Added zoom feature for node editor

EvoEngine_SDK/include/Utilities/NodeGraph.hpp

@@ -827,6 +827,12 @@ bool NodeGraph<Id, Od, Nd, Ld>::OnInspect(
   }
   ImNodes::MiniMap();
   ImNodes::EndNodeEditor();
+
+  if (ImNodes::IsEditorHovered() && ImGui::GetIO().MouseWheel != 0) {
+    const float zoom = ImNodes::EditorContextGetZoom() + ImGui::GetIO().MouseWheel * 0.1f;
+    ImNodes::EditorContextSetZoom(zoom, ImGui::GetMousePos());
+  }
+
   NodeGraphNodeHandle hovered_node_handle = -1;
   NodeGraphLinkHandle hovered_link_handle = -1;
   NodeGraphInputPinHandle hovered_input_pin_handle = -1;
@@ -893,6 +899,11 @@ void NodeGraph<Id, Od, Nd, Ld>::Serialize(YAML::Emitter& out,
   if (editor_layer) {
     prev_editor_context = ImNodes::GetCurrentContext()->EditorCtx;
     ImNodes::EditorContextSet(const_cast<ImNodesEditorContext*>(&editor_context_));
+
+    out << YAML::Key << "ZoomScale" << YAML::Value << editor_context_.ZoomScale;
+    out << YAML::Key << "Panning" << YAML::Value << glm::vec2(editor_context_.Panning.x, editor_context_.Panning.y);
+    out << YAML::Key << "AutoPanningDelta" << YAML::Value
+        << glm::vec2(editor_context_.AutoPanningDelta.x, editor_context_.AutoPanningDelta.y);
   }
 
   std::unordered_map<NodeGraphOutputPinHandle, int> output_pin_map;
@@ -1022,6 +1033,17 @@ void NodeGraph<Id, Od, Nd, Ld>::Deserialize(const YAML::Node& in,
   if (editor_layer) {
     prev_editor_context = ImNodes::GetCurrentContext()->EditorCtx;
     ImNodes::EditorContextSet(const_cast<ImNodesEditorContext*>(&editor_context_));
+    if (in["ZoomScale"]) {
+      editor_context_.ZoomScale = in["ZoomScale"].as<float>();
+    }
+    if (in["Panning"]) {
+      const auto t = in["Panning"].as<glm::vec2>();
+      editor_context_.Panning = ImVec2(t.x, t.y);
+    }
+    if (in["AutoPanningDelta"]) {
+      const auto t = in["AutoPanningDelta"].as<glm::vec2>();
+      editor_context_.Panning = ImVec2(t.x, t.y);
+    }
   }
 
   nodes_.clear();

EvoEngine_SDK/include/Utilities/imnodes.hpp

@@ -243,6 +243,10 @@ ImVec2 EditorContextGetPanning();
 void EditorContextResetPanning(const ImVec2& pos);
 void EditorContextMoveToNode(const int node_id);
 
+// Get the separate ImGui context that ImNodes uses for zoom functionality
+// this is the active context when between BeginNodeEditor and EndNodeEditor
+ImGuiContext* GetNodeEditorImGuiContext();
+
 ImNodesIO& GetIO();
 
 // Returns the global style struct. See the struct declaration for default values.
@@ -265,6 +269,10 @@ void MiniMap(const float minimap_size_fraction = 0.2f,
              const ImNodesMiniMapNodeHoveringCallback node_hovering_callback = NULL,
              const ImNodesMiniMapNodeHoveringCallbackUserData node_hovering_callback_data = NULL);
 
+// Editor zoom controls
+float EditorContextGetZoom();
+void EditorContextSetZoom(float zoom_scale, ImVec2 zoom_center);
+
 // Use PushColorStyle and PopColorStyle to modify ImNodesStyle::Colors mid-frame.
 void PushColorStyle(ImNodesCol item, unsigned int color);
 void PopColorStyle();

EvoEngine_SDK/include/Utilities/imnodes_internal.hpp

@@ -2,7 +2,7 @@
 
 #define IMGUI_DEFINE_MATH_OPERATORS
 #include <imgui.h>
-#include "imgui_internal.h"
+#include <imgui_internal.h>
 
 #include "imnodes.hpp"
 
@@ -248,6 +248,7 @@ struct ImNodesEditorContext {
   ImVector<int> NodeDepthOrder;
 
   // ui related fields
+  float ZoomScale;
   ImVec2 Panning;
   ImVec2 AutoPanningDelta;
   // Minimum and maximum extents of all content in grid space. Valid after final
@@ -282,6 +283,7 @@ struct ImNodesEditorContext {
       : Nodes(),
         Pins(),
         Links(),
+        ZoomScale(1.f),
         Panning(0.f, 0.f),
         SelectedNodeIndices(),
         SelectedLinkIndices(),
@@ -301,13 +303,16 @@ struct ImNodesContext {
   ImNodesEditorContext* EditorCtx;
 
   // Canvas draw list and helper state
+  ImGuiContext* NodeEditorImgCtx;
+  ImGuiContext* OriginalImgCtx;
   ImDrawList* CanvasDrawList;
   ImGuiStorage NodeIdxToSubmissionIdx;
   ImVector<int> NodeIdxSubmissionOrder;
   ImVector<int> NodeIndicesOverlappingWithMouse;
   ImVector<int> OccludedPinIndices;
 
   // Canvas extents
+  ImVec2 CanvasOriginalOrigin;
   ImVec2 CanvasOriginScreenSpace;
   ImRect CanvasRectScreenSpace;
 
@@ -347,6 +352,7 @@ struct ImNodesContext {
   // ImGui::IO cache
 
   ImVec2 MousePos;
+  bool IsHovered;
 
   bool LeftMouseClicked;
   bool LeftMouseReleased;