143 lines
3.5 KiB
C
143 lines
3.5 KiB
C
/*
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* This file is part of the DXX-Rebirth project <http://www.dxx-rebirth.com/>.
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* It is copyright by its individual contributors, as recorded in the
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* project's Git history. See COPYING.txt at the top level for license
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* terms and a link to the Git history.
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*/
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/* Maths.h library header file */
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#ifndef _MATHS_H
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#define _MATHS_H
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#include <stdlib.h>
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#include "pstypes.h"
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#define D_RAND_MAX 32767
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#ifdef __cplusplus
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void d_srand (unsigned int seed);
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int d_rand (); // Random number function which returns in the range 0-0x7FFF
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//=============================== FIXED POINT ===============================
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typedef int64_t fix64; //64 bits int, for timers
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typedef int32_t fix; //16 bits int, 16 bits frac
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typedef int16_t fixang; //angles
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typedef struct quadint // integer 64 bit, previously called "quad"
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{
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u_int32_t low;
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int32_t high;
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}
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quadint;
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//Convert an int to a fix/fix64 and back
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#define i2f(i) ((i)<<16)
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#define f2i(f) ((f)>>16)
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//Get the int part of a fix, with rounding
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#define f2ir(f) (((f)+f0_5)>>16)
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//Convert fix to float and float to fix
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#define f2fl(f) (((float) (f)) / 65536.0)
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#define f2db(f) (((double) (f)) / 65536.0)
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#define fl2f(f) ((fix) ((f) * 65536))
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//Some handy constants
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#define f0_0 0
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#define f1_0 0x10000
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#define f2_0 0x20000
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#define f3_0 0x30000
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#define f10_0 0xa0000
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#define f0_5 0x8000
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#define f0_1 0x199a
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#define F0_0 f0_0
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#define F1_0 f1_0
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#define F2_0 f2_0
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#define F3_0 f3_0
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#define F10_0 f10_0
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#define F0_5 f0_5
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#define F0_1 f0_1
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//multiply two fixes, return a fix(64)
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fix fixmul (fix a, fix b);
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fix64 fixmul64 (fix a, fix b);
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//divide two fixes, return a fix
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fix fixdiv (fix a, fix b);
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//multiply two fixes, then divide by a third, return a fix
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fix fixmuldiv (fix a, fix b, fix c);
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//multiply two fixes, and add 64-bit product to a quadint
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void fixmulaccum (quadint * q, fix a, fix b);
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//extract a fix from a quadint product
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fix fixquadadjust (quadint * q);
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//divide a quadint by a long
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int32_t fixdivquadlong (u_int32_t qlow, u_int32_t qhigh, u_int32_t d);
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//negate a quadint
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void fixquadnegate (quadint * q);
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//computes the square root of a long, returning a short
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ushort long_sqrt (int32_t a);
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//computes the square root of a quadint, returning a long
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u_int32_t quad_sqrt (u_int32_t low, int32_t high);
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//unsigned long quad_sqrt (long low, long high);
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//computes the square root of a fix, returning a fix
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fix fix_sqrt (fix a);
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//compute sine and cosine of an angle, filling in the variables
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//either of the pointers can be NULL
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void fix_sincos (fix a, fix * s, fix * c); //with interpolation
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void fix_fastsincos (fix a, fix * s, fix * c); //no interpolation
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//compute inverse sine & cosine
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fixang fix_asin (fix v);
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fixang fix_acos (fix v);
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//given cos & sin of an angle, return that angle.
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//parms need not be normalized, that is, the ratio of the parms cos/sin must
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//equal the ratio of the actual cos & sin for the result angle, but the parms
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//need not be the actual cos & sin.
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//NOTE: this is different from the standard C atan2, since it is left-handed.
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fixang fix_atan2 (fix cos, fix sin);
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int checkmuldiv(fix *r,fix a,fix b,fix c);
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extern const ubyte guess_table[256];
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extern const short sincos_table[321];
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extern const ushort asin_table[258];
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extern const ushort acos_table[258];
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static inline void clamp_fix_lh(fix& f, const fix& low, const fix& high)
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{
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if (f < low)
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f = low;
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else if (high < f)
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f = high;
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}
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static inline void clamp_fix_symmetric(fix& f, const fix& bound)
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{
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clamp_fix_lh(f, -bound, bound);
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}
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#endif
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#endif
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