ref: 2c0d5e026f50ae4f2a069b882a598e9a8a4d553b
dir: /us.asm/
IDEAL MODEL MEDIUM,C ; Assembly portion of the User Mgr. This is just John Carmack's table ; driven pseudo-random number generator, and we put it in the User Mgr ; because we couldn't figure out where it should go ;============================================================================ ; ; RANDOM ROUTINES ; ;============================================================================ FARDATA rndindex dw ? rndtable db 0, 8, 109, 220, 222, 241, 149, 107, 75, 248, 254, 140, 16, 66 db 74, 21, 211, 47, 80, 242, 154, 27, 205, 128, 161, 89, 77, 36 db 95, 110, 85, 48, 212, 140, 211, 249, 22, 79, 200, 50, 28, 188 db 52, 140, 202, 120, 68, 145, 62, 70, 184, 190, 91, 197, 152, 224 db 149, 104, 25, 178, 252, 182, 202, 182, 141, 197, 4, 81, 181, 242 db 145, 42, 39, 227, 156, 198, 225, 193, 219, 93, 122, 175, 249, 0 db 175, 143, 70, 239, 46, 246, 163, 53, 163, 109, 168, 135, 2, 235 db 25, 92, 20, 145, 138, 77, 69, 166, 78, 176, 173, 212, 166, 113 db 94, 161, 41, 50, 239, 49, 111, 164, 70, 60, 2, 37, 171, 75 db 136, 156, 11, 56, 42, 146, 138, 229, 73, 146, 77, 61, 98, 196 db 135, 106, 63, 197, 195, 86, 96, 203, 113, 101, 170, 247, 181, 113 db 80, 250, 108, 7, 255, 237, 129, 226, 79, 107, 112, 166, 103, 241 db 24, 223, 239, 120, 198, 58, 60, 82, 128, 3, 184, 66, 143, 224 db 145, 224, 81, 206, 163, 45, 63, 90, 168, 114, 59, 33, 159, 95 db 28, 139, 123, 98, 125, 196, 15, 70, 194, 253, 54, 14, 109, 226 db 71, 17, 161, 93, 186, 87, 244, 138, 20, 52, 123, 251, 26, 36 db 17, 46, 52, 231, 232, 76, 31, 221, 84, 37, 216, 165, 212, 106 db 197, 242, 98, 43, 39, 175, 254, 145, 190, 84, 118, 222, 187, 136 db 120, 163, 236, 249 PUBLIC rndtable CODESEG LastRnd dw ? ;================================================= ; ; void US_InitRndT (int randomize) ; Init table based RND generator ; if randomize is false, the counter is set to 0 ; ;================================================= PROC US_InitRndT randomize:word uses si,di public US_InitRndT mov ax,SEG rndtable mov es,ax mov ax,[randomize] or ax,ax jne @@timeit ;if randomize is true, really random mov dx,0 ;set to a definite value jmp @@setit @@timeit: mov ah,2ch int 21h ;GetSystemTime and dx,0ffh @@setit: mov [es:rndindex],dx ret ENDP ;================================================= ; ; int US_RndT (void) ; Return a random # between 0-255 ; Exit : AX = value ; ;================================================= PROC US_RndT public US_RndT mov ax,SEG rndtable mov es,ax mov bx,[es:rndindex] inc bx and bx,0ffh mov [es:rndindex],bx mov al,[es:rndtable+BX] xor ah,ah ret ENDP END