1 ; NASM Version: Erdogan Tan (22/08/2016) 2 3 ; 4ge's Xmas 94 Intro fractalzoom source 4 ; ====================================== 5 6 ; Copyright (C) 1994/5 Samuel Marshall. All rights reserved. 7 8 ; Text and program code by Samuel Marshall, a.k.a. CuteElf / 4ge. 9 10 ; Contact me at the following email address: 11 12 ; Samuel.Marshall@durham.ac.uk 13 14 ; and if you don't get a response, probably it's not during termtime, and 15 ; I am at home - in which case, I check email here only about once a month 16 ; (if that). You will get a reply eventually. 17 18 ; My WWW homepage is 19 20 ; http://www.dur.ac.uk/~d405ua/ 21 22 ; Enjoy the program... hope it helps you. Don't expect a wonderfully- 23 ; optimised piece of code, because 1) the zoom routine wasn't really time- 24 ; critical, and 2) this is the first time I ever wrote a fractal program, 25 ; in my entire life, and 3) I didn't know how to do fixed-point numbers 26 ; properly when I wrote this ;) 27 28 ; General Principles for a real-time fractalzoom using this method 29 ; ================================================================ 30 ; 31 ; First, we calculate a fractal at twice the size, each way (i.e. 4 times 32 ; the area) as the screen display area. 33 ; 34 ; We then display that fractal, zoomed-out to half size each way, so that 35 ; it will exactly fill the screen display area. 36 ; 37 ; Then, we calculate another fractal twice the size of the display area, 38 ; but this one is calculated "zoomed in" so that this fractal is a more 39 ; detailed view of one-quarter of the area of the fractal just calculated. 40 ; 41 ; While we are calculating this, which takes a few seconds, we gradually 42 ; zoom in the fractal we already have - using standard bitmap-zoom 43 ; techniques - until eventually by the time the new fractal is finished, 44 ; the old fractal will be showing at 1:1 size, and will can then be 45 ; seamlessly replaced on the display by the new fractal at 1:2. Then 46 ; repeat. 47 ; 48 ; Note: the fractal being DISPLAYED, i.e. the one that's already been 49 ; calculated, can be zoomed to any point at all within the region, but 50 ; this decision must be known in advance so that the next fractal is 51 ; calculated from the right point. That's why you can't change the direction 52 ; "realtime", only every so often. 53 54 ; I would include references here but I worked the method out myself with 55 ; no help from anything or anyone, so there aren't any... (oh, by the 56 ; way, I assume this is the standard method everyone else uses too, it's 57 ; nothing special or anything, just that I reinvented the wheel one more 58 ; time ;) 59 60 ; More details are included in the individual function descriptions. 61 62 [ORG 100h] 63 64 00000000 E93408 jmp Start 65 66 Getch: 67 00000003 B80000 mov ax, 0 68 00000006 CD16 int 16h 69 00000008 C3 retn 70 71 ; You can probably change height without messing things up, but 72 ; changing the width will I think need some work. 73 74 FRACWIDTH equ 256 75 FRACHEIGHT equ 128 76 77 ; Fractal parameter 78 00000009 03000000 frac: dd 3 79 80 ; Memory 81 0000000D 0000 enlargebufferseg: dw 0 ; segment address of the 64*32 enlarge buf. 82 0000000F 0000 textureseg: dw 0 ; the segment address of texture to display. 83 00000011 0000 fractalseg: dw 0 ; the segment address of texture to create 84 85 ;==================================================================== 86 ;ZOOMTEXTURE - display picture at given zoom fraction 87 ;-------------------------------------------------------------------- 88 89 ; This is pretty obvious; just a standard, fixed-point bitmap 90 ; display routine. The only extra bit you might notice is that 91 ; it doubles each pixel, so as to get a larger screen display without 92 ; taking too long to calculate the fractals. 93 94 ; Data_______________________________________________________________ 95 96 00000013 0000 lfrac: dw 0 97 00000015 0000 hfrac: dw 0 ; texture pixels per real pixel 98 00000017 00 hfracb: db 0 ; same but a byte 99 100 00000018 00 ystart: db 0 101 00000019 00 xstart: db 0 ; where to start, in texturemap 102 103 0000001A 0000 oldbx: dw 0 104 0000001C 0000 oldss: dw 0 105 106 0000001E 0000 yfracpos: dw 0 ; fractional y-position 107 108 00000020 0000 stopat: dw 0 ; where to stop in screen ram 109 110 ; Source_____________________________________________________________ 111 112 ZoomTexture: 113 00000022 50 push ax 114 00000023 53 push bx 115 00000024 51 push cx 116 00000025 52 push dx 117 00000026 56 push si 118 00000027 57 push di 119 120 00000028 8B3E[3C03] mov di, [screenstart] ; start position on display memory 121 0000002C 893E[2000] mov [stopat], di 122 00000030 8106[2000]00A0 add word [stopat], FRACHEIGHT*320 ; stop position on display memory 123 00000036 8A3E[1800] mov bh, [ystart] 124 0000003A 8A1E[1900] mov bl, [xstart] ; start position on texture memory 125 126 0000003E A1[1500] mov ax, [hfrac] 127 00000041 A2[1700] mov [hfracb], al 128 00000044 8B16[1300] mov dx, [lfrac] 129 130 00000048 8CD0 mov ax, ss 131 0000004A A3[1C00] mov [oldss], ax 132 0000004D A1[0F00] mov ax, [textureseg] 133 00000050 8ED0 mov ss, ax 134 135 ZoomYLoop: 136 137 00000052 BE8000 mov si, FRACWIDTH/2 138 00000055 891E[1A00] mov [oldbx], bx 139 00000059 B90000 mov cx, 0 140 141 ZoomXLoop: 142 143 0000005C 368A07 mov al, [ss:bx] 144 0000005F 88C4 mov ah, al 145 00000061 268905 mov [es:di], ax 146 00000064 2689854001 mov [es:di+320], ax 147 00000069 83C702 add di, 2 148 0000006C 030E[1300] add cx, [lfrac] 149 00000070 131E[1500] adc bx, [hfrac] 150 151 00000074 4E dec si 152 00000075 75E5 jnz short ZoomXLoop 153 154 00000077 8B1E[1A00] mov bx, [oldbx] 155 156 0000007B 0116[1E00] add [yfracpos], dx 157 0000007F 123E[1700] adc bh, [hfracb] 158 159 00000083 81C78001 add di, 640-FRACWIDTH 160 00000087 3B3E[2000] cmp di, [stopat] 161 0000008B 72C5 jb short ZoomYLoop 162 163 0000008D A1[1C00] mov ax, [oldss] 164 00000090 8ED0 mov ss, ax 165 166 ; Check for keypress 167 00000092 B401 mov ah,1 168 00000094 CD16 int 16h 169 00000096 7403 jz short zt_afterkeyhit 170 171 00000098 E94F06 jmp dfs_keyhit 172 173 zt_afterkeyhit: 174 175 0000009B 5F pop di 176 0000009C 5E pop si 177 0000009D 5A pop dx 178 0000009E 59 pop cx 179 0000009F 5B pop bx 180 000000A0 58 pop ax 181 000000A1 C3 retn 182 183 ;==================================================================== 184 ;CALCULATE - work out one pixel of Mandelbrot fractal 185 ;-------------------------------------------------------------------- 186 187 ; The fractal formula used, with coordinates x,y, is: 188 ; A = B = 0. Colour=starting colour. 189 ; 190 ; new A = a squared - b squared - x 191 ; new B = 2 * a * b - y 192 ; 193 ; If A squared + B squared > some number frac, then stop. 194 ; If been round loop more than colour limit (64) times, then stop too. 195 ; 196 ; Otherwise, work out next A and B, and increment the colour we're going 197 ; to use for the pixel. 198 ; 199 ; When we get out of the loop, that colour value is the one to draw at 200 ; this pixel. 201 202 ; Note: 203 ; The fixed point sections of this are pretty crap; there are proper ways 204 ; to do fixed point (I think...) so for god's sake don't copy those 205 ; bits for your own fixed point code. 206 207 ; Data_______________________________________________________________ 208 209 000000A2 00 colour: db 0 ; colour to plot the pixel 210 211 000000A3 00 esign: db 0 ; esign of multiplication result 212 213 000000A4 00000000 la: dd 0 214 000000A8 00000000 ha: dd 0 215 000000AC 00000000 lb: dd 0 216 000000B0 00000000 hb: dd 0 ; a,b from a+bi. Low and high words thereof. 217 218 000000B4 00000000 lasq: dd 0 219 000000B8 00000000 hasq: dd 0 220 000000BC 00000000 lbsq: dd 0 221 000000C0 00000000 hbsq: dd 0 ; a squared, b squared, low and high words. 222 223 000000C4 00000000 lnewa: dd 0 224 000000C8 00000000 hnewa: dd 0 ; temporary storage for `new' veresion of `a'. 225 226 000000CC 00000000 lx: dd 0 227 000000D0 00000000 hx: dd 0 228 000000D4 00000000 ly: dd 0 229 000000D8 00000000 hy: dd 0 ; co-oredinates in complex plane of this point 230 231 ; Source_____________________________________________________________ 232 233 Calculate: 234 000000DC 6650 push eax 235 000000DE 6653 push ebx 236 000000E0 6651 push ecx 237 000000E2 6652 push edx 238 000000E4 6656 push esi 239 000000E6 6657 push edi 240 241 ; 0) Fix up the x,y data to specific point 242 ; mov dword [lx], 2621 243 ; mov dword [hx], 1 244 ; mov dword [ly], 11107 245 ; mov dword [hy], 1 246 247 ; 1) setup colour 248 000000E8 C606[A200]20 mov byte [colour], 32 249 250 ; 2) clear the a,b and squared variables, 251 000000ED 6631C0 xor eax, eax ; 0 252 000000F0 66A3[A400] mov [la], eax 253 000000F4 66A3[A800] mov [ha], eax 254 000000F8 66A3[AC00] mov [lb], eax 255 000000FC 66A3[B000] mov [hb], eax 256 00000100 66A3[B400] mov [lasq], eax 257 00000104 66A3[B800] mov [hasq], eax 258 00000108 66A3[BC00] mov [lbsq], eax 259 0000010C 66A3[C000] mov [hbsq], eax 260 261 CalcLoop: 262 263 ; 3) increment colour 264 00000110 FE06[A200] inc byte [colour] 265 266 ; 4) set up a-squared 267 asquared: 268 00000114 66A1[B400] mov eax, [lasq] 269 00000118 668B16[B800] mov edx, [hasq] 270 271 minusbsquared: 272 ; 5) subtract b-squared 273 0000011D 662B06[BC00] sub eax, [lbsq] 274 00000122 661B16[C000] sbb edx, [hbsq] 275 276 minusx: 277 ; 6) subtract x and store result in new-a 278 00000127 662B06[CC00] sub eax, [lx] 279 0000012C 661B16[D000] sbb edx, [hx] 280 00000131 66A3[C400] mov [lnewa], eax 281 00000135 668916[C800] mov [hnewa], edx 282 283 ; 7) multiply a and b 284 285 atimesb: 286 ; a. setup variables 287 0000013A 668B1E[A400] mov ebx, [la] 288 0000013F 668B0E[A800] mov ecx, [ha] 289 00000144 668B36[AC00] mov esi, [lb] 290 00000149 668B3E[B000] mov edi, [hb] 291 292 fixesigns: 293 ; b. sort out esigns to be poesitive 294 0000014E C606[A300]00 mov byte [esign], 0 295 00000153 6683F900 cmp ecx, 0 296 00000157 7D14 jge short ecxok_1 297 00000159 6683F1FF xor ecx, 0ffffffffh 298 0000015D 6683F3FF xor ebx, 0ffffffffh 299 00000161 6683C301 add ebx, 1 300 00000165 6683D100 adc ecx, 0 301 00000169 FE06[A300] inc byte [esign] 302 ecxok_1: 303 0000016D 6683FF00 cmp edi, 0 304 00000171 7D14 jge short ediok_1 305 00000173 6683F7FF xor edi, 0ffffffffh 306 00000177 6683F6FF xor esi, 0ffffffffh 307 0000017B 6683C601 add esi, 1 308 0000017F 6683D700 adc edi, 0 309 00000183 FE06[A300] inc byte [esign] 310 ediok_1: 311 312 multiply: 313 ; c. multiply the two numbers 314 00000187 66C706[B000]000000- mov dword [hb], 0 315 0000018F 00 316 00000190 6689D8 mov eax, ebx 317 00000193 6689F2 mov edx, esi 318 00000196 66F7E2 mul edx 319 00000199 668916[AC00] mov [lb], edx 320 0000019E 6689D8 mov eax, ebx 321 000001A1 6689FA mov edx, edi 322 000001A4 66F7E2 mul edx 323 000001A7 660106[AC00] add [lb], eax 324 000001AC 661116[B000] adc [hb], edx 325 000001B1 6689C8 mov eax, ecx 326 000001B4 6689F2 mov edx, esi 327 000001B7 66F7E2 mul edx 328 000001BA 660106[AC00] add [lb], eax 329 000001BF 661116[B000] adc [hb], edx 330 000001C4 6689C8 mov eax, ecx 331 000001C7 6689FA mov edx, edi 332 000001CA 66F7E2 mul edx 333 000001CD 660106[B000] add [hb], eax 334 335 fixresultesign: 336 ; d. fix the esign of the result 337 000001D2 F606[A300]01 test byte [esign], 1 338 000001D7 7418 jz short esignok_1 339 000001D9 668336[B000]FF xor dword [hb], 0ffffffffh 340 000001DF 668336[AC00]FF xor dword [lb], 0ffffffffh 341 000001E5 668306[CC00]01 add dword [lx], 1 342 000001EB 668316[B000]00 adc dword [hb], 0 343 esignok_1: 344 345 doublenumber: 346 ; 8) Add this to itself, (with carry) 347 000001F1 66A1[AC00] mov eax, [lb] 348 000001F5 668B16[B000] mov edx, [hb] 349 000001FA 6601C0 add eax, eax 350 000001FD 6611D2 adc edx, edx 351 352 subtracty: 353 ; 9) Subtract y and store in b 354 00000200 662B06[D400] sub eax, [ly] 355 00000205 661B16[D800] sbb edx, [hy] 356 0000020A 66A3[AC00] mov [lb], eax 357 0000020E 668916[B000] mov [hb], edx 358 359 ; 10) Update a from new-a : combined with 360 ; 11) Square a and store in a-squared 361 ; a. setup variable 362 starttosquare: 363 00000213 668B1E[C400] mov ebx, [lnewa] 364 00000218 668B0E[C800] mov ecx, [hnewa] 365 0000021D 66891E[A400] mov [la], ebx 366 00000222 66890E[A800] mov [ha], ecx 367 368 fixesign: 369 ; b. sort out esign to be poesitive 370 00000227 6683F900 cmp ecx, 0 371 0000022B 7D10 jge short ecxok_2 372 0000022D 6683F1FF xor ecx, 0ffffffffh 373 00000231 6683F3FF xor ebx, 0ffffffffh 374 00000235 6683C301 add ebx, 1 375 00000239 6683D100 adc ecx, 0 376 ecxok_2: 377 378 squareit: 379 ; c. square data 380 0000023D 66C706[B800]000000- mov dword [hasq], 0 381 00000245 00 382 00000246 6689D8 mov eax, ebx 383 00000249 66F7E0 mul eax 384 0000024C 668916[B400] mov [lasq], edx 385 00000251 6689D8 mov eax, ebx 386 00000254 66F7E1 mul ecx 387 00000257 660106[B400] add [lasq], eax 388 0000025C 661116[B800] adc [hasq], edx 389 00000261 660106[B400] add [lasq], eax 390 00000266 661116[B800] adc [hasq], edx 391 0000026B 6689C8 mov eax, ecx 392 0000026E 66F7E0 mul eax 393 00000271 660106[B800] add [hasq], eax 394 395 sametosquareb: 396 ; 12) Square b and store in b-squared 397 ; a. setup variable 398 00000276 668B1E[AC00] mov ebx, [lb] 399 0000027B 668B0E[B000] mov ecx, [hb] 400 401 ; b. sort out esign to be poesitive 402 00000280 6683F900 cmp ecx, 0 403 00000284 7D10 jge short ecxok_3 404 00000286 6683F1FF xor ecx, 0ffffffffh 405 0000028A 6683F3FF xor ebx, 0ffffffffh 406 0000028E 6683C301 add ebx, 1 407 00000292 6683D100 adc ecx, 0 408 ecxok_3: 409 410 ; c. square data 411 00000296 66C706[C000]000000- mov dword [hbsq], 0 412 0000029E 00 413 0000029F 6689D8 mov eax, ebx 414 000002A2 66F7E0 mul eax 415 000002A5 668916[BC00] mov [lbsq], edx 416 000002AA 6689D8 mov eax, ebx 417 000002AD 66F7E1 mul ecx 418 000002B0 660106[BC00] add [lbsq], eax 419 000002B5 661116[C000] adc [hbsq], edx 420 000002BA 660106[BC00] add [lbsq], eax 421 000002BF 661116[C000] adc [hbsq], edx 422 000002C4 6689C8 mov eax, ecx 423 000002C7 66F7E0 mul eax 424 000002CA 660106[C000] add [hbsq], eax 425 426 asquaredaddbsquared: 427 ; 13) Setup a-squared 428 000002CF 66A1[B400] mov eax, [lasq] 429 000002D3 668B16[B800] mov edx, [hasq] 430 431 ; 14) Add b-squared 432 000002D8 660306[BC00] add eax, [lbsq] 433 000002DD 661316[C000] adc edx, [hbsq] 434 435 ; 15) Compare with *n*, stop if > 436 000002E2 663B16[0900] cmp edx, [frac] 437 000002E7 7F0A jg short CalcFinish 438 439 ; 16) If colour > *c*, stop 440 000002E9 803E[A200]3F cmp byte [colour], 63 441 000002EE 7F03 jg short CalcFinish 442 443 000002F0 E91DFE jmp CalcLoop 444 445 CalcFinish: 446 ; 17) Return pixel colour 447 000002F3 665F pop edi 448 000002F5 665E pop esi 449 000002F7 665A pop edx 450 000002F9 6659 pop ecx 451 000002FB 665B pop ebx 452 000002FD 6658 pop eax 453 000002FF A0[A200] mov al, [colour] 454 00000302 C3 retn 455 456 ;==================================================================== 457 ;FRACTAL - loop round to draw a 256x256 fractal using Calculate 458 ;-------------------------------------------------------------------- 459 460 ; Basically, this just uses fixed-point to go through all the 461 ; x and y coordinates corresponding to SCREEN x and y. 462 ; If you're confused about the "normaltime", "othertime", etc crap 463 ; in the zooming-in section, well, I *think* this is because the 464 ; Y-position sometimes needs to start at a half-pixel (i.e. "othertime") 465 ; but usually ("normaltime") starts on a whole pixel. 466 467 ; Note, it would be possible to speed this up by 1/4, simply by re-using 468 ; the relevant pixels from the fractal calculated last: see this diagram 469 470 ; We're zooming in to top left corner. 471 472 ; Original fractal Fractal needs calculating next 473 ; 474 ; abcd.... a?b?c?d? 475 ; efgh.... ???????? 476 ; ijkl.... e?f?g?h? 477 ; mnop.... ???????? 478 ; ........ i?j?k?l? 479 ; ........ ???????? 480 ; ........ m?n?o?p? 481 ; ........ ???????? 482 ; 483 ; where "." has been calculated on original fractal, but will not be used 484 ; for the new one, and ? represents what actually needs to be calculated 485 ; in the new one. (a,b,c,... could be copied from the old one). 486 ; 487 ; Actually, this routine doesn't copy over a,b,c,..., they are recalculated. 488 489 ; Data_______________________________________________________________ 490 491 00000303 00000000 lxcentre: dd 0 492 00000307 00000000 hxcentre: dd 0 493 0000030B 00000000 lycentre: dd 0 494 0000030F 00000000 hycentre: dd 0 ; co-ordinates of the window's centre, not used here 495 ; (they are used in the main loop...) 496 00000313 00000000 lxs: dd 0 497 00000317 00000000 hxs: dd 0 498 0000031B 00000000 lys: dd 0 499 0000031F 00000000 hys: dd 0 ; co-oredinates of the window's top left corner 500 501 00000323 00000000 lxi: dd 0 502 00000327 00000000 hxi: dd 0 503 0000032B 00000000 lyi: dd 0 504 0000032F 00000000 hyi: dd 0 ; amount to increment fractal parameter per pixel 505 506 00000333 0000 ycount: dw 0 507 00000335 0000 xcount: dw 0 ; loop counters 508 509 00000337 01 nodraw: db 1 ; whether or not to draw the last one 510 511 00000338 01 ydirection: db 1 512 00000339 01 xdirection: db 1 ; direction of the zoom (0 = left/up, 1=centre, 2=rt/down) 513 0000033A 01 newxdirection: db 1 514 0000033B 01 newydirection: db 1 515 516 0000033C 0000 screenstart: dw 0 ; screen edisplay offset 517 518 ; Source_____________________________________________________________ 519 520 Fractal: 521 0000033E 6650 push eax 522 00000340 6653 push ebx 523 00000342 6651 push ecx 524 00000344 6652 push edx 525 00000346 6656 push esi 526 00000348 6657 push edi 527 528 ; 1) Initialise x and y parameters of fractal to xstart,ystart 529 0000034A 66A1[1303] mov eax, [lxs] 530 0000034E 668B16[1703] mov edx, [hxs] 531 00000353 66A3[CC00] mov [lx], eax 532 00000357 668916[D000] mov [hx], edx 533 0000035C 66A1[1B03] mov eax, [lys] 534 00000360 668B16[1F03] mov edx, [hys] 535 00000365 66A3[D400] mov [ly], eax 536 00000369 668916[D800] mov [hy], edx 537 538 ; 1.5) Initialise zoom parameters 539 0000036E C706[1300]00FC mov word [lfrac], 1024*63 540 00000374 C706[1500]0100 mov word [hfrac], 1 541 0000037A C606[1800]00 mov byte [ystart], 0 542 0000037F C606[1900]00 mov byte [xstart], 0 543 544 ; 2) Set up screen pointer 545 00000384 06 push es 546 00000385 A1[1100] mov ax, [fractalseg] 547 00000388 8EC0 mov es, ax 548 0000038A 66BF00000000 mov edi, 0 549 550 00000390 C706[3303]8000 mov word [ycount], FRACHEIGHT 551 FracYLoop: 552 553 00000396 C706[3503]0001 mov word [xcount], FRACWIDTH 554 FracXLoop: 555 556 ; 3) Calculate pixel 557 0000039C E83DFD call Calculate 558 559 ; 4) Draw pixel 560 0000039F 26678807 mov [es:edi], al 561 562 ; 5) Add X increment to X 563 000003A3 66A1[2303] mov eax, [lxi] 564 000003A7 668B16[2703] mov edx, [hxi] 565 000003AC 660106[CC00] add [lx], eax 566 000003B1 661116[D000] adc [hx], edx 567 568 ; 6) Increment screen poesition 569 000003B6 6647 inc edi 570 571 ; 7) If count >127, stop 572 000003B8 FF0E[3503] dec word [xcount] 573 000003BC 75DE jnz short FracXLoop 574 575 ; 8) Set X to xstart 576 000003BE 66A1[1303] mov eax, [lxs] 577 000003C2 668B16[1703] mov edx, [hxs] 578 000003C7 66A3[CC00] mov [lx], eax 579 000003CB 668916[D000] mov [hx], edx 580 581 ; 10) Add Y increment to Y 582 000003D0 66A1[2303] mov eax, [lxi] 583 000003D4 668B16[2703] mov edx, [hxi] 584 000003D9 660106[D400] add [ly], eax 585 000003DE 661116[D800] adc [hy], edx 586 587 ; 10.5) Draw zoomed last fractal if count%2==0 588 000003E3 A1[3303] mov ax, [ycount] 589 000003E6 2401 and al, 1 590 000003E8 754C jnz short notthistime 591 000003EA 06 push es 592 000003EB B800A0 mov ax, 0a000h 593 000003EE 8EC0 mov es, ax 594 ; Update zoom position 595 000003F0 C706[1E00]0000 mov word [yfracpos], 0 596 000003F6 A0[3903] mov al, [xdirection] 597 000003F9 0006[1900] add [xstart], al 598 000003FD 803E[3803]00 cmp byte [ydirection], 0 599 00000402 7421 je short normaltime 600 00000404 803E[3803]02 cmp byte [ydirection], 2 601 00000409 7506 jne short ydirection1 602 0000040B FE06[1800] inc byte [ystart] 603 0000040F EB14 jmp short normaltime 604 ydirection1: 605 00000411 F706[3303]0200 test word [ycount], 2 606 00000417 7406 jz short othertime 607 00000419 FE06[1800] inc byte [ystart] 608 0000041D EB06 jmp short normaltime 609 610 othertime: 611 0000041F C706[1E00]0080 mov word [yfracpos], 8000h 612 613 normaltime: 614 00000425 803E[3703]00 cmp byte [nodraw], 0 615 0000042A 7503 jne short dontdraw 616 0000042C E8F3FB call ZoomTexture 617 dontdraw: 618 0000042F 07 pop es 619 00000430 812E[1300]0004 sub word [lfrac], 1024 620 621 notthistime: 622 623 ; 11) If count>127, stop 624 00000436 FF0E[3303] dec word [ycount] 625 0000043A 0F8558FF jnz FracYLoop 626 627 0000043E 07 pop es 628 629 0000043F 665F pop edi 630 00000441 665E pop esi 631 00000443 665A pop edx 632 00000445 6659 pop ecx 633 00000447 665B pop ebx 634 00000449 6658 pop eax 635 0000044B C3 retn 636 637 ;==================================================================== 638 ; SWITCHTEXTURES - switch around the two buffers 639 ;-------------------------------------------------------------------- 640 641 ; This just changes the two buffers when one has been finished; so 642 ; that the new fractal becomes the one that gets drawn to screen, and 643 ; the old fractal will get written over by the one newly being 644 ; calculated. 645 646 ; This is a separate function, because if you decide to implement 647 ; the 25% saving described above, you'll need to copy over those 648 ; re-cycled pixels at some point, and this is a good time to do that. 649 650 ; Source_____________________________________________________________ 651 652 SwitchTextures: 653 0000044C 50 push ax 654 0000044D 53 push bx 655 656 0000044E A1[1100] mov ax, [fractalseg] 657 00000451 8B1E[0F00] mov bx, [textureseg] 658 00000455 891E[1100] mov [fractalseg], bx 659 00000459 A3[0F00] mov [textureseg], ax 660 661 0000045C 5B pop bx 662 0000045D 58 pop ax 663 0000045E C3 retn 664 665 ;==================================================================== 666 ;DOBACKGROUND - the background for lo-res part of demo 667 ;-------------------------------------------------------------------- 668 669 ; Just draws the swirly background things, very simple. 670 671 DoBackground: 672 0000045F 50 push ax 673 00000460 53 push bx 674 00000461 51 push cx 675 00000462 57 push di 676 677 00000463 06 push es 678 679 00000464 B800A0 mov ax, 0a000h 680 00000467 8EC0 mov es, ax 681 682 00000469 BB0000 mov bx, 0 ; bh=y, bl=x 683 684 0000046C 89DF mov di, bx ;0 685 0000046E B900FA mov cx, 64000 686 00000471 88D8 mov al, bl ;0 687 00000473 F3AA rep stosb 688 689 00000475 89DF mov di, bx ; 0 690 691 db_loop: 692 00000477 88F8 mov al, bh 693 00000479 F6E3 mul bl 694 0000047B 240F and al, 0fh 695 0000047D 0410 add al, 16 696 0000047F 268805 mov [es:di], al 697 00000482 47 inc di 698 00000483 43 inc bx 699 00000484 80FB00 cmp bl, 0 700 00000487 7503 jne short notnextline 701 00000489 83C740 add di, 320-256 702 notnextline: 703 0000048C 81FB00C1 cmp bx, 256*193 704 00000490 72E5 jb short db_loop 705 706 00000492 BE0000 mov si, 0 707 00000495 BF0001 mov di, 256 708 00000498 1E push ds 709 00000499 06 push es 710 0000049A 1F pop ds 711 0000049B BAC000 mov dx, 192 712 713 copy_loop: 714 0000049E B92000 mov cx, 32 715 000004A1 F3A5 rep movsw 716 000004A3 81C60001 add si, 320-64 717 000004A7 81C70001 add di, 320-64 718 000004AB 4A dec dx 719 000004AC 75F0 jnz short copy_loop 720 721 000004AE 1F pop ds 722 723 ;mov di, 256*193 724 ;mov cx, 8*320 725 ;mov al, 0 726 ;rep stosb 727 728 000004AF 07 pop es 729 730 000004B0 5F pop di 731 000004B1 59 pop cx 732 000004B2 5B pop bx 733 000004B3 58 pop ax 734 735 000004B4 C3 retn 736 737 ;==================================================================== 738 ;DRAWSQUARE - fills a square, for showing which way things are going 739 ;-------------------------------------------------------------------- 740 741 ; I won't bother explaining this, you can all manage to draw a square 742 ; by now... 743 744 DrawSquare: 745 000004B5 50 push ax 746 000004B6 52 push dx 747 000004B7 56 push si 748 000004B8 57 push di 749 000004B9 06 push es 750 751 000004BA 89C6 mov si, ax 752 000004BC B800A0 mov ax, 0a000h 753 000004BF 8EC0 mov es, ax 754 755 ; bh=starty, ax(now si)=startx 756 ; dx=width and height 757 ; cl=colour 758 000004C1 52 push dx 759 000004C2 89DF mov di, bx 760 000004C4 C1EF08 shr di, 8 761 000004C7 B84001 mov ax, 320 762 000004CA F7E7 mul di 763 000004CC 01F0 add ax, si 764 000004CE 89C7 mov di, ax 765 000004D0 5A pop dx 766 767 000004D1 88C8 mov al, cl 768 769 000004D3 89D6 mov si, dx 770 ds_yloop: 771 000004D5 89D1 mov cx, dx 772 000004D7 F3AA rep stosb 773 000004D9 81C74001 add di, 320 774 000004DD 29D7 sub di, dx 775 000004DF 4E dec si 776 000004E0 75F3 jnz short ds_yloop 777 778 000004E2 07 pop es 779 000004E3 5F pop di 780 000004E4 5E pop si 781 000004E5 5A pop dx 782 000004E6 58 pop ax 783 000004E7 C3 retn 784 785 ;==================================================================== 786 ;DRAWDIRECTIONSQUARES - draw the motion direction indicators 787 ;-------------------------------------------------------------------- 788 789 ; this is pretty trivial too. 790 791 DrawDirectionSquares: 792 000004E8 50 push ax 793 000004E9 53 push bx 794 000004EA 51 push cx 795 000004EB 52 push dx 796 000004EC 56 push si 797 000004ED 57 push di 798 799 ; Clear all squares 800 000004EE B700 mov bh, 0 ; was 16 801 000004F0 B80000 mov ax, 0 ; was 16 802 000004F3 B100 mov cl, 0 803 000004F5 BA2000 mov dx, 32 804 805 000004F8 BE0300 mov si, 3 806 dds_yloop: 807 000004FB BF0300 mov di, 3 808 dds_xloop: 809 000004FE 83FF02 cmp di, 2 810 00000501 7505 jne short dds_drawit 811 00000503 83FE02 cmp si, 2 812 00000506 7403 je short dds_skipit 813 814 dds_drawit: 815 00000508 E8AAFF call DrawSquare 816 817 dds_skipit: 818 0000050B 059000 add ax, 9*16 819 0000050E 4F dec di 820 0000050F 75ED jnz short dds_xloop 821 00000511 B80000 mov ax, 0 822 00000514 80C750 add bh, 5*16 823 00000517 4E dec si 824 00000518 75E1 jnz short dds_yloop 825 826 ; Draw chosen square 827 0000051A 803E[3B03]01 cmp byte [newydirection], 1 828 0000051F 7507 jne short drawchosen 829 00000521 803E[3A03]01 cmp byte [newxdirection], 1 830 00000526 742B je short afterchosen 831 832 drawchosen: 833 00000528 B400 mov ah, 0 834 0000052A A0[3B03] mov al, [newydirection] 835 0000052D 6BC050 imul ax, 5*16 836 00000530 88C7 mov bh, al 837 ;mov eax, 0 838 ;mov al, [newxdirection] 839 00000532 660FB606[3A03] movzx eax, byte [newxdirection] 840 00000538 BE9000 mov si, 9*16 841 0000053B F7E6 mul si 842 0000053D BA2000 mov dx, 32 ; square side length 843 00000540 B101 mov cl, 1 844 00000542 E870FF call DrawSquare 845 00000545 80C704 add bh, 4 846 00000548 83C004 add ax, 4 847 0000054B 83EA08 sub dx, 8 848 0000054E B100 mov cl, 0 849 00000550 E862FF call DrawSquare ; clear the inside 850 851 afterchosen: 852 ; Draw actual (current) square 853 00000553 803E[3803]01 cmp byte [ydirection], 1 854 00000558 7507 jne short drawcurrent 855 0000055A 803E[3903]01 cmp byte [xdirection], 1 856 0000055F 7425 je short aftercurrent 857 858 drawcurrent: 859 00000561 B400 mov ah, 0 860 00000563 A0[3803] mov al, [ydirection] 861 00000566 6BC050 imul ax ,5*16 862 00000569 83C000 add ax, 0 863 0000056C 88C7 mov bh, al 864 0000056E B400 mov ah, 0 865 00000570 A0[3903] mov al, [xdirection] 866 00000573 BE9000 mov si, 9*16 867 00000576 F7E6 mul si 868 00000578 80C704 add bh, 4 869 0000057B 83C004 add ax, 4 ; current square start now in bx. 870 0000057E BA1800 mov dx, 24 ; square side length 871 00000581 B102 mov cl, 2 872 00000583 E82FFF call DrawSquare 873 874 aftercurrent: 875 00000586 5F pop di 876 00000587 5E pop si 877 00000588 5A pop dx 878 00000589 59 pop cx 879 0000058A 5B pop bx 880 0000058B 58 pop ax 881 0000058C C3 retn 882 883 ;==================================================================== 884 ;DOFRACTALSECTION - the controllable fractals part of the demo 885 ;-------------------------------------------------------------------- 886 887 ; hopefully what with the background you have already read, this 888 ; routine is self-explanatory. 889 890 DoFractalSection: 891 ; Now setup fractal parameters 892 ; Start at preplanned position 893 0000058D 66C706[0703]000000- mov dword [hxcentre], 000000000h 894 00000595 00 895 00000596 66C706[0303]FFDFFA- mov dword [lxcentre], 04afadfffh 896 0000059E 4A 897 0000059F 66C706[0F03]FEFFFF- mov dword [hycentre], 0fffffffeh 898 000005A7 FF 899 000005A8 66C706[0B03]FFBF71- mov dword [lycentre], 08f71bfffh 900 000005B0 8F 901 902 ; and increment by 1/64 per pixel 903 000005B1 66C706[2703]000000- mov dword [hxi], 0 904 000005B9 00 905 000005BA 66C706[2303]000000- mov dword [lxi], 1024*65536 906 000005C2 04 907 000005C3 66C706[2F03]000000- mov dword [hyi], 0 908 000005CB 00 909 000005CC 66C706[2B03]000000- mov dword [lyi], 1024*65536 910 000005D4 04 911 912 000005D5 C706[3C03]6029 mov word [screenstart], 33*320+32 913 914 dfs_fracloop: 915 916 ; Calculate new hxcentre etc depending on xdirection,ydirection 917 ; (new position = FW/4*(xdirection+1),FH/4*(ydirection+1) on the display) 918 919 ; xcentre=xcentre+fw/4*(xdirection-1)*xi 920 000005DB 803E[3903]01 cmp byte [xdirection], 1 921 000005E0 742A je short xchangedone 922 000005E2 66BA80000000 mov edx, FRACWIDTH/2 923 000005E8 66A1[2303] mov eax, [lxi] 924 000005EC 66F7E2 mul edx 925 000005EF 803E[3903]02 cmp byte [xdirection], 2 926 000005F4 750C jne short xchangeminus 927 000005F6 660106[0303] add [lxcentre], eax 928 000005FB 661116[0703] adc [hxcentre], edx 929 00000600 EB0A jmp short xchangedone 930 xchangeminus: 931 00000602 662906[0303] sub [lxcentre], eax 932 00000607 661916[0703] sbb [hxcentre], edx 933 xchangedone: 934 935 ; Same for Y: 936 0000060C 803E[3803]01 cmp byte [ydirection], 1 937 00000611 742A je short ychangedone 938 00000613 66BA40000000 mov edx, FRACHEIGHT/2 939 00000619 66A1[2B03] mov eax, [lyi] 940 0000061D 66F7E2 mul edx 941 00000620 803E[3803]02 cmp byte [ydirection], 2 942 00000625 750C jne short ychangeminus 943 00000627 660106[0B03] add [lycentre], eax 944 0000062C 661116[0F03] adc [hycentre], edx 945 00000631 EB0A jmp short ychangedone 946 ychangeminus: 947 00000633 662906[0B03] sub [lycentre], eax 948 00000638 661916[0F03] sbb [hycentre], edx 949 ychangedone: 950 951 ; Calculate start hxs,lxs hys,lys to keep hxcentre in middle (at 128,128) 952 953 ; xs=xcentre-128*xi ys=ycentre-128*yi 954 0000063D 66A1[2303] mov eax, [lxi] 955 00000641 66BA80000000 mov edx, FRACWIDTH/2 956 00000647 66F7E2 mul edx 957 0000064A 6689C3 mov ebx, eax ; bx is l(xi*128) 958 0000064D 6689D1 mov ecx, edx ; cx is h(xi*128) 959 00000650 6683F3FF xor ebx, 0ffffffffh 960 00000654 6683F1FF xor ecx, 0ffffffffh 961 00000658 6641 inc ecx ; cx:bx now negative'd 962 0000065A 66031E[0303] add ebx, [lxcentre] 963 0000065F 66130E[0703] adc ecx, [hxcentre] 964 00000664 66891E[1303] mov [lxs], ebx 965 00000669 66890E[1703] mov [hxs], ecx 966 967 ; Same for Y: 968 0000066E 66A1[2B03] mov eax, [lyi] 969 00000672 66BA40000000 mov edx, FRACHEIGHT/2 970 00000678 66F7E2 mul edx 971 0000067B 6689C3 mov ebx, eax ; bx is l(xi*128) 972 0000067E 6689D1 mov ecx, edx ; cx is h(xi*128) 973 00000681 6683F3FF xor ebx, 0ffffffffh 974 00000685 6683F1FF xor ecx, 0ffffffffh 975 00000689 6641 inc ecx ; cx:bx now negative'd 976 0000068B 66031E[0B03] add ebx, [lycentre] 977 00000690 66130E[0F03] adc ecx, [hycentre] 978 00000695 66891E[1B03] mov [lys], ebx 979 0000069A 66890E[1F03] mov [hys], ecx 980 981 ; Calculate next fractal while we zoom the last one 982 0000069F E89CFC call Fractal 983 984 ; Switch the texture buffers, including copying 1/4 of the pixels 985 000006A2 E8A7FD call SwitchTextures 986 987 000006A5 803E[3703]01 cmp byte [nodraw], 1 988 000006AA 750B jne alreadydrawing 989 000006AC C606[3703]00 mov byte [nodraw], 0 990 000006B1 E8ABFD call DoBackground 991 000006B4 B90000 mov cx, 0 992 alreadydrawing: 993 994 ; Double magnification 995 000006B7 66A1[2303] mov eax, [lxi] 996 000006BB 668B16[2703] mov edx, [hxi] 997 000006C0 66D1E8 shr eax, 1 998 000006C3 66D1EA shr edx, 1 999 000006C6 66A3[2303] mov [lxi], eax 1000 000006CA 668916[2703] mov [hxi], edx 1001 000006CF 66A3[2B03] mov [lyi], eax 1002 000006D3 668916[2F03] mov [hyi], edx 1003 1004 ; Update direction 1005 000006D8 A0[3A03] mov al, [newxdirection] 1006 000006DB A2[3903] mov [xdirection], al 1007 000006DE A0[3B03] mov al, [newydirection] 1008 000006E1 A2[3803] mov [ydirection], al 1009 1010 000006E4 E801FE call DrawDirectionSquares 1011 1012 000006E7 E9F1FE jmp dfs_fracloop 1013 1014 dfs_keyhit: 1015 1016 000006EA E816F9 call Getch 1017 1018 000006ED 3C37 cmp al,'7' 1019 000006EF 750A jne short not7 1020 000006F1 C606[3A03]00 mov byte [newxdirection], 0 1021 000006F6 C606[3B03]00 mov byte [newydirection], 0 1022 not7: 1023 1024 000006FB 3C34 cmp al,'4' 1025 000006FD 750A jne short not4 1026 000006FF C606[3A03]00 mov byte [newxdirection], 0 1027 00000704 C606[3B03]01 mov byte [newydirection], 1 1028 not4: 1029 1030 00000709 3C31 cmp al,'1' 1031 0000070B 750A jne short not1 1032 0000070D C606[3A03]00 mov byte [newxdirection], 0 1033 00000712 C606[3B03]02 mov byte [newydirection], 2 1034 not1: 1035 1036 00000717 3C38 cmp al,'8' 1037 00000719 750A jne short not8 1038 0000071B C606[3A03]01 mov byte [newxdirection], 1 1039 00000720 C606[3B03]00 mov byte [newydirection], 0 1040 not8: 1041 1042 00000725 3C35 cmp al,'5' 1043 00000727 750A jne short not5 1044 00000729 C606[3A03]01 mov byte [newxdirection], 1 1045 0000072E C606[3B03]01 mov byte [newydirection], 1 1046 not5: 1047 1048 00000733 3C32 cmp al,'2' 1049 00000735 750A jne short not2 1050 00000737 C606[3A03]01 mov byte [newxdirection], 1 1051 0000073C C606[3B03]02 mov byte [newydirection], 2 1052 not2: 1053 1054 00000741 3C39 cmp al, '9' 1055 00000743 750A jne short not9 1056 00000745 C606[3A03]02 mov byte [newxdirection], 2 1057 0000074A C606[3B03]00 mov byte [newydirection], 0 1058 not9: 1059 1060 0000074F 3C36 cmp al, '6' 1061 00000751 750A jne short not6 1062 00000753 C606[3A03]02 mov byte [newxdirection], 2 1063 00000758 C606[3B03]01 mov byte [newydirection], 1 1064 not6: 1065 1066 0000075D 3C33 cmp al,'3' 1067 0000075F 750A jne not3 1068 00000761 C606[3A03]02 mov byte [newxdirection],2 1069 00000766 C606[3B03]02 mov byte [newydirection],2 1070 not3: 1071 1072 0000076B 3C1B cmp al, 27 1073 0000076D 0F84CC00 je breakout 1074 1075 00000771 E874FD call DrawDirectionSquares 1076 1077 donethecentrechange: 1078 00000774 E924F9 jmp zt_afterkeyhit 1079 1080 ;==================================================================== 1081 ;MAIN SECTION & MISC 1082 ;-------------------------------------------------------------------- 1083 1084 Init: 1085 00000777 50 push ax 1086 00000778 53 push bx 1087 ; 1) Setup ES segment 1088 00000779 B800A0 mov ax, 0a000h 1089 0000077C 8EC0 mov es, ax 1090 ; 2) Allocate RAM 1091 ; This is a COM program, so we just set the segments to spare 1092 ; space in memory. (well, hopefully spare space :) 1093 0000077E 0E push cs 1094 0000077F 58 pop ax 1095 00000780 050010 add ax, 4096 ; textureseg is 64k above our segment 1096 00000783 A3[0F00] mov [textureseg], ax 1097 00000786 050010 add ax, 4096 ; and fractalseg is 128k above 1098 00000789 A3[1100] mov [fractalseg], ax 1099 0000078C 2D0010 sub ax, 4096 1100 0000078F 2D0008 sub ax, 2048 ; enlargebuffer is 1/2 way through our segment. 1101 00000792 A3[0D00] mov [enlargebufferseg], ax 1102 ; 3) Do graphics mode 1103 00000795 B81300 mov ax, 0013h 1104 00000798 CD10 int 10h 1105 0000079A 5B pop bx 1106 0000079B 58 pop ax 1107 0000079C C3 retn 1108 1109 Shutdown: 1110 0000079D 50 push ax 1111 0000079E B80300 mov ax, 0003h 1112 000007A1 CD10 int 10h 1113 000007A3 58 pop ax 1114 000007A4 C3 retn 1115 1116 000007A5 5468616E6B7320666F- message db 'Thanks for watching the modified version of 4ge',39,'S XMaS 94 iNTRo.' 1117 000007AE 72207761746368696E- 1118 000007B7 6720746865206D6F64- 1119 000007C0 696669656420766572- 1120 000007C9 73696F6E206F662034- 1121 000007D2 6765275320584D6153- 1122 000007DB 20393420694E54526F- 1123 000007E4 2E 1124 000007E5 0D0A0D0A db 13,10,13,10 1125 000007E9 476574203467652D78- db 'Get 4ge-xmas.zip from ftp.cdrom.com for the full version, Tseng gfx only.',13,10,13,10,'$' 1126 000007F2 6D61732E7A69702066- 1127 000007FB 726F6D206674702E63- 1128 00000804 64726F6D2E636F6D20- 1129 0000080D 666F72207468652066- 1130 00000816 756C6C207665727369- 1131 0000081F 6F6E2C205473656E67- 1132 00000828 20676678206F6E6C79- 1133 00000831 2E0D0A0D0A24 1134 1135 Start: 1136 00000837 E83DFF call Init 1137 0000083A E850FD call DoFractalSection 1138 breakout: 1139 0000083D E85DFF call Shutdown 1140 00000840 B409 mov ah, 09h 1141 00000842 BA[A507] mov dx, message 1142 00000845 CD21 int 21h 1143 1144 00000847 CD20 int 20h 1145 1146 _end: 1147