From bfcc4388320d55a365d6bc427d58f47f359d2ac3 Mon Sep 17 00:00:00 2001
From: dooglus <dooglus@1f10aa63-cdf2-0310-b900-c93c546f37ac>
Date: Sun, 23 Sep 2007 20:25:41 +0000
Subject: [PATCH] Allow the 'BLine Tangent' to be used to convert angles.  The
 resulting value is the angle of the tangent to the bline at the given point
 to the horizontal.

git-svn-id: http://svn.voria.com/code@745 1f10aa63-cdf2-0310-b900-c93c546f37ac
---
 .../src/synfig/valuenode_blinecalctangent.cpp      | 29 +++++++++++++++++-----
 synfig-core/trunk/src/synfig/vector.h              |  4 +++
 2 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/synfig-core/trunk/src/synfig/valuenode_blinecalctangent.cpp b/synfig-core/trunk/src/synfig/valuenode_blinecalctangent.cpp
index 778fb42..b7bf0d4 100644
--- a/synfig-core/trunk/src/synfig/valuenode_blinecalctangent.cpp
+++ b/synfig-core/trunk/src/synfig/valuenode_blinecalctangent.cpp
@@ -57,7 +57,7 @@ using namespace synfig;
 ValueNode_BLineCalcTangent::ValueNode_BLineCalcTangent(const ValueBase::Type &x):
 	LinkableValueNode(x)
 {
-	if(x!=ValueBase::TYPE_VECTOR)
+	if(x!=ValueBase::TYPE_ANGLE && x!=ValueBase::TYPE_VECTOR)
 		throw Exception::BadType(ValueBase::type_name(x));
 
 	ValueNode_BLine* value_node(new ValueNode_BLine());
@@ -69,7 +69,7 @@ ValueNode_BLineCalcTangent::ValueNode_BLineCalcTangent(const ValueBase::Type &x)
 LinkableValueNode*
 ValueNode_BLineCalcTangent::create_new()const
 {
-	return new ValueNode_BLineCalcTangent(ValueBase::TYPE_VECTOR);
+	return new ValueNode_BLineCalcTangent(get_type());
 }
 
 ValueNode_BLineCalcTangent*
@@ -95,7 +95,13 @@ ValueNode_BLineCalcTangent::operator()(Time t)const
 	BLinePoint blinepoint0, blinepoint1;
 
 	if (!looped) size--;
-	if (size < 1) return Vector();
+	if (size < 1)
+		switch (get_type())
+		{
+			case ValueBase::TYPE_ANGLE:  return Angle();
+			case ValueBase::TYPE_VECTOR: return Vector();
+			default: assert(0); return ValueBase();
+		}
 	if (loop)
 	{
 		amount = amount - int(amount);
@@ -121,9 +127,19 @@ ValueNode_BLineCalcTangent::operator()(Time t)const
 	etl::derivative< etl::hermite<Vector> > deriv(curve);
 
 #ifdef ETL_FIXED_DERIVATIVE
-	return deriv(amount-from_vertex)*(0.5);
+	switch (get_type())
+	{
+		case ValueBase::TYPE_ANGLE:  return (deriv(amount-from_vertex)*(0.5)).angle();
+		case ValueBase::TYPE_VECTOR: return deriv(amount-from_vertex)*(0.5);
+		default: assert(0); return ValueBase();
+	}
 #else
-	return deriv(amount-from_vertex)*(-0.5);
+	switch (get_type())
+	{
+		case ValueBase::TYPE_ANGLE:  return (deriv(amount-from_vertex)*(-0.5)).angle();
+		case ValueBase::TYPE_VECTOR: return deriv(amount-from_vertex)*(-0.5);
+		default: assert(0); return ValueBase();
+	}
 #endif
 }
 
@@ -219,5 +235,6 @@ ValueNode_BLineCalcTangent::get_link_index_from_name(const String &name)const
 bool
 ValueNode_BLineCalcTangent::check_type(ValueBase::Type type)
 {
-	return type==ValueBase::TYPE_VECTOR;
+	return (type==ValueBase::TYPE_ANGLE ||
+			type==ValueBase::TYPE_VECTOR);
 }
diff --git a/synfig-core/trunk/src/synfig/vector.h b/synfig-core/trunk/src/synfig/vector.h
index c509c3c..61314f1 100644
--- a/synfig-core/trunk/src/synfig/vector.h
+++ b/synfig-core/trunk/src/synfig/vector.h
@@ -27,6 +27,7 @@
 
 /* === H E A D E R S ======================================================= */
 
+#include "angle.h"
 #include "real.h"
 #include <math.h>
 
@@ -169,6 +170,9 @@ public:
 	Vector perp()const
 		{ return Vector(_y,-_x); }
 
+	Angle angle()const
+		{ return Angle::rad(atan2(_y, _x)); }
+
 	bool is_equal_to(const Vector& rhs)const
 	{
 		static const value_type epsilon(0.0000000000001);
-- 
2.7.4