Issue/425 (#860)

* Working on the fix for the depth sorting problem.
* Changed grids and billboards to additive blending.

modules/base/rendering/renderablesphere.cpp

@@ -111,6 +111,12 @@ namespace {
         "Disable Fade-In/Fade-Out effects",
         "Enables/Disables the Fade-In/Out effects."
     };
+
+    constexpr openspace::properties::Property::PropertyInfo BackgroundInfo = {
+        "Background",
+        "Sets the current sphere rendering as a background rendering type",
+        "Enables/Disables background rendering."
+    };
 } // namespace
 
 namespace openspace {
@@ -175,6 +181,12 @@ documentation::Documentation RenderableSphere::Documentation() {
                 Optional::Yes,
                 DisableFadeInOutInfo.description
             },
+            {
+                BackgroundInfo.identifier,
+                new BoolVerifier,
+                Optional::Yes,
+                BackgroundInfo.description
+            },
         }
     };
 }
@@ -189,6 +201,7 @@ RenderableSphere::RenderableSphere(const ghoul::Dictionary& dictionary)
     , _mirrorTexture(MirrorTextureInfo, false)
     , _useAdditiveBlending(UseAdditiveBlendingInfo, false)
     , _disableFadeInDistance(DisableFadeInOutInfo, true)
+    , _backgroundRendering(BackgroundInfo, false)
     , _fadeInThreshold(FadeInThresholdInfo, -1.f, 0.f, 1.f)
     , _fadeOutThreshold(FadeOutThresholdInfo, -1.f, 0.f, 1.f)
 {
@@ -249,6 +262,10 @@ RenderableSphere::RenderableSphere(const ghoul::Dictionary& dictionary)
     }
     if (dictionary.hasKey(UseAdditiveBlendingInfo.identifier)) {
         _useAdditiveBlending = dictionary.value<bool>(UseAdditiveBlendingInfo.identifier);
+
+        if (_useAdditiveBlending) {
+            setRenderBin(Renderable::RenderBin::Transparent);
+        }
     }
 
     if (dictionary.hasKey(FadeOutThresholdInfo.identifier)) {
@@ -270,6 +287,14 @@ RenderableSphere::RenderableSphere(const ghoul::Dictionary& dictionary)
         _disableFadeInDistance.set(false);
         addProperty(_disableFadeInDistance);
     }
+
+    if (dictionary.hasKey(BackgroundInfo.identifier)) {
+        _backgroundRendering = dictionary.value<bool>(BackgroundInfo.identifier);
+
+        if (_backgroundRendering) {
+            setRenderBin(Renderable::RenderBin::Background);
+        }
+    }
 }
 
 bool RenderableSphere::isReady() const {

modules/base/rendering/renderablesphere.h

@@ -72,6 +72,7 @@ private:
     properties::BoolProperty _mirrorTexture;
     properties::BoolProperty _useAdditiveBlending;
     properties::BoolProperty _disableFadeInDistance;
+    properties::BoolProperty _backgroundRendering;
 
     properties::FloatProperty _fadeInThreshold;
     properties::FloatProperty _fadeOutThreshold;

modules/digitaluniverse/rendering/renderablebillboardscloud.cpp

@@ -643,6 +643,8 @@ void RenderableBillboardsCloud::initialize() {
         // entry is the one selected by default.
         _colorOption.setValue(static_cast<int>(_colorRangeData.size() - 1));
     }
+
+    setRenderBin(Renderable::RenderBin::Transparent);
 }
 
 void RenderableBillboardsCloud::initializeGL() {
@@ -722,6 +724,7 @@ void RenderableBillboardsCloud::renderBillboards(const RenderData& data,
                                                  float fadeInVariable)
 {
     glDepthMask(false);
+    glEnable(GL_DEPTH_TEST);
 
     // Saving current OpenGL state
     GLboolean blendEnabled = glIsEnabledi(GL_BLEND, 0);
@@ -746,8 +749,7 @@ void RenderableBillboardsCloud::renderBillboards(const RenderData& data,
 
     glEnablei(GL_BLEND, 0);
     glBlendFunc(GL_SRC_ALPHA, GL_ONE);
-    //glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
-
+    
     _program->activate();
 
     const glm::dmat4 projMatrix = glm::dmat4(data.camera.projectionMatrix());

modules/digitaluniverse/rendering/renderabledumeshes.cpp

@@ -387,6 +387,8 @@ RenderableDUMeshes::RenderableDUMeshes(const ghoul::Dictionary& dictionary)
         }
 
     }
+
+    setRenderBin(Renderable::RenderBin::Opaque);
 }
 
 bool RenderableDUMeshes::isReady() const {
@@ -473,9 +475,10 @@ void RenderableDUMeshes::renderMeshes(const RenderData&,
     glGetIntegerv(GL_BLEND_SRC_RGB, &blendSrcRGB);
 
     glEnablei(GL_BLEND, 0);
-    //glBlendFunc(GL_SRC_ALPHA, GL_ONE);
-    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+    glBlendFunc(GL_SRC_ALPHA, GL_ONE);
+    //glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
     glDepthMask(false);
+    glEnable(GL_DEPTH_TEST);
 
     _program->activate();
 

modules/digitaluniverse/shaders/billboard_fs.glsl

@@ -52,8 +52,8 @@ Fragment getFragment() {
 
     fullColor.a *= fadeInValue * ta;
     
-    if (fullColor.a == 0.f || 
-        fullColor.rgb == vec3(0.0)) {
+    float textureOpacity = dot(fullColor.rgb, vec3(1.0));
+    if (fullColor.a == 0.f || textureOpacity == 0.0) {
         discard;
     }