CydandClaude Fable 5
63312e07f9
- BORLAND/: Borland C++ 4.52 (chosen over 4.5 by byte-match: CODE/RP/CW32.LIB
is identical to 4.52's install lib). BCC32/TLINK32/TLIB/MAKE run natively on
Win11; CODE/BT/OPT.MAK is the shipped BTL4OPT.EXE's exact flag recipe
(extender = Borland PowerPack DPMI32, not Phar Lap TNT).
- restoration/source410/: the literal 1995-form reconstruction of the missing
BT game source (never mixed into CODE/). Round 1-3 state:
* 6 of 10 surviving original TUs COMPILE CLEAN under the period toolchain
(BTMSSN, BTCNSL, BTSCNRL, BTTEAM, BTL4MODE, BTL4ARND) - first builds
since 1996.
* BT_L4/BTL4APP.CPP pilot reconstruction: 12/12 functions, Fail() lands on
its binary-recorded line 400 exactly.
* BT/BTCNSL.HPP: console wire IDs recovered from the binary's ctors
(Killed=9, Damaged=10, ScoreUpdate=13, DeathWithoutHonor=15 [T1];
TeamScore=12 flagged [T4]).
* MUNGA/: 8 engine-header backfills back-dated from the BT412 WinTesla tree
(VDATA numbering decomp-verified; AUDREND's OpenAL-era virtual removed -
the period compiler is the drift detector).
* Tooling: backdate.py (WinTesla->1995 header transform), compile410.sh
(per-TU verification sweep under authentic OPT.MAK flags).
* README: corrected roadmap - MECH.HPP is the capstone grown with the mech
TU reconstructions; BTREG.CPP green = the header-family milestone.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
149 lines
4.3 KiB
Plaintext
149 lines
4.3 KiB
Plaintext
/*------------------------------------------------------------------------
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* filename - atan2.cas
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*
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* function(s)
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* atan2 - trigonometric function
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*-----------------------------------------------------------------------*/
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/*
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* C/C++ Run Time Library - Version 6.5
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*
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* Copyright (c) 1987, 1994 by Borland International
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* All Rights Reserved.
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*
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*/
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#pragma inline
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#include <asmrules.h>
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#include <_math.h>
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#include <math.h>
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#include <errno.h>
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static unsigned short piBy2 [] = {0xC235, 0x2168, 0xDAA2, 0xC90F, 0x3FFF};
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static unsigned short NANINVTRIG [4] = {0,0,0x0440, 0x7FF8};
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/*--------------------------------------------------------------------------*
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Name atan2 - trigonometric function
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Usage double atan2(double y, double x);
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Prototype in math.h
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Description atan2 returns the arc tangent of y/x and will produce
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correct results even when resulting is near pi/2 or -pi/2
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(x near 0).
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Return value atan2 returns a value in the range -pi to pi.
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If a ratio of 0/0 is supplied then _RANGE_VAL is returned
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and errno is set to:
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EDOM Domain error
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Caution: atan2(+0,-1) = +pi but atan2(-0,-1) = -pi.
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*---------------------------------------------------------------------------*/
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#pragma warn -use
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double _FARFUNC atan2( double y, double x )
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{
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asm FLD DOUBLE (x)
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asm mov ax, x [6] /* select MSW of x .. */
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asm and al, 0F0h /* ignore fraction */
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asm mov bx, y [6] /* .. and of y */
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asm and bl, 0F0h
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asm shl bx, 1 /* discard sign */
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asm FLD DOUBLE (y)
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asm jz at2_yIsZero
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asm shl ax, 1 /* discard sign */
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asm jz at2_xIsZero
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asm cmp ax, 0FFE0h
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asm jnb at2_xIsInf
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asm cmp bx, 0FFE0h
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asm jnb at2_yIsInf
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asm FDIVRP ST(1), ST(0)
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#ifdef _Windows
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_f87_ArcTan();
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#else
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asm _FAST_ (_FATAN_)
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#endif
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/* convert the simple answer to a four quadrant answer. */
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at2_setQuad:
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asm test BY0 (x [7]), 80h /* the sign bit */
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asm jz at2_end
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asm FLDPI
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asm test BY0 (y [7]), 80h
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asm jz at2_2ndQuad
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at2_3rdQuad:
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asm FSUBP ST(1), ST
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asm jmp short at2_end
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at2_2ndQuad:
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asm FADDP ST(1), ST
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at2_end:
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#pragma noretval
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return;
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/* Special cases.
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*/
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at2_yIsZero:
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asm rcl cx, 1 /* save sign of y = 0 */
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asm shl ax, 1
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asm jz at2_indeterminate /* if both are zero */
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asm jc at2_retPi /* x<0, return Pi */
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asm FSTP ST(1) /* else y is result */
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asm jmp short at2_end
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at2_retPi: /* y = 0, x < 0 */
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asm FSTP ST(0) /* discard x and y */
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asm FSTP ST(0)
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asm FLDPI /* and return PI */
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asm shr cx, 1 /* was y +0 or -0 ? */
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asm jnc at2_end
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asm FCHS
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asm jmp short at2_end
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at2_xIsZero: /* and y is not zero */
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/* or */
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at2_yIsInf: /* and x is finite */
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asm FSTP ST(0) /* discard x and y */
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asm FSTP ST(0)
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asm FLD tbyte ptr (piBy2)
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asm test BY0 (y [7]), 80h /* check sign of Y */
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asm jz at2_HPi /* positive - return PI/2 */
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asm FCHS /* negative - return -PI/2 */
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at2_HPi:
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asm jmp short at2_end
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at2_xIsInf:
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asm cmp bx, 0FFE0h
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asm jnb at2_indeterminate /* if both are infinite */
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asm FSTP ST(0) /* discard x and y */
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asm FSTP ST(0)
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asm FLDZ
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asm jmp short at2_setQuad
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/*
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There are two cases considered irresolvable: both operands zero, or
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both operands infinite.
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*/
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at2_indeterminate: /* either equal or both infinite */
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asm FSTP ST(0) /* discard x and y */
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asm FSTP ST(0)
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#pragma warn -ret
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return __matherr (DOMAIN, "atan2", &x, &y, *((double *) NANINVTRIG));
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#pragma warn .ret
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}
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#pragma warn .use
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