/// <summary>
/// Casts a scalar node to a C# object following the rules:
/// Single-Length, single quoted strings become char
/// Else, quoted (single or double), literal or folded values become strings
/// Else, plain values equal to the string "null" become null
/// Else, plain values that start with "~" become scene resources
/// Else, plain values that can be cast to int become int
/// Else, plain values that can be cast to float become float
/// Else, plain values are cast to a object using the parameterless constructor
/// (For parameterized constructors, see casting a mapping node)
/// </summary>
/// <param name="node"></param>
private object parseArgument(YamlScalarNode node)
{
switch (node.Style)
{
case ScalarStyle.SingleQuoted:
if (node.String().Length == 1)
{
return(node.String()[0]);
}
else
{
return(node.String());
}
case ScalarStyle.DoubleQuoted:
case ScalarStyle.Literal:
case ScalarStyle.Folded:
return(node.String());
case ScalarStyle.Plain:
if (node.String() == "null")
{
return(null);
}
if (node.String().StartsWith("~"))
{
return(new ObjectModel
{
Type = typeof(Resource),
CtorArgs = new Object[] { node.String().Substring(1) }
});
}
int i;
float f;
if (node.TryInt(out i))
{
return(i);
}
if (node.TryFloat(out f))
{
return(f);
}
return(new ObjectModel
{
Type = RegisteredTypes.GetType(node.String()),
CtorArgs = new object[] { }
});
default:
throw new Exception("Trying to parse arguments from invalid node!");
}
}
private ObjectModel parseObject(YamlNode node)
{
if (node.NodeType == YamlNodeType.Scalar)
{
return(new ObjectModel
{
Type = RegisteredTypes.GetType(node.Val().String()),
CtorArgs = new object[] { }
});
}
else if (node.NodeType == YamlNodeType.Mapping)
{
return(parseObject(node.Map().Children));
}
throw new YamlException(node.Start, node.End, "Invalid object structure");
}
private ObjectModel parseObject(IDictionary <YamlNode, YamlNode> map)
{
if (map.Count != 1)
{
throw new YamlException(
map.First().Key.Start,
map.First().Key.End,
"Invalid object structure"
);
}
var component = map.First();
return(new ObjectModel
{
Type = RegisteredTypes.GetType(component.Key.Val().String()),
CtorArgs = parseArguments(component.Value.Seq())
});
}
private SceneInitializer fromText(string text)
{
var yaml = new YamlStream();
yaml.Load(new StringReader(text));
var root = yaml.Documents[0].RootNode.Map();
var size = new Point(1280, 720);
var scaler = new LetterboxingScaler();
var systems = new List <ObjectModel>();
var renderers = new List <ObjectModel>();
var entities = new List <EntityModel>();
var actions = new List <InputAction>();
if (root.Children.ContainsKey("size"))
{
// TODO
}
if (root.Children.ContainsKey("scaler"))
{
// TODO
}
// Add systems
if (root.Children.ContainsKey("systems"))
{
foreach (var system in root["systems"].Seq().Children)
{
switch (system.NodeType)
{
case YamlNodeType.Scalar:
systems.Add(
new ObjectModel
{
Type = RegisteredTypes.GetType(system.Val().String()),
CtorArgs = new object[] { },
}
);
break;
case YamlNodeType.Mapping:
systems.Add(
new ObjectModel
{
Type = RegisteredTypes.GetType(system.Map().First().Key.Val().String()),
CtorArgs = parseArguments(system.Map().First().Value),
}
);
break;
}
}
}
// Add renderers
if (root.Children.ContainsKey("renderers"))
{
foreach (var renderer in root["renderers"].Seq().Children)
{
switch (renderer.NodeType)
{
case YamlNodeType.Scalar:
renderers.Add(
new ObjectModel
{
Type = RegisteredTypes.GetType(renderer.Val().String()),
CtorArgs = new object[] { },
}
);
break;
case YamlNodeType.Mapping:
renderers.Add(
new ObjectModel
{
Type = RegisteredTypes.GetType(renderer.Map().First().Key.Val().String()),
CtorArgs = parseArguments(renderer.Map().First().Value),
}
);
break;
}
}
}
// Add entities
if (root.Children.ContainsKey("entities"))
{
foreach (var entity in root["entities"].Seq().Children)
{
var model = parseEntity(entity);
entities.Add(model);
}
}
// Add actions
if (root.Children.ContainsKey("actions"))
{
foreach (var actionPair in root["actions"].Map())
{
var name = actionPair.Key.Val().String();
var yamlKeys = actionPair.Value;
String[] keys;
switch (yamlKeys.NodeType)
{
// Single key
case YamlNodeType.Scalar:
keys = new string[] { yamlKeys.Val().String() };
break;
// Many keys
case YamlNodeType.Sequence:
keys = yamlKeys.Seq().Select(n => n.Val().String()).ToArray();
break;
default:
throw new YamlException(
yamlKeys.Start,
yamlKeys.End,
"Expected a sequence or value node, but got none!"
);
}
var buttons = keys.Select(k => (Buttons)Enum.Parse(typeof(Buttons), k));
actions.Add(new InputAction(name, buttons.ToArray()));
}
}
return(new SceneInitializer(size, scaler, systems, renderers, entities, actions));
}
