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    Types: TextFile
    Names: »zmath.c«

└─⟦a05ed705a⟧ Bits:30007078 DKUUG GNU 2/12/89
    └─⟦ff23ba0e6⟧ »./ghostscript-1.3.tar.Z« 
        └─⟦a24a58cd3⟧ 
            └─⟦this⟧ »zmath.c« 

TextFile

/* Copyright (C) 1989 Aladdin Enterprises.  All rights reserved.
   Distributed by Free Software Foundation, Inc.

This file is part of Ghostscript.

Ghostscript is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY.  No author or distributor accepts responsibility
to anyone for the consequences of using it or for whether it serves any
particular purpose or works at all, unless he says so in writing.  Refer
to the Ghostscript General Public License for full details.

Everyone is granted permission to copy, modify and redistribute
Ghostscript, but only under the conditions described in the Ghostscript
General Public License.  A copy of this license is supposed to have been
given to you along with Ghostscript so you can know your rights and
responsibilities.  It should be in a file named COPYING.  Among other
things, the copyright notice and this notice must be preserved on all
copies.  */

/* zmath.c */
/* Mathematical operators for GhostScript */
#include <math.h>
#include "ghost.h"
#include "errors.h"
#include "oper.h"
#include "store.h"

/* Imported from util.h */
extern int num_params(P3(ref *, int, float *));

/* Factors for converting between degrees and radians */
double degrees_to_radians = M_PI / 180.0;
double radians_to_degrees = 180.0 / M_PI;

/* Iteration count for random number generator */
private long rand_count;

/* Initialize the random number generator. */
void
zmath_init()
{	rand_count = 0;
	srand(1);
}

/****** NOTE: none of these operators currently ******/
/****** check for floating over- or underflow.	******/

/* sqrt */
int
zsqrt(register ref *op)
{	float num;
	int code = num_params(op, 1, &num);
	if ( code < 0 ) return code;
	if ( num < 0.0 ) return e_rangecheck;
	make_real(op, sqrt(num));
	return 0;
}

/* arccos */
int
zarccos(register ref *op)
{	float num, result;
	int code = num_params(op, 1, &num);
	if ( code < 0 ) return code;
	result = acos(num) * radians_to_degrees;
	make_real(op, result);
	return 0;
}

/* arcsin */
int
zarcsin(register ref *op)
{	float num, result;
	int code = num_params(op, 1, &num);
	if ( code < 0 ) return code;
	result = asin(num) * radians_to_degrees;
	make_real(op, result);
	return 0;
}

/* atan */
int
zatan(register ref *op)
{	float args[2];
	float result;
	int code = num_params(op, 2, args);
	if ( code < 0 ) return code;
	if ( args[0] == 0 )		/* on X-axis, special case */
	   {	if ( args[1] == 0 ) return e_undefinedresult;
		result = (args[1] < 0 ? 180 : 0);
	   }
	else
	   {	result = atan2(args[0], args[1]) * radians_to_degrees;
		/* Normalize quadrants by PostScript convention. */
		/* The result of atan2 is in the range (-pi..pi) */
		/* (we got rid of the endpoints above). */
		if ( result < 0 )
			{ do { result += 180; } while ( result < 0 ); }
		else	{ while ( result >= 180 ) result -= 180; }
		if ( args[0] < 0 ) result += 180;
	   }
	make_real(op - 1, result);
	pop(1);
	return 0;
}

/* cos */
int
zcos(register ref *op)
{	float angle;
	int code = num_params(op, 1, &angle);
	if ( code < 0 ) return code;
	make_real(op, cos(angle * degrees_to_radians));
	return 0;
}

/* sin */
int
zsin(register ref *op)
{	float angle;
	int code = num_params(op, 1, &angle);
	if ( code < 0 ) return code;
	make_real(op, sin(angle * degrees_to_radians));
	return 0;
}

/* exp */
int
zexp(register ref *op)
{	float args[2];
	float result;
	double frac;
	int code = num_params(op, 2, args);
	if ( code < 0 ) return code;
	if ( args[0] == 0.0 && args[1] == 0.0 ) return e_undefinedresult;
	if ( args[0] < 0.0 && (modf(args[1], &frac), frac != 0.0) )
		return e_undefinedresult;
	result = pow(args[0], args[1]);
	make_real(op - 1, result);
	pop(1);
	return 0;
}

/* ln */
int
zln(register ref *op)
{	float num;
	int code = num_params(op, 1, &num);
	if ( code < 0 ) return code;
	if ( num <= 0.0 ) return e_rangecheck;
	make_real(op, log(num));
	return 0;
}

/* log */
int
zlog(register ref *op)
{	float num;
	int code = num_params(op, 1, &num);
	if ( code < 0 ) return code;
	if ( num <= 0.0 ) return e_rangecheck;
	make_real(op, log10(num));
	return 0;
}

/* rand */
int
zrand(register ref *op)
{	long value;
	/* The Unix man page for rand suggests dropping the lowest bits, */
	/* so that's effectively what we do here. */
	value = (long)rand() << 21;
	value += (long)rand() << 10;
	value += rand() >> 3;
	value &= 0x7fffffff;
	push(1);
	make_int(op, value);
	return 0;
}

/* srand */
int
zsrand(register ref *op)
{	long niter;
	check_type(*op, t_integer);
	niter = op->value.intval;
	rand_count = niter;
	srand(1);
	while ( niter-- ) rand(), rand(), rand();
	pop(1);
	return 0;
}

/* rrand */
int
zrrand(register ref *op)
{	push(1);
	make_int(op, rand_count);
	return 0;
}

/* ------ Initialization procedure ------ */

void
zmath_op_init()
{	static op_def my_defs[] = {
		{"1arccos", zarccos},		/* extension */
		{"1arcsin", zarcsin},		/* extension */
		{"2atan", zatan},
		{"1cos", zcos},
		{"2exp", zexp},
		{"1ln", zln},
		{"1log", zlog},
		{"0rand", zrand},
		{"0rrand", zrrand},
		{"0sin", zsin},
		{"0sqrt", zsqrt},
		{"0srand", zsrand},
		op_def_end
	};
	z_op_init(my_defs);
}