fix: duplicated item legend entry

Author: brenocq

implot3d.cpp

@@ -1364,6 +1364,10 @@ void EndPlot() {
     // Reset current plot
     gp.CurrentPlot = nullptr;
     gp.CurrentItems = nullptr;
+
+    // Reset the plot items for the next frame
+    for (int i = 0; i < plot.Items.GetItemCount(); i++)
+        plot.Items.GetItemByIndex(i)->SeenThisFrame = false;
 }
 
 //-----------------------------------------------------------------------------

implot3d_internal.h

@@ -287,13 +287,15 @@ struct ImPlot3DItem {
     int NameOffset;
     bool Show;
     bool LegendHovered;
+    bool SeenThisFrame;
 
     ImPlot3DItem() {
         ID = 0;
         Color = IM_COL32_WHITE;
         NameOffset = -1;
         Show = true;
         LegendHovered = false;
+        SeenThisFrame = false;
     }
     ~ImPlot3DItem() { ID = 0; }
 };

implot3d_items.cpp

@@ -231,6 +231,13 @@ ImPlot3DItem* RegisterOrGetItem(const char* label_id, ImPlot3DItemFlags flags, b
     if (just_created != nullptr)
         *just_created = Items.GetItem(id) == nullptr;
     ImPlot3DItem* item = Items.GetOrAddItem(id);
+
+    // Avoid re-adding the same item to the legend (the legend is reset every frame)
+    if (item->SeenThisFrame)
+        return item;
+    item->SeenThisFrame = true;
+
+    // Add item to the legend
     int idx = Items.GetItemIndex(item);
     item->ID = id;
     if (!ImHasFlag(flags, ImPlot3DItemFlags_NoLegend) && ImGui::FindRenderedTextEnd(label_id, nullptr) != label_id) {