This repository has been archived by the owner on Nov 29, 2023. It is now read-only.
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathR2IMGASM.ASM
executable file
·1208 lines (916 loc) · 26.1 KB
/
R2IMGASM.ASM
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
.486
.MODEL flat
LOCALS
.DATA
EXTRN _PITCH:DWORD,_SCREENX:DWORD,_SCREENY:DWORD
IMG STRUC
type dd 2
size dd ?
xw dd ?
yw dd ?
IMG ENDS
.CODE
PUBLIC _drawimager2,_loadpalette8,_loadpalette6,_drawrect,_drawrectmap
PUBLIC _drawhline,_drawvline,_drawscr
;;QUAD PALETTES!!!!!
;sets an 6-bit palette
_loadpalette6 PROC NEAR
ARG @@PAL:DWORD,@@FIRST:DWORD,@@CNT:DWORD
push ebp
mov ebp,esp
push esi
mov esi,@@PAL
mov eax,@@FIRST
mov ecx,@@CNT
mov edx,3C8h
out dx,al ;Set first
inc dx
@@LP: mov al,[esi+2]
out dx,al
mov al,[esi+1]
out dx,al
mov al,[esi+0]
out dx,al
add esi,4
dec ecx
jnz @@LP
pop esi
pop ebp
ret
_loadpalette6 ENDP
;sets a 8-bit palette (converting it to 6bit)
_loadpalette8 PROC NEAR
ARG @@PAL:DWORD,@@FIRST:DWORD,@@CNT:DWORD
push ebp
mov ebp,esp
push esi
mov esi,@@PAL
mov eax,@@FIRST
mov ecx,@@CNT
mov edx,3C8h
out dx,al ;Set first
cld
inc dx
@@LP: mov al,[esi+2]
shr al,2
out dx,al
mov al,[esi+1]
shr al,2
out dx,al
mov al,[esi+0]
shr al,2
out dx,al
add esi,4
dec ecx
jnz @@LP
pop esi
pop ebp
ret
_loadpalette8 ENDP
;void drawimager2(IMG *src,char *dest,int x,int y,int o)
_drawimager2 PROC
ARG @@SRC,@@DEST,@@X,@@Y,@@O
push ebp
mov ebp,esp
push ebx
push esi
push edi
mov esi,[@@SRC] ;source IMG
mov edi,[@@DEST] ;dest
test esi,esi
jz @@DONE
;do clip testing
xor eax,eax
mov ecx,@@X
mov edx,@@Y
add ecx,[esi.xw] ;right extent of image
add edx,[esi.yw] ;bottom extent of image
cmp [@@X],eax ;left clip
jl drawimager2clip
cmp [_SCREENX],ecx ;right clip
jl drawimager2clip
cmp [@@Y],eax ;top clip
jl drawimager2clip
cmp [_SCREENY],edx ;bottom clip
jl drawimager2clip
;point to memory for dest
mov eax,_PITCH
mul @@Y
add eax,@@X
add edi,eax
;test x flip
test [@@O],2
jnz @@XFLIP
call drawr2
jmp @@DONE
@@XFLIP:call drawr2_xflip
@@DONE:
pop edi
pop esi
pop ebx
pop ebp
ret
_drawimager2 ENDP
;image drawing prep function
;determines clipping values and calls clip core function
drawimager2clip PROC
ARG @@SRC,@@DEST,@@X,@@Y,@@O
xor ebx,ebx
;top clip
xor eax,eax
cmp [@@Y],eax
jg @@NOTOP
cmp edx,eax ;top edge is <0
jle @@DONE
sub eax,@@Y ;ystart=0-Y
mov @@Y,ebx ;Y=0
@@NOTOP: push eax ;store YSTART
;bottom clip
mov eax,[esi.yw]
sub edx,[_SCREENY]
jle @@NOBOTTOM
sub eax,edx ;ylen=SCREENY-Y
jle @@DONE
@@NOBOTTOM:
sub eax,[esp] ;ylen-=ystart
push eax ;store YLEN
;left clip
xor eax,eax
cmp [@@X],eax
jg @@NOLEFT
cmp ecx,eax ;right edge is <0
jle @@DONE
sub eax,@@X ;xstart=0-X
mov [@@X],ebx ;X=0
@@NOLEFT: push eax ;store XSTART
;right clip
mov eax,[esi.xw]
sub ecx,[_SCREENX]
jle @@NORIGHT
sub eax,ecx
jle @@DONE
@@NORIGHT:
sub eax,[esp] ;xlen-=xstart
push eax ;store XLEN
push @@O
;point to memory for dest
mov eax,_PITCH
push eax
mul @@Y
add eax,@@X
add edi,eax
;test x flip
test [@@O],2
jnz @@XFLIP
call drawr2_xyclip
jmp @@DONE
@@XFLIP:call drawr2_xyclip_xflip
@@DONE: lea esp,[ebp-3*4]
pop edi
pop esi
pop ebx
pop ebp
ret
drawimager2clip ENDP
;-------------------------------------------------
;core image drawing routine
;no clipping
;y flipping
drawr2 PROC
ARG @@SRC,@@DEST,@@X,@@Y,@@O
;negate diskip if yflip
mov eax,@@O
mov ebp,_PITCH
test eax,1b ;yflip
jz @@NOYFLIP
mov eax,[esi.yw] ;ywidth
dec eax
mul ebp
add edi,eax ;point to last scanline
neg ebp
@@NOYFLIP:
;get image dimensions
mov ebx,[esi.xw] ;xwidth
mov edx,[esi.yw] ;ywidth
sub ebp,ebx ;ebp=diskip
xor eax,eax
xor ecx,ecx
;point to data
lea esi,[esi+edx*4+16]
@@YLOOP:
push ebx ;save xwidth
@@XLOOP:
;transparent
mov al,[esi]
inc esi
add edi,eax
sub ebx,eax
jle @@DONELINE
;opaque
mov al,[esi]
inc esi
xor ecx,ecx
sub ebx,eax
;---------------------------------
;copy forward esi->edi, eax bytes ecx=0
sub ecx,edi ;amount to pre-copy
and ecx, 3
sub eax, ecx
jle short @@ENDCOPY
rep movsb
mov ecx, eax ;main copy
and eax, 3
shr ecx, 2
rep movsd
@@ENDCOPY: add ecx, eax ;end copy
xor eax,eax
rep movsb
;done copy
;--------------------------------
test ebx,ebx
jg @@XLOOP
@@DONELINE:
pop ebx ;restore xwidth
add edi,ebp ;position to next line
dec edx
jnz @@YLOOP
ret
@@DONE: pop ebx
ret
drawr2 ENDP
;core image drawing routine
;no clipping
;y flipping
drawr2_xflip PROC
ARG @@SRC,@@DEST,@@X,@@Y,@@O
;negate diskip if yflip
mov eax,@@O
mov ebp,_PITCH
test eax,1b ;yflip
jz @@NOYFLIP
mov eax,[esi.yw] ;ywidth
dec eax
mul ebp
add edi,eax ;point to last scanline
neg ebp
@@NOYFLIP:
;get image dimensions
mov ebx,[esi.xw] ;xwidth
mov edx,[esi.yw] ;ywidth
;point to data
lea esi,[esi+edx*4+16]
add ebp,ebx ;ebp=diskip (add cause we're flipped)
add edi,ebx ;point to end of scanline to copy leftwards
xor eax,eax
xor ecx,ecx
@@YLOOP:
push ebx ;save xwidth
@@XLOOP:
;transparent
mov al,[esi]
inc esi
sub edi,eax
sub ebx,eax
jle @@DONELINE
;opaque
mov al,[esi]
inc esi
sub ebx,eax
;copy backward esi->edi, ecx bytes
;@@COPY: dec edi
; mov al,[esi]
; inc esi
; mov [edi],al
; dec ecx
; jnz @@COPY
;;;backwards memory copy! esi->~edi ecx=count
;;precopy
mov ecx,edi
and ecx, 3
jz @@NOC1
sub eax, ecx
jle short @@LEndBytes
push eax
@@C1: dec edi
mov al,[esi] ; rep movsb
inc esi
mov [edi],al
dec ecx
jg @@C1
pop eax
;;copy
@@NOC1: mov ecx, eax
and eax, 3
shr ecx, 2
jz @@LEndBytes ;rep movsd
push eax
@@COPY: sub edi,4
mov eax,[esi]
add esi,4
bswap eax
dec ecx
mov [edi],eax
jnz @@COPY
pop eax
;;postcopy
@@LEndBytes: add ecx, eax
jle @@DONEC3 ; rep movsb
@@C3: dec edi
mov al,[esi] ; rep movsb
inc esi
mov [edi],al
dec ecx
jg @@C3
@@DONEC3:
;;------------------------------------
xor eax,eax
test ebx,ebx
jg @@XLOOP
@@DONELINE:
pop ebx ;restore xwidth
add edi,ebp ;position to next line
dec edx
jnz @@YLOOP
ret
@@DONE: pop ebx
ret
drawr2_xflip ENDP
;core image drawing routine
;xy clipping
;y flipping
drawr2_xyclip PROC
ARG @@DISKIP,@@O,@@XLEN,@@XSTART,@@YLEN,@@YSTART
push ebp
mov ebp,esp
;negate diskip if yflip
mov eax,@@O
test eax,1b ;yflip
jz @@NOYFLIP
mov eax,[esi.yw]
sub eax,@@YLEN
sub eax,@@YSTART
mov @@YSTART,eax
mov eax,[@@YLEN] ;ywidth
dec eax
mul [@@DISKIP]
add edi,eax ;point to last scanline
neg [@@DISKIP]
@@NOYFLIP:
xor eax,eax
xor ecx,ecx
push esi ;save @@SRC
@@YLOOP:
;point to source scanline
pop esi ;esi=@@SRC
mov ebx,[@@YSTART]
push esi
add esi,[esi+ebx*4+16]
inc [@@YSTART]
;get image dimensions
mov ebx,@@XLEN ;number of pixels to draw horizontally
mov edx,@@XSTART ;number of pixels to skip per scanline before drawing
push edi ;save dest
@@XLOOP:
;------------------------------------------------
;skip through XSTART
test edx,edx
jle @@PHASE2
@@PHASE1:
;transparent
@@T1: mov al,[esi]
inc esi
sub edx,eax
jle @@T1DONE
;opaque
@@O1: mov al,[esi]
inc esi
add esi,eax
sub edx,eax
jg @@PHASE1
;opaque phase 1 completed
xor ecx,ecx
add esi,edx ;scoot back left
sub ecx,edx ;eax=-edx (amt left to copy)
jmp @@O2
@@T1DONE: ;transparent phase 1 completed
sub edi,edx
add ebx,edx
jle @@DONELINE
mov cl,[esi] ;resume at opaque phase2
inc esi
jmp @@O2
;------------------------------------------------
;draw through XLEN
@@PHASE2:
;transparent
mov al,[esi]
inc esi
add edi,eax
sub ebx,eax
jle @@DONELINE
;opaque
mov cl,[esi]
inc esi
@@O2: sub ebx,ecx ;if ebx<0 ecx+=ebx
jg @@NORIGHTCLIP
add ecx,ebx
@@NORIGHTCLIP:
; rep movsb
;---------------------------------
;copy forward esi->edi, eax bytes ecx=0
mov eax,ecx
sub ecx,edi ;amount to pre-copy
sub ecx,eax
and ecx, 3
sub eax, ecx
jle short @@ENDCOPY
rep movsb
mov ecx, eax ;main copy
and eax, 3
shr ecx, 2
rep movsd
@@ENDCOPY: add ecx, eax ;end copy
xor eax,eax
rep movsb
;done copy
;--------------------------------
test ebx,ebx
jg @@PHASE2
@@DONELINE:
pop edi ;restore dest
add edi,@@DISKIP ;position to next line
dec [@@YLEN]
jnz @@YLOOP
@@DONE: pop esi
pop ebp
ret 6*4 ;return and pop
drawr2_xyclip ENDP
;core image drawing routine
;xy clipping
;xy flipping
drawr2_xyclip_xflip PROC
ARG @@DISKIP,@@O,@@XLEN,@@XSTART,@@YLEN,@@YSTART
push ebp
mov ebp,esp
mov eax,[esi.xw] ;ax=xlength
sub eax,@@XLEN
sub eax,@@XSTART
mov @@XSTART,eax
;negate diskip if yflip
mov eax,@@O
test eax,1b ;yflip
jz @@NOYFLIP
mov eax,[esi.yw]
sub eax,@@YLEN
sub eax,@@YSTART
mov @@YSTART,eax
mov eax,[@@YLEN] ;ywidth
dec eax
mul [@@DISKIP]
add edi,eax ;point to last scanline
neg [@@DISKIP]
@@NOYFLIP:
xor eax,eax
xor ecx,ecx
add edi,@@XLEN ;point to end of scanline to copy leftwards
push esi ;save @@SRC
@@YLOOP:
;point to source scanline
pop esi ;esi=@@SRC
mov ebx,[@@YSTART]
push esi
add esi,[esi+ebx*4+16]
inc [@@YSTART]
;get image dimensions
mov ebx,@@XLEN ;number of pixels to draw horizontally
mov edx,@@XSTART ;number of pixels to skip per scanline before drawing
push edi ;save dest
@@XLOOP:
;------------------------------------------------
;skip through XSTART
test edx,edx
jle @@PHASE2
@@PHASE1:
;transparent
@@T1: mov al,[esi]
inc esi
sub edx,eax
jle @@T1DONE
;opaque
@@O1: mov al,[esi]
inc esi
add esi,eax
sub edx,eax
jg @@PHASE1
;opaque phase 1 completed
xor ecx,ecx
add esi,edx ;scoot back left
sub ecx,edx ;eax=-edx (amt left to copy)
jmp @@O2
@@T1DONE: ;transparent phase 1 completed
add edi,edx
add ebx,edx
jle @@DONELINE
mov cl,[esi] ;resume at opaque phase2
inc esi
jmp @@O2
;------------------------------------------------
;draw through XLEN
@@PHASE2:
;transparent
mov al,[esi]
inc esi
sub edi,eax
sub ebx,eax
jle @@DONELINE
;opaque
mov cl,[esi]
inc esi
@@O2: sub ebx,ecx ;if ebx<0 ecx+=ebx
jg @@NORIGHTCLIP
add ecx,ebx
@@NORIGHTCLIP:
test ecx,ecx
jle @@NOCOPY
;copy backward esi->edi, ecx bytes
@@COPY: dec edi
mov al,[esi]
inc esi
mov [edi],al
dec ecx
jnz @@COPY
@@NOCOPY:
test ebx,ebx
jg @@PHASE2
@@DONELINE:
pop edi ;restore dest
add edi,@@DISKIP ;position to next line
dec [@@YLEN]
jnz @@YLOOP
@@DONE: pop esi
pop ebp
ret 6*4 ;return and pop
drawr2_xyclip_xflip ENDP
_drawhline PROC
ARG @@DEST,@@COLOR,@@X,@@Y,@@X2
push ebp
mov ebp,esp
push edi
;vertical clipping
mov eax,@@Y
test eax,eax
jl @@DONE
cmp eax,_SCREENY
jge @@DONE
mov eax,@@X
cmp eax,_SCREENX
jge @@DONE
test eax,eax
jge @@NOLEFTCLIP
xor eax,eax
@@NOLEFTCLIP:
mov ecx,@@X2
test ecx,ecx
jl @@DONE
cmp ecx,_SCREENX
jl @@NORIGHTCLIP
mov ecx,_SCREENX
dec ecx
@@NORIGHTCLIP:
;inc ecx
sub ecx,eax ;;get length
jle @@DONE
;get pointer to dest
mov edi,@@DEST
add edi,eax
mov eax,@@Y
mul _PITCH
add edi,eax
;set up storing word
mov al,byte ptr @@COLOR
mov ah,al
mov edx,eax
shl eax,16
mov ax,dx
; rep stosb
;---------------------------------
;copy forward esi->edi, eax bytes ecx=0
mov edx,ecx
sub ecx,edi ;amount to pre-copy
sub ecx,edx
and ecx, 3
sub edx, ecx
jle short @@ENDCOPY
rep stosb
mov ecx, edx ;main copy
and edx, 3
shr ecx, 2
rep stosd
@@ENDCOPY: add ecx, edx ;end copy
rep stosb
;done store
;--------------------------------
@@DONE:
pop edi
pop ebp
ret
_drawhline ENDP
_drawvline PROC
ARG @@DEST,@@COLOR,@@X,@@Y,@@Y2
push ebp
mov ebp,esp
push edi
;horiz clipping
mov eax,@@X
test eax,eax
jl @@DONE
cmp eax,_SCREENX
jge @@DONE
mov eax,@@Y
cmp eax,_SCREENY
jg @@DONE
test eax,eax
jg @@NOTOPCLIP
xor eax,eax
@@NOTOPCLIP:
mov ecx,@@Y2
test ecx,ecx
jl @@DONE
cmp ecx,_SCREENY
jl @@NOBOTTOMCLIP
mov ecx,_SCREENY
dec ecx
@@NOBOTTOMCLIP:
;inc ecx
sub ecx,eax ;;get length
jle @@DONE
;get pointer to dest
mov edi,@@DEST
mul _PITCH
add edi,eax
add edi,@@X
;set up storing word
mov al,byte ptr @@COLOR
mov edx,[_PITCH]
@@LP: mov [edi],al
add edi,edx
dec ecx
jnz @@LP
@@DONE:
pop edi
pop ebp
ret
_drawvline ENDP
_drawrect PROC
ARG @@B:DWORD,@@COLOR:DWORD,@@X:DWORD,@@Y:DWORD,@@XW:DWORD,@@YW:DWORD
push ebp
mov ebp,esp
push ebx
push edi
mov eax,_SCREENX
cmp [@@X],eax
jge @@DONE
mov eax,_SCREENY
cmp [@@Y],eax
jge @@DONE
mov eax,_SCREENX
mov ebx,@@X
add ebx,@@XW
cmp ebx,eax
jl @@NOXO
sub eax,@@X
mov @@XW,eax
@@NOXO:
mov eax,_SCREENY
mov ebx,@@Y
add ebx,@@YW
cmp ebx,eax
jl @@NOYO
sub eax,@@Y
mov @@YW,eax
@@NOYO:
cmp @@X,0
jge @@NOXU
mov eax,@@X
add [@@XW],eax
mov @@X,0
@@NOXU:
cmp @@Y,0
jge @@NOYU
mov eax,@@Y
add [@@YW],eax
mov @@Y,0
@@NOYU:
cmp [@@XW],0
jle @@DONE
cmp [@@YW],0
jle @@DONE
mov eax,@@Y
mul _PITCH
add eax,@@X
mov edi,@@B
add edi,eax
mov ebx,@@COLOR
mov al,bl
shl eax,8
mov al,bl
shl eax,8
mov al,bl
shl eax,8
mov al,bl
cld
@@YLOOP:
mov ecx, @@XW
;---------------------------------
;copy forward esi->edi, eax bytes ecx=0
mov edx,ecx
sub ecx,edi ;amount to pre-copy
sub ecx,edx
and ecx, 3
sub edx, ecx
jle short @@ENDCOPY
rep stosb
mov ecx, edx ;main copy
and edx, 3
shr ecx, 2
rep stosd
@@ENDCOPY: add ecx, edx ;end copy
rep stosb
;done store
;--------------------------------
add edi,_PITCH
sub edi,@@XW
dec @@YW
jg @@YLOOP
@@DONE:
pop edi
pop ebx
pop ebp
ret
_drawrect ENDP
;draw rectangle with color mapping
_drawrectmap PROC
ARG @@B:DWORD,@@MAP:DWORD,@@X:DWORD,@@Y:DWORD,@@XW:DWORD,@@YW:DWORD
push ebp
mov ebp,esp
push ebx
push esi
push edi
mov eax,_SCREENX
cmp [@@X],eax
jge @@DONE
mov eax,_SCREENY
cmp [@@Y],eax
jge @@DONE
mov eax,_SCREENX
mov ebx,@@X
add ebx,@@XW
cmp ebx,eax
jl @@NOXO
sub eax,@@X
mov @@XW,eax
@@NOXO:
mov eax,_SCREENY
mov ebx,@@Y
add ebx,@@YW
cmp ebx,eax
jl @@NOYO
sub eax,@@Y
mov @@YW,eax
@@NOYO:
cmp @@X,0
jge @@NOXU
mov eax,@@X
add [@@XW],eax
mov @@X,0
@@NOXU:
cmp @@Y,0
jge @@NOYU
mov eax,@@Y
add [@@YW],eax
mov @@Y,0
@@NOYU:
cmp [@@XW],0