And introduce a clean sorted select of the items so we keep the order of rendering of the boxes of the zone in the ZOne stack order, the color of box reflect the order (from red to blue)

libraries/render-utils/src/ZoneRenderer.cpp

@@ -19,7 +19,7 @@ const Selection::Name ZoneRendererTask::ZONES_SELECTION { "RankedZones" };
 
 void ZoneRendererTask::build(JobModel& task, const Varying& input, Varying& ouput) {
 
-    const auto zoneItems = task.addJob<render::SelectItems>("FilterZones", input, ZONES_SELECTION.c_str());
+    const auto zoneItems = task.addJob<render::SelectSortItems>("FilterZones", input, ZONES_SELECTION.c_str());
 
     // just draw them...
     task.addJob<DrawBounds>("DrawZones", zoneItems);

libraries/render/src/render/DrawTask.cpp

@@ -150,6 +150,7 @@ const gpu::PipelinePointer DrawBounds::getPipeline() {
 
         _cornerLocation = program->getUniforms().findLocation("inBoundPos");
         _scaleLocation = program->getUniforms().findLocation("inBoundDim");
+        _colorLocation = program->getUniforms().findLocation("inColor");
 
         auto state = std::make_shared<gpu::State>();
         state->setDepthTest(true, false, gpu::LESS_EQUAL);
@@ -184,12 +185,16 @@ void DrawBounds::run(const SceneContextPointer& sceneContext, const RenderContex
         assert(_scaleLocation >= 0);
 
         // Render bounds
+        float numItems = (float) items.size();
+        float itemNum = 0.0f;
         for (const auto& item : items) {
             batch._glUniform3fv(_cornerLocation, 1, (const float*)(&item.bound.getCorner()));
             batch._glUniform3fv(_scaleLocation, 1, (const float*)(&item.bound.getScale()));
+            batch._glUniform4fv(_colorLocation, 1, (const float*)(&glm::vec4(glm::vec3(itemNum / numItems), 1.0f)));
 
             static const int NUM_VERTICES_PER_CUBE = 24;
             batch.draw(gpu::LINES, NUM_VERTICES_PER_CUBE, 0);
+            itemNum += 1.0f;
         }
     });
 }

libraries/render/src/render/DrawTask.h

@@ -67,6 +67,7 @@ private:
     gpu::PipelinePointer _boundsPipeline;
     int _cornerLocation { -1 };
     int _scaleLocation { -1 };
+    int _colorLocation { -1 };
 };
 
 }

libraries/render/src/render/FilterTask.cpp

@@ -52,12 +52,13 @@ void SliceItems::run(const SceneContextPointer& sceneContext, const RenderContex
 }
 
 void SelectItems::run(const SceneContextPointer& sceneContext, const RenderContextPointer& renderContext, const ItemBounds& inItems, ItemBounds& outItems) {
-    auto& scene = sceneContext->_scene;
-
-    outItems.clear();
-    auto selection = scene->getSelection(_name);
+    auto selection = sceneContext->_scene->getSelection(_name);
     const auto& selectedItems = selection.getItems();
+    outItems.clear();
+
     if (!selectedItems.empty()) {
+        outItems.reserve(selectedItems.size());
+
         for (auto src : inItems) {
             if (selection.contains(src.id)) {
                 outItems.emplace_back(src);
@@ -66,6 +67,37 @@ void SelectItems::run(const SceneContextPointer& sceneContext, const RenderConte
     }
 }
 
+void SelectSortItems::run(const SceneContextPointer& sceneContext, const RenderContextPointer& renderContext, const ItemBounds& inItems, ItemBounds& outItems) {
+    auto selection = sceneContext->_scene->getSelection(_name);
+    const auto& selectedItems = selection.getItems();
+    outItems.clear();
+
+    if (!selectedItems.empty()) {
+        struct Pair { int src; int dst; };
+        std::vector<Pair> indices;
+        indices.reserve(selectedItems.size());
+
+        // Collect
+        for (int srcIndex = 0; (srcIndex < inItems.size()) && (indices.size() < selectedItems.size()) ; srcIndex++ ) {
+            int index = selection.find(inItems[srcIndex].id);
+            if (index != Selection::NOT_FOUND) {
+                indices.emplace_back( Pair{ srcIndex, index } );
+            }
+        }
+
+        // Then sort
+        if (!indices.empty()) {
+            std::sort(indices.begin(), indices.end(), [] (Pair a, Pair b) { 
+                return (a.dst < b.dst);
+            });
+
+            for (auto& pair: indices) {
+               outItems.emplace_back(inItems[pair.src]);
+            }
+        }
+    }
+}
+
 void MetaToSubItems::run(const SceneContextPointer& sceneContext, const RenderContextPointer& renderContext, const ItemBounds& inItems, ItemIDs& outItems) {
     auto& scene = sceneContext->_scene;
 

libraries/render/src/render/FilterTask.h

@@ -121,6 +121,17 @@ namespace render {
         void run(const SceneContextPointer& sceneContext, const RenderContextPointer& renderContext, const ItemBounds& inItems, ItemBounds& outItems);
     };
 
+    // Same as SelectItems but reorder the output to match the selection order
+    class SelectSortItems {
+    public:
+        using JobModel = Job::ModelIO<SelectSortItems, ItemBounds, ItemBounds>;
+        
+        std::string _name;
+        SelectSortItems(const Selection::Name& name) : _name(name) {}
+        
+        void run(const SceneContextPointer& sceneContext, const RenderContextPointer& renderContext, const ItemBounds& inItems, ItemBounds& outItems);
+    };
+
     // From meta-Items, generate the sub-items
     class MetaToSubItems {
     public:

libraries/render/src/render/Selection.cpp

@@ -56,11 +56,13 @@ Selection::Selection(const Name& name, const ItemIDs& items) :
 {
 }
 
-bool Selection::contains(ItemID id) const {
+int Selection::find(ItemID id) const {
+    int index = 0;
     for (auto selected : _items) {
         if (selected == id) {
-            return true;
+            return index;
         }
+        index++;
     }
-    return false;
-}
+    return NOT_FOUND;
+}

libraries/render/src/render/Selection.h

@@ -34,7 +34,12 @@ namespace render {
         const ItemIDs& getItems() const { return _items; }
 
         bool isEmpty() const { return _items.empty(); }
-        bool contains(ItemID id) const;
+
+        // Test if the ID is in the selection, return the index or -1 if not present
+        static const int NOT_FOUND{ -1 };
+                
+        int find(ItemID id) const;
+        bool contains(ItemID id) const { return find(id) > NOT_FOUND; }
 
     protected:
         Name _name;

libraries/render/src/render/drawItemBounds.slv

@@ -20,7 +20,7 @@
 
 uniform vec3 inBoundPos;
 uniform vec3 inBoundDim;
-uniform ivec4 inCellLocation;
+uniform vec4 inColor;
 
 out vec4 varColor;
 out vec2 varTexcoord;
@@ -59,9 +59,7 @@ void main(void) {
     TransformObject obj = getTransformObject();
     <$transformModelToClipPos(cam, obj, pos, gl_Position)$>
 
-    bool subcell = bool((inCellLocation.z));
-    float cellDepth = float(inCellLocation.w);
-    varColor = vec4(colorWheel(fract(cellDepth / 5.0)), 1.0 - float(subcell));
+    varColor = vec4(colorWheel(inColor.x), 1.0);
     varTexcoord = vec2(cubeVec.w, length(inBoundDim));
 
 }