view src/libm/k_cos.c @ 4447:947201caa46e

Added automated test to Xcode project plus needed changes to SDL_RWFromFile to be OS X bundle aware. The Mac OS X project has a new target called testsdl which builds the automated test. I looked at using Xcode's native unit test support, but the impedance mismatch between the existing automated test structure and Apple's was more than I could handle. As such, the testsdl application is a full blown proper OS X application, which means it is a self-contained .app bundle. This immediately revealed some problems from the automated test. The largest problem was the assumption about the current working directory and where to find resources. (I suspect Windows may have a similar problem depending on circumstance.) To open resources, the test was looking in directories relative to the SDL source directory, but this will not work well with self-contained .app bundles and Xcode which can place its built applications almost anywhere. And for real-world situations, this is pretty useless anyway. So I modified SDL_RWFromFile to do special things on OS X. First, it will look for a file in the .app bundle. If not found, it will fallback and just call fopen as it used to do. I also had to modify the automated test itself because it had a contrieved test which called fopen directly to do read from an existing FILE pointer. In addition, there was a write test. Since a .app bundle is likely going to be read-only, I added a special case for OS X to write to NSTemporaryDirectory. I expect these changes should work for both Mac and iPhone OS (which includes iPad). I will update the iPhone Xcode project next. Finally, FYI, the X11 automated test seems to be failing. Below is my output. Pending breakpoint 4 - "-[NSException raise]" resolved Platform : All tests successful (2) SDL_RWops : All tests successful (5) Rect : All tests successful (1) SDL_Surface : All tests successful (6) Rendering with cocoa driver : All tests successful (3) Assert Failed! Blit output not the same. Test Case 'Renderer x11' Test Suite 'Rendering with x11 driver' Last SDL error '' Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetSurfaceBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorFailure: Set a breakpoint @ CGErrorBreakpoint() to catch errors as they are logged. Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetWindowBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetSurfaceBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetWindowBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetSurfaceBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetWindowBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetSurfaceBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetWindowBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetSurfaceBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetWindowBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetSurfaceBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetWindowBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetSurfaceBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Rendering with x11 driver : Failed 1 out of 4 testcases! Rendering with dummy driver : All tests successful (3) SDL_Audio : All tests successful (1) Tests run with SDL 1.3.0 revision 1095906 System is running Mac OS X and is little endian
author Eric Wing <ewing . public |-at-| gmail . com>
date Sat, 08 May 2010 00:54:22 -0700
parents dc1eb82ffdaa
children
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/* @(#)k_cos.c 5.1 93/09/24 */
/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunPro, a Sun Microsystems, Inc. business.
 * Permission to use, copy, modify, and distribute this
 * software is freely granted, provided that this notice
 * is preserved.
 * ====================================================
 */

#if defined(LIBM_SCCS) && !defined(lint)
static const char rcsid[] =
    "$NetBSD: k_cos.c,v 1.8 1995/05/10 20:46:22 jtc Exp $";
#endif

/*
 * __kernel_cos( x,  y )
 * kernel cos function on [-pi/4, pi/4], pi/4 ~ 0.785398164
 * Input x is assumed to be bounded by ~pi/4 in magnitude.
 * Input y is the tail of x.
 *
 * Algorithm
 *	1. Since cos(-x) = cos(x), we need only to consider positive x.
 *	2. if x < 2^-27 (hx<0x3e400000 0), return 1 with inexact if x!=0.
 *	3. cos(x) is approximated by a polynomial of degree 14 on
 *	   [0,pi/4]
 *		  	                 4            14
 *	   	cos(x) ~ 1 - x*x/2 + C1*x + ... + C6*x
 *	   where the remez error is
 *
 * 	|              2     4     6     8     10    12     14 |     -58
 * 	|cos(x)-(1-.5*x +C1*x +C2*x +C3*x +C4*x +C5*x  +C6*x  )| <= 2
 * 	|    					               |
 *
 * 	               4     6     8     10    12     14
 *	4. let r = C1*x +C2*x +C3*x +C4*x +C5*x  +C6*x  , then
 *	       cos(x) = 1 - x*x/2 + r
 *	   since cos(x+y) ~ cos(x) - sin(x)*y
 *			  ~ cos(x) - x*y,
 *	   a correction term is necessary in cos(x) and hence
 *		cos(x+y) = 1 - (x*x/2 - (r - x*y))
 *	   For better accuracy when x > 0.3, let qx = |x|/4 with
 *	   the last 32 bits mask off, and if x > 0.78125, let qx = 0.28125.
 *	   Then
 *		cos(x+y) = (1-qx) - ((x*x/2-qx) - (r-x*y)).
 *	   Note that 1-qx and (x*x/2-qx) is EXACT here, and the
 *	   magnitude of the latter is at least a quarter of x*x/2,
 *	   thus, reducing the rounding error in the subtraction.
 */

#include "math.h"
#include "math_private.h"

#ifdef __STDC__
static const double
#else
static double
#endif
  one = 1.00000000000000000000e+00,     /* 0x3FF00000, 0x00000000 */
    C1 = 4.16666666666666019037e-02,    /* 0x3FA55555, 0x5555554C */
    C2 = -1.38888888888741095749e-03,   /* 0xBF56C16C, 0x16C15177 */
    C3 = 2.48015872894767294178e-05,    /* 0x3EFA01A0, 0x19CB1590 */
    C4 = -2.75573143513906633035e-07,   /* 0xBE927E4F, 0x809C52AD */
    C5 = 2.08757232129817482790e-09,    /* 0x3E21EE9E, 0xBDB4B1C4 */
    C6 = -1.13596475577881948265e-11;   /* 0xBDA8FAE9, 0xBE8838D4 */

#ifdef __STDC__
double attribute_hidden
__kernel_cos(double x, double y)
#else
double attribute_hidden
__kernel_cos(x, y)
     double x, y;
#endif
{
    double a, hz, z, r, qx;
    int32_t ix;
    GET_HIGH_WORD(ix, x);
    ix &= 0x7fffffff;           /* ix = |x|'s high word */
    if (ix < 0x3e400000) {      /* if x < 2**27 */
        if (((int) x) == 0)
            return one;         /* generate inexact */
    }
    z = x * x;
    r = z * (C1 + z * (C2 + z * (C3 + z * (C4 + z * (C5 + z * C6)))));
    if (ix < 0x3FD33333)        /* if |x| < 0.3 */
        return one - (0.5 * z - (z * r - x * y));
    else {
        if (ix > 0x3fe90000) {  /* x > 0.78125 */
            qx = 0.28125;
        } else {
            INSERT_WORDS(qx, ix - 0x00200000, 0);       /* x/4 */
        }
        hz = 0.5 * z - qx;
        a = one - qx;
        return a - (hz - (z * r - x * y));
    }
}