Merge pull request #2072 from jrimclean/master

Interpolation for affine transformations/Bound rot/pos Matrix32 constructor

2 files changed, 39 insertions, 2 deletions

diff --git a/core/math/math_2d.cpp b/core/math/math_2d.cpp
index 0a3963f88f..88717723ce 100644
--- a/core/math/math_2d.cpp
+++ b/core/math/math_2d.cpp
@@ -622,9 +622,39 @@ float Matrix32::basis_determinant() const {
 }
 
 Matrix32 Matrix32::interpolate_with(const Matrix32& p_transform, float p_c) const {
+	
+	//extract parameters
+	Vector2 p1 = get_origin();
+	Vector2 p2 = p_transform.get_origin();
+	
+	real_t r1 = get_rotation();
+	real_t r2 = p_transform.get_rotation();
+	
+	Vector2 s1 = get_scale();
+	Vector2 s2 = p_transform.get_scale();
+	
+	//slerp rotation
+	Vector2 v1(Math::cos(r1), Math::sin(r1));
+	Vector2 v2(Math::cos(r2), Math::sin(r2));
+	
+	real_t dot = v1.dot(v2);
+	
+	dot = (dot < -1.0) ? -1.0 : ((dot > 1.0) ? 1.0 : dot); //clamp dot to [-1,1]
+	
+	Vector2 v;
 
-
-	return Matrix32();
+	if (dot > 0.9995) {
+		v = Vector2::linear_interpolate(v1, v2, p_c).normalized(); //linearly interpolate to avoid numerical precision issues
+	} else {
+		real_t angle = p_c*Math::acos(dot);
+		Vector2 v3 = (v2 - v1*dot).normalized();
+		v = v1*Math::cos(angle) + v3*Math::sin(angle);
+	}
+	
+	//construct matrix
+	Matrix32 res(Math::atan2(v.y, v.x), Vector2::linear_interpolate(p1, p2, p_c));
+	res.scale_basis(Vector2::linear_interpolate(s1, s2, p_c));
+	return res;
 }
 
 Matrix32::operator String() const {
diff --git a/core/variant_call.cpp b/core/variant_call.cpp
index 2f7e0205dc..7dd0eb8a0c 100644
--- a/core/variant_call.cpp
+++ b/core/variant_call.cpp
@@ -750,6 +750,12 @@ static void _call_##m_type##_##m_method(Variant& r_ret,Variant& p_self,const Var
 		r_ret=Rect2(*p_args[0],*p_args[1],*p_args[2],*p_args[3]);
 	}
 
+	static void Matrix32_init2(Variant& r_ret,const Variant** p_args) {
+		
+		Matrix32 m(*p_args[0], *p_args[1]);
+		r_ret=m;
+	}
+
 	static void Matrix32_init3(Variant& r_ret,const Variant** p_args) {
 
 		Matrix32 m;
@@ -1544,6 +1550,7 @@ _VariantCall::addfunc(Variant::m_vtype,Variant::m_ret,_SCS(#m_method),VCALL(m_cl
 	_VariantCall::add_constructor(_VariantCall::Rect2_init1,Variant::RECT2,"pos",Variant::VECTOR2,"size",Variant::VECTOR2);
 	_VariantCall::add_constructor(_VariantCall::Rect2_init2,Variant::RECT2,"x",Variant::REAL,"y",Variant::REAL,"width",Variant::REAL,"height",Variant::REAL);
 
+	_VariantCall::add_constructor(_VariantCall::Matrix32_init2,Variant::MATRIX32,"rot",Variant::REAL,"pos",Variant::VECTOR2);
 	_VariantCall::add_constructor(_VariantCall::Matrix32_init3,Variant::MATRIX32,"x_axis",Variant::VECTOR2,"y_axis",Variant::VECTOR2,"origin",Variant::VECTOR2);
 
 	_VariantCall::add_constructor(_VariantCall::Vector3_init1,Variant::VECTOR3,"x",Variant::REAL,"y",Variant::REAL,"z",Variant::REAL);