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Assembly Source File | 1993-11-18 | 113.7 KB | 3,335 lines

; ======================================================== ; MODEX.ASM - A Complete Mode X Library ; ; Version 1.04 Release, 3 May 1993, By Matt Pritchard ; With considerable input from Michael Abrash ; ; The following information is donated to the public domain in ; the hopes that save other programmers much frustration. ; ; If you do use this code in a product, it would be nice if ; you include a line like "Mode X routines by Matt Pritchard" ; in the credits. ; ; Protected Mode modification by John McCarthy ; John McCarthy thanks Matt Pritchard for providing this code, ; and hopes Matt Pritchard is not offended by the changes. ; ; ======================================================== ; ; All of this code is designed to be assembled with MASM 5.10a ; but TASM 3.0 could be used as well. ; ; The routines contained are designed for use in a MEDIUM model ; program. All Routines are FAR, and is assumed that a DGROUP ; data segment exists and that DS will point to it on entry. ; ; For all routines, the AX, BX, CX, DX, ES and FLAGS registers ; will not be preserved, while the DS, BP, SI and DI registers ; will be preserved. ; ; Unless specifically noted, All Parameters are assumed to be ; "PASSED BY VALUE". That is, the actual value is placed on ; the stack. When a reference is passed it is assumed to be ; a near pointer to a variable in the DGROUP segment. ; ; Routines that return a single 16-Bit integer value will ; return that value in the AX register. ; ; This code will *NOT* run on an 8086/8088 because 80286+ ; specific instructions are used. If you have an 8088/86 ; and VGA, you can buy an 80386-40 motherboard for about ; $160 and move into the 90's. ; ; JM - revision, this code will *NOT* run on 80286 because of ; 80368+ code is used (and protected mode). ; ; This code is reasonably optimized: Most drawing loops have ; been unrolled once and memory references are minimized by ; keeping stuff in registers when possible. ; ; Error Trapping varies by Routine. No Clipping is performed ; so the caller should verify that all coordinates are valid. ; ; Several Macros are used to simplify common 2 or 3 instruction ; sequences. Several Single letter Text Constants also ; simplify common assembler expressions like "WORD PTR". ; ; ------------------ Mode X Variations ------------------ ; ; Mode # Screen Size Max Pages Aspect Ratio (X:Y) ; ; 0 320 x 200 4 Pages 1.2:1 ; 1 320 x 400 2 Pages 2.4:1 ; 2 360 x 200 3 Pages 1.35:1 ; 3 360 x 400 1 Page 2.7:1 ; 4 320 x 240 3 Pages 1:1 ; 5 320 x 480 1 Page 2:1 ; 6 360 x 240 3 Pages 1.125:1 ; 7 360 x 480 1 Page 2.25:1 ; ; -------------------- The Legal Stuff ------------------ ; ; No warranty, either written or implied, is made as to ; the accuracy and usability of this code product. Use ; at your own risk. Batteries not included. Pepperoni ; and extra cheese available for an additional charge. ; ; ----------------------- The Author -------------------- ; ; Matt Pritchard is a paid programmer who'd rather be ; writing games. He can be reached at: P.O. Box 140264, ; Irving, TX 75014 USA. Michael Abrash is a living ; god, who now works for Bill Gates (Microsoft). ; ; -------------------- Revision History ----------------- ; 4-12-93: v1.02 - SET_POINT & READ_POINT now saves DI ; SET_MODEX now saves SI ; 5-3-93: v1.04 - added LOAD_DAC_REGISTERS and ; READ_DAC_REGISTERS. Expanded CLR Macro ; to handle multiple registers ; ; Revisions by John McCarthy - sometime throughout June/93: ; ; - Protected mode addressing for all routines. ; - Conditional assembley for routines not wanted by user ; - Bios text addressing removed - see set_vga_modex ; - File assembles for protected mode, variables and routines made public ; - Mode03 routine added to return to DOS mode. Must be used in conjunction ; with TRAN's protected mode header. ; - Also added routines to turn off the screen to avoid that screen flicker ; when changing into xmode. ; ; A note from John McCarthy: ; ; When converting to protected mode, loop's, rep's, stosb's and such ; must have the high word of the ecx,edi,esi registers set. I have tested ; the routines now that they have been converted and they seem to all work ; fine, but if you find they don't jive, please send me a message/letter and ; I will get right on it. ; ; These routines originally came with all kinds of extra files for font ; editing, pallet editing, C stuff and demos. I have only supplied the ; critical files from Matt to cut down on .zip file size. ; x_fill_block equ 1 ; small routines are automatically included x_draw_line equ 1 ; which x mode routines should be included x_set_point equ 0 ; when assembled; 1 = enabled x_read_point equ 0 x_gprintc equ 0 x_tgprintc equ 1 x_set_window equ 0 x_print_str equ 0 x_tprint_str equ 0 x_set_font equ 0 x_draw_bitmap equ 0 x_tdraw_bitmap equ 1 x_copy_page equ 0 x_copy_bitmap equ 0 .386p jumps code32 segment para public use32 assume cs:code32, ds:code32 include pmode.inc ; protected mode externals include macros.inc ; guess... include equ.inc ; list of constants ; xmode routines by matt prichard ; modified for 386 protected mode by john mccarthy ; protected mode header courtesy of TRAN ; ===== data tables ===== ; bit mask tables for left/right/character masks public left_clip_mask public right_clip_mask left_clip_mask db 0fh, 0eh, 0ch, 08h right_clip_mask db 01h, 03h, 07h, 0fh ; bit patterns for converting character fonts char_plane_data db 00h,08h,04h,0ch,02h,0ah,06h,0eh db 01h,09h,05h,0dh,03h,0bh,07h,0fh ; crtc register values for various configurations mode_single_line: ; crtc setup data for 400/480 line modes dw 04009h ; cell height (1 scan line) dw 00014h ; dword mode off dw 0e317h ; turn on byte mode dw nil ; end of crtc data for 400/480 line mode mode_double_line: ; crtc setup data for 200/240 line modes dw 04109h ; cell height (2 scan lines) dw 00014h ; dword mode off dw 0e317h ; turn on byte mode dw nil ; end of crtc data for 200/240 line mode mode_320_wide: ; crtc setup data for 320 horz pixels dw 05f00h ; horz total dw 04f01h ; horz displayed dw 05002h ; start horz blanking dw 08203h ; end horz blanking dw 05404h ; start h sync dw 08005h ; end h sync dw nil ; end of crtc data for 320 horz pixels mode_360_wide: ; crtc setup data for 360 horz pixels dw 06b00h ; horz total dw 05901h ; horz displayed dw 05a02h ; start horz blanking dw 08e03h ; end horz blanking dw 05e04h ; start h sync dw 08a05h ; end h sync dw nil ; end of crtc data for 360 horz pixels mode_200_tall: mode_400_tall: ; crtc setup data for 200/400 line modes dw 0bf06h ; vertical total dw 01f07h ; overflow dw 09c10h ; v sync start dw 08e11h ; v sync end/prot cr0 cr7 dw 08f12h ; vertical displayed dw 09615h ; v blank start dw 0b916h ; v blank end dw nil ; end of crtc data for 200/400 lines mode_240_tall: mode_480_tall: ; crtc setup data for 240/480 line modes dw 00d06h ; vertical total dw 03e07h ; overflow dw 0ea10h ; v sync start dw 08c11h ; v sync end/prot cr0 cr7 dw 0df12h ; vertical displayed dw 0e715h ; v blank start dw 00616h ; v blank end dw nil ; end of crtc data for 240/480 lines ; table of display mode tables mode_table: dd o mode_320x200, o mode_320x400 dd o mode_360x200, o mode_360x400 dd o mode_320x240, o mode_320x480 dd o mode_360x240, o mode_360x480 ; table of display mode components mode_320x200: ; data for 320 by 200 pixels db 063h ; 400 scan lines & 25 mhz clock db 4 ; maximum of 4 pages dw 320, 200 ; displayed pixels (x,y) dw 1302, 816 ; max possible x and y sizes dd o mode_320_wide, o mode_200_tall dd o mode_double_line, nil mode_320x400: ; data for 320 by 400 pixels db 063h ; 400 scan lines & 25 mhz clock db 2 ; maximum of 2 pages dw 320, 400 ; displayed pixels x,y dw 648, 816 ; max possible x and y sizes dd o mode_320_wide, o mode_400_tall dd o mode_single_line, nil mode_360x240: ; data for 360 by 240 pixels db 0e7h ; 480 scan lines & 28 mhz clock db 3 ; maximum of 3 pages dw 360, 240 ; displayed pixels x,y dw 1092, 728 ; max possible x and y sizes dd o mode_360_wide, o mode_240_tall dd o mode_double_line , nil mode_360x480: ; data for 360 by 480 pixels db 0e7h ; 480 scan lines & 28 mhz clock db 1 ; only 1 page possible dw 360, 480 ; displayed pixels x,y dw 544, 728 ; max possible x and y sizes dd o mode_360_wide, o mode_480_tall dd o mode_single_line , nil mode_320x240: ; data for 320 by 240 pixels db 0e3h ; 480 scan lines & 25 mhz clock db 3 ; maximum of 3 pages dw 320, 240 ; displayed pixels x,y dw 1088, 818 ; max possible x and y sizes dd o mode_320_wide, o mode_240_tall dd o mode_double_line, nil mode_320x480: ; data for 320 by 480 pixels db 0e3h ; 480 scan lines & 25 mhz clock db 1 ; only 1 page possible dw 320, 480 ; displayed pixels x,y dw 540, 818 ; max possible x and y sizes dd o mode_320_wide, o mode_480_tall dd o mode_single_line, nil mode_360x200: ; data for 360 by 200 pixels db 067h ; 400 scan lines & 28 mhz clock db 3 ; maximum of 3 pages dw 360, 200 ; displayed pixels (x,y) dw 1302, 728 ; max possible x and y sizes dd o mode_360_wide, o mode_200_tall dd o mode_double_line, nil mode_360x400: ; data for 360 by 400 pixels db 067h ; 400 scan lines & 28 mhz clock db 1 ; maximum of 1 pages dw 360, 400 ; displayed pixels x,y dw 648, 816 ; max possible x and y sizes dd o mode_360_wide, o mode_400_tall dd o mode_single_line, nil mode_data_table struc m_miscr db ? ; value of misc_output register m_pages db ? ; maximum possible # of pages m_xsize dw ? ; x size displayed on screen m_ysize dw ? ; y size displayed on screen m_xmax dw ? ; maximum possible x size m_ymax dw ? ; maximum possible y size m_crtc dd ? ; table of crtc register values mode_data_table ends ; specific x mode data table format... screen_width dw 0 ; actual width of a line in bytes screen_height dw 0 ; actual vertical height in pixels last_page dw 0 ; # of display pages page_addr dd 4 dup (0) ; offsets to start of each page page_size dw 0 ; size of page in addr bytes display_page dw 0 ; page # currently displayed active_page dw 0 ; page # currently active current_page dd 0 ; address of current page current_xoffset dw 0 ; current display x offset current_yoffset dw 0 ; current display y offset current_moffset dd 0 ; current start offset max_xoffset dw 0 ; current display x offset max_yoffset dw 0 ; current display y offset charset_low dd 0 ; far ptr to char set: 0-127 charset_hi dd 0 ; far ptr to char set: 128-255 public screen_width public screen_height public last_page public page_addr public page_size public display_page public active_page public current_page public current_xoffset public current_yoffset public current_moffset public max_xoffset public max_yoffset public charset_low public charset_hi ; ===== mode x setup routines ===== ;====================================================== ;set_vga_modex% (modetype%, maxxpos%, maxypos%, pages%) ;====================================================== ; ; sets up the specified version of mode x. allows for ; the setup of multiple video pages, and a virtual ; screen which can be larger than the displayed screen ; (which can then be scrolled a pixel at a time) ; ; entry: modetype = desired screen resolution (0-7) ; ; 0 = 320 x 200, 4 pages max, 1.2:1 aspect ratio ; 1 = 320 x 400, 2 pages max, 2.4:1 aspect ratio ; 2 = 360 x 200, 3 pages max, 1.35:1 aspect ratio ; 3 = 360 x 400, 1 page max, 2.7:1 aspect ratio ; 4 = 320 x 240, 3 pages max, 1:1 aspect ratio ; 5 = 320 x 480, 1 page max, 2:1 aspect ratio ; 6 = 360 x 240, 3 pages max, 1.125:1 aspect ratio ; 7 = 360 x 480, 1 page max, 2.25:1 aspect ratio ; ; maxxpos = the desired virtual screen width ; maxypos = the desired virtual screen height ; pages = the desired # of video pages ; ; exit: ax = success flag: 0 = failure / -1= success ; svm_stack struc svm_table dd ? ; offset of mode info table dd ?x3 ; edi, esi, ebp dd ? ; caller svm_pages dw ? ; # of screen pages desired svm_ysize dw ? ; vertical screen size desired svm_xsize dw ? ; horizontal screen size desired svm_mode dw ? ; display resolution desired svm_stack ends public set_vga_modex set_vga_modex: push ebp esi edi ; preserve important registers sub esp, 4 ; allocate workspace mov ebp, esp ; set up stack frame ; check legality of mode request.... movzx ebx, [ebp].svm_mode ; get requested mode # cmp bx, num_modes ; is it 0..7? jae @svm_badmodesetup ; if not, error out shl bx, 2 ; scale bx mov esi, d mode_table[ebx] ; si -> mode info mov [ebp].svm_table, esi ; save ptr for later use ; check # of requested display pages mov cx, [ebp].svm_pages ; get # of requested pages clr ch ; set hi word = 0! cmp cl, [esi].m_pages ; check # pages for mode ja @svm_badmodesetup ; report error if too many pages jcxz @svm_badmodesetup ; report error if 0 pages ; check validity of x size and [ebp].svm_xsize, 0fff8h ; x size mod 8 must = 0 mov ax, [ebp].svm_xsize ; get logical screen width cmp ax, [esi].m_xsize ; check against displayed x jb @svm_badmodesetup ; report error if too small cmp ax, [esi].m_xmax ; check against max x ja @svm_badmodesetup ; report error if too big ; check validity of y size mov bx, [ebp].svm_ysize ; get logical screen height cmp bx, [esi].m_ysize ; check against displayed y jb @svm_badmodesetup ; report error if too small cmp bx, [esi].m_ymax ; check against max y ja @svm_badmodesetup ; report error if too big ; enough memory to fit it all? shr ax, 2 ; # of bytes:line = xsize/4 mul cx ; ax = bytes/line * pages mul bx ; dx:ax = total vga mem needed jno @svm_continue ; exit if total size > 256k dec dx ; was it exactly 256k??? or dx, ax ; (dx = 1, ax = 0000) jz @svm_continue ; if so, it's valid... @svm_badmodesetup: clr ax ; return value = false jmp @svm_exit ; normal exit @svm_continue: mov v86r_ax,13h ; start with mode 13h mov al,10h ; bios int 10h int 33h ; let v86 handler call bios int 10h call turn_screen_off ; prevent flicker out_16 sc_index, chain4_off ; disable chain 4 mode out_16 sc_index, async_reset ; (a)synchronous reset out_8 misc_output, [esi].m_miscr ; set new timing/size out_16 sc_index, sequ_restart ; restart sequencer ... out_8 crtc_index, 11h ; select vert retrace end register inc dx ; point to data in al, dx ; get value, bit 7 = protect and al, 7fh ; mask out write protect out dx, al ; and send it back mov dx, crtc_index ; vga crtc registers add esi, m_crtc ; si -> crtc parameter data ; load tables of crtc parameters from list of tables @svm_setup_table: mov edi, [esi] ; get pointer to crtc data tbl add esi, 4 ; point to next ptr entry or edi, edi ; a nil ptr means that we have jz @svm_set_data ; finished crtc programming @svm_setup_crtc: mov ax, [edi] ; get crtc data from table add edi, 2 ; advance pointer or ax, ax ; at end of data table? jz @svm_setup_table ; if so, exit & get next table out dx, ax ; reprogram vga crtc reg jmp s @svm_setup_crtc ; process next table entry ; initialize page & scroll info, edi = 0 @svm_set_data: mov display_page, di ; display page = 0 mov active_page, di ; active page = 0 mov current_xoffset, di ; horz scroll index = 0 mov current_yoffset, di ; vert scroll index = 0 mov current_moffset,edi ; memory scroll index = 0 @rlp esi, vga_segment ; segment for vga memory mov current_page, esi ; set logical screen width, x scroll and our data mov esi, [ebp].svm_table ; get saved ptr to mode info mov ax, [ebp].svm_xsize ; get display width mov cx, ax ; cx = logical width sub cx, [esi].m_xsize ; cx = max x scroll value mov max_xoffset, cx ; set maximum x scroll shr ax, 2 ; bytes = pixels / 4 mov screen_width, ax ; save width in pixels shr ax, 1 ; offset value = bytes / 2 mov ah, 13h ; crtc offset register index xchg al, ah ; switch format for out out dx, ax ; set vga crtc offset reg ; setup data table, y scroll, misc for other routines mov ax, [ebp].svm_ysize ; get logical screen height mov cx, ax ; cx = logical height sub bx, [esi].m_ysize ; cx = max y scroll value mov max_yoffset, cx ; set maximum y scroll mov screen_height, ax ; save height in pixels mul screen_width ; ax = page size in bytes, mov page_size, ax ; save page size mov cx, [ebp].svm_pages ; get # of pages mov last_page, cx ; save # of pages clr bx ; page # = 0 @rlp edx, vga_segment ; page 0 offset = 0a0000h movzx eax,ax ; clear top word of eax movzx ebx,bx @svm_set_pages: mov page_addr[ebx], edx ; set page #(bx) offset add bx, 4 ; page#++ add edx, eax ; compute addr of next page loopx cx, @svm_set_pages ; loop until all pages set ; clear vga memory out_16 sc_index, all_planes_on ; select all planes mov edi, current_page ; -> start of vga memory clr ax ; ax = 0 cld ; block xfer forwards mov ecx, 8000h ; 32k * 4 * 2 = 256k rep stosw ; clear dat memory! ; setup font pointers, in protected mode. you must shl 8 then add but ; i don't know how to correctly convert segmented code to flat memory. ; ; mov v86r_bh, rom_8x8_lo ; ask for 8x8 font, 0-127 ; mov v86r_ax, get_char_ptr ; service to get pointer ; mov al,10h ; int 33h ; call vga bios through v86 handler ; ; mov charset_low, bp ; save char set offset ; mov charset_low+2, es ; save char set segment ; ; mov v86r_bh, rom_8x8_hi ; ask for 8x8 font, 128-255 ; mov v86r_ax, get_char_ptr ; service to get pointer ; mov al,10h ; int 33h ; call vga bios ; ; mov charset_hi, bp ; save char set offset ; mov charset_hi+2, es ; save char set segment call turn_screen_on ; prevent flicker mov ax, true ; return success code @svm_exit: add esp, 4 ; deallocate workspace pop edi esi ebp ; restore saved registers ret 8 ; exit & clean up stack ;================== ;set_modex% (mode%) ;================== ; ; quickie mode set - sets up mode x to default configuration ; ; entry: modetype = desired screen resolution (0-7) ; (see set_vga_modex for list) ; ; exit: ax = success flag: 0 = failure / -1= success ; sm_stack struc dd ?,? ; ebp, esi dd ? ; caller sm_mode dw ? ; desired screen resolution sm_stack ends public set_modex set_modex: push ebp esi ; preserve important registers mov ebp, esp ; set up stack frame clr ax ; assume failure movzx ebx, [ebp].sm_mode ; get desired mode # cmp bx, num_modes ; is it a valid mode #? jae @smx_exit ; if not, don't bother push bx ; push mode parameter shl bx, 2 ; scale bx to dword indexer mov esi, d mode_table[ebx] ; esi -> mode info push [esi].m_xsize ; push default x size push [esi].m_ysize ; push default y size mov al, [esi].m_pages ; get default # of pages clr ah ; hi byte = 0 push ax ; push # pages call set_vga_modex ; set up mode x! @smx_exit: pop esi ebp ; restore registers ret 2 ; exit & clean up stack ; ===== basic graphics primitives ===== ;============================ ;clear_vga_screen (colornum%) ;============================ ; ; clears the active display page ; ; entry: colornum = color value to fill the page with ; ; exit: no meaningful values returned ; cvs_stack struc dd ?,? ; edi, ebp dd ? ; caller cvs_color db ?,? ; color to set screen to cvs_stack ends public clear_vga_screen clear_vga_screen: push ebp edi ; preserve important registers mov ebp, esp ; set up stack frame out_16 sc_index, all_planes_on ; select all planes mov edi, current_page ; point to active vga page mov al, [ebp].cvs_color ; get color mov ah, al ; copy for dword write mov bp,ax shl eax,16 mov ax,bp cld ; block fill forwards movzx ecx, page_size ; get size of page shr cx, 2 ; divide by 4 for dwords rep stosd ; block fill vga memory pop edi ebp ; restore saved registers ret 2 ; exit & clean up stack ;=================================== ;set_point (xpos%, ypos%, colornum%) ;=================================== ; ; plots a single pixel on the active display page ; ; entry: xpos = x position to plot pixel at ; ypos = y position to plot pixel at ; colornum = color to plot pixel with ; ; exit: no meaningful values returned ; sp_stack struc dd ?,? ; ebp, edi dd ? ; caller setp_color db ?,? ; color of point to plot setp_ypos dw ? ; y pos of point to plot setp_xpos dw ? ; x pos of point to plot sp_stack ends public set_point set_point: push ebp edi ; preserve registers mov ebp, esp ; set up stack frame mov edi, current_page ; point to active vga page mov ax, [ebp].setp_ypos ; get line # of pixel mul screen_width ; get offset to start of line clr ebx ; wipe high word mov bx, [ebp].setp_xpos ; get xpos mov cx, bx ; copy to extract plane # from shr bx, 2 ; x offset (bytes) = xpos/4 add bx, ax ; offset = width*ypos + xpos/4 mov ax, map_mask_plane1 ; map mask & plane select register and cl, plane_bits ; get plane bits shl ah, cl ; get plane select value out_16 sc_index, ax ; select plane mov al,[ebp].setp_color ; get pixel color mov [edi+ebx], al ; draw pixel pop edi ebp ; restore saved registers ret 6 ; exit and clean up stack ;========================== ;read_point% (xpos%, ypos%) ;========================== ; ; read the color of a pixel from the active display page ; ; entry: xpos = x position of pixel to read ; ypos = y position of pixel to read ; ; exit: ax = color of pixel at (xpos, ypos) ; rp_stack struc dd ?,? ; ebp, edi dd ? ; caller rp_ypos dw ? ; y pos of point to read rp_xpos dw ? ; x pos of point to read rp_stack ends public read_point read_point: push ebp edi ; preserve registers mov ebp, esp ; set up stack frame mov edi, current_page ; point to active vga page mov ax, [ebp].rp_ypos ; get line # of pixel mul screen_width ; get offset to start of line clr ebx ; wipe high word mov bx, [ebp].rp_xpos ; get xpos mov cx, bx shr bx, 2 ; x offset (bytes) = xpos/4 add bx, ax ; offset = width*ypos + xpos/4 mov al, read_map ; gc read mask register mov ah, cl ; get xpos and ah, plane_bits ; & mask out plane # out_16 gc_index, ax ; select plane to read in clr eax ; clear return value hi byte mov al, [edi+ebx] ; get color of pixel pop edi ebp ; restore saved registers ret 4 ; exit and clean up stack if x_fill_block eq 1 ;====================================================== ;fill_block (xpos1%, ypos1%, xpos2%, ypos2%, colornum%) ;====================================================== ; ; fills a rectangular block on the active display page ; ; entry: xpos1 = left x position of area to fill ; ypos1 = top y position of area to fill ; xpos2 = right x position of area to fill ; ypos2 = bottom y position of area to fill ; colornum = color to fill area with ; ; exit: no meaningful values returned ; fb_stack struc dd ?x3 ; edi, esi, ebp dd ? ; caller fb_color db ?,? ; fill color fb_ypos2 dw ? ; y pos of lower right pixel fb_xpos2 dw ? ; x pos of lower right pixel fb_ypos1 dw ? ; y pos of upper left pixel fb_xpos1 dw ? ; x pos of upper left pixel fb_stack ends public fill_block fill_block: push ebp esi edi ; preserve important registers mov ebp, esp ; set up stack frame mov edi, current_page ; point to active vga page cld ; direction flag = forward out_8 sc_index, map_mask ; set up for plane select ; validate pixel coordinates ; if necessary, swap so x1 <= x2, y1 <= y2 clr eax clr ecx mov ax, [ebp].fb_ypos1 ; ax = y1 is y1< y2? mov bx, [ebp].fb_ypos2 ; bx = y2 cmp ax, bx jle @fb_noswap1 mov [ebp].fb_ypos1, bx ; swap y1 and y2 and save y1 xchg ax, bx ; on stack for future use @fb_noswap1: sub bx, ax ; get y width inc bx ; add 1 to avoid 0 value mov [ebp].fb_ypos2, bx ; save in ypos2 mul screen_width ; mul y1 by bytes per line add edi, eax ; di = start of line y1 mov ax, [ebp].fb_xpos1 ; check x1 <= x2 mov bx, [ebp].fb_xpos2 ; cmp ax, bx jle @fb_noswap2 ; skip ahead if ok mov [ebp].fb_xpos2, ax ; swap x1 and x2 and save x2 xchg ax, bx ; on stack for future use ; all our input values are in order, now determine ; how many full "bands" 4 pixels wide (aligned) there ; are, and if there are partial bands (<4 pixels) on ; the left and right edges. @fb_noswap2: movzx edx, ax ; dx = x1 (pixel position) shr edx, 2 ; dx/4 = bytes into line add edi, edx ; di = addr of upper-left corner movzx ecx, bx ; cx = x2 (pixel position) shr cx, 2 ; cx/4 = bytes into line cmp dx, cx ; start and end in same band? jne @fb_normal ; if not, check for l & r edges jmp @fb_one_band_only ; if so, then special processing @fb_normal: sub cx, dx ; cx = # bands -1 movzx esi, ax ; si = plane#(x1) and si, plane_bits ; if left edge is aligned then jz @fb_l_plane_flush ; no special processing.. ; draw "left edge" vertical strip of 1-3 pixels... out_8 sc_data, left_clip_mask[esi] ; set left edge plane mask mov esi, edi ; si = copy of start addr (ul) mov dx, [ebp].fb_ypos2 ; get # of lines to draw mov al, [ebp].fb_color ; get fill color movzx ebx, screen_width ; get vertical increment value @fb_left_loop: mov [esi], al ; fill in left edge pixels add esi, ebx ; point to next line (below) loopjz dx, @fb_left_cont ; exit loop if all lines drawn mov [esi], al ; fill in left edge pixels add esi, ebx ; point to next line (below) loopx dx, @fb_left_loop ; loop until left strip is drawn @fb_left_cont: inc edi ; point to middle (or right) block dec cx ; reset cx instead of jmp @fb_right @fb_l_plane_flush: inc cx ; add in left band to middle block ; di = addr of 1st middle pixel (band) to fill ; cx = # of bands to fill -1 @fb_right: movzx esi, [ebp].fb_xpos2 ; get xpos2 and si, plane_bits ; get plane values cmp si, 0003 ; plane = 3? je @fb_r_edge_flush ; hey, add to middle ; draw "right edge" vertical strip of 1-3 pixels... out_8 sc_data, right_clip_mask[esi] ; right edge plane mask mov esi, edi ; get addr of left edge add esi, ecx ; add width-1 (bands) dec esi ; to point to top of right edge mov dx, [ebp].fb_ypos2 ; get # of lines to draw mov al, [ebp].fb_color ; get fill color movzx ebx, screen_width ; get vertical increment value @fb_right_loop: mov [esi], al ; fill in right edge pixels add esi, ebx ; point to next line (below) loopjz dx, @fb_right_cont ; exit loop if all lines drawn mov [esi], al ; fill in right edge pixels add esi, ebx ; point to next line (below) loopx dx, @fb_right_loop ; loop until left strip is drawn @fb_right_cont: dec cx ; minus 1 for middle bands jz @fb_exit ; uh.. no middle bands... @fb_r_edge_flush: ; di = addr of upper left block to fill ; cx = # of bands to fill in (width) out_8 sc_data, all_planes ; write to all planes mov dx, screen_width ; dx = di increment sub dx, cx ; = screen_width-# planes filled mov ebx, ecx ; bx = quick refill for cx mov si, [ebp].fb_ypos2 ; si = # of line to fill mov al, [ebp].fb_color ; get fill color @fb_middle_loop: rep stosb ; fill in entire line mov ecx, ebx ; recharge cx (line width) add edi, edx ; point to start of next line loopx si, @fb_middle_loop ; loop until all lines drawn jmp s @fb_exit ; outa here @fb_one_band_only: movzx esi, ax ; get left clip mask, save x1 and si, plane_bits ; mask out row # mov al, left_clip_mask[esi] ; get left edge mask mov si, bx ; get right clip mask, save x2 and si, plane_bits ; mask out row # and al, right_clip_mask[esi] ; get right edge mask byte out_8 sc_data, al ; clip for left & right masks mov cx, [ebp].fb_ypos2 ; get # of lines to draw mov al, [ebp].fb_color ; get fill color clr ebx ; wipe high word mov bx, screen_width ; get vertical increment value @fb_one_loop: mov [edi], al ; fill in pixels add edi, ebx ; point to next line (below) loopjz cx, @fb_exit ; exit loop if all lines drawn mov [edi], al ; fill in pixels add edi, ebx ; point to next line (below) loopx cx, @fb_one_loop ; loop until left strip is drawn @fb_exit: pop edi esi ebp ; restore saved registers ret 10 ; exit and clean up stack endif if x_draw_line eq 1 ;===================================================== ;draw_line (xpos1%, ypos1%, xpos2%, ypos2%, colornum%) ;===================================================== ; ; draws a line on the active display page ; ; entry: xpos1 = x position of first point on line ; ypos1 = y position of first point on line ; xpos2 = x position of last point on line ; ypos2 = y position of last point on line ; colornum = color to draw line with ; ; exit: no meaningful values returned ; dl_stack struc dd ?x3 ; edi, esi, ebp dd ? ; caller dl_colorf db ?,? ; line draw color dl_ypos2 dw ? ; y pos of last point dl_xpos2 dw ? ; x pos of last point dl_ypos1 dw ? ; y pos of first point dl_xpos1 dw ? ; x pos of first point dl_stack ends public draw_line draw_line: push ebp esi edi ; preserve important registers mov ebp, esp ; set up stack frame cld ; direction flag = forward out_8 sc_index, map_mask ; set up for plane select mov ch, [ebp].dl_colorf ; save line color in ch ; check line type movzx esi, [ebp].dl_xpos1 ; ax = x1 is x1< x2? movzx edi, [ebp].dl_xpos2 ; dx = x2 cmp si, di ; is x1 < x2 je @dl_vline ; if x1=x2, draw vertical line jl @dl_noswap1 ; if x1 < x2, don't swap xchg si, di ; x2 is > x1, so swap them @dl_noswap1: ; si = x1, di = x2 mov ax, [ebp].dl_ypos1 ; ax = y1 is y1 <> y2? cmp ax, [ebp].dl_ypos2 ; y1 = y2? je @dl_horz ; if so, draw a horizontal line jmp @dl_brezham ; diagonal line... go do it... ; this code draws a horizontal line in mode x where: ; si = x1, di = x2, and ax = y1/y2 @dl_horz: mul screen_width ; offset = ypos * screen_width mov dx, ax ; cx = line offset into page mov ax, si ; get left edge, save x1 and si, plane_bits ; mask out row # mov bl, left_clip_mask[esi] ; get left edge mask mov cx, di ; get right edge, save x2 and di, plane_bits ; mask out row # mov bh, right_clip_mask[edi] ; get right edge mask byte shr ax, 2 ; get x1 byte # (=x1/4) shr cx, 2 ; get x2 byte # (=x2/4) movzx eax, ax ; zero high words for add movzx edx, dx movzx ecx, cx mov edi, current_page ; point to active vga page add edi, edx ; point to start of line add edi, eax ; point to pixel x1 sub cx, ax ; cx = # of bands (-1) to set jnz @dl_longln ; jump if longer than one segment and bl, bh ; otherwise, merge clip masks @dl_longln: out_8 sc_data, bl ; set the left clip mask mov al, [ebp].dl_colorf ; get line color mov bl, al ; bl = copy of line color stosb ; set left (1-4) pixels jcxz @dl_exit3 ; done if only one line segment dec cx ; cx = # of middle segments jz @dl_xrseg ; if no middle segments.... ; draw middle segments out_8 dx, all_planes ; write to all planes mov al, bl ; get color from bl rep stosb ; draw middle (4 pixel) segments @dl_xrseg: out_8 dx, bh ; select planes for right clip mask mov al, bl ; get color value stosb ; draw right (1-4) pixels @dl_exit3: jmp s @dl_exit ; we are done... ; this code draws a vertical line. on entry: ; ch = line color, si & di = x1 @dl_vline: mov ax, [ebp].dl_ypos1 ; ax = y1 mov si, [ebp].dl_ypos2 ; si = y2 cmp ax, si ; is y1 < y2? jle @dl_noswap2 ; if so, don't swap them xchg ax, si ; ok, now y1 < y2 @dl_noswap2: sub si, ax ; si = line height (y2-y1+1) inc si ; ax = y1, di = x1, get offset into page into ax mul screen_width ; offset = y1 (ax) * screen width mov dx, di ; copy xpos into dx shr di, 2 ; di = xpos/4 add ax, di ; di = xpos/4 + screenwidth * y1 movzx eax, ax mov edi, current_page ; point to active vga page add edi, eax ; point to pixel x1, y1 ;select plane mov cl, dl ; cl = save x1 and cl, plane_bits ; get x1 mod 4 (plane #) mov ax, map_mask_plane1 ; code to set plane #1 shl ah, cl ; change to correct plane # out_16 sc_index, ax ; select plane mov al, ch ; get saved color mov bx, screen_width ; get offset to advance line by movzx ebx, bx @dl_vloop: mov [edi], al ; draw single pixel add edi, ebx ; point to next line loopjz si, @dl_exit ; lines--, exit if done mov [edi], al ; draw single pixel add edi, ebx ; point to next line loopx si, @dl_vloop ; lines--, loop until done @dl_exit: jmp @dl_exit2 ; done! ; this code draws a diagonal line in mode x @dl_brezham: mov edi, current_page ; point to active vga page mov ax, [ebp].dl_ypos1 ; get y1 value mov bx, [ebp].dl_ypos2 ; get y2 value mov cx, [ebp].dl_xpos1 ; get starting xpos cmp bx, ax ; y2-y1 is? jnc @dl_deltayok ; if y2>=y1 then goto... xchg bx, ax ; swap em... mov cx, [ebp].dl_xpos2 ; get new starting xpos @dl_deltayok: mul screen_width ; offset = screen_width * y1 movzx eax, ax add edi, eax ; di -> start of line y1 on page mov ax, cx ; ax = xpos (x1) shr ax, 2 ; /4 = byte offset into line add edi, eax ; di = starting pos (x1,y1) mov al, 11h ; staring mask and cl, plane_bits ; get plane # shl al, cl ; and shift into place mov ah, [ebp].dl_colorf ; color in hi bytes push ax ; save mask,color... mov ah, al ; plane # in ah mov al, map_mask ; select plane register out_16 sc_index, ax ; select initial plane mov ax, [ebp].dl_xpos1 ; get x1 value mov bx, [ebp].dl_ypos1 ; get y1 value mov cx, [ebp].dl_xpos2 ; get x2 value mov dx, [ebp].dl_ypos2 ; get y2 value movzx ebp, screen_width ; use bp for line width to ; to avoid extra memory access sub dx, bx ; figure delta_y jnc @dl_deltayok2 ; jump if y2 >= y1 add bx, dx ; put y2 into y1 neg dx ; abs(delta_y) xchg ax, cx ; and exchange x1 and x2 @dl_deltayok2: mov bx, 08000h ; seed for fraction accumulator sub cx, ax ; figure delta_x jc @dl_drawleft ; if negative, go left jmp @dl_drawright ; draw line that slopes right @dl_drawleft: neg cx ; abs(delta_x) cmp cx, dx ; is delta_x < delta_y? jb @dl_steepleft ; yes, so go do steep line ; (delta_y iterations) ; draw a shallow line to the left in mode x @dl_shallowleft: clr ax ; zero low word of delta_y * 10000h sub ax, dx ; dx:ax <- dx * 0ffffh sbb dx, 0 ; include carry div cx ; divide by delta_x mov si, bx ; si = accumulator mov bx, ax ; bx = add fraction pop ax ; get color, bit mask mov dx, sc_data ; sequence controller data register inc cx ; inc delta_x so we can unroll loop ; loop (x2) to draw pixels, move left, and maybe down... @dl_sllloop: mov [edi], ah ; set first pixel, plane data set up loopjz cx, @dl_sllexit ; delta_x--, exit if done add si, bx ; add numerator to accumulator jnc @dl_slll2nc ; move down on carry add edi, ebp ; move down one line... @dl_slll2nc: dec edi ; left one addr ror al, 1 ; move left one plane, back on 0 1 2 cmp al, 87h ; wrap?, if al <88 then carry set adc edi, 0 ; adjust address: di = di + carry out dx, al ; set up new bit plane mask mov [edi], ah ; set pixel loopjz cx, @dl_sllexit ; delta_x--, exit if done add si, bx ; add numerator to accumulator, jnc @dl_slll3nc ; move down on carry add edi, ebp ; move down one line... @dl_slll3nc: ; now move left a pixel... dec edi ; left one addr ror al, 1 ; move left one plane, back on 0 1 2 cmp al, 87h ; wrap?, if al <88 then carry set adc edi, 0 ; adjust address: di = di + carry out dx, al ; set up new bit plane mask jmp s @dl_sllloop ; loop until done @dl_sllexit: jmp @dl_exit2 ; and exit ; draw a steep line to the left in mode x @dl_steepleft: clr ax ; zero low word of delta_y * 10000h xchg dx, cx ; delta_y switched with delta_x div cx ; divide by delta_y mov si, bx ; si = accumulator mov bx, ax ; bx = add fraction pop ax ; get color, bit mask mov dx, sc_data ; sequence controller data register inc cx ; inc delta_y so we can unroll loop ; loop (x2) to draw pixels, move down, and maybe left @dl_stlloop: mov [edi], ah ; set first pixel loopjz cx, @dl_stlexit ; delta_y--, exit if done add si, bx ; add numerator to accumulator jnc @dl_stlnc2 ; no carry, just move down! dec edi ; move left one addr ror al, 1 ; move left one plane, back on 0 1 2 cmp al, 87h ; wrap?, if al <88 then carry set adc edi, 0 ; adjust address: di = di + carry out dx, al ; set up new bit plane mask @dl_stlnc2: add edi, ebp ; advance to next line. mov [edi], ah ; set pixel loopjz cx, @dl_stlexit ; delta_y--, exit if done add si, bx ; add numerator to accumulator jnc @dl_stlnc3 ; no carry, just move down! dec edi ; move left one addr ror al, 1 ; move left one plane, back on 0 1 2 cmp al, 87h ; wrap?, if al <88 then carry set adc edi, 0 ; adjust address: di = di + carry out dx, al ; set up new bit plane mask @dl_stlnc3: add edi, ebp ; advance to next line. jmp s @dl_stlloop ; loop until done @dl_stlexit: jmp @dl_exit2 ; and exit ; draw a line that goes to the right... @dl_drawright: cmp cx, dx ; is delta_x < delta_y? jb @dl_steepright ; yes, so go do steep line ; (delta_y iterations) ; draw a shallow line to the right in mode x @dl_shallowright: clr ax ; zero low word of delta_y * 10000h sub ax, dx ; dx:ax <- dx * 0ffffh sbb dx, 0 ; include carry div cx ; divide by delta_x mov si, bx ; si = accumulator mov bx, ax ; bx = add fraction pop ax ; get color, bit mask mov dx, sc_data ; sequence controller data register inc cx ; inc delta_x so we can unroll loop ; loop (x2) to draw pixels, move right, and maybe down... @dl_slrloop: mov [edi], ah ; set first pixel, mask is set up loopjz cx, @dl_slrexit ; delta_x--, exit if done.. add si, bx ; add numerator to accumulator jnc @dl_slr2nc ; don't move down if carry not set add edi, ebp ; move down one line... @dl_slr2nc: ; now move right a pixel... rol al, 1 ; move right one addr if plane = 0 cmp al, 12h ; wrap? if al >12 then carry not set adc edi, 0 ; adjust address: di = di + carry out dx, al ; set up new bit plane mask mov [edi], ah ; set pixel loopjz cx, @dl_slrexit ; delta_x--, exit if done.. add si, bx ; add numerator to accumulator jnc @dl_slr3nc ; don't move down if carry not set add edi, ebp ; move down one line... @dl_slr3nc: rol al, 1 ; move right one addr if plane = 0 cmp al, 12h ; wrap? if al >12 then carry not set adc edi, 0 ; adjust address: di = di + carry out dx, al ; set up new bit plane mask jmp s @dl_slrloop ; loop till done @dl_slrexit: jmp @dl_exit2 ; and exit ; draw a steep line to the right in mode x @dl_steepright: clr ax ; zero low word of delta_y * 10000h xchg dx, cx ; delta_y switched with delta_x div cx ; divide by delta_y mov si, bx ; si = accumulator mov bx, ax ; bx = add fraction pop ax ; get color, bit mask mov dx, sc_data ; sequence controller data register inc cx ; inc delta_y so we can unroll loop ; loop (x2) to draw pixels, move down, and maybe right @strloop: mov [edi], ah ; set first pixel, mask is set up loopjz cx, @dl_exit2 ; delta_y--, exit if done add si, bx ; add numerator to accumulator jnc @strnc2 ; if no carry then just go down... rol al, 1 ; move right one addr if plane = 0 cmp al, 12h ; wrap? if al >12 then carry not set adc edi, 0 ; adjust address: di = di + carry out dx, al ; set up new bit plane mask @strnc2: add edi, ebp ; advance to next line. mov [edi], ah ; set pixel loopjz cx, @dl_exit2 ; delta_y--, exit if done add si, bx ; add numerator to accumulator jnc @strnc3 ; if no carry then just go down... rol al, 1 ; move right one addr if plane = 0 cmp al, 12h ; wrap? if al >12 then carry not set adc edi, 0 ; adjust address: di = di + carry out dx, al ; set up new bit plane mask @strnc3: add edi, ebp ; advance to next line. jmp s @strloop ; loop till done @dl_exit2: pop edi esi ebp ; restore saved registers ret 10 ; exit and clean up stack endif ; ===== dac color register routines ===== ;================================================= ;set_dac_register (register%, red%, green%, blue%) ;================================================= ; ; sets a single (rgb) vga palette register ; ; entry: register = the dac # to modify (0-255) ; red = the new red intensity (0-63) ; green = the new green intensity (0-63) ; blue = the new blue intensity (0-63) ; ; exit: no meaningful values returned ; sdr_stack struc dd ? ; ebp dd ? ; caller sdr_blue db ?,? ; blue data value sdr_green db ?,? ; green data value sdr_red db ?,? ; red data value sdr_register db ?,? ; palette register # sdr_stack ends public set_dac_register set_dac_register: push ebp ; save bp mov ebp, esp ; set up stack frame ; select which dac register to modify out_8 dac_write_addr, [ebp].sdr_register mov dx, pel_data_reg ; dac data register out_8 dx, [ebp].sdr_red ; set red intensity out_8 dx, [ebp].sdr_green ; set green intensity out_8 dx, [ebp].sdr_blue ; set blue intensity pop ebp ; restore registers ret 8 ; exit & clean up stack ;==================================================== ;get_dac_register (register%, &red%, &green%, &blue%) ;==================================================== ; ; reads the rgb values of a single vga palette register ; ; entry: register = the dac # to read (0-255) ; red = offset to red variable in ds ; green = offset to green variable in ds ; blue = offset to blue variable in ds ; ; exit: the values of the integer variables red, ; green, and blue are set to the values ; taken from the specified dac register. ; gdr_stack struc dd ? ; ebp dd ? ; caller gdr_blue dd ? ; addr of blue data value (where to put) gdr_green dd ? ; addr of green data value gdr_red dd ? ; addr of red data value gdr_register db ?,? ; palette register # gdr_stack ends public get_dac_register get_dac_register: push ebp ; save bp mov ebp, esp ; set up stack frame ; select which dac register to read in out_8 dac_read_addr, [ebp].gdr_register mov dx, pel_data_reg ; dac data register clr ax ; clear ax in al, dx ; read red value mov ebx, [ebp].gdr_red ; get address of red% mov [ebx], ax ; *red% = ax in al, dx ; read green value mov ebx, [ebp].gdr_green; get address of green% mov [ebx], ax ; *green% = ax in al, dx ; read blue value mov ebx, [ebp].gdr_blue ; get address of blue% mov [ebx], ax ; *blue% = ax pop ebp ; restore registers ret 14 ; exit & clean up stack ;=========================================================== ;load_dac_registers (seg paldata, startreg%, endreg%, sync%) ;=========================================================== ; ; sets a block of vga palette registers ; ; entry: paldata = far pointer to block of palette data ; startreg = first register # in range to set (0-255) ; endreg = last register # in range to set (0-255) ; sync = wait for vertical retrace flag (boolean) ; ; exit: no meaningful values returned ; ; notes: paldata is a lifar array of 3 byte palette values ; in the order: red (0-63), green (0-63), blue (0-63) ; ldr_stack struc dd ?,? ; ebp, esi dd ? ; caller ldr_sync dw ? ; vertical sync flag ldr_endreg db ?,? ; last register # ldr_startreg db ?,? ; first register # ldr_paldata dd ? ; far ptr to palette data ldr_stack ends public load_dac_registers load_dac_registers: push ebp esi ; save registers mov ebp, esp ; set up stack frame mov ax, [ebp].ldr_sync ; get vertical sync flag or ax, ax ; is sync flag = 0? jz @ldr_load ; if so, skip call call sync_display ; wait for vsync ; determine register #'s, size to copy, etc @ldr_load: mov esi, [ebp].ldr_paldata ; esi -> palette data mov dx, dac_write_addr ; dac register # selector clr ax, bx ; clear for byte loads mov al, [ebp].ldr_startreg ; get start register mov bl, [ebp].ldr_endreg ; get end register sub bx, ax ; bx = # of dac registers -1 inc bx ; bx = # of dac registers mov cx, bx ; cx = # of dac registers add cx, bx ; cx = " " * 2 add cx, bx ; cx = " " * 3 cld ; block outs forward out dx, al ; set up correct register # ; load a block of dac registers mov dx, pel_data_reg ; dac data register movzx ecx,cx rep outsb ; block set dac registers pop esi ebp ; restore registers ret 10 ; exit & clean up stack ;==================================================== ;read_dac_registers (seg paldata, startreg%, endreg%) ;==================================================== ; ; reads a block of vga palette registers ; ; entry: paldata = far pointer to block to store palette data ; startreg = first register # in range to read (0-255) ; endreg = last register # in range to read (0-255) ; ; exit: no meaningful values returned ; ; notes: paldata is a lifar array of 3 byte palette values ; in the order: red (0-63), green (0-63), blue (0-63) ; rdr_stack struc dd ?,? ; ebp, edi dd ? ; caller rdr_endreg db ?,? ; last register # rdr_startreg db ?,? ; first register # rdr_paldata dd ? ; far ptr to palette data rdr_stack ends public read_dac_registers read_dac_registers: push ebp edi ; save registers mov ebp, esp ; set up stack frame ; determine register #'s, size to copy, etc mov edi, [ebp].rdr_paldata ; edi -> palette buffer mov dx, dac_read_addr ; dac register # selector clr ax, bx ; clear for byte loads mov al, [ebp].rdr_startreg ; get start register mov bl, [ebp].rdr_endreg ; get end register sub bx, ax ; bx = # of dac registers -1 inc bx ; bx = # of dac registers mov cx, bx ; cx = # of dac registers add cx, bx ; cx = " " * 2 add cx, bx ; cx = " " * 3 cld ; block ins forward ; read a block of dac registers out dx, al ; set up correct register # mov dx, pel_data_reg ; dac data register movzx ecx,cx rep insb ; block read dac registers pop edi ebp ; restore registers ret 8 ; exit & clean up stack ; ===== page flipping and scrolling routines ===== ;========================= ;set_active_page (pageno%) ;========================= ; ; sets the active display page to be used for future drawing ; ; entry: pageno = display page to make active ; (values: 0 to number of pages - 1) ; ; exit: no meaningful values returned ; sap_stack struc dd ? ; ebp dd ? ; caller sap_page dw ? ; page # for drawing sap_stack ends public set_active_page set_active_page: push ebp ; preserve registers mov ebp, esp ; set up stack frame movzx ebx, [ebp].sap_page ; get desired page # cmp bx, last_page ; is page # valid? jae @sap_exit ; if not, do nothing mov active_page, bx ; set active page # shl bx, 2 ; scale page # to dword mov eax, page_addr[ebx] ; get offset to page mov current_page, eax ; and set for future mov's @sap_exit: pop ebp ; restore registers ret 2 ; exit and clean up stack ;================ ;get_active_page% ;================ ; ; returns the video page # currently used for drawing ; ; entry: no parameters are passed ; ; exit: ax = current video page used for drawing ; public get_active_page get_active_page: mov ax, active_page ; get active page # ret ; exit and clean up stack ;=============================== ;set_display_page (displaypage%) ;=============================== ; ; sets the currently visible display page. ; when called this routine syncronizes the display ; to the vertical blank. ; ; entry: pageno = display page to show on the screen ; (values: 0 to number of pages - 1) ; ; exit: no meaningful values returned ; sdp_stack struc dd ? ; ebp dd ? ; caller sdp_page dw ? ; page # to display... sdp_stack ends public set_display_page set_display_page: push ebp ; preserve registers mov ebp, esp ; set up stack frame movzx ebx, [ebp].sdp_page ; get desired page # cmp bx, last_page ; is page # valid? jae @sdp_exit ; if not, do nothing mov display_page, bx ; set display page # shl bx, 2 ; scale page # to dword mov ecx, page_addr[ebx] ; get offset in memory to page add ecx, current_moffset ; adjust for any scrolling add ecx,_code32a ; adjust for protected mode ; wait if we are currently in a vertical retrace mov dx, input_1 ; input status #1 register @dp_wait0: in al, dx ; get vga status and al, vert_retrace ; in display mode yet? jnz @dp_wait0 ; if not, wait for it ; set the start display address to the new page mov dx, crtc_index ; we change the vga sequencer mov al, start_disp_lo ; display start low register mov ah, cl ; low 8 bits of start addr out dx, ax ; set display addr low mov al, start_disp_hi ; display start high register mov ah, ch ; high 8 bits of start addr out dx, ax ; set display addr high ; wait for a vertical retrace to smooth out things mov dx, input_1 ; input status #1 register @dp_wait1: in al, dx ; get vga status and al, vert_retrace ; vertical retrace start? jz @dp_wait1 ; if not, wait for it @sdp_exit: pop ebp ; restore registers ret 2 ; exit and clean up stack ;================= ;get_display_page% ;================= ; ; returns the video page # currently displayed ; ; entry: no parameters are passed ; ; exit: ax = current video page being displayed ; public get_display_page get_display_page: mov ax, display_page ; get display page # ret ; exit & clean up stack if x_set_window eq 1 ;======================================= ;set_window (displaypage%, xpos%, ypos%) ;======================================= ; ; since a logical screen can be larger than the physical ; screen, scrolling is possible. this routine sets the ; upper left corner of the screen to the specified pixel. ; also sets the display page to simplify combined page ; flipping and scrolling. when called this routine ; syncronizes the display to the vertical blank. ; ; entry: displaypage = display page to show on the screen ; xpos = # of pixels to shift screen right ; ypos = # of lines to shift screen down ; ; exit: no meaningful values returned ; sw_stack struc dd ? ; ebp dd ? ; caller sw_ypos dw ? ; y pos of ul screen corner sw_xpos dw ? ; x pos of ul screen corner sw_page dw ? ; (new) display page sw_stack ends public set_window set_window: push ebp ; preserve registers mov ebp, esp ; set up stack frame ; check if our scroll offsets are valid mov bx, [ebp].sw_page ; get desired page # cmp bx, last_page ; is page # valid? jae @sw_exit ; if not, do nothing mov ax, [ebp].sw_ypos ; get desired y offset cmp ax, max_yoffset ; is it within limits? ja @sw_exit ; if not, exit mov cx, [ebp].sw_xpos ; get desired x offset cmp cx, max_xoffset ; is it within limits? ja @sw_exit ; if not, exit ; compute proper display start address to use mul screen_width ; ax = yoffset * line width shr cx, 2 ; cx / 4 = bytes into line add ax, cx ; ax = offset of upper left pixel movzx eax, ax movzx ebx, bx mov current_moffset, eax ; save offset info mov display_page, bx ; set current page # shl bx, 2 ; scale page # to dword add eax, page_addr[ebx] ; get offset in vga to page add eax,_code32a ; adjust for protected mode segment mov bx, ax ; bx = desired display start mov dx, input_1 ; input status #1 register ; wait if we are currently in a vertical retrace @sw_wait0: in al, dx ; get vga status and al, vert_retrace ; in display mode yet? jnz @sw_wait0 ; if not, wait for it ; set the start display address to the new window mov dx, crtc_index ; we change the vga sequencer mov al, start_disp_lo ; display start low register mov ah, bl ; low 8 bits of start addr out dx, ax ; set display addr low mov al, start_disp_hi ; display start high register mov ah, bh ; high 8 bits of start addr out dx, ax ; set display addr high ; wait for a vertical retrace to smooth out things mov dx, input_1 ; input status #1 register @sw_wait1: in al, dx ; get vga status and al, vert_retrace ; vertical retrace start? jz @sw_wait1 ; if not, wait for it ; now set the horizontal pixel pan values out_8 attrib_ctrl, pixel_pan_reg ; select pixel pan register mov ax, [ebp].sw_xpos ; get desired x offset and al, 03 ; get # of pixels to pan (0-3) shl al, 1 ; shift for 256 color mode out dx, al ; fine tune the display! @sw_exit: pop ebp ; restore saved registers ret 6 ; exit and clean up stack ;============= ;get_x_offset% ;============= ; ; returns the x coordinate of the pixel currently display ; in the upper left corner of the display ; ; entry: no parameters are passed ; ; exit: ax = current horizontal scroll offset ; public get_x_offset get_x_offset: mov ax, current_xoffset ; get current horz offset ret ; exit & clean up stack ;============= ;get_y_offset% ;============= ; ; returns the y coordinate of the pixel currently display ; in the upper left corner of the display ; ; entry: no parameters are passed ; ; exit: ax = current vertical scroll offset ; public get_y_offset get_y_offset: mov ax, current_yoffset ; get current vertical offset ret ; exit & clean up stack endif ;============ ;sync_display ;============ ; ; pauses the computer until the next vertical retrace starts ; ; entry: no parameters are passed ; ; exit: no meaningful values returned ; public sync_display sync_display: mov dx, input_1 ; input status #1 register ; wait for any current retrace to end @sd_wait0: in al, dx ; get vga status and al, vert_retrace ; in display mode yet? jnz @sd_wait0 ; if not, wait for it ; wait for the start of the next vertical retrace @sd_wait1: in al, dx ; get vga status and al, vert_retrace ; vertical retrace start? jz @sd_wait1 ; if not, wait for it ret ; ===== text display routines ===== if x_gprintc eq 1 ;================================================== ;gprintc (charnum%, xpos%, ypos%, colorf%, colorb%) ;================================================== ; ; draws an ascii text character using the currently selected ; 8x8 font on the active display page. it would be a simple ; exercise to make this routine process variable height fonts. ; ; entry: charnum = ascii character # to draw ; xpos = x position to draw character at ; ypos = y position of to draw character at ; colorf = color to draw text character in ; colorb = color to set background to ; ; exit: no meaningful values returned ; gpc_stack struc gpc_width dd ? ; screen width-1 gpc_lines db ?,? ; scan lines to decode gpc_t_sets dd ? ; saved charset segment dd ?x3 ; edi, esi, ebp dd ? ; caller gpc_colorb db ?,? ; background color gpc_colorf db ?,? ; text color gpc_ypos dw ? ; y position to print at gpc_xpos dw ? ; x position to print at gpc_char db ?,? ; character to print gpc_stack ends public gprintc gprintc: push ebp esi edi ; preserve important registers sub esp, 10 ; allocate workspace on stack mov ebp, esp ; set up stack frame mov edi, current_page ; point to active vga page movzx eax, screen_width ; get logical line width mov ebx, eax ; bx = screen width dec bx ; = screen width-1 mov [ebp].gpc_width,ebx ; save for later use mul [ebp].gpc_ypos ; start of line = ypos * width add edi, eax ; di -> start of line ypos movzx eax, [ebp].gpc_xpos ; get xpos of character mov cx, ax ; save copy of xpos shr ax, 2 ; bytes into line = xpos/4 add edi, eax ; di -> (xpos, ypos) ;get source addr of character bit map & save mov al, [ebp].gpc_char ; get character # test al, 080h ; is hi bit set? jz @gpc_lowchar ; nope, use low char set ptr mov ebx, charset_hi ; bx = char set ptr:offset jmp s @gpc_set_char ; go setup character ptr @gpc_lowchar: mov ebx, charset_low ; bx = char set ptr:offset @gpc_set_char: and eax, 07fh ; mask out hi bits shl ax, 3 ; * 8 bytes per bitmap add ebx, eax ; bx = offset of selected char mov [ebp].gpc_t_sets, ebx ; save segment on stack and cx, plane_bits ; get plane # mov ch, all_planes ; get initial plane mask shl ch, cl ; and shift into position and ch, all_planes ; and mask to lower nibble mov al, 04 ; 4-plane # = # of initial sub al, cl ; shifts to align bit mask mov cl, al ; shift count for shl ;get segment of character map out_8 sc_index, map_mask ; setup plane selections inc dx ; dx -> sc_data mov al, 08 ; 8 lines to process mov [ebp].gpc_lines, al ; save on stack @gpc_decode_char_byte: mov esi, [ebp].gpc_t_sets ; get esi = string mov bh, [esi] ; get bit map inc esi ; point to next line mov [ebp].gpc_t_sets, esi ; and save new pointer... clr eax ; clear ax clr bl ; clear bl rol bx, cl ; bl holds left edge bits movzx esi, bx ; use as table index and si, char_bits ; get low bits mov al, char_plane_data[esi] ; get mask in al jz @gpc_no_left1bits ; skip if no pixels to set mov ah, [ebp].gpc_colorf ; get foreground color out dx, al ; set up screen mask mov [edi], ah ; write foreground color @gpc_no_left1bits: xor al, ch ; invert mask for background jz @gpc_no_left0bits ; hey, no need for this mov ah, [ebp].gpc_colorb ; get background color out dx, al ; set up screen mask mov [edi], ah ; write foreground color ;now do middle/last band @gpc_no_left0bits: inc edi ; point to next byte rol bx, 4 ; shift 4 bits movzx esi, bx ; make lookup pointer and si, char_bits ; get low bits mov al, char_plane_data[esi] ; get mask in al jz @gpc_no_middle1bits ; skip if no pixels to set mov ah, [ebp].gpc_colorf ; get foreground color out dx, al ; set up screen mask mov [edi], ah ; write foreground color @gpc_no_middle1bits: xor al, all_planes ; invert mask for background jz @gpc_no_middle0bits ; hey, no need for this mov ah, [ebp].gpc_colorb ; get background color out dx, al ; set up screen mask mov [edi], ah ; write foreground color @gpc_no_middle0bits: xor ch, all_planes ; invert clip mask cmp cl, 4 ; aligned by 4? jz @gpc_next_line ; if so, exit now.. inc edi ; point to next byte rol bx, 4 ; shift 4 bits movzx esi, bx ; make lookup pointer and si, char_bits ; get low bits mov al, char_plane_data[esi] ; get mask in al jz @gpc_no_right1bits ; skip if no pixels to set mov ah, [ebp].gpc_colorf ; get foreground color out dx, al ; set up screen mask mov [edi], ah ; write foreground color @gpc_no_right1bits: xor al, ch ; invert mask for background jz @gpc_no_right0bits ; hey, no need for this mov ah, [ebp].gpc_colorb ; get background color out dx, al ; set up screen mask mov [edi], ah ; write foreground color @gpc_no_right0bits: dec edi ; adjust for next line advance @gpc_next_line: add edi, [ebp].gpc_width ; point to next line xor ch, char_bits ; flip the clip mask back dec [ebp].gpc_lines ; count down lines jz @gpc_exit ; ok... done! jmp @gpc_decode_char_byte ; again! hey! @gpc_exit: add esp, 10 ; deallocate stack workspace pop edi esi ebp ; restore saved registers ret 10 ; exit and clean up stack endif if x_tgprintc eq 1 ;========================================== ;tgprintc (charnum%, xpos%, ypos%, colorf%) ;========================================== ; ; transparently draws an ascii text character using the ; currently selected 8x8 font on the active display page. ; ; entry: charnum = ascii character # to draw ; xpos = x position to draw character at ; ypos = y position of to draw character at ; colorf = color to draw text character in ; ; exit: no meaningful values returned ; tpc_stack struc tpc_width dd ? ; screen width-1 tpc_lines db ?,? ; scan lines to decode tpc_t_sets dd ? ; saved charset segment dd ?x3 ; edi, esi, ebp dd ? ; caller tpc_colorf db ?,? ; text color tpc_ypos dw ? ; y position to print at tpc_xpos dw ? ; x position to print at tpc_char db ?,? ; character to print tpc_stack ends public tgprintc tgprintc: push ebp esi edi ; preserve important registers sub esp, 10 ; allocate workspace on stack mov ebp, esp ; set up stack frame mov edi, current_page ; point to active vga page movzx eax, screen_width ; get logical line width mov ebx, eax ; bx = screen width dec bx ; = screen width-1 mov [ebp].tpc_width,ebx ; save for later use mul [ebp].tpc_ypos ; start of line = ypos * width add edi, eax ; di -> start of line ypos movzx eax, [ebp].tpc_xpos ; get xpos of character mov cx, ax ; save copy of xpos shr ax, 2 ; bytes into line = xpos/4 add edi, eax ; di -> (xpos, ypos) ;get source addr of character bit map & save mov al, [ebp].tpc_char ; get character # test al, 080h ; is hi bit set? jz @tpc_lowchar ; nope, use low char set ptr mov ebx, charset_hi ; bx = char set ptr:offset jmp s @tpc_set_char ; go setup character ptr @tpc_lowchar: mov ebx, charset_low ; bx = char set ptr:offset @tpc_set_char: and eax, 07fh ; mask out hi bits shl ax, 3 ; * 8 bytes per bitmap add ebx, eax ; bx = offset of selected char mov [ebp].tpc_t_sets, ebx ; save segment on stack and cx, plane_bits ; get plane # mov ch, all_planes ; get initial plane mask shl ch, cl ; and shift into position and ch, all_planes ; and mask to lower nibble mov al, 04 ; 4-plane # = # of initial sub al, cl ; shifts to align bit mask mov cl, al ; shift count for shl ;get segment of character map out_8 sc_index, map_mask ; setup plane selections inc dx ; dx -> sc_data mov al, 08 ; 8 lines to process mov [ebp].tpc_lines, al ; save on stack @tpc_decode_char_byte: mov esi, [ebp].tpc_t_sets ; get esi = string mov bh, [esi] ; get bit map inc esi ; point to next line mov [ebp].tpc_t_sets, esi ; and save new pointer... clr eax ; clear ax clr bl ; clear bl rol bx, cl ; bl holds left edge bits movzx esi, bx ; use as table index and si, char_bits ; get low bits mov al, char_plane_data[esi] ; get mask in al jz @tpc_no_left1bits ; skip if no pixels to set mov ah, [ebp].tpc_colorf ; get foreground color out dx, al ; set up screen mask mov [edi], ah ; write foreground color ;now do middle/last band @tpc_no_left1bits: inc edi ; point to next byte rol bx, 4 ; shift 4 bits movzx esi, bx ; make lookup pointer and si, char_bits ; get low bits mov al, char_plane_data[esi] ; get mask in al jz @tpc_no_middle1bits ; skip if no pixels to set mov ah, [ebp].tpc_colorf ; get foreground color out dx, al ; set up screen mask mov [edi], ah ; write foreground color @tpc_no_middle1bits: xor ch, all_planes ; invert clip mask cmp cl, 4 ; aligned by 4? jz @tpc_next_line ; if so, exit now.. inc edi ; point to next byte rol bx, 4 ; shift 4 bits movzx esi, bx ; make lookup pointer and si, char_bits ; get low bits mov al, char_plane_data[esi] ; get mask in al jz @tpc_no_right1bits ; skip if no pixels to set mov ah, [ebp].tpc_colorf ; get foreground color out dx, al ; set up screen mask mov [edi], ah ; write foreground color @tpc_no_right1bits: dec edi ; adjust for next line advance @tpc_next_line: add edi, [ebp].tpc_width ; point to next line xor ch, char_bits ; flip the clip mask back dec [ebp].tpc_lines ; count down lines jz @tpc_exit ; ok... done! jmp @tpc_decode_char_byte ; again! hey! @tpc_exit: add esp, 10 ; deallocate stack workspace pop edi esi ebp ; restore saved registers ret 8 ; exit and clean up stack endif if x_gprintc eq 1 ;=============================================================== ;print_str (seg string, maxlen%, xpos%, ypos%, colorf%, colorb%) ;=============================================================== ; ; routine to quickly print a null terminated ascii string on the ; active display page up to a maximum length. ; ; entry: string = far pointer to ascii string to print ; maxlen = # of characters to print if no null found ; xpos = x position to draw text at ; ypos = y position of to draw text at ; colorf = color to draw text in ; colorb = color to set background to ; ; exit: no meaningful values returned ; ps_stack struc dd ?x3 ; edi, esi, ebp dd ? ; caller ps_colorb dw ? ; background color ps_colorf dw ? ; text color ps_ypos dw ? ; y position to print at ps_xpos dw ? ; x position to print at ps_len dw ? ; maximum length of string to print ps_text dd ? ; far ptr to text string ps_stack ends public print_str print_str: push ebp esi edi ; preserve important registers mov ebp, esp ; set up stack frame @ps_print_it: mov cx, [ebp].ps_len ; get remaining text length jcxz @ps_exit ; exit when out of text mov edi, [ebp].ps_text ; edi -> current char in text mov al, [edi] ; al = text character and ax, 00ffh ; clear high word jz @ps_exit ; exit if null character dec [ebp].ps_len ; remaining text length-- inc [ebp].ps_text ; point to next text char ; set up call to gprintc push ax ; set character parameter mov bx, [ebp].ps_xpos ; get xpos push bx ; set xpos parameter add bx, 8 ; advance 1 char to right mov [ebp].ps_xpos, bx ; save for next time through mov bx, [ebp].ps_ypos ; get ypos push bx ; set ypos parameter mov bx, [ebp].ps_colorf ; get text color push bx ; set colorf parameter mov bx, [ebp].ps_colorb ; get background color push bx ; set colorb parameter call gprintc ; print character! jmp s @ps_print_it ; process next character @ps_exit: pop edi esi ebp ; restore saved registers ret 14 ; exit and clean up stack endif if x_tgprintc eq 1 ;================================================================ ;tprint_str (seg string, maxlen%, xpos%, ypos%, colorf%, colorb%) ;================================================================ ; ; routine to quickly transparently print a null terminated ascii ; string on the active display page up to a maximum length. ; ; entry: string = far pointer to ascii string to print ; maxlen = # of characters to print if no null found ; xpos = x position to draw text at ; ypos = y position of to draw text at ; colorf = color to draw text in ; ; exit: no meaningful values returned ; tps_stack struc dd ?x3 ; edi, esi, ebp dd ? ; caller tps_colorf dw ? ; text color tps_ypos dw ? ; y position to print at tps_xpos dw ? ; x position to print at tps_len dw ? ; maximum length of string to print tps_text dd ? ; far ptr to text string tps_stack ends public tprint_str tprint_str: push ebp esi edi ; preserve important registers mov ebp, esp ; set up stack frame @ts_print_it: mov cx, [ebp].tps_len ; get remaining text length jcxz @ts_exit ; exit when out of text mov edi, [ebp].tps_text ; edi -> current char in text mov al, [edi] ; al = text character and ax, 00ffh ; clear high word jz @ts_exit ; exit if null character dec [ebp].tps_len ; remaining text length-- inc [ebp].tps_text ; point to next text char ; set up call to tgprintc push ax ; set character parameter mov bx, [ebp].tps_xpos ; get xpos push bx ; set xpos parameter add bx, 8 ; advance 1 char to right mov [ebp].tps_xpos, bx ; save for next time through mov bx, [ebp].tps_ypos ; get ypos push bx ; set ypos parameter mov bx, [ebp].tps_colorf ; get text color push bx ; set colorf parameter call tgprintc ; print character! jmp s @ts_print_it ; process next character @ts_exit: pop edi esi ebp ; restore saved registers ret 12 ; exit and clean up stack endif ;=========================================== ;set_display_font(seg fontdata, fontnumber%) ;=========================================== ; ; allows the user to specify their own font data for ; wither the lower or upper 128 characters. ; ; entry: fontdata = far pointer to font bitmaps ; fontnumber = which half of set this is ; = 0, lower 128 characters ; = 1, upper 128 characters ; ; exit: no meaningful values returned ; sdf_stack struc dd ? ; ebp dd ? ; caller sdf_which dw ? ; hi table/low table flag sdf_font dd ? ; far ptr to font table sdf_stack ends public set_display_font set_display_font: push ebp ; preserve registers mov ebp, esp ; set up stack frame mov edi, [ebp].sdf_font ; get far ptr to font mov esi, o charset_low ; assume lower 128 chars test [ebp].sdf_which, 1 ; font #1 selected? jz @sdf_set_font ; if not, skip ahead mov esi, o charset_hi ; ah, really it's 128-255 @sdf_set_font: mov [esi], edi ; set font pointer offset pop ebp ; restore registers ret 6 ; we are done.. outa here ; ===== bitmap (sprite) display routines ===== ;====================================================== ;draw_bitmap (seg image, xpos%, ypos% ) ;====================================================== ; ; draws a variable sized graphics bitmap such as a ; picture or an icon on the current display page in ; mode x. the bitmap is stored in a lifar byte array ; corresponding to (0,0) (1,0), (2,0) .. (width, height) ; this is the same lifar manner as mode 13h graphics. ; ; entry: image = far pointer to bitmap data ; xpos = x position to place upper left pixel at ; ypos = y position to place upper left pixel at ; width = width of the bitmap in pixels - ommitted ; height = height of the bitmap in pixels - ommitted ; ; exit: no meaningful values returned ; ; routine has been modified so that first two words of bitmap define ; bitmap x and y size ; db_stack struc db_lineo dw ? ; offset to next line db_pixcount dw ? ; (minimum) # of pixels/line db_start dd ? ; addr of upper left pixel db_pixskew dw ? ; # of bytes to adjust eol db_skewflag dw ? ; extra pix on plane flag db_height dw ? ; height of bitmap in pixels dd ?x3 ; edi, esi, ebp dd ? ; caller db_ypos dw ? ; y position to draw bitmap at db_xpos dw ? ; x position to draw bitmap at db_image dd ? ; far pointer to graphics bitmap db_stack ends public draw_bitmap draw_bitmap: push ebp esi edi ; preserve important registers sub esp, 14 ; allocate workspace mov ebp, esp ; set up stack frame mov edi, current_page ; point to active vga page cld ; direction flag = forward movzx eax, [ebp].db_ypos ; get ul corner ypos mul screen_width ; ax = offset to line ypos movzx ebx, [ebp].db_xpos ; get ul corner xpos mov cl, bl ; save plane # in cl shr bx, 2 ; xpos/4 = offset into line add edi, eax ; edi -> start of line add edi, ebx ; edi -> upper left pixel mov [ebp].db_start, edi ; save starting addr ; compute line to line offset mov esi, [ebp].db_image ; esi-> source image lodsw ; get x width mov bx,ax lodsw mov [ebp].db_height,ax add [ebp].db_image,4 mov dx, bx ; save copy in dx shr bx, 2 ; /4 = width in bands mov ax, screen_width ; get screen width sub ax, bx ; - (bitmap width/4) mov [ebp].db_lineo, ax ; save line width offset mov [ebp].db_pixcount, bx ; minimum # pix to copy and dx, plane_bits ; get "partial band" size (0-3) mov [ebp].db_pixskew, dx ; also end of line skew mov [ebp].db_skewflag, dx ; save as flag/count and cx, plane_bits ; cl = starting plane # mov ax, map_mask_plane2 ; plane mask & plane select shl ah, cl ; select correct plane out_16 sc_index, ax ; select plane... mov bh, ah ; bh = saved plane mask mov bl, 4 ; bl = planes to copy @db_copy_plane: mov esi, [ebp].db_image ; esi-> source image mov dx, [ebp].db_height ; # of lines to copy mov edi, [ebp].db_start ; edi-> dest pos @db_copy_line: mov cx, [ebp].db_pixcount ; min # to copy test cl, 0fch ; 16+pixwide? jz @db_copy_remainder ; nope... ; pixel copy loop has been unrolled to x4 @db_copy_loop: movsb ; copy bitmap pixel add esi, 3 ; skip to next byte in same plane movsb ; copy bitmap pixel add esi, 3 ; skip to next byte in same plane movsb ; copy bitmap pixel add esi, 3 ; skip to next byte in same plane movsb ; copy bitmap pixel add esi, 3 ; skip to next byte in same plane sub cl, 4 ; pixels to copy=-4 test cl, 0fch ; 4+ pixels left? jnz @db_copy_loop ; if so, do another block @db_copy_remainder: jcxz @db_next_line ; any pixels left on line @db_copy2: movsb ; copy bitmap pixel add esi,3 ; skip to next byte in same plane loopx cx, @db_copy2 ; pixels to copy--, loop until done @db_next_line: ; any partial pixels? (some planes only) or cx, [ebp].db_skewflag ; get skew count jz @db_next2 ; if no partial pixels movsb ; copy bitmap pixel dec edi ; back up to align dec esi ; back up to align @db_next2: movzx eax, [ebp].db_pixskew ; adjust skew add esi, eax movzx eax, [ebp].db_lineo ; set to next display line add edi, eax loopx dx, @db_copy_line ; lines to copy--, loop if more ; copy next plane.... dec bl ; planes to go-- jz @db_exit ; hey! we are done rol bh, 1 ; next plane in line... out_8 sc_data, bh ; select plane cmp al, 12h ; carry set if al=11h adc [ebp].db_start, 0 ; screen addr =+carry inc w [ebp].db_image ; start @ next byte sub [ebp].db_skewflag, 1 ; reduce planes to skew adc [ebp].db_skewflag, 0 ; back to 0 if it was -1 jmp f @db_copy_plane ; go copy the next plane @db_exit: add esp, 14 ; deallocate workspace pop edi esi ebp ; restore saved registers ret 8 ; exit and clean up stack ;======================================================= ;tdraw_bitmap (seg image, xpos%, ypos%) ;======================================================= ; ; transparently draws a variable sized graphics bitmap ; such as a picture or an icon on the current display page ; in mode x. pixels with a value of 0 are not drawn, ; leaving the previous "background" contents intact. ; ; the bitmap format is the same as for the draw_bitmap function. ; ; entry: image = far pointer to bitmap data ; xpos = x position to place upper left pixel at ; ypos = y position to place upper left pixel at ; width = width of the bitmap in pixels - ommitted ; height = height of the bitmap in pixels - ommitted ; ; exit: no meaningful values returned ; ; routine has been modified so that first two words of bitmap define ; bitmap x and y size ; tb_stack struc tb_lineo dw ? ; offset to next line tb_pixcount dw ? ; (minimum) # of pixels/line tb_start dd ? ; addr of upper left pixel tb_pixskew dw ? ; # of bytes to adjust eol tb_skewflag dw ? ; extra pix on plane flag tb_height dw ? ; height of bitmap in pixels dd ?x3 ; edi, esi, ebp dd ? ; caller tb_ypos dw ? ; y position to draw bitmap at tb_xpos dw ? ; x position to draw bitmap at tb_image dd ? ; far pointer to graphics bitmap tb_stack ends public tdraw_bitmap tdraw_bitmap: push ebp esi edi ; preserve important registers sub esp, 14 ; allocate workspace mov ebp, esp ; set up stack frame mov edi, current_page ; point to active vga page cld ; direction flag = forward movzx eax, [ebp].tb_ypos ; get ul corner ypos mul screen_width ; ax = offset to line ypos movzx ebx, [ebp].tb_xpos ; get ul corner xpos mov cl, bl ; save plane # in cl shr bx, 2 ; xpos/4 = offset into line add edi, eax ; edi -> start of line add edi, ebx ; edi -> upper left pixel mov [ebp].tb_start, edi ; save starting addr ; compute line to line offset mov esi, [ebp].tb_image ; esi-> source image lodsw ; get x width mov bx,ax lodsw mov [ebp].tb_height,ax add [ebp].tb_image,4 mov dx, bx ; save copy in dx shr bx, 2 ; /4 = width in bands mov ax, screen_width ; get screen width sub ax, bx ; - (bitmap width/4) mov [ebp].tb_lineo, ax ; save line width offset mov [ebp].tb_pixcount, bx ; minimum # pix to copy and dx, plane_bits ; get "partial band" size (0-3) mov [ebp].tb_pixskew, dx ; also end of line skew mov [ebp].tb_skewflag, dx ; save as flag/count and cx, plane_bits ; cl = starting plane # mov ax, map_mask_plane2 ; plane mask & plane select shl ah, cl ; select correct plane out_16 sc_index, ax ; select plane... mov bh, ah ; bh = saved plane mask mov bl, 4 ; bl = planes to copy @tb_copy_plane: mov esi, [ebp].tb_image ; esi-> source image mov dx, [ebp].tb_height ; # of lines to copy mov edi, [ebp].tb_start ; edi-> dest pos ; here ah is set with the value to be considered ; "transparent". it can be changed! @tb_copy_line: mov ah, 0 ; value to detect 0 mov cx, [ebp].tb_pixcount ; min # to copy test cl, 0fch ; 16+pixwide? jz @tb_copy_remainder ; nope... ; pixel copy loop has been unrolled to x4 @tb_copy_loop: lodsb ; get pixel value in al add esi, 3 ; skip to next byte in same plane cmp al, ah ; it is "transparent"? je @tb_skip_01 ; skip ahead if so mov [edi], al ; copy pixel to vga screen @tb_skip_01: lodsb ; get pixel value in al add esi, 3 ; skip to next byte in same plane cmp al, ah ; it is "transparent"? je @tb_skip_02 ; skip ahead if so mov [edi+1], al ; copy pixel to vga screen @tb_skip_02: lodsb ; get pixel value in al add esi, 3 ; skip to next byte in same plane cmp al, ah ; it is "transparent"? je @tb_skip_03 ; skip ahead if so mov [edi+2], al ; copy pixel to vga screen @tb_skip_03: lodsb ; get pixel value in al add esi, 3 ; skip to next byte in same plane cmp al, ah ; it is "transparent"? je @tb_skip_04 ; skip ahead if so mov [edi+3], al ; copy pixel to vga screen @tb_skip_04: add edi, 4 ; adjust pixel write location sub cl, 4 ; pixels to copy=-4 test cl, 0fch ; 4+ pixels left? jnz @tb_copy_loop ; if so, do another block @tb_copy_remainder: jcxz @tb_next_line ; any pixels left on line @tb_copy2: lodsb ; get pixel value in al add esi, 3 ; skip to next byte in same plane cmp al, ah ; it is "transparent"? je @tb_skip_05 ; skip ahead if so mov [edi], al ; copy pixel to vga screen @tb_skip_05: inc edi ; advance dest addr loopx cx, @tb_copy2 ; pixels to copy--, loop until done @tb_next_line: ; any partial pixels? (some planes only) or cx, [ebp].tb_skewflag ; get skew count jz @tb_next2 ; if no partial pixels lodsb ; get pixel value in al dec esi ; backup to align cmp al, ah ; it is "transparent"? je @tb_next2 ; skip ahead if so mov [edi], al ; copy pixel to vga screen @tb_next2: movzx eax, [ebp].tb_pixskew ; adjust skew add esi, eax movzx eax, [ebp].tb_lineo ; set to next display line add edi, eax loopx dx, @tb_copy_line ; lines to copy--, loop if more ;copy next plane.... dec bl ; planes to go-- jz @tb_exit ; hey! we are done rol bh, 1 ; next plane in line... out_8 sc_data, bh ; select plane cmp al, 12h ; carry set if al=11h adc [ebp].tb_start, 0 ; screen addr =+carry inc w [ebp].tb_image ; start @ next byte sub [ebp].tb_skewflag, 1 ; reduce planes to skew adc [ebp].tb_skewflag, 0 ; back to 0 if it was -1 jmp @tb_copy_plane ; go copy the next plane @tb_exit: add esp, 14 ; deallocate workspace pop edi esi ebp ; restore saved registers ret 8 ; exit and clean up stack ; ==== video memory to video memory copy routines ===== ;================================== ;copy_page (sourcepage%, destpage%) ;================================== ; ; duplicate on display page onto another ; ; entry: sourcepage = display page # to duplicate ; destpage = display page # to hold copy ; ; exit: no meaningful values returned ; cp_stack struc dd ?x3 ; edi, esi, ebp dd ? ; caller cp_destp dw ? ; page to hold copied image cp_sourcep dw ? ; page to make copy from cp_stack ends public copy_page copy_page: push ebp esi edi ; preserve important registers mov ebp, esp ; set up stack frame cld ; block xfer forwards ; make sure page #'s are valid mov ax, [ebp].cp_sourcep ; get source page # cmp ax, last_page ; is it > max page #? jae @cp_exit ; if so, abort mov bx, [ebp].cp_destp ; get destination page # cmp bx, last_page ; is it > max page #? jae @cp_exit ; if so, abort cmp ax, bx ; pages #'s the same? je @cp_exit ; if so, abort ; setup esi and edi to video pages shl bx, 2 ; scale index to dword mov edi, page_addr[ebx] ; offset to dest page mov bx, ax ; index to source page shl bx, 2 ; scale index to dword mov esi, page_addr[ebx] ; offset to source page movzx ecx, page_size ; get size of page ; setup vga registers for mem to mem copy out_16 gc_index, latches_on ; data from latches = on out_16 sc_index, all_planes_on ; copy all planes ; note.. do *not* use movsw or movsd - they will ; screw with the latches which are 8 bits x 4 rep movsb ; copy entire page! ; reset vga for normal memory access out_16 gc_index, latches_off ; data from latches = off @cp_exit: pop edi esi ebp ; restore saved registers ret 4 ; exit and clean up stack ;========================================================================== ;copy_bitmap (sourcepage%, x1%, y1%, x2%, y2%, destpage%, destx1%, desty1%) ;========================================================================== ; ; copies a bitmap image from one display page to another ; this routine is limited to copying images with the same ; plane alignment. to work: (x1 mod 4) must = (destx1 mod 4) ; copying an image to the same page is supported, but results ; may be defined when the when the rectangular areas ; (x1, y1) - (x2, y2) and (destx1, desty1) - ; (destx1+(x2-x1), desty1+(y2-y1)) overlap... ; no paramter checking to done to insure that ; x2 >= x1 and y2 >= y1. be careful... ; ; entry: sourcepage = display page # with source image ; x1 = upper left xpos of source image ; y1 = upper left ypos of source image ; x2 = lower right xpos of source image ; y2 = lower right ypos of source image ; destpage = display page # to copy image to ; destx1 = xpos to copy ul corner of image to ; desty1 = ypos to copy ul corner of image to ; ; exit: ax = success flag: 0 = failure / -1= success ; cb_stack struc cb_height dw ? ; height of image in lines cb_width dw ? ; width of image in "bands" dd ?x3 ; edi, esi, ebp dd ? ; caller cb_desty1 dw ? ; destination ypos cb_destx1 dw ? ; destination xpos cb_destp dw ? ; page to copy bitmap to cb_y2 dw ? ; lr ypos of image cb_x2 dw ? ; lr xpos of image cb_y1 dw ? ; ul ypos of image cb_x1 dw ? ; ul xpos of image cb_sourcep dw ? ; page containing source bitmap cb_stack ends public copy_bitmap copy_bitmap: push ebp esi edi ; preserve important registers sub esp, 4 ; allocate workspace on stack mov ebp, esp ; set up stack frame ; prep registers (and keep jumps short!) cld ; block xfer forwards ; make sure parameters are valid movzx ebx, [ebp].cb_sourcep ; get source page # cmp bx, last_page ; is it > max page #? jae @cb_abort ; if so, abort mov cx, [ebp].cb_destp ; get destination page # cmp cx, last_page ; is it > max page #? jae @cb_abort ; if so, abort mov ax, [ebp].cb_x1 ; get source x1 xor ax, [ebp].cb_destx1 ; compare bits 0-1 and ax, plane_bits ; check plane bits jnz @cb_abort ; they should cancel out ; setup for copy processing out_8 sc_index, map_mask ; set up for plane select out_16 gc_index, latches_on ; data from latches = on ; compute info about images, setup esi & edi mov ax, [ebp].cb_y2 ; height of bitmap in lines sub ax, [ebp].cb_y1 ; is y2 - y1 + 1 inc ax ; (add 1 since were not 0 based) mov [ebp].cb_height, ax ; save on stack for later use mov ax, [ebp].cb_x2 ; get # of "bands" of 4 pixels mov dx, [ebp].cb_x1 ; the bitmap occupies as x2-x1 shr ax, 2 ; get x2 band (x2 / 4) shr dx, 2 ; get x1 band (x1 / 4) sub ax, dx ; ax = # of bands - 1 inc ax ; ax = # of bands mov [ebp].cb_width, ax ; save on stack for later use shl bx, 2 ; scale source page to dword mov esi, page_addr[ebx] ; si = offset of source page mov ax, [ebp].cb_y1 ; get source y1 line mul screen_width ; ax = offset to line y1 movzx eax, ax add esi, eax ; si = offset to line y1 mov ax, [ebp].cb_x1 ; get source x1 shr ax, 2 ; x1 / 4 = byte offset add esi, eax ; si = byte offset to (x1,y1) mov bx, cx ; dest page index to bx shl bx, 2 ; scale source page to dword mov edi, page_addr[ebx] ; di = offset of dest page mov ax, [ebp].cb_desty1 ; get dest y1 line mul screen_width ; ax = offset to line y1 movzx eax, ax add edi, eax ; di = offset to line y1 mov ax, [ebp].cb_destx1 ; get dest x1 shr ax, 2 ; x1 / 4 = byte offset add edi, eax ; di = byte offset to (d-x1,d-y1) mov cx, [ebp].cb_width ; cx = width of image (bands) dec cx ; cx = 1? je @cb_only_one_band ; 0 means image width of 1 band mov bx, [ebp].cb_x1 ; get source x1 and bx, plane_bits ; aligned? (bits 0-1 = 00?) jz @cb_check_right ; if so, check right alignment jnz @cb_left_band ; not aligned? well.. @cb_abort: clr ax ; return false (failure) jmp @cb_exit ; and finish up ; copy when left & right clip masks overlap... @cb_only_one_band: mov bx, [ebp].cb_x1 ; get left clip mask and bx, plane_bits ; mask out row # mov al, left_clip_mask[ebx] ; get left edge mask mov bx, [ebp].cb_x2 ; get right clip mask and bx, plane_bits ; mask out row # and al, right_clip_mask[ebx] ; get right edge mask byte out_8 sc_data, al ; clip for left & right masks mov cx, [ebp].cb_height ; cx = # of lines to copy movzx edx, screen_width ; dx = width of screen clr ebx ; bx = offset into image @cb_one_loop: mov al, [esi+ebx] ; load latches mov [edi+ebx], al ; unload latches add bx, dx ; advance offset to next line loopjz cx, @cb_one_done ; exit loop if finished mov al, [esi+ebx] ; load latches mov [edi+ebx], al ; unload latches add bx, dx ; advance offset to next line loopx cx, @cb_one_loop ; loop until finished @cb_one_done: jmp @cb_finish ; outa here! ; copy left edge of bitmap @cb_left_band: out_8 sc_data, left_clip_mask[ebx] ; set left edge plane mask mov cx, [ebp].cb_height ; cx = # of lines to copy mov dx, screen_width ; dx = width of screen clr ebx ; bx = offset into image @cb_left_loop: mov al, [esi+ebx] ; load latches mov [edi+ebx], al ; unload latches add bx, dx ; advance offset to next line loopjz cx, @cb_left_done ; exit loop if finished mov al, [esi+ebx] ; load latches mov [edi+ebx], al ; unload latches add bx, dx ; advance offset to next line loopx cx, @cb_left_loop ; loop until finished @cb_left_done: inc edi ; move dest over 1 band inc esi ; move source over 1 band dec [ebp].cb_width ; band width-- ; determine if right edge of bitmap needs special copy @cb_check_right: mov bx, [ebp].cb_x2 ; get source x2 and bx, plane_bits ; aligned? (bits 0-1 = 11?) cmp bl, 03h ; plane = 3? je @cb_copy_middle ; copy the middle then! ; copy right edge of bitmap @cb_right_band: out_8 sc_data, right_clip_mask[ebx] ; set right edge plane mask dec [ebp].cb_width ; band width-- mov cx, [ebp].cb_height ; cx = # of lines to copy mov dx, screen_width ; dx = width of screen movzx ebx, [ebp].cb_width ; bx = offset to right edge @cb_right_loop: mov al, [esi+ebx] ; load latches mov [edi+ebx], al ; unload latches add bx, dx ; advance offset to next line loopjz cx, @cb_right_done ; exit loop if finished mov al, [esi+ebx] ; load latches mov [edi+ebx], al ; unload latches add bx, dx ; advance offset to next line loopx cx, @cb_right_loop ; loop until finished @cb_right_done: ; copy the main block of the bitmap @cb_copy_middle: mov cx, [ebp].cb_width ; get width remaining jcxz @cb_finish ; exit if done out_8 sc_data, all_planes ; copy all planes mov dx, screen_width ; get width of screen minus sub dx, cx ; image width (for adjustment) movzx edx, dx mov ax, [ebp].cb_height ; ax = # of lines to copy movzx ecx,cx mov ebx, ecx ; bx = quick rep reload count ; actual copy loop. rep movsb does the work @cb_middle_copy: mov ecx, ebx ; recharge rep count rep movsb ; move bands loopjz ax, @cb_finish ; exit loop if finished add esi, edx ; adjust esi to next line add edi, edx ; adjust edi to next line mov ecx, ebx ; recharge rep count rep movsb ; move bands add esi, edx ; adjust esi to next line add edi, edx ; adjust edi to next line loopx ax, @cb_middle_copy ; copy lines until done @cb_finish: out_16 gc_index, latches_off ; data from latches = on @cb_exit: add esp, 4 ; deallocate stack workspace pop edi esi ebp ; restore saved registers ret 16 ; exit and clean up stack ; return to mode 03 before exiting to dos public mode03 mode03: mov v86r_ax,3h mov al,10h int 33h ret fb_stack struc fb_add dw ? fb_count dd ? dd ?x3 ; edi, esi, ebp dd ? ; caller fb_pal dd ? ; source palette fb_stack ends public wipeoffpalette public fadeoffpalette public fadeonpalette ; load esi to palette tmppal db 768 dup (0) wipeoffpalette: xor al,al ; wipe palette, clear all to r0,g0,b0 mov dx,3c8h out dx,al inc dx mov cx,768 xor al,al wipeit: out dx,al loop wipeit ret fadeoffpalette: mov bh, 2 ; bh = step mov ah,0 ; ah = starting subtact jmp fadepalette fadeonpalette: mov bh,-2 mov ah,64 fadepalette: push ebp esi edi ; preserve important registers sub esp, 6 mov ebp, esp ; set up stack frame mov ecx,32 cld ; block xfer forwards fonp2: mov esi,[ebp].fb_pal mov [ebp].fb_add,ax mov [ebp].fb_count,ecx mov edi,offset tmppal mov ecx,768 fonp1: lodsb sub al,ah jnc fonp3 xor al,al fonp3: stosb loop fonp1 call sync_display mov dx,3c8h mov esi,offset tmppal mov ecx,768/6 xor al,al out dx,al inc dx fonp4: lodsb out dx,al lodsb out dx,al lodsb out dx,al lodsb out dx,al lodsb out dx,al lodsb out dx,al loop fonp4 call sync_display mov ecx,[ebp].fb_count mov ax,[ebp].fb_add add ah,bh loop fonp2 add esp,6 pop edi esi ebp ret 4 public turn_screen_off public turn_screen_on turn_screen_off: ; guess what these do! mov dx,03dah ; these are used when changing video modes in al,dx ; to avoid any flicker mov dx,03c0h mov al,0 out dx,al ret turn_screen_on: mov dx,03dah in al,dx mov dx,03c0h mov al,20h out dx,al ret code32 ends end