Mercurial > sdl-ios-xcode
view README.WinCE @ 2752:edd2839b36f7
http://sources.redhat.com/ml/newlib/2002/msg00230.html
Stephen L Moshier wrote:
>
> pow(x,y) returns 0 when x is very close to -1.0 and y is very large.
> The following test program prints
>
> pow(1.0000000000000002e+00 4.5035996273704970e+15) = 2.7182818284590455e+00
> pow(-1.0000000000000002e+00 4.5035996273704970e+15) =0.0000000000000000e+00
> pow(9.9999999999999978e-01 4.5035996273704970e+15) = 3.6787944117144222e-01
> pow(-9.9999999999999978e-01 4.5035996273704970e+15) = 0.0000000000000000e+00
>
> which is incorrect for the negative arguments raised to an odd integer
> power.
>
> -----
> double pow (double, double);
>
> int
> main ()
> {
> double x, y, z;
>
> x = 1.0 + pow (2.0, -52.0);
> y = 1.0 + pow (2.0, 52.0);
> z = pow (x, y);
> printf ("pow(%.16e %.16e) = %.16e\n", x, y, z);
> x = -x;
> z = pow (x, y);
> printf ("pow(%.16e %.16e) = %.16e\n", x, y, z);
> x = 1.0 - pow (2.0, -52.0);
> z = pow (x, y);
> printf ("pow(%.16e %.16e) = %.16e\n", x, y, z);
> x = -x;
> z = pow (x, y);
> printf ("pow(%.16e %.16e) = %.16e\n", x, y, z);
> }
> -----
>
> Here is a patch for newlib/libm/math/epow.c:
Patch checked in and duplicated for ef_pow.c. Thanks.
-- Jeff J.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Mon, 15 Sep 2008 04:31:30 +0000 |
parents | 86d0d01290ea |
children |
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Project files for embedded Visual C++ 3.0, 4.0 and Visual Studio 2005 can be found in VisualCE.zip SDL supports GAPI and WinDib output for Windows CE. GAPI driver supports: - all possible WinCE devices (Pocket PC, Smartphones, HPC) with different orientations of video memory and resolutions. - 4, 8 and 16 bpp devices - special handling of 8bpp on 8bpp devices - VGA mode, you can even switch between VGA and GAPI in runtime (between 240x320 and 480x640 for example). On VGA devices you can use either GAPI or VGA. - Landscape mode and automatic rotation of buttons and stylus coordinates. To enable landscape mode make width of video screen bigger than height. For example: SDL_SetVideoMode(320,240,16,SDL_FULLSCREEN) - WM2005 - SDL_ListModes NOTE: There are several SDL features not available in the WinCE port of SDL. - DirectX is not yet available - Semaphores are not available - Joystick support is not available - CD-ROM control is not available In addition, there are several features that run in "degraded" mode: Preprocessor Symbol Effect =================== ================================= SDL_systimer.c: USE_GETTICKCOUNT Less accurate values for SDL time functions USE_SETTIMER Use only a single marginally accurate timer SDL_syswm.c: DISABLE_ICON_SUPPORT Can't set the runtime window icon SDL_sysmouse.c: USE_STATIC_CURSOR Only the arrow cursor is available SDL_sysevents.c: NO_GETKEYBOARDSTATE Can't get modifier state on keyboard focus SDL_dibevents.c: NO_GETKEYBOARDSTATE Very limited keycode translation SDL_dibvideo.c: NO_GETDIBITS Can't distinguish between 15 bpp and 16 bpp NO_CHANGEDISPLAYSETTINGS No fullscreen support NO_GAMMA_SUPPORT Gamma correction not available