From 8671836b76e8723a1d9021f8d7bf56ce5fdcc6f3 Mon Sep 17 00:00:00 2001
From: Mateusz Adamczyk <matek_a@outlook.com>
Date: Sat, 8 Oct 2016 12:33:10 +0200
Subject: [PATCH] Added simple check to viewport, if matrix32 is invesile
 (https://github.com/godotengine/godot/issues/6296).

---
 core/math/math_2d.cpp   | 2 +-
 scene/main/viewport.cpp | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/core/math/math_2d.cpp b/core/math/math_2d.cpp
index 2cc11aa7387..e616f05914f 100644
--- a/core/math/math_2d.cpp
+++ b/core/math/math_2d.cpp
@@ -424,7 +424,7 @@ Matrix32 Matrix32::inverse() const {
 
 void Matrix32::affine_invert() {
 
-	float det = elements[0][0]*elements[1][1] - elements[1][0]*elements[0][1];
+	float det = basis_determinant();
 	ERR_FAIL_COND(det==0);
 	float idet = 1.0 / det;
 
diff --git a/scene/main/viewport.cpp b/scene/main/viewport.cpp
index b22d1fcdf44..0c243bd4739 100644
--- a/scene/main/viewport.cpp
+++ b/scene/main/viewport.cpp
@@ -1715,6 +1715,9 @@ Control* Viewport::_gui_find_control_at_pos(CanvasItem* p_node,const Point2& p_g
 	}
 
 	Matrix32 matrix = p_xform * p_node->get_transform();
+	// matrix.basis_determinant() == 0.0f implies that node does not exist on scene
+	if(matrix.basis_determinant() == 0.0f)
+		return NULL;
 
 	if (!c || !c->clips_input() || c->has_point(matrix.affine_inverse().xform(p_global))) {