Increase float precision in the inspector for Quaternions

Author: aaronfranke

editor/gui/editor_spin_slider.cpp

@@ -128,7 +128,10 @@ void EditorSpinSlider::gui_input(const Ref<InputEvent> &p_event) {
 					pre_grab_value = get_max();
 				}
 
-				double new_value = pre_grab_value + get_step() * grabbing_spinner_dist_cache;
+				// Prevent dragging properties with very precise steps from being agonizingly slow.
+				const double default_float_step = EDITOR_GET("interface/inspector/default_float_step");
+				const double drag_step = MAX(get_step(), default_float_step);
+				const double new_value = pre_grab_value + drag_step * grabbing_spinner_dist_cache;
 				set_value((mm->is_command_or_control_pressed() && !editing_integer) ? Math::round(new_value) : new_value);
 			}
 		} else if (updown_offset != -1) {

editor/inspector/editor_properties.cpp

@@ -4029,7 +4029,14 @@ EditorProperty *EditorInspectorDefaultPlugin::get_editor_for_property(Object *p_
 		} break;
 		case Variant::QUATERNION: {
 			EditorPropertyQuaternion *editor = memnew(EditorPropertyQuaternion);
-			editor->setup(_parse_range_hint(p_hint, p_hint_text, default_float_step), p_hint == PROPERTY_HINT_HIDE_QUATERNION_EDIT);
+			// Quaternions are almost never used for human-readable values that need stepifying,
+			// so we should be more precise with their step, as much as the float precision allows.
+#ifdef REAL_T_IS_DOUBLE
+			constexpr double QUATERNION_STEP = 1e-14;
+#else
+			constexpr double QUATERNION_STEP = 1e-6;
+#endif
+			editor->setup(_parse_range_hint(p_hint, p_hint_text, QUATERNION_STEP), p_hint == PROPERTY_HINT_HIDE_QUATERNION_EDIT);
 			return editor;
 		} break;
 		case Variant::AABB: {

editor/scene/3d/skeleton_3d_editor_plugin.cpp

@@ -78,7 +78,18 @@ void BonePropertiesEditor::create_editors() {
 
 	// Rotation property.
 	rotation_property = memnew(EditorPropertyQuaternion());
-	rotation_property->setup(large_range_hint);
+	// Quaternions are almost never used for human-readable values that need stepifying,
+	// so we should be more precise with their step, as much as the float precision allows.
+#ifdef REAL_T_IS_DOUBLE
+	constexpr double QUATERNION_STEP = 1e-14;
+#else
+	constexpr double QUATERNION_STEP = 1e-6;
+#endif
+	EditorPropertyRangeHint quaternion_range_hint;
+	quaternion_range_hint.min = -1.0;
+	quaternion_range_hint.max = 1.0;
+	quaternion_range_hint.step = QUATERNION_STEP;
+	rotation_property->setup(quaternion_range_hint);
 	rotation_property->set_label("Rotation");
 	rotation_property->set_selectable(false);
 	rotation_property->connect("property_changed", callable_mp(this, &BonePropertiesEditor::_value_changed));