels to draw jmp [Routine] ; jump to appropriate routine ;**************************************************************************** ; ; Routine for dy <= dx (slope <= 1) ; FS:_BX -> video buffer ; _CX = # pixels to draw ; _DX = Bank number for first pixel ; _DI = decision variable ; EIncr - East pixel increment ; NEIncr - North East pixel increment ; ;**************************************************************************** @@LoSlopeLine: mov ax,[USHORT color] ; AX := pixel value to fill mov dh,[BYTE color+2] ; DH := top byte of pixel value @@LoopLo: cmp dl,[BYTE _curBank] je @@SetPixelLo push _ax ; Save color value mov al,dl ; AL := new bank number call setBank ; Program this bank pop _ax ; Restore color value @@SetPixelLo: cmp bx,0FFFEh jae @@BankSwitchLo @@SetLo: mov [fs:_bx],ax ; Set pixel value in buffer mov [fs:_bx+2],dh add bx,3 ; Increment x coordinate adc dl,0 ; Adjust bank number @@DonePixelLo: or _di,_di ; Test sign of d jns @@LoPosDi ; Jump if d >= 0 add _di,[EIncr] ; d := d + EIncr loop @@LoopLo ; Loop for remaining pixels jmp @@Exit ; We are all done @@LoPosDi: add _di,[NEIncr] ; d := d + NEIncr add bx,[USHORT VertInc] ; increment y adc dl,[BYTE VertInc+2] ; adjust page number loop @@LoopLo ; Loop for remaining pixels jmp @@Exit ; We are all done @@BankSwitchLo: call DrawPixelSlow16m inc dl jmp @@DonePixelLo ;**************************************************************************** ; ; Routine for dy > dx (slope > 1) ; FS:_BX -> video buffer ; _CX = # pixels to draw ; _DX = Bank number for first pixel ; _DI = decision variable ; EIncr - East pixel increment ; NEIncr - North East pixel increment ; ;**************************************************************************** @@HiSlopeLine: mov ax,[USHORT color] ; AL := pixel value to fill mov dh,[BYTE color+2] ; DH := current bank number @@LoopHi: cmp dl,[BYTE _curBank] je @@SetPixelHi push _ax ; Save color value mov al,dl ; AL := new bank number call setBank ; Program this bank pop _ax ; Restore color value @@SetPixelHi: cmp bx,0FFFEh jae @@BankSwitchHi @@SetHi: mov [fs:_bx],ax ; Set pixel value in buffer mov [fs:_bx+2],dh @@DonePixelHi: add bx,[USHORT VertInc] ; increment y adc dl,[BYTE VertInc+2] ; Adjust bank number or _di,_di ; Test sign of d jns @@HiPosDi ; Jump if d >= 0 add _di,[EIncr] ; d := d + EIncr loop @@LoopHi ; Loop for remaining pixels jmp @@Exit ; We are all done @@HiPosDi: add _di,[NEIncr] ; d := d + NEIncr add bx,3 ; Increment x adc dl,0 ; Adjust bank number loop @@LoopHi ; Loop for remaining pixels jmp @@Exit @@BankSwitchHi: call DrawPixelSlow16m sub bx,3 jmp @@DonePixelHi @@Exit: leave_c ret procend __line16m ;---------------------------------------------------------------------------- ; void _line4G(int x1,int y1,int x2,int y2, long color) ;---------------------------------------------------------------------------- ; Routine draws a line in native VGA graphics modes. ; ; Differentiates between horizontal, vertical and sloping lines. Horizontal ; and vertical lines are special cases and can be drawn extremely quickly. ; The sloping lines are drawn using the Midpoint line algorithm. ; ; Entry: x1 - X1 coordinate of line to draw ; y1 - Y1 coordinate of line to draw ; x2 - X2 coordinate of line to draw ; y2 - Y2 coordinate of line to draw ; color - color to draw the line in ; ;---------------------------------------------------------------------------- procstart __line4G ARG x1:UINT, y1:UINT, x2:UINT, y2:UINT, color:ULONG LOCAL Routine:NCPTR, VertInc:ULONG, EIncr:UINT, \ NEIncr:UINT = LocalSize enter_c LocalSize push eax cld mov si,[_bytesperline] ; Increment for video buffer mov [USHORT VertInc+2],0 ; Zero out sign for vertical increment mov _ax,[x2] sub _ax,[x1] ; _AX := X2 - X1 ; Force X1 < X2 jns @@X2Greater ; Jump if X2 > X1 neg _ax ; _AX := X1 - X2 mov _bx,[x2] ; Exchange X1 and X2 xchg _bx,[x1] mov [x2],_bx mov _bx,[y2] ; Exchange Y1 and Y2 xchg _bx,[y1] mov [y2],_bx ; calcluate dy = ABS(Y2-Y1) @@X2Greater: mov _bx,[y2] sub _bx,[y1] ; _BX := Y2 - Y1 jns @@Y2Greater ; Jump if slope is positive neg _bx ; _BX := Y1 - Y2 neg si ; negative increment for buffer mov [USHORT VertInc+2],0FFFFh ; ensure vert increment is negative ; select appropriate routine for slope of line @@Y2Greater: mov [USHORT VertInc],si ; save increment mov [Routine],offset @@LoSlopeLine cmp _bx,_ax jle @@LoSlope ; Jump if dy <= dx (Slope <= 1) mov [Routine],offset @@HiSlopeLine xchg _bx,_ax ; exchange dy and dx ; calculate initial decision variable and increments @@LoSlope: shl _bx,1 ; _BX := 2 * dy mov [EIncr],_bx ; EIncr := 2 * dy sub _bx,_ax ; d = 2 * dy - dx mov _di,_bx ; _DI := initial decision variable sub _bx,_ax mov [NEIncr],_bx ; NEIncr := 2 * (dy - dx) ; calculate first pixel address push _ax ; preserve dx mov _ax,[y1] mov _bx,[x1] call PixelAddr4G ; FS:_BX -> buffer pop _cx ; Restore dx inc _cx ; _CX := # pixels to draw jmp [Routine] ; jump to appropriate routine ;**************************************************************************** ; ; Routine for dy <= dx (slope <= 1) ; ES:_BX -> video buffer ; _CX = # pixels to draw ; _DX = Bank number for first pixel ; _DI = decision variable ; EIncr - East pixel increment ; NEIncr - North East pixel increment ; ;**************************************************************************** @@LoSlopeLine: mov eax,[color] ; EAX := pixel value to fill mov dh,[BYTE _curBank] ; DH := current bank number @@LoopLo: cmp dl,dh je @@SetLo push _ax ; Save color value mov al,dl ; AL := new bank number call setBank ; Program this bank mov dh,dl ; DH := current bank number pop _ax ; Restore color value @@SetLo: mov [fs:_bx],eax ; Set pixel value in buffer add bx,4 ; Increment x coordinate adc dl,0 ; Adjust bank number or _di,_di ; Test sign of d jns @@LoPosDi ; Jump if d >= 0 add _di,[EIncr] ; d := d + EIncr loop @@LoopLo ; Loop for remaining pixels jmp @@Exit ; We are all done @@LoPosDi: add _di,[NEIncr] ; d := d + NEIncr add bx,[USHORT VertInc] ; increment y adc dl,[BYTE VertInc+2] ; adjust page number loop @@LoopLo ; Loop for remaining pixels jmp @@Exit ; We are all done ;**************************************************************************** ; ; Routine for dy > dx (slope > 1) ; ES:_BX -> video buffer ; _CX = # pixels to draw ; _DX = Bank number for first pixel ; _DI = decision variable ; EIncr - East pixel increment ; NEIncr - North East pixel increment ; ;**************************************************************************** @@HiSlopeLine: mov eax,[color] ; EAX := pixel value to fill mov dh,[BYTE _curBank] ; DH := current bank number @@LoopHi: cmp dh,dl je @@SetHi push _ax ; Save color value mov al,dl ; AL := new bank number call setBank ; Program this bank mov dh,dl ; DH := current bank number pop _ax ; Restore color value @@SetHi: mov [fs:_bx],eax ; Set pixel value in buffer add bx,[USHORT VertInc] ; increment y adc dl,[BYTE VertInc+2] ; Adjust bank number or _di,_di ; Test sign of d jns @@HiPosDi ; Jump if d >= 0 add _di,[EIncr] ; d := d + EIncr loop @@LoopHi ; Loop for remaining pixels jmp @@Exit ; We are all done @@HiPosDi: add _di,[NEIncr] ; d := d + NEIncr add bx,4 ; Increment x adc dl,0 ; Adjust bank number loop @@LoopHi ; Loop for remaining pixels @@Exit: pop eax leave_c ret procend __line4G ;---------------------------------------------------------------------------- ; void setActivePage(int which) ;---------------------------------------------------------------------------- ; Routine to set the video page for active output. ; ; Entry: page - Page number of page to use ; ;---------------------------------------------------------------------------- procstart _setActivePage ARG which:UINT enter_c 0 ; Calculate 18 bit address of page in video memory xor eax,eax mov _ax,[which] ; EAX := page number mul [_pagesize] ; EDX:EAX := result mov [originOffset],ax ; Save video buffer offset shr eax,16 mov [bankOffset],ax ; Save video bank offset leave_c ret procend _setActivePage ;---------------------------------------------------------------------------- ; void setVisualPage(int which) ;---------------------------------------------------------------------------- ; Routine to set the visible video page. ; ; Entry: page - Page number of page to use ; ;---------------------------------------------------------------------------- procstart _setVisualPage ARG which:UINT enter_c 0 cmp [_maxpage],0 ; No flipping if only one page je @@Exit ; Calculate 18 bit address of page in video memory xor eax,eax mov _ax,[which] ; EAX := page number mul [_pagesize] ; EAX := starting address in memory mov edx,eax shr edx,16 ; DX:AX := starting address in memory cmp [_extendedflipping],0 je @@VGAFlip ; We have no extended page flipping div [_bytesperline] ; AX := starting scanline, ; DX := starting byte mov cx,dx cmp [USHORT _maxcolor],0Fh je @@16Color cmp [USHORT _maxcolor],0FFh je @@SetIt cmp [USHORT _maxcolor+2],0FFh je @@16MColor shr cx,1 ; CX := starting pixel in buffer jmp @@SetIt @@16Color: shl cx,3 ; CX := starting pixel in buffer jmp @@SetIt @@16MColor: mov bx,ax ; Preserve AX xor dx,dx mov ax,cx mov cx,3 div cx mov cx,ax ; CX := starting pixel in buffer mov ax,bx ; Restore AX @@SetIt: mov bx,ax ; BX := starting scanline in buffer mov _ax,04F07h mov _dx,_bx ; DX := starting scanline number xor _bx,_bx ; BX := 0 - set display start int 10h ; Set the display start address jmp @@Exit @@VGAFlip: mov bx,ax ; BX := bottom 16 bits of address ; Wait for display enable to be active (active low), to be sure that ; both halves of the start address will take place in one frame. We ; preload a few values here to save time after the DE has been ; detected. mov cl,0Ch ; CL := Start Address High register mov ch,bh ; CH := high byte of new address mov bh,bl ; BH := low byte of new address mov bl,0Dh ; BL := Start Address Low register mov dx,03DAh ; DX := video status port @@WaitDEVGA: in al,dx test al,1 jnz @@WaitDEVGA ; Wait for Display Enable cli mov dx,03D4h ; DX := CRTC I/O port (3D4h) mov ax,bx out dx,ax mov ax,cx out dx,ax sti ; Now wait for the start of the vertical sync, to ensure that the old ; page will be invisible before anything is drawn on it. mov dx,03DAh ; DX := video status port @@WaitStartVert: in al,dx ; Wait for start of vertical retrace test al,8 jz @@WaitStartVert @@Exit: leave_c ret procend _setVisualPage ;---------------------------------------------------------------------------- ; setBank Sets the read/write bank from assembly language ;---------------------------------------------------------------------------- ; ; Entry: AL - New read/write bank number ; ; Exit: AL - New read/write bank number ; ; Registers: All preserved! ; ; Note that some VESA BIOSes and TSR's set the first window to be ; write only and the second window to be read only, so we need to set both ; windows for most common operations to the same value. The Universal ; VESA VBE sets both the read and write banks to the same value for ; Window A, and changed the read bank only for Window B, hence the second ; call is _not_ required when the Universal VESA VBE is installed. You can ; determine what the window does by looking at the WindowAAttributes in ; the SuperVGAInfo block returned by function 00h. You could use this ; information to optimise bank switching when using faster VBE's like ; the Universal VESA VBE (but I have no bothered to do that here). ;---------------------------------------------------------------------------- procstart setBank push _dx ife flatmodel push ds mov dx,DGROUP ; Address our data segment mov ds,dx endif mov [_curBank],_ax ; Save current write bank number cmp [_writeBank],0 je @@VESABank mov _dx,_ax ; DX := bank number call [_writeBank] ; Call relocated version ife flatmodel pop ds endif pop _dx ret @@VESABank: push _ax push _bx push _cx mov cl,[BYTE _bankShift]; Adjust to VESA granularity shl al,cl push _ax mov _dx,_ax ; DX := bank number xor _bx,_bx ; BX := select window A cmp [_bankSwitch],0 je @@UseInt10 call [_bankSwitch] ; Set write window pop _dx inc _bx call [_bankSwitch] ; Set read window jmp @@Exit ; Use the int 10h interface if the bankSwitch routine is NULL, which will ; be the case in protected mode until VBE 2.0 (unless UniVBE 5.0 or above ; is installed). @@UseInt10: mov _ax,04F05h int 10h pop _dx inc _bx mov _ax,04F05h int 10h @@Exit: pop _cx pop _bx pop _ax ife flatmodel pop ds endif pop _dx ret procend setBank ;---------------------------------------------------------------------------- ; setReadBank Sets the read bank from assembly language ;---------------------------------------------------------------------------- ; ; Entry: AL - New read bank number ; ; Exit: AL - New read bank number ; ; Registers: All preserved! ; ;---------------------------------------------------------------------------- procstart setReadBank push _dx ife flatmodel push ds mov dx,DGROUP ; Address our data segment mov ds,dx endif mov [_curBank],-1 ; Ensure banking will be re-loaded cmp [_readBank],0 je @@VESABank mov _dx,_ax ; DX := bank number call [_readBank] ; Call relocated version ife flatmodel pop ds endif pop _dx ret @@VESABank: push _ax push _bx push _cx mov cl,[BYTE _bankShift]; Adjust to VESA granularity shl al,cl mov _dx,_ax ; DX := bank number mov _bx,1 ; BX := select window B cmp [_bankSwitch],0 je @@UseInt10 call [_bankSwitch] ; Set read window jmp @@Exit ; Use the int 10h interface if the bankSwitch routine is NULL, which will ; be the case in protected mode until VBE 2.0 (unless UniVBE 4.4 or above ; is installed). @@UseInt10: mov _ax,04F05h int 10h @@Exit: pop _cx pop _bx pop _ax ife flatmodel pop ds endif pop _dx ret procend setReadBank ;---------------------------------------------------------------------------- ; void setBank(int bank) ;---------------------------------------------------------------------------- ; Sets the new read/write bank number from C ;---------------------------------------------------------------------------- procstart _setBank ARG bank:UINT push _bp mov _bp,_sp mov _ax,[bank] call setBank pop _bp ret procend _setBank ;---------------------------------------------------------------------------- ; void setReadBank(int bank) ;---------------------------------------------------------------------------- ; Sets the new reading bank number from C ;---------------------------------------------------------------------------- procstart _setReadBank ARG bank:UINT push _bp mov _bp,_sp mov _ax,[bank] call setReadBank pop _bp ret procend _setReadBank endcodeseg svga END