1 files changed, 80 insertions, 0 deletions
diff --git a/bin/values.rb b/bin/values.rb
new file mode 100644
index 0000000..3ff1578
--- /dev/null
+++ b/bin/values.rb
@@ -0,0 +1,80 @@
+#!/usr/bin/env ruby
+
+##
+# Generate the different values on `config/values/*.s` by parsing the values on
+# `config/values.yml`. The values on that file are agnostic to NTSC or PAL, and
+# it's up to this script to produce constants which make sense for NTSC and PAL.
+# That is, it's a way to ensure that both NTSC and PAL have the same experience
+# (or at least as close as possible).
+
+##
+# Parse the configuration.
+
+require 'yaml'
+
+config_path = File.join("#{File.dirname(__FILE__)}/..", 'config/')
+config = YAML.safe_load_file(File.join(config_path, 'values.yml'))
+
+# Converts the given floating point value into a signed fixed point value in the
+# 4.4 format.
+def to_signed_fixed_point(value)
+  integer = value.to_i
+  raise "bad signed fixed point value" if integer > 7 || integer < -7
+  integer &= 0b00001111
+
+  decimal = (value % 1) * 100
+  decimal = ((decimal * 15) / 100.0).round & 0b00001111
+
+  (integer << 4) | decimal
+end
+
+##
+# Loop through the configuration and fetch values for NTSC and PAL.
+
+res = {}
+config.each do |model, properties|
+  res[model] ||= { ntsc: {}, pal: {} }
+
+  properties.each do |name, ntsc|
+    name = name.upcase
+    pal  = (ntsc * 6) / 5.0
+
+    res[model][:ntsc][name] = to_signed_fixed_point(ntsc)
+    res[model][:pal][name] = to_signed_fixed_point(pal)
+  end
+end
+
+##
+# Generate each model as expected.
+
+def to_hex(value)
+  hex = value.to_s(16).upcase
+
+  if hex.size == 1
+    "$0#{hex}"
+  else
+    "$#{hex}"
+  end
+end
+
+def values_to_asm(values)
+  contents = ""
+  values.each { |k, v| contents << "    #{k} = #{to_hex(v)}\n" }
+  contents.rstrip
+end
+
+res.each do |model, formats|
+  path = File.join(config_path, "values/#{model}.s")
+  contents = <<HERE
+;; This file has been automatically generated via bin/values.rb.
+;; DO NOT MODIFY this file directly: check config/values.yml instead.
+
+.ifdef PAL
+#{values_to_asm(formats[:pal])}
+.else
+#{values_to_asm(formats[:ntsc])}
+.endif
+HERE
+
+  File.open(path, 'w') { |f| f.write(contents) }
+end