#!/usr/bin/perl

use integer;
use strict;

# 1 bit/byte patterns
print "#if BITS_PER_PATTERN_BYTE == 1\n\n";

print "static const uint8_t fm_pat[2] = {\n";
print "\t0xff, 0x0f";

print "\n};\n\n";

# 2 bits/byte patterns
print "#elif BITS_PER_PATTERN_BYTE == 2\n\n";

print "static const uint8_t fm_pat[4] = {\n";
for (my $i = 0; $i < 4; $i++) {
    my $pat = 0;
    my $inc = 0;		# Previous bit

    for (my $j = 0; $j < 2; $j++) {
	my $bp = ($i & (1 << $j)) ? 0x3 : 0xf;
	$bp ^= $inc * 15;
	$inc = $bp >> 3;
	$pat |= $bp << ($j*4);
    }

    printf "%s0x%02x", ($i ? ', ' : "\t"), $pat;
}
print "\n};\n\n";

print "\n#elif BITS_PER_PATTERN_BYTE == 4\n\n";

# 4 bits/byte patterns
print "static const uint8_t fm_pat[16] = {\n";
for (my $i = 0; $i < 16; $i++) {
    my $pat = 0;
    my $inc = 0;		# Previous bit

    for (my $j = 0; $j < 4; $j++) {
	my $bp = ($i & (1 << $j)) ? 0x1 : 0x3;
	$bp ^= $inc * 3;
	$inc = $bp >> 1;
	$pat |= $bp << ($j*2);
    }

    printf "%s0x%02x", ($i ? ', ' : "\t"), $pat;
}
print "\n};\n\n";

print "#else\n\n";
print "#error \"Invalid BITS_PER_PATTERN_BYTE\"\n";
print "\n#endif\n";