; POINTS -- Display, shift, rotate and morph points in 3D with ; color fading. ; Written by Arno W. Brouwer ; ; Thanks go to the authors of XLIB for their Mode X screen routines. IDEAL DOSSEG MODEL small STACK 256 mx EQU 160 ; middle of screen (project point my EQU 100 ; of [0, 0, 0] ) maxx EQU 319 ; max. screen x coord. maxy EQU 199 ; max. screen y coord. numpts EQU 120 ; number of points point_color EQU 46 ; color of points DATASEG returncode db 0 ex dw 0 ; eye x-coord. ey dw 0 ; eye y-coord. ez dw 256 ; distance eye-screen esz dw 8 ; (ez = 2 ^ esz) sz dw 30000 ; screen z coord. ; (distance screen <-> [0, 0, 0] ) rot_x dw 0 ; current rotation around x axis rot_y dw 0 ; y axis rot_z dw 0 ; z axis delta_x dw 0 ; delta rotation x axis delta_y dw 0 ; y axis delta_z dw 0 ; z axis morph1_ofs dw 0 ; offset shape 1 for morphing morph2_ofs dw 0 ; shape 2 morph_steps dw 0 ; number of steps needed for morphing curr_morph_step dw 0 ; current morph step [0 ... morph_steps] points dw 0 ; offset of point-table for DrawPoints label Sin256 ; sine tabel 256 * sin(x); x = 2*pi*i/256; i = [0, 255] dw 0, 6, 12, 18, 25, 31, 37, 43, 49, 56, 62 dw 68, 74, 80, 86, 92, 97, 103, 109, 115, 120, 126 dw 131, 136, 142, 147, 152, 157, 162, 167, 171, 176, 181 dw 185, 189, 193, 197, 201, 205, 209, 212, 216, 219, 222 dw 225, 228, 231, 234, 236, 238, 241, 243, 244, 246, 248 dw 249, 251, 252, 253, 254, 254, 255, 255, 255, 256, 255 dw 255, 255, 254, 254, 253, 252, 251, 249, 248, 246, 244 dw 243, 241, 238, 236, 234, 231, 228, 225, 222, 219, 216 dw 212, 209, 205, 201, 197, 193, 189, 185, 181, 176, 171 dw 167, 162, 157, 152, 147, 142, 136, 131, 126, 120, 115 dw 109, 103, 97, 92, 86, 80, 74, 68, 62, 56, 49 dw 43, 37, 31, 25, 18, 12, 6, 0, -6, -12, -18 dw -25, -31, -37, -43, -49, -56, -62, -68, -74, -80, -86 dw -92, -97, -103, -109, -115, -120, -126, -131, -136, -142, -147 dw -152, -157, -162, -167, -171, -176, -181, -185, -189, -193, -197 dw -201, -205, -209, -212, -216, -219, -222, -225, -228, -231, -234 dw -236, -238, -241, -243, -244, -246, -248, -249, -251, -252, -253 dw -254, -254, -255, -255, -255, -255, -255, -255, -255, -254, -254 dw -253, -252, -251, -249, -248, -246, -244, -243, -241, -238, -236 dw -234, -231, -228, -225, -222, -219, -216, -212, -209, -205, -201 dw -197, -193, -189, -185, -181, -176, -171, -167, -162, -157, -152 dw -147, -142, -136, -131, -126, -120, -115, -109, -103, -97, -92 dw -86, -80, -74, -68, -62, -56, -49, -43, -37, -31, -25 dw -18, -12, -6 label cube ; points for cube INCLUDE 'CUBE.INC' label ball ; points for ball INCLUDE 'BALL.INC' tmp_pts1 dw numpts*2 DUP (0) ; temp. buffer for points tmp_pts2 dw numpts*2 DUP (0) ; to speed up clrscr CODESEG ;----------------------------------------------------------------------- HiddenOfs dw 03e80h ; offset hidden page VisibleOfs dw 0 ; visible HiddenPoints dw offset tmp_pts1 ; offset hidden point-table VisiblePoints dw offset tmp_pts2 ; visible C_tabel db 1, 2, 4, 8 ; needed for plane selection sin_x dw 0 ; current sin for rot. x axis cos_x dw 0 ; cos x sin_y dw 0 ; sin y cos_y dw 0 ; cos y sin_z dw 0 ; sin z cos_z dw 0 ; sin z ;----------------------------------------------------------------------- proc WaitVsyncStart ; wait for vertical sync. start push ax push dx mov dx, 03dah @@11: in al,dx test al,08h jnz @@11 @@22: in al,dx test al,08h jz @@22 pop dx pop ax ret ENDP ;-------------------------------------------------------------------------- proc WaitVsyncEnd ; wait for vert. sync end mov dx,03dah @@33: in al,dx test al,08h jz @@33 @@44: in al,dx test al,08h jnz @@44 ret ENDP ;-------------------------------------------------------------------------- PROC InitScreen ; switch to 320 x 200 mode X push ax cx dx es di mov ax, 0013h int 10h ; switch to 320x200x256c (non-tweaked) mov dx, 03c4h mov ax, 0604h out dx, ax ; disable chain4 mode mov ax, 0100h out dx, ax ; sync. reset while setting Misc. mov dx, 03c2h mov al, 0e3h out dx, al ; select dot clock & horiz. scan rate mov dx, 03c4h mov ax, 0300h out dx, ax ; undo reset (restart sequencer) mov dx, 03d4h mov al, 11h out dx, al inc dx in al, dx and al, 07fh out dx, al ; clear protection bit dec dx mov ax, 0014h out dx, ax ; clear dword mode mov ax, 0e317h out dx, ax ; set byte mode mov dx, 03c4h mov ax, 0f02h out dx, ax ; enable writes to all four planes mov dx, 03d4h mov al, 13h out dx, al ; set logical screen width inc dx mov al, 28h out dx, al ; to 320 pixels (== 40 bytes == 28h) mov ax, 0a000h mov es, ax xor di, di xor ax, ax mov cx, 08000h rep stosw ; clear display memory pop di es dx cx ax ret ENDP InitScreen ;-------------------------------------------------------------------------- PROC InitPalette ; fill first 64 colors with grays push ax bx cx dx xor ax, ax mov cx, 64 @@33: mov bx, 10 ; number of colors to set in one retrace ; (10 is a good value for even the slower ; computers.. like mine) call WaitVsyncStart mov dx, 03c9h @@11: push cx push ax dec dx ; dx = 03c8h out dx, al ; select palette entry inc dx mov cx, 3 @@22: out dx, al ; set red, green and blue to same value loop @@22 pop ax pop cx inc al dec cx jz @@00 dec bx ; Time to wait for vert. retrace? jz @@33 ; yes: do so jmp @@11 ; no : next color @@00: pop dx cx bx ax ret ENDP InitPalette ;-------------------------------------------------------------------------- PROC FlipPages ; switch hidden and visible page. push ax bx cx dx mov bx, [cs:HiddenPoints] ; exchange hidden and visible points xchg bx, [cs:VisiblePoints] xchg bx, [cs:HiddenPoints] mov bx, [cs:HiddenOfs] ; exchange hidden and visible page xchg bx, [cs:VisibleOfs] xchg [cs:HiddenOfs], bx mov ax, bx ; ax now contains HiddenOfs mov bh, al mov ch, ah mov bl, 0dh ; page address low mov cl, 0ch ; page address high mov dx, 03dah ; wait for trailing edge of Vsync @@WaitDE: in al, dx test al, 01h jnz @@WaitDE mov dx, 03d4h mov ax, bx out dx, ax ; start address low mov ax, cx out dx, ax ; start address high call WaitVsyncStart ; wait for start vert. retrace ; to avoid screen flickering pop dx cx bx ax ret ENDP FlipPages ;----------------------------------------------------------------------- PROC ClrScr ; clear the hidden screen by ; drawing the hidden pixels in black. push ax bx cx dx es di ds si mov dx, 03c4h mov ax, 0f02h ; enable write to all four planes out dx, ax mov ax, 0a000h mov es, ax mov ax, [cs:HiddenPoints] mov si, ax ; ds:si -> HiddenPoints tabel mov cx, numpts @@ClrLoop: lodsw ; get x coord. push ax lodsw ; get y coord. mov bx, 320 mul bx mov di, ax pop ax add di, ax shr di, 1 shr di, 1 ; correction for use of planes mov ax, [cs:HiddenOfs] add di, ax xor ax, ax stosb ; clear pixel loop @@ClrLoop pop si ds di es dx cx bx ax ret ENDP ClrScr ;----------------------------------------------------------------------- PROC GetSinCos ; get sine and cosine values ; from tabel. ax contains ; 'angle' (ax = [0 .. 255]) ; returns: ax = sin(ax) ; bx = cos(ax) push ds si lea si, [Sin256] mov bx, ax push bx shl bx, 1 ; bx = bx * 2.. word is 2 bytes mov ax, [ds:si + bx] ; get sin() pop bx push ax add bx, 64 ; since sine tabel ranges from and bx, 0ffh ; [0 .. 255], so cos(x) = sin(x+64) shl bx, 1 mov ax, [si + bx] ; get cos() mov bx, ax pop ax pop si ds ret ENDP GetSinCos ;----------------------------------------------------------------------- PROC SetRotation ; specify x, y, z rotation ; ax = x rot, bx = y rot, cx = z rot push ax bx cx and ax, 0ffh ; range sine table [0 .. 255] and bx, 0ffh and cx, 0ffh push cx push bx call GetSinCos mov [cs:sin_x], ax mov [cs:cos_x], bx pop ax call GetSinCos mov [cs:sin_y], ax mov [cs:cos_y], bx pop ax call GetSinCos mov [cs:sin_z], ax mov [cs:cos_z], bx pop cx bx ax ret ENDP SetRotation ;----------------------------------------------------------------------- PROC UpdateRotation ; update rotation params. ; add delta_x, delta_y and delta_z push ax bx cx ; to rot_x, rot_y and rot_z, ; then calculate the sines and cosines. mov ax, [rot_x] mov bx, [rot_y] mov cx, [rot_z] add ax, [delta_x] mov [rot_x], ax add bx, [delta_y] mov [rot_y], bx add cx, [delta_z] mov [rot_z], cx call SetRotation pop cx bx ax ret ENDP UpdateRotation ;-------------------------------------------------------------------------- PROC SetMorph ; Set parameters for morphing. ; Both shapes must have the same ; number of points. ; Input: ax = offset shape1. ; bx = offset shape2. ; cx = total number of steps mov [morph1_ofs], ax mov [morph2_ofs], bx mov [morph_steps], cx mov [curr_morph_step], 0 ret ENDP SetMorph ;-------------------------------------------------------------------------- PROC project_point ; project a point to screen ; using x,y,z rotations ARG z, y, x: word ; returns: ax = x coord. ; bx = y coord. ; cx = distance to screen. push bp mov bp, sp push dx ; first rotate around x-axis mov cx, 256 mov ax, [y] mov bx, [cos_x] imul bx idiv cx ; divide by 256 since sin-tabel ranges ; from -256 to 256 instead of -1 to 1. cmp dx, 128 ; Check remainder to decrease integer math jl @@Skip1 ; inaccuracy. or ax, ax jl @@Neg1 inc ax jmp @@Skip1 @@Neg1: dec ax @@Skip1: push ax mov ax, [z] mov bx, [sin_x] imul bx idiv cx cmp dx, 128 jl @@Skip2 or ax, ax jl @@Neg2 inc ax jmp @@Skip2 @@Neg2: dec ax @@Skip2: pop bx sub bx, ax ; bx now contains new y-coord. push bx mov ax, [y] mov bx, [sin_x] imul bx idiv cx cmp dx, 128 jl @@Skip3 or ax, ax jl @@Neg3 inc ax jmp @@Skip3 @@Neg3: dec ax @@Skip3: push ax mov ax, [z] mov bx, [cos_x] imul bx idiv cx cmp dx, 128 jl @@Skip4 or ax, ax jl @@Neg4 inc ax jmp @@Skip4 @@Neg4: dec ax @@Skip4: pop bx add ax, bx mov [z], ax ; z = y sin_x + z cos_x pop ax mov [y], ax ; y' = y cos_x - z sin_x ; now rotate around y-axis mov cx, 256 mov ax, [z] mov bx, [cos_y] imul bx idiv cx cmp dx, 128 jl @@Skip5 or ax, ax jl @@Neg5 inc ax jmp @@Skip5 @@Neg5: dec ax @@Skip5: push ax mov ax, [x] mov bx, [sin_y] imul bx idiv cx cmp dx, 128 jl @@Skip6 or ax, ax jl @@Neg6 inc ax jmp @@Skip6 @@Neg6: dec ax @@Skip6: pop bx sub bx, ax ; bx now contains new y-coord. push bx mov ax, [z] mov bx, [sin_y] imul bx idiv cx cmp dx, 128 jl @@Skip7 or ax, ax jl @@Neg7 inc ax jmp @@Skip7 @@Neg7: dec ax @@Skip7: push ax mov ax, [x] mov bx, [cos_y] imul bx idiv cx cmp dx, 128 jl @@Skip8 or ax, ax jl @@Neg8 inc ax jmp @@Skip8 @@Neg8: dec ax @@Skip8: pop bx add ax, bx mov [x], ax ; x' = z sin_y + x cos_y pop ax mov [z], ax ; z' = z cos_y - x sin_y ; now rotate around z-axis mov cx, 256 mov ax, [x] mov bx, [cos_z] imul bx idiv cx cmp dx, 128 jl @@Skip9 or ax, ax jl @@Neg9 inc ax jmp @@Skip9 @@Neg9: dec ax @@Skip9: push ax mov ax, [y] mov bx, [sin_z] imul bx idiv cx cmp dx, 128 jl @@Skip10 or ax, ax jl @@Neg10 inc ax jmp @@Skip10 @@Neg10: dec ax @@Skip10: pop bx sub bx, ax ; bx now contains new y-coord. push bx mov ax, [x] mov bx, [sin_z] imul bx idiv cx cmp dx, 128 jl @@Skip11 or ax, ax jl @@Neg11 inc ax jmp @@Skip11 @@Neg11: dec ax @@Skip11: push ax mov ax, [y] mov bx, [cos_z] imul bx idiv cx cmp dx, 128 jl @@Skip12 or ax, ax jl @@Neg12 inc ax jmp @@Skip12 @@Neg12: dec ax @@Skip12: pop bx add ax, bx mov [y], ax ; y' = x sin_z + y cos_z pop ax ; x' = x cos_z - y sin_z mov [x], ax mov bx, [sz] sub bx, [z] add bx, [ez] mov cx, [esz] mov ax, [y] ; first project y coord. sub ax, [ey] pushf jge @@Pos1 ; is ax < 0? neg ax ; yes: ax = -ax @@Pos1: shl ax, cl ; since ax >= 0, we can use xor dx, dx ; a shift here instead of a imul. idiv bx ; ax = ((y - ey) * ez) / (sz - z) push bx ; save bx shr bx, 1 cmp dx, bx ; again a check to decrease jl @@NoRound1 ; integer math inaccuracy inc ax @@NoRound1: pop bx popf ; was ax negative? jge @@Pos1_1 neg ax ; yes: ax = -ax. @@Pos1_1: add ax, my ; add coords of center of screen push ax mov ax, [x] ; now project x coord. sub ax, [ex] pushf jge @@Pos2 neg ax @@Pos2: shl ax, cl xor dx, dx idiv bx push bx shr bx, 1 cmp dx, bx jl @@NoRound2 inc ax @@NoRound2: pop bx popf jge @@Pos2_1 neg ax @@Pos2_1: add ax, mx mov cx, [sz] mov bx, [z] sub cx, bx pop bx pop dx pop bp ret ENDP project_point ;----------------------------------------------------------------------- PROC plot_point ; expects that ax = px, bx = py ; cx = distance point <-> screen or ax, ax jl @@Exit ; first check wether the point is on the cmp ax, maxx ; screen. jg @@Exit or bx, bx jl @@Exit cmp bx, maxy jg @@Exit or cx, cx jl @@Exit push ax bx cx dx es di push cx push ax push bx mov ax, 0a000h mov es, ax pop ax ; ax = y-coord. mov bx, 320 mul bx mov di, ax pop ax add di, ax ; es:di points to position in video RAM mov bx, di mov cl, 2h shr di, cl mov ax, [cs:HiddenOfs] add di, ax mov dx, 03c4h mov al, 02h and bx, 03h ; filter out plane bits mov ah, [cs:C_tabel + bx] out dx, ax ; select plane pop ax ; ax = distance point <-> screen sub ax, 60 ; calculate the color of the pixel jge @@NotNegative xor ax, ax @@NotNegative: xor bx, bx @@NotZero: inc bx shr ax, 1 jnz @@NotZero shl bx, 1 shl bx, 1 mov ax, 64 sub ax, bx ; ax contains the color of the pixel stosb ; plot pixel pop di es dx cx bx ax @@Exit: ret ENDP plot_point ;-------------------------------------------------------------------------- PROC MorphPoints ; morph points from shape1 ; to shape2. push cx ; Also updates rotation and mov cx, [curr_morph_step] ; plots points. cmp cx, [morph_steps] ; Do we still have morph steps pop cx ; to go? jl @@StepOk ; yes: Jump to StepOk push ax ; no: Draw the second image on mov ax, [morph2_ofs] ; the screen and return. mov [points], ax pop ax call DrawPoints ret @@StepOk: push ax bx cx dx si es di call UpdateRotation ; Update rotation params. mov cx, numpts mov si, [morph1_ofs] mov di, [morph2_ofs] mov ax, ds mov es, ax mov dx, [cs:HiddenPoints] ; use dx as a temp. pointer to @@MorphLoop: ; the HiddenPoints tabel push cx push dx mov cx, 3 ; morph x, y, z coord. @@CoordLoop: mov ax, [di] mov bx, [si] sub ax, bx ; ax is distance p2 - p1 mov bx, [curr_morph_step] imul bx mov bx, [morph_steps] idiv bx ; ax = ax * curr_morph_step / morph_steps add ax, [si] push ax ; save value ax inc di inc di inc si inc si loop @@CoordLoop ; repeat until x, y and z values are morphed. call project_point ; calculate x and y values of point on screen add sp, 6 call plot_point ; plot 'em. pop dx ; dx = offset HiddenPoints tabel xchg dx, di ; exchange dx and di stosw ; store x coord. in HiddenPoints tabel mov ax, bx stosw ; store y coord. in HiddenPoints tabel xchg dx, di ; swap dx and di pop cx loop @@MorphLoop ; any more points? call FlipPages ; no: flip the pages. call ClrScr ; clear the hidden page. mov cx, [curr_morph_step] inc cx ; increase the current morph step mov [curr_morph_step], cx pop di es si dx cx bx ax ret ENDP MorphPoints ;----------------------------------------------------------------------- PROC DrawPoints ; project points, plot'em and update ; rotation data. push ax bx cx dx ds si es di call UpdateRotation ; update the rotation params. mov si, [points] ; ds:si -> point tabel mov ax, ds mov es, ax mov ax, [cs:HiddenPoints] mov di, ax ; es:di -> HiddenPoints tabel mov cx, numpts @@PlotLoop: push cx lodsw ; get x coord. push ax lodsw ; get y coord. push ax lodsw ; get z coord. push ax call project_point ; project the point onto the screen add sp, 6 call plot_point ; plot the point stosw ; store x coord. for fast clrscr. mov ax, bx stosw ; store y coord. pop cx loop @@PlotLoop ; any more points? call FlipPages ; no: flip the pages call ClrScr ; clear the hidden page. pop di es si ds dx cx bx ax ret ENDP DrawPoints ;----------------------------------------------------------------------- Begin: mov ax, @data mov ds, ax call InitScreen ; initialize the screen call InitPalette ; and the palette @@BigLoop: mov ax, offset cube mov [points], ax ; first draw the cube mov [delta_x], 0 ; halt all rotations mov [delta_y], 0 mov [delta_z], 0 mov [ex], 0 ; put the eye x coord. to zero mov cx, 20h ; show cube at a VERY large distance @@RotLoop0: call DrawPoints ; draw the points mov ah, 1h ; check for a keypress int 16h jz @@NoPress0 jmp RestoreScreen ; key pressed -> restore screen and @@NoPress0: ; exit. loop @@RotLoop0 mov cx, 8 ; Zoom in @@LoopLoop3: push cx call DrawPoints mov ah, 01h ; check for keypress int 16h jz @@NoPress1 jmp RestoreScreen @@NoPress1: mov ax, [sz] ; move the screen closer to shr ax, 1 ; (0, 0, 0) mov [sz], ax pop cx loop @@LoopLoop3 mov cx, 0a0h ; let cube rotate round y for a while xor bx, bx @@RotLoop1: call DrawPoints mov ah, 1h int 16h jz @@NoPress2 jmp RestoreScreen @@NoPress2: push bx shl bx, 1 mov ax, [cs:Sin256 + bx] ; get rotation speed from sine tabel pop bx shr ax, 1 shr ax, 1 shr ax, 1 shr ax, 1 shr ax, 1 ; adjust speed a bit mov [delta_y], ax ; store new speed. inc bx and bx, 0ffh loop @@RotLoop1 mov [delta_x], 1 ; add x rotation. mov cx, 80h @@RotLoop2: call DrawPoints mov ah, 1h int 16h jz @@NoPress3 jmp RestoreScreen @@NoPress3: loop @@RotLoop2 mov [delta_x], -3 mov [delta_z], 2 mov cx, 40h ; add some more rot's @@RotLoop3: call DrawPoints mov ah, 1h int 16h jz @@NoPress4 jmp RestoreScreen @@NoPress4: loop @@RotLoop3 mov [delta_x], 0 mov [delta_y], 2 mov [delta_z], -1 xor bx, bx ; index in sine tabel mov cx, 256 ; let the cube move from @@RotLoop4: ; left to right call DrawPoints mov ah, 1h int 16h jz @@NoPress5 jmp RestoreScreen @@NoPress5: mov ax, [cs:Sin256 + bx] ; ax = [-256 .. 256] add ax, 256 ; ax = [ 0 .. 512] shr ax, 1 ; ax = [ 0 .. 256] sub ax, 128 ; ax = [-128 .. 128] mov [ex], ax ; store new eye x coord. inc bx inc bx ; set bx to new entry in sine tabel and bx, 01ffh loop @@RotLoop4 push bx ; save the value of bx mov ax, offset cube mov bx, offset ball mov cx, 100h ; 256 morph steps call SetMorph ; set morphing params. mov cx, 256 @@MorphLoop: call MorphPoints ; morph and draw the points. mov ah, 1h int 16h jz @@NoPress6 jmp RestoreScreen @@NoPress6: loop @@MorphLoop mov ax, offset ball mov [points], ax ; set points tabel to ball pop bx ; restore the value of bx mov cx, 512 mov [delta_x], 1 mov [delta_y], -2 ; add a up-down movement @@RotLoop5: ; + fancy rotation push cx call DrawPoints ; draw the points mov ah, 1h int 16h jz @@NoPress7 jmp RestoreScreen @@NoPress7: mov ax, [cs:Sin256 + bx] add ax, 256 shr ax, 1 sub ax, 128 mov [ex], ax ; set new eye x coord. push bx shl bx, 1 ; y movement = twice as fast as and bx, 01ffh ; x movement mov ax, [cs:Sin256 + bx] ; ax = [-256 .. 256] add ax, 256 ; ax = [ 0 .. 512] shr ax, 1 ; ax = [ 0 .. 256] shr ax, 1 ; ax = [ 0 .. 128] sub ax, 64 ; ax = [ -64 .. 64] mov [ey], ax ; store new eye y coord. pop bx mov ax, [cs:Sin256 + bx] add ax, 256 shr ax, 1 shr ax, 1 shr ax, 1 shr ax, 1 shr ax, 1 sub ax, 8 ; ax = [-8 .. 8] mov [delta_z], ax ; set new z rotation delta. inc bx inc bx and bx, 01ffh ; bx = new entry in sine tabel pop cx loop @@RotLoop5 mov cx, 8 ; Zoom out @@LoopLoop4: push cx call DrawPoints mov ah, 01h ; check for keypress int 16h jz @@NoPress8 jmp RestoreScreen @@NoPress8: mov ax, [sz] ; reverse of zoom in shl ax, 1 mov [sz], ax pop cx loop @@LoopLoop4 jmp @@BigLoop RestoreScreen: mov ax, 0003h ; set text mode (80 x 25, 16c) int 10h Uitgang: @@CheckForKeys: mov ah, 01h ; clear the keybuffer int 16h jz @@NoKeyWaiting xor ah, ah int 16h ; get key jmp @@CheckForKeys @@NoKeyWaiting: mov ah, 04ch mov al, [returncode] int 21h ; and done. END Begin