private Expression WidenType <T>(Expression source)
{
var tref = ShaderDefinition.ToCecil(typeof(T));
var n = new ObjectCreateExpression(AstBuilder.ConvertType(tref), new[] { source.Clone() });
return(n);
}
/// <summary>
/// Redirects the invocation to the explicitly specified method
/// </summary>
protected Func <MethodDefinition, InvocationExpression, StringBuilder> Redirect(Expression <Action> wrapper)
{
var fun = ShaderDefinition.ToCecil(((MethodCallExpression)wrapper.Body).Method);
CheckWarnings(fun);
return((m, i) =>
{
// replace the current node with a call to fun and process again
i.RemoveAnnotations(typeof(MethodDefinition));
i.RemoveAnnotations(typeof(MethodReference));
i.AddAnnotation(fun);
return i.AcceptVisitor(this, 0);
});
}
/// <summary>
/// Redirects the invocation to the specified class, by searching for a
/// method with the specified name if given or same name otherwise
/// matching the original method signature.
/// </summary>
/// <returns></returns>
protected Func <MethodDefinition, InvocationExpression, StringBuilder> Redirect <T>(string name = null)
{
var t = ShaderDefinition.ToCecil(typeof(T));
return((m, i) =>
{
var redirected = t.Methods.Single(j => j.Name == (name ?? m.Name) &&
SameSignature(j, m));
CheckWarnings(redirected);
i.RemoveAnnotations(typeof(MethodDefinition));
i.RemoveAnnotations(typeof(MethodReference));
i.AddAnnotation(redirected);
return i.AcceptVisitor(this, 0);
});
}
private StringBuilder TextureLod(MethodDefinition m, InvocationExpression i)
{
Debug.Assert(i.Arguments.Count == 3);
var args = i.Arguments.ToArray();
var sampler = args[0];
var pos = args[1];
var lod = args[2];
var tref = ShaderDefinition.ToCecil(typeof(ShaderDefinition.vec4));
var zero = new PrimitiveExpression("0.0f");
var newPos = new ObjectCreateExpression(AstBuilder.ConvertType(tref), new[] { pos.Clone(), zero, lod.Clone() });
var result = new StringBuilder();
return(result.Append("tex2Dlod(").Append(ArgsToString(new[] { sampler, newPos })).Append(")"));
}
