Experiment: Preview and Select Node via Mouse Hover in Viewport

This experiment aims to introduce a feature that allows users to preview and select nodes by hovering their mouse over them in the viewport. This will provide a more intuitive and efficient way of interacting with nodes.

Todo
* To address potential performance concerns, the hover-based node selection feature will be disabled by default until a high-performance algorithm is implemented.
* Users can enable it in the settings as an experimental option, allowing for testing and feedback while minimizing performance impacts.

source/creator/panels/viewport.d

@@ -186,6 +186,9 @@ protected:
             }
             igPopStyleVar();
 
+            import creator.viewport.model : incSelectIO;
+            incSelectIO();
+
             igPushStyleVar(ImGuiStyleVar.FrameBorderSize, 0);
                 incBeginViewportToolArea("ToolArea", ImGuiDir.Left);
                     igPushStyleVar_Vec2(ImGuiStyleVar.FramePadding, ImVec2(6, 6));

source/creator/viewport/model/package.d

@@ -23,6 +23,7 @@ import std.stdio;
 
 private {
     Part[] foundParts;
+    Part[] mouseOverParts;
 
     enum ENTRY_SIZE = 48;
 }
@@ -39,8 +40,8 @@ enum ViewporMenuSortMode {
 
 ViewporMenuSortMode incViewportModelMenuSortMode = ViewporMenuSortMode.ZSort;
 
-void incViewportModelMenuOpening() {
-    foundParts.length = 0;
+void incFoundParts(ref Part[] parts) {
+    parts.length = 0;
 
     vec2 mpos = incInputGetMousePosition()*-1;
     mloop: foreach(ref Part part; incActivePuppet.getAllParts()) {
@@ -51,29 +52,52 @@ void incViewportModelMenuOpening() {
             foreach(pn; incSelectedNodes()) {
                 if (pn.uuid == part.uuid) continue mloop;
             }
-            foundParts ~= part;
+            parts ~= part;
         }
     }
+}
 
+void incSortFoundParts(ref Part[] parts, ViewporMenuSortMode mode) {
     import std.algorithm.sorting : sort;
     import std.algorithm.mutation : SwapStrategy;
     import std.math : cmp;
 
-    if (incViewportModelMenuSortMode == ViewporMenuSortMode.ZSort) {
+    if (mode == ViewporMenuSortMode.ZSort) {
         sort!((a, b) => cmp(
             a.zSortNoOffset, 
-            b.zSortNoOffset) < 0, SwapStrategy.stable)(foundParts);
+            b.zSortNoOffset) < 0, SwapStrategy.stable)(parts);
 
-    } else if (incViewportModelMenuSortMode == ViewporMenuSortMode.SizeSort) {
+    } else if (mode == ViewporMenuSortMode.SizeSort) {
         sort!((a, b) => cmp(
             (a.bounds.z - a.bounds.x) * (a.bounds.w - a.bounds.y), 
-            (b.bounds.z - b.bounds.x) * (b.bounds.w - b.bounds.y)) < 0, SwapStrategy.stable)(foundParts);
+            (b.bounds.z - b.bounds.x) * (b.bounds.w - b.bounds.y)) < 0, SwapStrategy.stable)(parts);
 
     } else {
         throw new Exception("Unknown sort mode");
     }
 }
 
+void incViewportModelMenuOpening() {
+    incFoundParts(foundParts);
+    incSortFoundParts(foundParts, incViewportModelMenuSortMode);
+}
+
+void incDrawMouse() {
+    if (mouseOverParts.length > 0)
+        mouseOverParts[0].drawBounds();
+}
+
+void incSelectIO() {
+    incFoundParts(mouseOverParts);
+    incSortFoundParts(mouseOverParts, ViewporMenuSortMode.ZSort);
+    if (mouseOverParts.length > 0) {
+        if (igIsItemClicked(ImGuiMouseButton.Left)) {
+            incSelectNode(mouseOverParts[0]);
+            //incFocusCamera(part);
+        }
+    }
+}
+
 void incViewportModelMenu() {
     if (auto editor = incViewportModelDeformGetEditor()) {
         editor.popupMenu();
@@ -266,6 +290,8 @@ void incViewportModelDraw(Camera camera) {
     incActivePuppet.update();
     incActivePuppet.draw();
 
+    incDrawMouse();
+
     if (param) {
         incViewportModelDeformDraw(camera, param);
     } else {