public static ValueOrDirective <T> GetDirective(string directive)
{
var result = new ValueOrDirective <T>();
result.Directive = directive;
result.Cancel = false;
result.HasValue = false;
return(result);
}
public static ValueOrDirective <T> GetValue(T value)
{
var result = new ValueOrDirective <T>();
result.value = value;
result.Cancel = false;
result.HasValue = true;
return(result);
}
public static async Task <ValueOrDirective <double> > GetAngleInDegrees(this IInputService inputService, string prompt, Func <double, IEnumerable <IPrimitive> > onCursorMove = null)
{
onCursorMove ??= (_) => Array.Empty <IPrimitive>();
prompt += " or [r]eference";
var angleCandidateValue = await inputService.GetText(prompt);
if (angleCandidateValue.Cancel || !angleCandidateValue.HasValue)
{
return(ValueOrDirective <double> .GetCancel());
}
if (double.TryParse(angleCandidateValue.Value, out var angle))
{
return(ValueOrDirective <double> .GetValue(angle));
}
else if (angleCandidateValue.Value == "r")
{
var pivotPoint = await inputService.GetPoint(new UserDirective("Pivot point"));
if (pivotPoint.Cancel || !pivotPoint.HasValue)
{
return(ValueOrDirective <double> .GetCancel());
}
var firstReferencePoint = await inputService.GetPoint(new UserDirective("Reference point"), onCursorMove : cursor =>
{
return(new IPrimitive[]
{
new PrimitiveLine(pivotPoint.Value, cursor)
});
});
if (firstReferencePoint.Cancel || !firstReferencePoint.HasValue)
{
return(ValueOrDirective <double> .GetCancel());
}
var v1 = firstReferencePoint.Value - pivotPoint.Value;
var secondReferencePoint = await inputService.GetPoint(new UserDirective("Second reference point"), onCursorMove : cursor =>
{
var v2Temp = cursor - pivotPoint.Value;
var angleInRadians = Vector.AngleBetweenInRadians(v1, v2Temp);
var angleInDegrees = angleInRadians *MathHelper.RadiansToDegrees;
return(new IPrimitive[]
{
new PrimitiveLine(pivotPoint.Value, firstReferencePoint.Value),
new PrimitiveLine(pivotPoint.Value, cursor)
}.Concat(onCursorMove(angleInDegrees)));
});
if (secondReferencePoint.Cancel || !secondReferencePoint.HasValue)
{
return(ValueOrDirective <double> .GetCancel());
}
var v2 = secondReferencePoint.Value - pivotPoint.Value;
var angleInRadians = Vector.AngleBetweenInRadians(v1, v2);
var angleInDegrees = angleInRadians * MathHelper.RadiansToDegrees;
return(ValueOrDirective <double> .GetValue(angleInDegrees));
}
else
{
return(ValueOrDirective <double> .GetCancel());
}
}