Fading of propertyowners through GUI, and more owners with fade property (#2557)

* Add property in OpenSpaceEngine for fading duration when enabling / disabling

* Add interface for fadeable components and apply to renderable

* Make layers a fadeable component

* Make globelabels a fadeable component

* Make labelscomponent a fadeable, and give it an enabled property

* Make screenspace renderables fadeable components

* Introduce concept of parent fadeables, to fade out subowners with parent

* Make rings fadeable as well

---------

Co-authored-by: Alexander Bock <alexander.bock@liu.se>

include/openspace/rendering/fadeable.h

@@ -0,0 +1,62 @@
+/*****************************************************************************************
+ *                                                                                       *
+ * OpenSpace                                                                             *
+ *                                                                                       *
+ * Copyright (c) 2014-2023                                                               *
+ *                                                                                       *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this  *
+ * software and associated documentation files (the "Software"), to deal in the Software *
+ * without restriction, including without limitation the rights to use, copy, modify,    *
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to    *
+ * permit persons to whom the Software is furnished to do so, subject to the following   *
+ * conditions:                                                                           *
+ *                                                                                       *
+ * The above copyright notice and this permission notice shall be included in all copies *
+ * or substantial portions of the Software.                                              *
+ *                                                                                       *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,   *
+ * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A         *
+ * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT    *
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF  *
+ * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE  *
+ * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                                         *
+ ****************************************************************************************/
+
+#ifndef __OPENSPACE_CORE___FADEABLE___H__
+#define __OPENSPACE_CORE___FADEABLE___H__
+
+#include <openspace/properties/scalar/floatproperty.h>
+
+namespace openspace {
+
+/**
+ * This class is an interface for all things fadeable in the software; things that need
+ * a fade and opacity property, which will be combined into a final opacity value
+ * 
+ * A Fadeable can also be dependent on the fade value from a specified parent fadeable,
+ * so that it fades out together with the parent
+ */
+class Fadeable {
+public:
+    Fadeable();
+    virtual ~Fadeable() = default;
+
+    void setFade(float fade);
+    void setParentFadeable(Fadeable* parent);
+
+    float fade() const;
+    virtual bool isVisible() const;
+
+    /// Returns the full opacity constructed from the _opacity and _fade property values
+    virtual float opacity() const;
+
+protected:
+    properties::FloatProperty _opacity;
+    properties::FloatProperty _fade;
+
+    Fadeable* _parentFadeable = nullptr;
+};
+
+} // namespace openspace
+
+#endif // __OPENSPACE_CORE___FADEABLE___H__

include/openspace/rendering/renderable.h

@@ -26,6 +26,7 @@
 #define __OPENSPACE_CORE___RENDERABLE___H__
 
 #include <openspace/properties/propertyowner.h>
+#include <openspace/rendering/fadeable.h>
 
 #include <openspace/properties/scalar/boolproperty.h>
 #include <openspace/properties/scalar/doubleproperty.h>
@@ -52,7 +53,7 @@ namespace documentation { struct Documentation; }
 
 class Camera;
 
-class Renderable : public properties::PropertyOwner {
+class Renderable : public properties::PropertyOwner, public Fadeable {
 public:
     enum class RenderBin : int {
         Background = 1,
@@ -102,9 +103,7 @@ public:
 
     bool matchesSecondaryRenderBin(int binMask) const noexcept;
 
-    void setFade(float fade);
-
-    bool isVisible() const;
+    bool isVisible() const override;
 
     void onEnabledChange(std::function<void(bool)> callback);
 
@@ -112,8 +111,6 @@ public:
 
 protected:
     properties::BoolProperty _enabled;
-    properties::FloatProperty _opacity;
-    properties::FloatProperty _fade;
     properties::StringProperty _renderableType;
     properties::BoolProperty _dimInAtmosphere;
 
@@ -124,7 +121,7 @@ protected:
     void registerUpdateRenderBinFromOpacity();
 
     /// Returns the full opacity constructed from the _opacity and _fade property values
-    float opacity() const;
+    float opacity() const override;
 
     double _boundingSphere = 0.0;
     double _interactionSphere = 0.0;

include/openspace/rendering/screenspacerenderable.h

@@ -26,6 +26,7 @@
 #define __OPENSPACE_CORE___SCREENSPACERENDERABLE___H__
 
 #include <openspace/properties/propertyowner.h>
+#include <openspace/rendering/fadeable.h>
 
 #include <openspace/properties/triggerproperty.h>
 #include <openspace/properties/scalar/boolproperty.h>
@@ -49,7 +50,7 @@ namespace documentation { struct Documentation; }
  * the planes from Spherical to Cartesian coordinates and back. It also specifies the
  * interface that its children need to implement.
  */
-class ScreenSpaceRenderable : public properties::PropertyOwner {
+class ScreenSpaceRenderable : public properties::PropertyOwner, public Fadeable {
 public:
     static std::unique_ptr<ScreenSpaceRenderable> createFromDictionary(
         const ghoul::Dictionary& dictionary);
@@ -111,7 +112,6 @@ protected:
     glm::vec3 cartesianToSpherical(const glm::vec3& cartesian) const;
     glm::vec3 sphericalToCartesian(glm::vec3 spherical) const;
     glm::vec3 sanitizeSphericalCoordinates(glm::vec3 spherical) const;
-    float opacity() const;
 
     properties::BoolProperty _enabled;
     properties::BoolProperty _usePerspectiveProjection;
@@ -133,8 +133,6 @@ protected:
     properties::FloatProperty _gamma;
     properties::Vec3Property _multiplyColor;
     properties::Vec4Property _backgroundColor;
-    properties::FloatProperty _opacity;
-    properties::FloatProperty _fade;
     properties::TriggerProperty _delete;
 
     glm::ivec2 _objectSize = glm::ivec2(0);