package Imager::Preprocess;
use strict;
require Exporter;
use vars qw(@ISA @EXPORT $VERSION);
use Getopt::Long;
use Text::ParseWords;
@EXPORT = qw(preprocess);
@ISA = qw(Exporter);
$VERSION = "1.000";
sub preprocess {
unshift @ARGV, grep /^-/, shellwords($ENV{IMAGER_PREPROCESS_OPTS})
if $ENV{IMAGER_PREPROCESS_OPTS};
my $skip_lines = 0;
GetOptions("l" => \$skip_lines)
or usage();
my $keep_lines = !$skip_lines;
my $src = shift @ARGV;
my $dest = shift @ARGV
or usage();
open SRC, "< $src"
or die "Cannot open $src: $!\n";
my $cond;
my $cond_line;
my $save_code;
my @code;
my $code_line;
my @out;
my $failed;
push @out,
"#define IM_ROUND_8(x) ((int)((x)+0.5))\n",
"#define IM_ROUND_double(x) (x)\n",
"#define IM_LIMIT_8(x) ((x) < 0 ? 0 : (x) > 255 ? 255 : (x))\n",
"#define IM_LIMIT_double(x) ((x) < 0.0 ? 0.0 : (x) > 1.0 ? 1.0 : (x))\n";
push @out, "#line 1 \"$src\"\n" if $keep_lines;
while (defined(my $line = <SRC>)) {
if ($line =~ /^\#code\s+(\S.+)$/) {
$save_code
and do { warn "$src:$code_line:Unclosed #code block\n"; ++$failed; };
$cond = $1;
$cond_line = $.;
$code_line = $. + 1;
$save_code = 1;
}
elsif ($line =~ /^\#code\s*$/) {
$save_code
and do { warn "$src:$code_line:Unclosed #code block\n"; ++$failed; };
$cond = '';
$cond_line = 0;
$code_line = $. + 1;
$save_code = 1;
}
elsif ($line =~ /^\#\/code\s*$/) {
$save_code
or do { warn "$src:$.:#/code without #code\n"; ++$failed; next; };
if ($cond) {
push @out, "#line $cond_line \"$src\"\n" if $keep_lines;
push @out, " if ($cond) {\n";
}
push @out,
"#undef IM_EIGHT_BIT\n",
"#define IM_EIGHT_BIT 1\n",
"#undef IM_FILL_COMBINE\n",
"#define IM_FILL_COMBINE(fill) ((fill)->combine)\n",
"#undef IM_FILL_FILLER\n",
"#define IM_FILL_FILLER(fill) ((fill)->f_fill_with_color)\n";
push @out, "#line $code_line \"$src\"\n" if $keep_lines;
push @out, byte_samples(@code);
push @out, " }\n", " else {\n"
if $cond;
push @out,
"#undef IM_EIGHT_BIT\n",
"#undef IM_FILL_COMBINE\n",
"#define IM_FILL_COMBINE(fill) ((fill)->combinef)\n",
"#undef IM_FILL_FILLER\n",
"#define IM_FILL_FILLER(fill) ((fill)->f_fill_with_fcolor)\n";
push @out, "#line $code_line \"$src\"\n" if $keep_lines;
push @out, double_samples(@code);
push @out, " }\n"
if $cond;
push @out, "#line ",$.+1," \"$src\"\n" if $keep_lines;
@code = ();
$save_code = 0;
}
elsif ($save_code) {
push @code, $line;
}
else {
push @out, $line;
}
}
if ($save_code) {
warn "$src:$code_line:#code block not closed by EOF\n";
++$failed;
}
close SRC;
$failed
and die "Errors during parsing, aborting\n";
open DEST, "> $dest"
or die "Cannot open $dest: $!\n";
print DEST @out;
close DEST;
}
sub byte_samples {
# important we make a copy
my @lines = @_;
for (@lines) {
s/\bIM_GPIX\b/i_gpix/g;
s/\bIM_GLIN\b/i_glin/g;
s/\bIM_PPIX\b/i_ppix/g;
s/\bIM_PLIN\b/i_plin/g;
s/\bIM_GSAMP\b/i_gsamp/g;
s/\bIM_SAMPLE_MAX\b/255/g;
s/\bIM_SAMPLE_MAX2\b/65025/g;
s/\bIM_SAMPLE_T/i_sample_t/g;
s/\bIM_COLOR\b/i_color/g;
s/\bIM_WORK_T\b/int/g;
s/\bIM_Sf\b/"%d"/g;
s/\bIM_Wf\b/"%d"/g;
s/\bIM_SUFFIX\((\w+)\)/$1_8/g;
s/\bIM_ROUND\(/IM_ROUND_8(/g;
s/\bIM_ADAPT_COLORS\(/i_adapt_colors(/g;
s/\bIM_LIMIT\(/IM_LIMIT_8(/g;
s/\bIM_RENDER_LINE\(/i_render_line(/g;
s/\bIM_FILL_COMBINE_F\b/i_fill_combine_f/g;
}
@lines;
}
sub double_samples {
# important we make a copy
my @lines = @_;
for (@lines) {
s/\bIM_GPIX\b/i_gpixf/g;
s/\bIM_GLIN\b/i_glinf/g;
s/\bIM_PPIX\b/i_ppixf/g;
s/\bIM_PLIN\b/i_plinf/g;
s/\bIM_GSAMP\b/i_gsampf/g;
s/\bIM_SAMPLE_MAX\b/1.0/g;
s/\bIM_SAMPLE_MAX2\b/1.0/g;
s/\bIM_SAMPLE_T/i_fsample_t/g;
s/\bIM_COLOR\b/i_fcolor/g;
s/\bIM_WORK_T\b/double/g;
s/\bIM_Sf\b/"%f"/g;
s/\bIM_Wf\b/"%f"/g;
s/\bIM_SUFFIX\((\w+)\)/$1_double/g;
s/\bIM_ROUND\(/IM_ROUND_double(/g;
s/\bIM_ADAPT_COLORS\(/i_adapt_fcolors(/g;
s/\bIM_LIMIT\(/IM_LIMIT_double(/g;
s/\bIM_RENDER_LINE\(/i_render_linef(/g;
s/\bIM_FILL_COMBINE_F\b/i_fill_combinef_f/g;
}
@lines;
}
sub usage {
die <<EOS;
Usage: perl -MImager::Preprocess -epreprocess [-l] infile outfile
-l don't produce #line directives
infile - input file
outfile output file
See perldoc Imager::Preprocess for details.
EOS
}
1;
__END__
=head1 NAME
=for stopwords preprocessor
Imager::Preprocess - simple preprocessor for handling multiple sample sizes
=head1 SYNOPSIS
/* in the source: */
#code condition true to work with 8-bit samples
... code using preprocessor types/values ...
#/code
# process and make #line directives
perl -MImager::Preprocess -epreprocess foo.im foo.c
# process and no #line directives
perl -MImager::Preprocess -epreprocess -l foo.im foo.c
=head1 DESCRIPTION
This is a simple preprocessor that aims to reduce duplication of
source code when implementing an algorithm both for 8-bit samples and
double samples in Imager.
Imager's C<Makefile.PL> currently scans the F<MANIFEST> for F<.im>
files and adds Makefile files to convert these to F<.c> files.
The beginning of a sample-independent section of code is preceded by:
#code expression
where I<expression> should return true if processing should be done at
8-bits/sample.
You can also use a #code block around a function definition to produce
8-bit and double sample versions of a function. In this case #code
has no expression and you will need to use IM_SUFFIX() to produce
different function names.
The end of a sample-independent section of code is terminated by:
#/code
#code sections cannot be nested.
#/code without a starting #code is an error.
The following types and values are defined in a #code section:
=over
=item *
IM_GPIX(C<im>, C<x>, C<y>, C<&col>)
=item *
IM_GLIN(C<im>, C<l>, C<r>, C<y>, C<colors>)
=item *
IM_PPIX(C<im>, C<x>, C<y>, C<&col>)
=item *
IM_PLIN(C<im>, C<x>, C<y>, C<colors>)
=item *
IM_GSAMP(C<im>, C<l>, C<r>, C<y>, C<samples>, C<chans>, C<chan_count>)
These correspond to the appropriate image function, eg. IM_GPIX()
becomes i_gpix() or i_gpixf() as appropriate.
=item *
IM_ADAPT_COLORS(C<dest_channels>, C<src_channels>, C<colors>, C<count>)
Call i_adapt_colors() or i_adapt_fcolors().
=item *
IM_FILL_COMBINE(C<fill>) - retrieve the combine function from a fill
object.
=item *
IM_FILL_FILLER(C<fill>) - retrieve the fill_with_* function from a fill
object.
=item *
IM_SAMPLE_MAX - maximum value for a sample
=item *
IM_SAMPLE_MAX2 - maximum value for a sample, squared
=item *
IM_SAMPLE_T - type of a sample (i_sample_t or i_fsample_t)
=item *
IM_COLOR - color type, either i_color or i_fcolor.
=item *
IM_WORK_T - working sample type, either int or double.
=item *
IM_Sf - format string for the sample type, C<"%d"> or C<"%f">.
=item *
IM_Wf - format string for the work type, C<"%d"> or C<"%f">.
=item *
IM_SUFFIX(identifier) - adds _8 or _double onto the end of identifier.
=item *
IM_EIGHT_BIT - this is a macro defined only in 8-bit/sample code.
=back
Other types, functions and values may be added in the future.
=head1 AUTHOR
Tony Cook <tonyc@cpan.org>
=cut