add position setter/getter

Author: nmwsharp

include/polyscope/transformation_gizmo.h

@@ -43,6 +43,10 @@ class TransformationGizmo : public Widget {
   glm::mat4 getTransform();
   void setTransform(glm::mat4 newT);
 
+  // the are helpers which access/update only the position component of the transform
+  glm::vec3 getPosition();
+  void setPosition(glm::vec3 newPos);
+
   bool getEnabled();
   void setEnabled(bool newVal);
 

src/transformation_gizmo.cpp

@@ -170,6 +170,12 @@ void TransformationGizmo::setTransform(glm::mat4 newT) {
   markUpdated();
 };
 
+glm::vec3 TransformationGizmo::getPosition() { return glm::vec3(Tref[3]); }
+void TransformationGizmo::setPosition(glm::vec3 newPos) {
+  Tref[3] = glm::vec4(newPos, 1.0);
+  markUpdated();
+}
+
 bool TransformationGizmo::getEnabled() { return enabled.get(); }
 void TransformationGizmo::setEnabled(bool newVal) { enabled = newVal; }
 

test/src/misc_test.cpp

@@ -116,6 +116,12 @@ TEST_F(PolyscopeTest, TransformationGizmoStandaloneTest) {
   polyscope::TransformationGizmo* gizmo5 = polyscope::addTransformationGizmo("my_gizmo_3", &externalT);
   EXPECT_EQ(gizmo5->getTransform(), externalT);
 
+  glm::mat4 T = gizmo5->getTransform();
+  glm::vec3 pos = gizmo5->getPosition();
+  pos.z += 4.0;
+  gizmo5->setPosition(pos);
+  polyscope::show(3);
+
   polyscope::removeAllTransformationGizmos();
 }