Issue/24 (#549)

* Implemented property animation mechanism
 * Added easing functions to Ghoul and make them usable in animation
 * Make sure that we don't leave properties around if SceneGraphNodes are deleted
 * Adding opacity settings to base renderables

modules/base/rendering/renderablesphere.cpp

@@ -71,13 +71,6 @@ namespace {
         "This value specifies the radius of the sphere in meters."
     };
 
-    static const openspace::properties::Property::PropertyInfo TransparencyInfo = {
-        "Alpha",
-        "Transparency",
-        "This value determines the transparency of the sphere. If this value is set to "
-        "1, the sphere is completely opaque. At 0, the sphere is completely transparent."
-    };
-
     static const openspace::properties::Property::PropertyInfo FadeOutThreshouldInfo = {
         "FadeOutThreshould",
         "Fade-Out Threshould",
@@ -131,12 +124,6 @@ documentation::Documentation RenderableSphere::Documentation() {
                 Optional::Yes,
                 OrientationInfo.description
             },
-            {
-                TransparencyInfo.identifier,
-                new DoubleInRangeVerifier(0.0, 1.0),
-                Optional::Yes,
-                TransparencyInfo.description
-            },
             {
                 FadeOutThreshouldInfo.identifier,
                 new DoubleInRangeVerifier(0.0, 1.0),
@@ -166,7 +153,6 @@ RenderableSphere::RenderableSphere(const ghoul::Dictionary& dictionary)
     , _orientation(OrientationInfo, properties::OptionProperty::DisplayType::Dropdown)
     , _size(SizeInfo, 1.f, 0.f, 1e35f)
     , _segments(SegmentsInfo, 8, 4, 1000)
-    , _transparency(TransparencyInfo, 1.f, 0.f, 1.f)
     , _disableFadeInDistance(DisableFadeInOuInfo, true)
     , _fadeOutThreshold(-1.0)
     , _fadeInThreshold(0.0)
@@ -181,6 +167,9 @@ RenderableSphere::RenderableSphere(const ghoul::Dictionary& dictionary)
         "RenderableSphere"
     );
 
+    addProperty(_opacity);
+    registerUpdateRenderBinFromOpacity();
+
     _size = static_cast<float>(dictionary.value<double>(SizeInfo.identifier));
     _segments = static_cast<int>(dictionary.value<double>(SegmentsInfo.identifier));
     _texturePath = absPath(dictionary.value<std::string>(TextureInfo.identifier));
@@ -217,21 +206,6 @@ RenderableSphere::RenderableSphere(const ghoul::Dictionary& dictionary)
     addProperty(_segments);
     _segments.onChange([this](){ _sphereIsDirty = true; });
 
-    _transparency.onChange([this](){
-        if (_transparency > 0.f && _transparency < 1.f) {
-            setRenderBin(Renderable::RenderBin::Transparent);
-        }
-        else {
-            setRenderBin(Renderable::RenderBin::Opaque);
-        }
-    });
-    if (dictionary.hasKey(TransparencyInfo.identifier)) {
-        _transparency = static_cast<float>(
-            dictionary.value<double>(TransparencyInfo.identifier)
-        );
-    }
-    addProperty(_transparency);
-
     addProperty(_texturePath);
     _texturePath.onChange([this]() { loadTexture(); });
 
@@ -252,7 +226,6 @@ RenderableSphere::RenderableSphere(const ghoul::Dictionary& dictionary)
         _disableFadeInDistance.set(false);
         addProperty(_disableFadeInDistance);
     }
-
 }
 
 bool RenderableSphere::isReady() const {
@@ -272,6 +245,11 @@ void RenderableSphere::initializeGL() {
         absPath("${MODULE_BASE}/shaders/sphere_fs.glsl")
     );
 
+    _uniformCache.opacity = _shader->uniformLocation("opacity");
+    _uniformCache.viewProjection = _shader->uniformLocation("ViewProjection");
+    _uniformCache.modelTransform = _shader->uniformLocation("ModelTransform");
+    _uniformCache.texture = _shader->uniformLocation("texture1");
+
     loadTexture();
 }
 
@@ -294,12 +272,12 @@ void RenderableSphere::render(const RenderData& data, RendererTasks&) {
     _shader->activate();
     _shader->setIgnoreUniformLocationError(IgnoreError::Yes);
 
-    _shader->setUniform("ViewProjection", data.camera.viewProjectionMatrix());
-    _shader->setUniform("ModelTransform", transform);
+    _shader->setUniform(_uniformCache.viewProjection, data.camera.viewProjectionMatrix());
+    _shader->setUniform(_uniformCache.modelTransform, transform);
 
     setPscUniforms(*_shader.get(), data.camera, data.position);
 
-    float adjustedTransparency = _transparency;
+    float adjustedTransparency = _opacity;
 
     if (_fadeInThreshold > 0.0) {
         double distCamera = glm::length(data.camera.positionVec3());
@@ -323,16 +301,16 @@ void RenderableSphere::render(const RenderData& data, RendererTasks&) {
     }
 
     // Performance wise
-    if (adjustedTransparency < 0.01) {
+    if (adjustedTransparency < 0.01f) {
         return;
     }
 
-    _shader->setUniform("alpha", adjustedTransparency);
+    _shader->setUniform(_uniformCache.opacity, _opacity);
 
     ghoul::opengl::TextureUnit unit;
     unit.activate();
     _texture->bind();
-    _shader->setUniform("texture1", unit);
+    _shader->setUniform(_uniformCache.texture, unit);
 
     glEnable(GL_CULL_FACE);
     glCullFace(GL_BACK);
@@ -366,6 +344,11 @@ void RenderableSphere::render(const RenderData& data, RendererTasks&) {
 void RenderableSphere::update(const UpdateData&) {
     if (_shader->isDirty()) {
         _shader->rebuildFromFile();
+
+        _uniformCache.opacity = _shader->uniformLocation("opacity");
+        _uniformCache.viewProjection = _shader->uniformLocation("ViewProjection");
+        _uniformCache.modelTransform = _shader->uniformLocation("ModelTransform");
+        _uniformCache.texture = _shader->uniformLocation("texture1");
     }
 
     if (_sphereIsDirty) {