;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;                                                              ;;
;; Copyright (C) KolibriOS team 2004-2008. All rights reserved. ;;
;; Distributed under terms of the GNU General Public License    ;;
;;                                                              ;;
;;  VESA20.INC                                                  ;;
;;                                                              ;;
;;  Vesa 2.0 functions for MenuetOS                             ;;
;;                                                              ;;
;;  Copyright 2002 Ville Turjanmaa                              ;;
;;  Alexey, kgaz@crosswindws.net                                ;;
;;  - Voodoo compatible graphics                                ;;
;;  Juan M. Caravaca                                            ;;
;;  - Graphics optimimizations eg. drawline                     ;;
;;                                                              ;;
;;  See file COPYING for details                                ;;
;;                                                              ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

$Revision$


;*************************************************
; getpixel
;
; in:
; eax = x coordinate
; ebx = y coordinate
;
; ret:
; ecx = 00 RR GG BB


get_pixel:
     mov     ecx, [BytesPerScanLine]
     imul    ecx, ebx
     lea     ecx, [ecx+eax*4]		; ecx = x*4+(y*y multiplier)
     mov     ecx, [ecx+LFB_BASE]
     and     ecx, 0xffffff
     ret

;*************************************************

virtual at esp
 putimg:
   .real_sx	   dd ?
   .real_sy	   dd ?
   .image_sx	   dd ?
   .image_sy	   dd ?
   .image_cx	   dd ?
   .image_cy	   dd ?
   .pti 	   dd ?
   .abs_cx	   dd ?
   .abs_cy	   dd ?
   .line_increment dd ?
   .winmap_newline dd ?
   .screen_newline dd ?
   .stack_data = 4*12
   .edi 	dd	?
   .esi 	dd	?
   .ebp 	dd	?
   .esp 	dd	?
   .ebx 	dd	?
   .edx 	dd	?
   .ecx 	dd	?
   .eax 	dd	?
   .ret_addr	dd	?
   .arg_0	dd	?
end virtual

align 16
; ebx = pointer
; ecx = size [x|y]
; edx = coordinates [x|y]
; ebp = pointer to 'get' function
; esi = pointer to 'init' function
; edi = parameter for 'get' function

vesa20_putimage:
     pushad
     call    [_display.disable_mouse]
     sub     esp, putimg.stack_data
; save pointer to image
     mov     [putimg.pti], ebx
; unpack the size
     mov     eax, ecx
     and     ecx, 0xFFFF
     shr     eax, 16
     mov     [putimg.image_sx], eax
     mov     [putimg.image_sy], ecx
; unpack the coordinates
     mov     eax, edx
     and     edx, 0xFFFF
     shr     eax, 16
     mov     [putimg.image_cx], eax
     mov     [putimg.image_cy], edx
; calculate absolute (i.e. screen) coordinates
     mov     eax, [TASK_BASE]
     mov     ebx, [eax-twdw + WDATA.box.left]
     add     ebx, [putimg.image_cx]
     mov     [putimg.abs_cx], ebx
     mov     ebx, [eax-twdw + WDATA.box.top]
     add     ebx, [putimg.image_cy]
     mov     [putimg.abs_cy], ebx
; real_sx = MIN(wnd_sx-image_cx, image_sx);
     mov     ebx, [eax-twdw + WDATA.box.width] ; ebx = wnd_sx
     inc     ebx	; WDATA.box.width is one pixel less than real window x-size
     sub     ebx, [putimg.image_cx]
     ja      @f
     add     esp, putimg.stack_data
     popad
     ret
@@:
     cmp     ebx, [putimg.image_sx]
     jbe     .end_x
     mov     ebx, [putimg.image_sx]
.end_x:
     mov     [putimg.real_sx], ebx
; init real_sy
     mov     ebx, [eax-twdw + WDATA.box.height] ; ebx = wnd_sy
     inc     ebx
     sub     ebx, [putimg.image_cy]
     ja      @f
     add     esp, putimg.stack_data
     popad
     ret
@@:
     cmp     ebx, [putimg.image_sy]
     jbe     .end_y
     mov     ebx, [putimg.image_sy]
.end_y:
     mov     [putimg.real_sy], ebx
; line increment
     mov     eax, [putimg.image_sx]
     mov     ecx, [putimg.real_sx]
     sub     eax, ecx
     call    esi
     add     eax, [putimg.arg_0]
     mov     [putimg.line_increment], eax
; winmap new line increment
     mov     eax, [Screen_Max_X]
     inc     eax
     sub     eax, [putimg.real_sx]
     mov     [putimg.winmap_newline], eax
; screen new line increment
     mov     eax, [BytesPerScanLine]
     shl     ecx, 1
     shl     ecx, 1
     sub     eax, ecx
     mov     [putimg.screen_newline], eax
; pointer to image
     mov     esi, [putimg.pti]
; pointer to screen
     mov     edx, [putimg.abs_cy]
     imul    edx, [BytesPerScanLine]
     mov     eax, [putimg.abs_cx]
     shl     eax, 1
     shl     eax, 1
     add     edx, eax
; pointer to pixel map
     mov     eax, [putimg.abs_cy]
     imul    eax, [Screen_Max_X]
     add     eax, [putimg.abs_cy]
     add     eax, [putimg.abs_cx]
     add     eax, [_WinMapAddress]
     xchg    eax, ebp
; get process number
     mov     ebx, [CURRENT_TASK]

put_image_end_32:
     mov     edi, [putimg.real_sy]
align	4
.new_line:
     mov     ecx, [putimg.real_sx]
align	4
.new_x:
     push    [putimg.edi]
     mov     eax, [putimg.ebp+4]
     call    eax
     cmp     [ebp], bl
     jne     .skip
     mov     [LFB_BASE+edx], eax
.skip:
     add     edx, 4
     inc     ebp
     dec     ecx
     jnz     .new_x
     add     esi, [putimg.line_increment]
     add     edx, [putimg.screen_newline] ;[BytesPerScanLine]
     add     ebp, [putimg.winmap_newline] ;[Screen_Max_X]
     cmp     [putimg.ebp], putimage_get1bpp
     jz      .correct
     cmp     [putimg.ebp], putimage_get2bpp
     jz      .correct
     cmp     [putimg.ebp], putimage_get4bpp
     jnz     @f
.correct:
     mov     eax, [putimg.edi]
     mov     byte [eax], 80h
@@:
     dec     edi
     jnz     .new_line
.finish:
     add     esp, putimg.stack_data
     popad
     ret

;*************************************************
align 4
__sys_putpixel:

; eax = x coordinate
; ebx = y coordinate
; ecx = ?? RR GG BB    ; 0x01000000 negation
; edi = 0x00000001 force

     cmp   [Screen_Max_X], eax
     jb    .exit
     cmp   [Screen_Max_Y], ebx
     jb    .exit
.check_forced:
     test    edi,1		 ; force ?
     jnz     .checked

.not_forced:
     push     edx
     mov      edx,[_display.width]	   ; screen x size
     imul     edx, ebx
     add      edx, [_WinMapAddress]
     movzx    edx, byte [eax+edx]
     cmp      edx, [CURRENT_TASK]
     pop      edx
     jne      .exit

; OK to set pixel
.checked:
     push  ebx
     imul  ebx, [BytesPerScanLine]
     lea   ebx, [ebx+eax*4]
     test  ecx,0x01000000
     jz    .noneg
     mov   ecx, [LFB_BASE+ebx]
     not   ecx
     and   ecx, 0x01FFFFFF
.noneg:
     mov   [LFB_BASE+ebx], ecx
     pop   ebx
.exit:
     ret



align 4
put_pixel:	; left for compatibility with Vesa20_putpixel32
; eax = x
; ebx = y
     imul    ebx, [BytesPerScanLine]	 ; ebx = y * y multiplier
     lea     edi, [ebx+eax*4]  ; edi = x*4+(y*y multiplier)
;     mov     eax, [esp+32-8+4] ; eax = color
     mov     [LFB_BASE+edi], ecx
     ret


;*************************************************

;align 4
calculate_edi:
     mov     edi, ebx
     imul    edi, [Screen_Max_X]
     add     edi, ebx
     add     edi, eax
     ret

;*************************************************

; DRAWLINE

align 4
__sys_draw_line:
     call    [_display.disable_mouse]

; draw a line
; eax = HIWORD = x1
;       LOWORD = x2
; ebx = HIWORD = y1
;       LOWORD = y2
; ecx = color
; edi = force ?
	pusha

dl_x1 equ esp+20
dl_y1 equ esp+16
dl_x2 equ esp+12
dl_y2 equ esp+8
dl_dx equ esp+4
dl_dy equ esp+0

     xor     edx, edx	   ; clear edx
     xor     esi, esi	   ; unpack arguments
     xor     ebp, ebp
     mov     si, ax	   ; esi = x2
     mov     bp, bx	   ; ebp = y2
     shr     eax, 16	   ; eax = x1
     shr     ebx, 16	   ; ebx = y1
     push    eax	   ; save x1
     push    ebx	   ; save y1
     push    esi	   ; save x2

     push    ebp	   ; save y2
; checking x-axis...
     sub     esi, eax	   ; esi = x2-x1
     push    esi	   ; save y2-y1
     jl      .x2lx1	   ; is x2 less than x1 ?
     jg      .no_vline	   ; x1 > x2 ?
     mov     edx, ebp	   ; else (if x1=x2)
     call    vline
     push    edx    ; necessary to rightly restore stack frame at .exit
     jmp     .exit
.x2lx1:
     neg     esi	    ; get esi absolute value
.no_vline:
; checking y-axis...
     sub     ebp, ebx	    ; ebp = y2-y1
     push    ebp	    ; save y2-y1
     jl      .y2ly1	    ; is y2 less than y1 ?
     jg      .no_hline	    ; y1 > y2 ?
     mov     edx, [dl_x2]   ; else (if y1=y2)
     call    hline
     jmp     .exit

.y2ly1:
     neg     ebp	    ; get ebp absolute value
.no_hline:
     cmp     ebp, esi
     jle     .x_rules	    ; |y2-y1| < |x2-x1|  ?
     cmp     [dl_y2], ebx   ; make sure y1 is at the begining
     jge     .no_reverse1
     neg     dword [dl_dx]
     mov     edx, [dl_x2]
     mov     [dl_x2], eax
     mov     [dl_x1], edx
     mov     edx, [dl_y2]
     mov     [dl_y2], ebx
     mov     [dl_y1], edx
.no_reverse1:
     mov     eax, [dl_dx]
     cdq		    ; extend eax sing to edx
     shl     eax, 16	    ; using 16bit fix-point maths
     idiv    ebp	    ; eax = ((x2-x1)*65536)/(y2-y1)
     mov     edx, ebp	    ; edx = counter (number of pixels to draw)
     mov     ebp, 1 *65536  ; <<16   ; ebp = dy = 1.0
     mov     esi, eax	    ; esi = dx
     jmp     .y_rules

.x_rules:
     cmp     [dl_x2], eax    ; make sure x1 is at the begining
     jge     .no_reverse2
     neg     dword [dl_dy]
     mov     edx, [dl_x2]
     mov     [dl_x2], eax
     mov     [dl_x1], edx
     mov     edx, [dl_y2]
     mov     [dl_y2], ebx
     mov     [dl_y1], edx
.no_reverse2:
     xor     edx, edx
     mov     eax, [dl_dy]
     cdq		    ; extend eax sing to edx
     shl     eax, 16	    ; using 16bit fix-point maths
     idiv    esi	    ; eax = ((y2-y1)*65536)/(x2-x1)
     mov     edx, esi	    ; edx = counter (number of pixels to draw)
     mov     esi, 1 *65536  ;<< 16   ; esi = dx = 1.0
     mov     ebp, eax	    ; ebp = dy
.y_rules:
     mov     eax, [dl_x1]
     mov     ebx, [dl_y1]
     shl     eax, 16
     shl     ebx, 16
align 4
.draw:
     push    eax ebx
     shr     eax, 16
     shr     ebx, 16
     call    [putpixel]
     pop     ebx eax
     add     ebx, ebp	     ; y = y+dy
     add     eax, esi	     ; x = x+dx
     dec     edx
     jnz     .draw
; force last drawn pixel to be at (x2,y2)
     mov     eax, [dl_x2]
     mov     ebx, [dl_y2]
     call    [putpixel]
.exit:
     add     esp, 6*4
     popa
     call   [draw_pointer]
     ret

align 4
hline:
; ------------  draw a horizontal line -------------
; eax = x1
; edx = x2
; ebx = y
; ecx = color
; edi = force ?
     cmp     ebx, [Screen_Max_Y]
     jge     .out
     push    eax ebp esi ebx edx
     bt      ecx, 24			; color inversion check
     rcl     edi,1			; forced graphics check

     mov     ebp, [_display.width]	; ebp = screen co-ords base
     imul    ebp, ebx
     add     ebp, [_WinMapAddress]

     cmp     edx, eax		; to make sure x2 > x1
     jge     @f
     xchg    eax, edx
@@:
     cmp     eax, [Screen_Max_X]
     jge     .exit
     imul    ebx, [BytesPerScanLine]
     add     ebx, LFB_BASE
     cmp     edx, [Screen_Max_X]	; last check
     jb      .draw
     mov     edx, [Screen_Max_X]

.draw:	; -- the line ---
     jmp     dword [hline.drawtable + edi*4]	; a coolhack (C) Serge

align 4
.invert_color:
     mov     ecx, [ebx+eax*4]
     xor     ecx, 0x00FFFFFF
     or      ecx, 0x01000000		; keep bit[24] high !
align 4
.check_overlap:
     movzx   esi, byte [ebp+eax]	; check whether the line covered by other windows
     cmp     esi, [CURRENT_TASK]
     je      .putpixel
     jmp     .nextpixel
align 4
.invert_force:
     mov     ecx, [ebx+eax*4]
     xor     ecx, 0x00FFFFFF
     or      ecx, 0x01000000		; keep bit[24] high !
align 4
.putpixel:
     mov     [ebx+eax*4], ecx
align 4
.nextpixel:
     inc     eax
     cmp     eax, edx
     ja     .exit
     jmp     dword [hline.drawtable + edi*4]	; close the loop

.exit:
     shr     edi, 1			; restore the 'force' bit
     pop     edx ebx esi ebp eax
.out:
     ret
align 4
.drawtable:
dd	.check_overlap  ; general case
dd	.invert_color
dd	.putpixel	; force to draw it
dd	.invert_force


align 4
vline:
; ---------  draw a vertical line  ------------
; eax = x
; ebx = y1
; edx = y2
; ecx = color
; edi = force ?
     cmp     eax, [Screen_Max_X]
     jge     .out
     push    eax ebp esi ebx edx
     mov     ebp, [_display.width]	; ebp = screen co-ords base
     imul    ebp, ebx
     add     ebp, [_WinMapAddress]
     add     ebp, eax

     cmp     edx, ebx			; to make sure y2 > y1
     jge     @f
     xchg    ebx, edx
@@:
     cmp     ebx, [Screen_Max_Y]
     jge     .exit
     push    ebx
     imul    ebx, [BytesPerScanLine]
     shl     eax, 1
     shl     eax, 1
     add     eax, ebx
     add     eax, LFB_BASE
     pop     ebx        		; restore ebx = y1
     cmp     edx, [Screen_Max_Y]	; the last check
     jb     .draw
     mov     edx, [Screen_Max_Y]	; to prevent off-screen drawing

.draw:	  
     jmp     dword [vline.drawtable + edi*4]	
align 4
.invert_color:
     mov     ecx, [eax]
     xor     ecx, 0x00FFFFFF
     or      ecx, 0x01000000		
align 4
.check_overlap:
     movzx   esi, byte [ebp]
     cmp     esi, [CURRENT_TASK]
     je      .putpixel
     jmp     .nextpixel

align 4
.invert_force:
     mov     ecx, [eax]
     xor     ecx, 0x00FFFFFF
     or      ecx, 0x01000000		
align 4
.putpixel:
     mov     [eax], ecx
align 4
.nextpixel:
     add     eax, [BytesPerScanLine]
     add     ebp, [_display.width]
     inc     ebx
     cmp     ebx, edx
     ja     .exit
     jmp     dword [vline.drawtable + edi*4]	
.exit:
     shr     edi, 1
     pop     edx ebx esi ebp eax
.out:
     ret
align 4
.drawtable:
dd	.check_overlap  ; general case
dd	.invert_color
dd	.putpixel	; force to draw it
dd	.invert_force


;*************************************************


virtual at esp
drbar:
     .bar_sx	   dd ?
     .bar_sy	   dd ?
     .bar_cx	   dd ?
     .bar_cy	   dd ?
     .abs_cx	   dd ?
     .abs_cy	   dd ?
     .real_sx	   dd ?
     .real_sy	   dd ?
     .color	   dd ?
     .line_inc_scr dd ?
     .line_inc_map dd ?
     .stack_data = 4*11
end virtual

align 4
; eax   cx
; ebx   cy
; ecx   xe
; edx   ye
; edi   color
vesa20_drawbar:
     pushad
     call    [_display.disable_mouse]
     sub     esp, drbar.stack_data
     mov     [drbar.color], edi
     sub     edx, ebx
     jle     .exit	    
     sub     ecx, eax
     jle     .exit	    
     mov     [drbar.bar_sy], edx
     mov     [drbar.bar_sx], ecx
     mov     [drbar.bar_cx], eax
     mov     [drbar.bar_cy], ebx
     mov     edi, [TASK_BASE]
     add     eax, [edi-twdw + WDATA.box.left] ; win_cx
     add     ebx, [edi-twdw + WDATA.box.top] ; win_cy
     mov     [drbar.abs_cx], eax
     mov     [drbar.abs_cy], ebx
; real_sx = MIN(wnd_sx-bar_cx, bar_sx);
     mov     ebx, [edi-twdw + WDATA.box.width] ; ebx = wnd_sx
; note that WDATA.box.width is one pixel less than real window x-size
     inc     ebx
     sub     ebx, [drbar.bar_cx]
     ja      @f
.exit:			     
     add     esp, drbar.stack_data
     popad
     xor     eax, eax
     inc     eax
     ret
@@:
     cmp     ebx, [drbar.bar_sx]
     jbe     .end_x
     mov     ebx, [drbar.bar_sx]
.end_x:
     mov     [drbar.real_sx], ebx
; real_sy = MIN(wnd_sy-bar_cy, bar_sy);
     mov     ebx, [edi-twdw + WDATA.box.height] ; ebx = wnd_sy
     inc     ebx
     sub     ebx, [drbar.bar_cy]
     ja      @f
     add     esp, drbar.stack_data
     popad
     xor     eax, eax
     inc     eax
     ret
@@:
     cmp     ebx, [drbar.bar_sy]
     jbe     .end_y
     mov     ebx, [drbar.bar_sy]
.end_y:
     mov     [drbar.real_sy], ebx
; line_inc_map
     mov     eax, [Screen_Max_X]
     sub     eax, [drbar.real_sx]
     inc     eax
     mov     [drbar.line_inc_map], eax
; line_inc_scr
     mov     eax, [drbar.real_sx]
     shl     eax, 1
     shl     eax, 1
     neg     eax
     add     eax, [BytesPerScanLine]
     mov     [drbar.line_inc_scr], eax
; pointer to screen
     mov     edx, [drbar.abs_cy]
     imul    edx, [BytesPerScanLine]
     mov     eax, [drbar.abs_cx]
     shl     eax, 1
     shl     eax, 1
     add     edx, eax
; pointer to pixel map
     mov     eax, [drbar.abs_cy]
     imul    eax, [Screen_Max_X]
     add     eax, [drbar.abs_cy]
     add     eax, [drbar.abs_cx]
     add     eax, [_WinMapAddress]
     xchg    eax, ebp
; get process number
     mov     ebx, [CURRENT_TASK]

draw_bar_end_32:
; eax - color high   RRGG
; bl - process num
; bh - color low    BB
; ecx - temp
; edx - pointer to screen
; esi - counter
; edi - counter
     mov     eax, [drbar.color]    ;; BBGGRR00
     mov     esi, [drbar.real_sy]
align	4
.new_y:
     mov     edi, [drbar.real_sx]
align	4
.new_x:
     cmp     byte [ebp], bl
     jne     .skip

     mov     [LFB_BASE+edx], eax
.skip:
; add pixel
     add     edx, 4
     inc     ebp
     dec     edi
     jnz     .new_x
; add line
     add     edx, [drbar.line_inc_scr]
     add     ebp, [drbar.line_inc_map]
; <Ivan 15.10.04> drawing gradient bars
     test    eax, 0x80000000
     jz      @f
     test    al, al
     jz      @f
     dec     al
@@:
; </Ivan 15.10.04>
     dec     esi
     jnz     .new_y
     add     esp, drbar.stack_data
     popad
     xor     eax, eax
     ret


align 4
vesa20_drawbackground_tiled:
	call	[_display.disable_mouse]
	pushad
; External loop for all y from start to end
	mov	ebx, [draw_data+32+RECT.top]	; y start
dp2:
	mov	ebp, [draw_data+32+RECT.left]	; x start
; 1) Calculate pointers in WinMapAddress (does pixel belong to OS thread?) [ebp]
;                       and LFB data (output for our function) [edi]
	mov	eax, [BytesPerScanLine]
	mul	ebx
	xchg	ebp, eax
	add	ebp, eax
	add	ebp, eax
	add	ebp, eax
	add	ebp, eax
	add	ebp, LFB_BASE
; ebp:=Y*BytesPerScanLine+X*BytesPerPixel+AddrLFB
	call	calculate_edi
	xchg	edi, ebp
	add ebp, [_WinMapAddress]
; Now eax=x, ebx=y, edi->output, ebp=offset in WinMapAddress
; 2) Calculate offset in background memory block
	push	eax
	xor	edx, edx
	mov	eax, ebx
	div	dword [BgrDataHeight]	; edx := y mod BgrDataHeight
	pop	eax
	push	eax
	mov	ecx, [BgrDataWidth]
	mov	esi, edx
	imul	esi, ecx		; esi := (y mod BgrDataHeight) * BgrDataWidth
	xor	edx, edx
	div	ecx		; edx := x mod BgrDataWidth
	sub	ecx, edx
	add	esi, edx	; esi := (y mod BgrDataHeight)*BgrDataWidth + (x mod BgrDataWidth)
	pop	eax
	lea	esi, [esi*3]
	add	esi, [img_background]
	xor	edx, edx
	inc	edx
; 3) Loop through redraw rectangle and copy background data
; Registers meaning:
; eax = x, ebx = y (screen coordinates)
; ecx = deltax - number of pixels left in current tile block
; edx = 1
; esi -> bgr memory, edi -> output
; ebp = offset in WinMapAddress
dp3:
	cmp	[ebp], dl
	jnz	nbgp
	movsb
	movsb
	movsb
	jmp	@f
nbgp:
	add	esi, 3
	add	edi, 3
@@:
	inc	edi   	 	; +1 for 32 bpp
	add	ebp, edx
	add	eax, edx
	cmp	eax, [draw_data+32+RECT.right]
	ja	dp4
	sub	ecx, edx
	jnz	dp3
; next tile block on x-axis
	mov	ecx, [BgrDataWidth]
	sub	esi, ecx
	sub	esi, ecx
	sub	esi, ecx
	jmp	dp3
dp4:
; next scan line
	inc	ebx
	cmp	ebx, [draw_data+32+RECT.bottom]
	jbe	dp2
	popad
	ret

; ----------


vesa20_drawbackground_stretch:
	call	[_display.disable_mouse]
	pushad
; Helper variables
; calculate 2^32*(BgrDataWidth-1) mod (ScreenWidth-1)
	mov	eax, [BgrDataWidth]
	dec	eax
	xor	edx, edx
	div	dword [Screen_Max_X]
	push	eax	; high
	xor	eax, eax
	div	dword [Screen_Max_X]
	push	eax	; low
; the same for height
	mov	eax, [BgrDataHeight]
	dec	eax
	xor	edx, edx
	div	dword [Screen_Max_Y]
	push	eax	; high
	xor	eax, eax
	div	dword [Screen_Max_Y]
	push	eax	; low
; External loop for all y from start to end
	mov	ebx, [draw_data+32+RECT.top]	; y start
	mov	ebp, [draw_data+32+RECT.left]	; x start
; 1) Calculate pointers in WinMapAddress (does pixel belong to OS thread?) [ebp]
;                       and LFB data (output for our function) [edi]
	mov	eax, [BytesPerScanLine]
	mul	ebx
	xchg	ebp, eax
	add	ebp, eax
	add	ebp, eax
	add	ebp, eax
	add	ebp, eax

; ebp:=Y*BytesPerScanLine+X*BytesPerPixel+AddrLFB
	call	calculate_edi
	xchg	edi, ebp
; Now eax=x, ebx=y, edi->output, ebp=offset in WinMapAddress
	push	ebx
	push	eax
; 2) Calculate offset in background memory block
	mov	eax, ebx
	imul	ebx, dword [esp+12]
	mul	dword [esp+8]
	add	edx, ebx	; edx:eax = y * 2^32*(BgrDataHeight-1)/(ScreenHeight-1)
	mov	esi, edx
	imul	esi, [BgrDataWidth]
	push	edx
	push	eax
	mov	eax, [esp+8]
	mul	dword [esp+28]
	push	eax
	mov	eax, [esp+12]
	mul	dword [esp+28]
	add	[esp], edx
	pop	edx		; edx:eax = x * 2^32*(BgrDataWidth-1)/(ScreenWidth-1)
	add	esi, edx
	lea	esi, [esi*3]
	add	esi, [img_background]
	push	eax
	push	edx
	push	esi
; 3) Smooth horizontal
bgr_resmooth0:
	mov	ecx, [esp+8]
	mov	edx, [esp+4]
	mov	esi, [esp]
	push	edi
	mov	edi, bgr_cur_line
	call	smooth_line
bgr_resmooth1:
	mov	eax, [esp+16+4]
	inc	eax
	cmp	eax, [BgrDataHeight]
	jae	bgr.no2nd
	mov	ecx, [esp+8+4]
	mov	edx, [esp+4+4]
	mov	esi, [esp+4]
	add	esi, [BgrDataWidth]
	add	esi, [BgrDataWidth]
	add	esi, [BgrDataWidth]
	mov	edi, bgr_next_line
	call	smooth_line
bgr.no2nd:
	pop	edi
sdp3:
	xor	esi, esi
	mov	ecx, [esp+12]
; 4) Loop through redraw rectangle and copy background data
; Registers meaning:
; esi = offset in current line, edi -> output
; ebp = offset in WinMapAddress
; dword [esp] = offset in bgr data
; qword [esp+4] = x * 2^32 * (BgrDataWidth-1) / (ScreenWidth-1)
; qword [esp+12] = y * 2^32 * (BgrDataHeight-1) / (ScreenHeight-1)
; dword [esp+20] = x
; dword [esp+24] = y
; precalculated constants:
; qword [esp+28] = 2^32*(BgrDataHeight-1)/(ScreenHeight-1)
; qword [esp+36] = 2^32*(BgrDataWidth-1)/(ScreenWidth-1)
sdp3a:
	mov eax, [_WinMapAddress]
	cmp	[ebp+eax], byte 1
	jnz	snbgp
	mov	eax, [bgr_cur_line+esi]
	test	ecx, ecx
	jz	.novert
	mov	ebx, [bgr_next_line+esi]
	call	[overlapping_of_points_ptr]
.novert:

	mov	[LFB_BASE+edi], ax
	shr	eax, 16

	mov	[LFB_BASE+edi+2], al
snbgp:
	add	edi, 4
	inc	ebp
	mov	eax, [esp+20]
	inc	eax
	mov	[esp+20], eax
	add	esi, 4
	cmp	eax, [draw_data+32+RECT.right]
	jbe	sdp3a
sdp4:
; next y
	mov	ebx, [esp+24]
	inc	ebx
	mov	[esp+24], ebx
	cmp	ebx, [draw_data+32+RECT.bottom]
	ja	sdpdone
; advance edi, ebp to next scan line
	sub	eax, [draw_data+32+RECT.left]
	sub	ebp, eax
	add	ebp, [Screen_Max_X]
	inc	ebp
	sub	edi, eax
	sub	edi, eax
	sub	edi, eax
	sub	edi, eax
	add	edi, [BytesPerScanLine]
; restore ecx,edx; advance esi to next background line
	mov	eax, [esp+28]
	mov	ebx, [esp+32]
	add	[esp+12], eax
	mov	eax, [esp+16]
	adc	[esp+16], ebx
	sub	eax, [esp+16]
	mov	ebx, eax
	lea	eax, [eax*3]
	imul	eax, [BgrDataWidth]
	sub	[esp], eax
	mov	eax, [draw_data+32+RECT.left]
	mov	[esp+20], eax
	test	ebx, ebx
	jz	sdp3
	cmp	ebx, -1
	jnz	bgr_resmooth0
	push	edi
	mov	esi, bgr_next_line
	mov	edi, bgr_cur_line
	mov	ecx, [Screen_Max_X]
	inc	ecx
	rep	movsd
	jmp	bgr_resmooth1
sdpdone:
	add	esp, 44
	popad
	ret

uglobal
align 4
bgr_cur_line	rd	1920	; maximum width of screen
bgr_next_line	rd	1920
endg

smooth_line:
	mov	al, [esi+2]
	shl	eax, 16
	mov	ax, [esi]
	test	ecx, ecx
	jz	@f
	mov	ebx, [esi+2]
	shr	ebx, 8
	call	[overlapping_of_points_ptr]
@@:
	stosd
	mov	eax, [esp+20+8]
	inc	eax
	mov	[esp+20+8], eax
	cmp	eax, [draw_data+32+RECT.right]
	ja	@f
	add	ecx, [esp+36+8]
	mov	eax, edx
	adc	edx, [esp+40+8]
	sub	eax, edx
	lea	eax, [eax*3]
	sub	esi, eax
	jmp	smooth_line
@@:
	mov	eax, [draw_data+32+RECT.left]
	mov	[esp+20+8], eax
	ret

align 16
overlapping_of_points:
	push	ecx edx
	mov	edx, eax
	push	esi
	shr	ecx, 26
	mov	esi, ecx
	mov	ecx, ebx
	shl	esi, 9
	movzx	ebx, dl
	movzx	eax, cl
	sub	eax, ebx
	movzx	ebx, dh
	add	dl, [BgrAuxTable+(eax+0x100)+esi]
	movzx	eax, ch
	sub	eax, ebx
	add	dh, [BgrAuxTable+(eax+0x100)+esi]
	ror	ecx, 16
	ror	edx, 16
	movzx	eax, cl
	movzx	ebx, dl
	sub	eax, ebx
	add	dl, [BgrAuxTable+(eax+0x100)+esi]
	pop	esi
	mov	eax, edx
	pop	edx
	ror	eax, 16
	pop	ecx
	ret

iglobal
align 4
overlapping_of_points_ptr	dd	overlapping_of_points
endg

init_background:
	mov	edi, BgrAuxTable
	xor	edx, edx
.loop2:
	mov	eax, edx
	shl	eax, 8
	neg	eax
	mov	ecx, 0x200
.loop1:
	mov	byte [edi], ah
	inc	edi
	add	eax, edx
	loop	.loop1
	add	dl, 4
	jnz	.loop2
	test	byte [cpu_caps+(CAPS_MMX/8)], 1 shl (CAPS_MMX mod 8)
	jz	@f
	mov	[overlapping_of_points_ptr], overlapping_of_points_mmx
@@:
	ret

align 16
overlapping_of_points_mmx:
        movd    mm0, eax
        movd    mm4, eax
        movd    mm1, ebx
        pxor    mm2, mm2
        punpcklbw mm0, mm2
        punpcklbw mm1, mm2
        psubw   mm1, mm0
        movd    mm3, ecx
        psrld   mm3, 24
        packuswb mm3, mm3
        packuswb mm3, mm3
        pmullw  mm1, mm3
        psrlw   mm1, 8
        packuswb mm1, mm2
        paddb   mm4, mm1
        movd    eax, mm4
        ret
diff16 "VESA2 code end ",0,$
diff16 "VESA2 code size",get_pixel,$