view test/acinclude.m4 @ 4216:5b99971a27b4 SDL-1.2

Fixed bug #698 Hans de Goede 2009-02-13 01:10:52 PST Since the new "glitch free" version of pulseaudio (used in Fedora 10 amongst others), the sound of SDL using apps (like a simple playmus call) has been crackling. While looking in to fixing this I noticed that the current pulseaudio code in SDL uses pa_simple. However pa_simple uses a thread to pump pulseaudio events and ipc, given that SDL already has its own thread for audio handling this is clearly suboptimal, leading to unnecessary context switching IPC, etc. Also pa_simple does not allow one to implement the WaitAudio() callback for SDL audiodrivers properly. Given that my work is mostly a rewrite (although some original pieces remain) I'm attaching the new .c and .h file, as that is easier to review then the huge diff. Let me know if you also want the diff. This new version has the following features: -no longer use an additional thread next to the SDL sound thread -do not crackle with glitch free audio -when used with a newer pulse, which does glitch free audio, the total latency is the same as with the alsa driver -proper WaitAudio() implementation, saving another mixlen worth of latency -adds a WaitDone() implementation This patch has been written in consultancy with Lennart Poetering (the pulseaudio author) and has been reviewed by him for correct use of the pa API.
author Sam Lantinga <slouken@libsdl.org>
date Mon, 21 Sep 2009 09:27:08 +0000
parents 91063c450171
children
line wrap: on
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# Configure paths for SDL
# Sam Lantinga 9/21/99
# stolen from Manish Singh
# stolen back from Frank Belew
# stolen from Manish Singh
# Shamelessly stolen from Owen Taylor

dnl AM_PATH_SDL([MINIMUM-VERSION, [ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND]]])
dnl Test for SDL, and define SDL_CFLAGS and SDL_LIBS
dnl
AC_DEFUN([AM_PATH_SDL],
[dnl 
dnl Get the cflags and libraries from the sdl-config script
dnl
AC_ARG_WITH(sdl-prefix,[  --with-sdl-prefix=PFX   Prefix where SDL is installed (optional)],
            sdl_prefix="$withval", sdl_prefix="")
AC_ARG_WITH(sdl-exec-prefix,[  --with-sdl-exec-prefix=PFX Exec prefix where SDL is installed (optional)],
            sdl_exec_prefix="$withval", sdl_exec_prefix="")
AC_ARG_ENABLE(sdltest, [  --disable-sdltest       Do not try to compile and run a test SDL program],
		    , enable_sdltest=yes)

  if test x$sdl_exec_prefix != x ; then
    sdl_args="$sdl_args --exec-prefix=$sdl_exec_prefix"
    if test x${SDL_CONFIG+set} != xset ; then
       SDL_CONFIG=$sdl_exec_prefix/bin/sdl-config
    fi
  fi
  if test x$sdl_prefix != x ; then
    sdl_args="$sdl_args --prefix=$sdl_prefix"
    if test x${SDL_CONFIG+set} != xset ; then
       SDL_CONFIG=$sdl_prefix/bin/sdl-config
    fi
  fi

  if test "x$prefix" != xNONE; then
    PATH="$prefix/bin:$prefix/usr/bin:$PATH"
  fi
  AC_PATH_PROG(SDL_CONFIG, sdl-config, no, [$PATH])
  min_sdl_version=ifelse([$1], ,0.11.0,$1)
  AC_MSG_CHECKING(for SDL - version >= $min_sdl_version)
  no_sdl=""
  if test "$SDL_CONFIG" = "no" ; then
    no_sdl=yes
  else
    SDL_CFLAGS=`$SDL_CONFIG $sdlconf_args --cflags`
    SDL_LIBS=`$SDL_CONFIG $sdlconf_args --libs`

    sdl_major_version=`$SDL_CONFIG $sdl_args --version | \
           sed 's/\([[0-9]]*\).\([[0-9]]*\).\([[0-9]]*\)/\1/'`
    sdl_minor_version=`$SDL_CONFIG $sdl_args --version | \
           sed 's/\([[0-9]]*\).\([[0-9]]*\).\([[0-9]]*\)/\2/'`
    sdl_micro_version=`$SDL_CONFIG $sdl_config_args --version | \
           sed 's/\([[0-9]]*\).\([[0-9]]*\).\([[0-9]]*\)/\3/'`
    if test "x$enable_sdltest" = "xyes" ; then
      ac_save_CFLAGS="$CFLAGS"
      ac_save_CXXFLAGS="$CXXFLAGS"
      ac_save_LIBS="$LIBS"
      CFLAGS="$CFLAGS $SDL_CFLAGS"
      CXXFLAGS="$CXXFLAGS $SDL_CFLAGS"
      LIBS="$LIBS $SDL_LIBS"
dnl
dnl Now check if the installed SDL is sufficiently new. (Also sanity
dnl checks the results of sdl-config to some extent
dnl
      rm -f conf.sdltest
      AC_TRY_RUN([
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "SDL.h"

char*
my_strdup (char *str)
{
  char *new_str;
  
  if (str)
    {
      new_str = (char *)malloc ((strlen (str) + 1) * sizeof(char));
      strcpy (new_str, str);
    }
  else
    new_str = NULL;
  
  return new_str;
}

int main (int argc, char *argv[])
{
  int major, minor, micro;
  char *tmp_version;

  /* This hangs on some systems (?)
  system ("touch conf.sdltest");
  */
  { FILE *fp = fopen("conf.sdltest", "a"); if ( fp ) fclose(fp); }

  /* HP/UX 9 (%@#!) writes to sscanf strings */
  tmp_version = my_strdup("$min_sdl_version");
  if (sscanf(tmp_version, "%d.%d.%d", &major, &minor, &micro) != 3) {
     printf("%s, bad version string\n", "$min_sdl_version");
     exit(1);
   }

   if (($sdl_major_version > major) ||
      (($sdl_major_version == major) && ($sdl_minor_version > minor)) ||
      (($sdl_major_version == major) && ($sdl_minor_version == minor) && ($sdl_micro_version >= micro)))
    {
      return 0;
    }
  else
    {
      printf("\n*** 'sdl-config --version' returned %d.%d.%d, but the minimum version\n", $sdl_major_version, $sdl_minor_version, $sdl_micro_version);
      printf("*** of SDL required is %d.%d.%d. If sdl-config is correct, then it is\n", major, minor, micro);
      printf("*** best to upgrade to the required version.\n");
      printf("*** If sdl-config was wrong, set the environment variable SDL_CONFIG\n");
      printf("*** to point to the correct copy of sdl-config, and remove the file\n");
      printf("*** config.cache before re-running configure\n");
      return 1;
    }
}

],, no_sdl=yes,[echo $ac_n "cross compiling; assumed OK... $ac_c"])
       CFLAGS="$ac_save_CFLAGS"
       CXXFLAGS="$ac_save_CXXFLAGS"
       LIBS="$ac_save_LIBS"
     fi
  fi
  if test "x$no_sdl" = x ; then
     AC_MSG_RESULT(yes)
     ifelse([$2], , :, [$2])     
  else
     AC_MSG_RESULT(no)
     if test "$SDL_CONFIG" = "no" ; then
       echo "*** The sdl-config script installed by SDL could not be found"
       echo "*** If SDL was installed in PREFIX, make sure PREFIX/bin is in"
       echo "*** your path, or set the SDL_CONFIG environment variable to the"
       echo "*** full path to sdl-config."
     else
       if test -f conf.sdltest ; then
        :
       else
          echo "*** Could not run SDL test program, checking why..."
          CFLAGS="$CFLAGS $SDL_CFLAGS"
          CXXFLAGS="$CXXFLAGS $SDL_CFLAGS"
          LIBS="$LIBS $SDL_LIBS"
          AC_TRY_LINK([
#include <stdio.h>
#include "SDL.h"

int main(int argc, char *argv[])
{ return 0; }
#undef  main
#define main K_and_R_C_main
],      [ return 0; ],
        [ echo "*** The test program compiled, but did not run. This usually means"
          echo "*** that the run-time linker is not finding SDL or finding the wrong"
          echo "*** version of SDL. If it is not finding SDL, you'll need to set your"
          echo "*** LD_LIBRARY_PATH environment variable, or edit /etc/ld.so.conf to point"
          echo "*** to the installed location  Also, make sure you have run ldconfig if that"
          echo "*** is required on your system"
	  echo "***"
          echo "*** If you have an old version installed, it is best to remove it, although"
          echo "*** you may also be able to get things to work by modifying LD_LIBRARY_PATH"],
        [ echo "*** The test program failed to compile or link. See the file config.log for the"
          echo "*** exact error that occured. This usually means SDL was incorrectly installed"
          echo "*** or that you have moved SDL since it was installed. In the latter case, you"
          echo "*** may want to edit the sdl-config script: $SDL_CONFIG" ])
          CFLAGS="$ac_save_CFLAGS"
          CXXFLAGS="$ac_save_CXXFLAGS"
          LIBS="$ac_save_LIBS"
       fi
     fi
     SDL_CFLAGS=""
     SDL_LIBS=""
     ifelse([$3], , :, [$3])
  fi
  AC_SUBST(SDL_CFLAGS)
  AC_SUBST(SDL_LIBS)
  rm -f conf.sdltest
])