#!/usr/bin/perl -w

use warnings;

use strict;

my @audiotypes = qw(

    U8

    S8

    U16LSB

    S16LSB

    U16MSB

    S16MSB

    S32LSB

    S32MSB

    F32LSB

    F32MSB

);

my %funcs;

my $custom_converters = 0;

sub outputHeader {

    print <<EOF;

/* DO NOT EDIT!  This file is generated by sdlgenaudiocvt.pl */

/*

    SDL - Simple DirectMedia Layer

    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or

    modify it under the terms of the GNU Lesser General Public

    License as published by the Free Software Foundation; either

    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public

    License along with this library; if not, write to the Free Software

    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga

    slouken\@libsdl.org

*/

#include "SDL_config.h"

#include "SDL_audio.h"

#include "SDL_audio_c.h"

/* *INDENT-OFF* */

EOF

    my @vals = ( 127, 32767, 2147483647 );

    foreach (@vals) {

        my $val = $_;

        my $fval = 1.0 / $val;

        print("#define DIVBY${val} ${fval}f\n");

    }

    print("\n");

}

sub outputFooter {

    print <<EOF;

/* *INDENT-ON* */

/* vi: set ts=4 sw=4 expandtab: */

EOF

}

sub splittype {

    my $t = shift;

    my ($signed, $size, $endian) = $t =~ /([USF])(\d+)([LM]SB|)/;

    my $float = ($signed eq 'F') ? 1 : 0;

    $signed = (($float) or ($signed eq 'S')) ? 1 : 0;

    $endian = 'NONE' if ($endian eq '');

    my $ctype = '';

    if ($float) {

        $ctype = (($size == 32) ? 'float' : 'double');

    } else {

        $ctype = (($signed) ? 'S' : 'U') . "int${size}";

    }

    return ($signed, $float, $size, $endian, $ctype);

}

sub getSwapFunc {

    my ($size, $signed, $float, $endian, $val) = @_;

    my $BEorLE = (($endian eq 'MSB') ? 'BE' : 'LE');

    my $code = '';

    if ($float) {

        $code = "SDL_SwapFloat${BEorLE}($val)";

    } else {

        if ($size > 8) {

            $code = "SDL_Swap${BEorLE}${size}($val)";

        } else {

            $code = $val;

        }

        if (($signed) and (!$float)) {

            $code = "((Sint${size}) $code)";

        }

    }

    return "${code}";

}

sub maxIntVal {

    my $size = shift;

    if ($size == 8) {

        return 0x7F;

    } elsif ($size == 16) {

        return 0x7FFF;

    } elsif ($size == 32) {

        return 0x7FFFFFFF;

    }

    die("bug in script.\n");

}

sub getFloatToIntMult {

    my $size = shift;

    my $val = maxIntVal($size) . '.0';

    $val .= 'f' if ($size < 32);

    return $val;

}

sub getIntToFloatDivBy {

    my $size = shift;

    return 'DIVBY' . maxIntVal($size);

}

sub getSignFlipVal {

    my $size = shift;

    if ($size == 8) {

        return '0x80';

    } elsif ($size == 16) {

        return '0x8000';

    } elsif ($size == 32) {

        return '0x80000000';

    }

    die("bug in script.\n");

}

sub buildCvtFunc {

    my ($from, $to) = @_;

    my ($fsigned, $ffloat, $fsize, $fendian, $fctype) = splittype($from);

    my ($tsigned, $tfloat, $tsize, $tendian, $tctype) = splittype($to);

    my $diffs = 0;

    $diffs++ if ($fsize != $tsize);

    $diffs++ if ($fsigned != $tsigned);

    $diffs++ if ($ffloat != $tfloat);

    $diffs++ if ($fendian ne $tendian);

    return if ($diffs == 0);

    my $hashid = "$from/$to";

    if (1) { # !!! FIXME: if ($diffs > 1) {

        my $sym = "SDL_Convert_${from}_to_${to}";

        $funcs{$hashid} = $sym;

        $custom_converters++;

        # Always unsigned for ints, for possible byteswaps.

        my $srctype = (($ffloat) ? 'float' : "Uint${fsize}");

        print <<EOF;

static void SDLCALL

${sym}(SDL_AudioCVT * cvt, SDL_AudioFormat format)

{

    int i;

    const $srctype *src;

    $tctype *dst;

#ifdef DEBUG_CONVERT

    fprintf(stderr, "Converting AUDIO_${from} to AUDIO_${to}.\\n");

#endif

EOF

        if ($fsize < $tsize) {

            my $mult = $tsize / $fsize;

            print <<EOF;

    src = (const $srctype *) (cvt->buf + cvt->len_cvt);

    dst = ($tctype *) (cvt->buf + cvt->len_cvt * $mult);

    for (i = cvt->len_cvt / sizeof ($srctype); i; --i, --src, --dst) {

EOF

        } else {

            print <<EOF;

    src = (const $srctype *) cvt->buf;

    dst = ($tctype *) cvt->buf;

    for (i = cvt->len_cvt / sizeof ($srctype); i; --i, ++src, ++dst) {

EOF

        }

        # Have to convert to/from float/int.

        # !!! FIXME: cast through double for int32<->float?

        my $code = getSwapFunc($fsize, $fsigned, $ffloat, $fendian, '*src');

        if ($ffloat != $tfloat) {

            if ($ffloat) {

                my $mult = getFloatToIntMult($tsize);

                if (!$tsigned) {   # bump from -1.0f/1.0f to 0.0f/2.0f

                    $code = "($code + 1.0f)";

                }

                $code = "(($tctype) ($code * $mult))";

            } else {

                # $divby will be the reciprocal, to avoid pipeline stalls

                #  from floating point division...so multiply it.

                my $divby = getIntToFloatDivBy($fsize);

                $code = "(((float) $code) * $divby)";

                if (!$fsigned) {   # bump from 0.0f/2.0f to -1.0f/1.0f.

                    $code = "($code - 1.0f)";

                }

            }

        } else {

            # All integer conversions here.

            if ($fsigned != $tsigned) {

                my $signflipval = getSignFlipVal($fsize);

                $code = "(($code) ^ $signflipval)";

            }

            my $shiftval = abs($fsize - $tsize);

            if ($fsize < $tsize) {

                $code = "((($tctype) $code) << $shiftval)";

            } elsif ($fsize > $tsize) {

                $code = "(($tctype) ($code >> $shiftval))";

            }

        }

        my $swap = getSwapFunc($tsize, $tsigned, $tfloat, $tendian, 'val');

        print <<EOF;

        const $tctype val = $code;

        *dst = ${swap};

    }

EOF

        if ($fsize > $tsize) {

            my $divby = $fsize / $tsize;

            print("    cvt->len_cvt /= $divby;\n");

        } elsif ($fsize < $tsize) {

            my $mult = $tsize / $fsize;

            print("    cvt->len_cvt *= $mult;\n");

        }

        print <<EOF;

    format = AUDIO_$to;

    if (cvt->filters[++cvt->filter_index]) {

        cvt->filters[cvt->filter_index] (cvt, format);

    }

}

EOF

    } else {

        if ($fsigned != $tsigned) {

            $funcs{$hashid} = 'SDL_ConvertSigned';

        } elsif ($ffloat != $tfloat) {

            $funcs{$hashid} = 'SDL_ConvertFloat';

        } elsif ($fsize != $tsize) {

            $funcs{$hashid} = 'SDL_ConvertSize';

        } elsif ($fendian ne $tendian) {

            $funcs{$hashid} = 'SDL_ConvertEndian';

        } else {

            die("error in script.\n");

        }

    }

}

outputHeader();

foreach (@audiotypes) {

    my $from = $_;

    foreach (@audiotypes) {

        my $to = $_;

        buildCvtFunc($from, $to);

    }

}

print <<EOF;

const SDL_AudioTypeFilters sdl_audio_type_filters[] =

{

EOF

foreach (@audiotypes) {

    my $from = $_;

    foreach (@audiotypes) {

        my $to = $_;

        if ($from ne $to) {

            my $hashid = "$from/$to";

            my $sym = $funcs{$hashid};

            print("    { AUDIO_$from, AUDIO_$to, $sym },\n");

        }

    }

}

print <<EOF;

};

EOF

outputFooter();

exit 0;

# end of sdlgenaudiocvt.pl ...