65 lines
1.3 KiB
Perl
Executable File
65 lines
1.3 KiB
Perl
Executable File
#!/usr/bin/perl -w
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#
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# Convert PNG image to raw font binary for Apple 1 emulator
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#
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# Makes lots of assumptions about the input image!
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use Compress::Zlib;
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# Input image and output data file
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my $input = 'font.png';
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my $output = 'font.bin';
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# Our characters are 6 pixels wide
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$chrw = 6;
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# Slurp the entire PNG image
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open INPUT, "<$input" and binmode INPUT or die "$input: $!\n";
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read INPUT, $data='', -s $input;
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close INPUT;
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# Find and extract the image dimensions
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$data =~ /IHDR(.{8})/s;
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($w,$h) = unpack "N2", $1;
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# Extract and expand the compressed image data
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($data) = $data =~ /IDAT(.*).{8}IEND/s;
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$data = Compress::Zlib::uncompress($data);
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# Remove the type byte from the start of each line
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$w_2 = $w/2;
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$data =~ s/.(.{$w_2})/$1/sg;
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@data = ();
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# Unpack the pixel nibbles
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foreach (unpack "C*", $data) {
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push @data, $_>>4, $_&1;
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}
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open OUTPUT, ">$output" and binmode OUTPUT or die "$output: $!\n";
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# Process all characters
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foreach $chr (0..$w/$chrw-1)
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{
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# Process the image line by line
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foreach $y (0..$h-1)
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{
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# Locate the pixel data for the current character
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my $x = $chr*$chrw + $w*$y;
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my $b = 0;
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# Pack the 1bpp data into a single byte
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foreach (@data[$x..$x+$chrw-1]) {
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$b = ($b << 1) | $_;
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}
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# Left-align within the byte and output it
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print OUTPUT chr($b << (8-$chrw));
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}
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}
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close OUTPUT;
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