IO: Tracking extra mouse dragging data which is convenient for implementating various manual drag and drop patterns.

imgui.cpp

@@ -2313,11 +2313,15 @@ void ImGui::NewFrame()
                 g.IO.MouseClickedTime[i] = g.Time;
             }
             g.IO.MouseClickedPos[i] = g.IO.MousePos;
+            g.IO.MouseDragMaxDistanceAbs[i] = ImVec2(0.0f, 0.0f);
             g.IO.MouseDragMaxDistanceSqr[i] = 0.0f;
         }
         else if (g.IO.MouseDown[i])
         {
-            g.IO.MouseDragMaxDistanceSqr[i] = ImMax(g.IO.MouseDragMaxDistanceSqr[i], ImLengthSqr(g.IO.MousePos - g.IO.MouseClickedPos[i]));
+            ImVec2 mouse_delta = g.IO.MousePos - g.IO.MouseClickedPos[i];
+            g.IO.MouseDragMaxDistanceAbs[i].x = ImMax(g.IO.MouseDragMaxDistanceAbs[i].x, mouse_delta.x < 0.0f ? -mouse_delta.x : mouse_delta.x);
+            g.IO.MouseDragMaxDistanceAbs[i].y = ImMax(g.IO.MouseDragMaxDistanceAbs[i].y, mouse_delta.y < 0.0f ? -mouse_delta.y : mouse_delta.y);
+            g.IO.MouseDragMaxDistanceSqr[i] = ImMax(g.IO.MouseDragMaxDistanceSqr[i], ImLengthSqr(mouse_delta));
         }
     }
 

imgui.h

@@ -877,7 +877,8 @@ struct ImGuiIO
     bool        MouseDownOwned[5];          // Track if button was clicked inside a window. We don't request mouse capture from the application if click started outside ImGui bounds.
     float       MouseDownDuration[5];       // Duration the mouse button has been down (0.0f == just clicked)
     float       MouseDownDurationPrev[5];   // Previous time the mouse button has been down
-    float       MouseDragMaxDistanceSqr[5]; // Squared maximum distance of how much mouse has traveled from the click point
+    ImVec2      MouseDragMaxDistanceAbs[5]; // Maximum distance, absolute, on each axis, of how much mouse has traveled from the clicking point
+    float       MouseDragMaxDistanceSqr[5]; // Squared maximum distance of how much mouse has traveled from the clicking point
     float       KeysDownDuration[512];      // Duration the keyboard key has been down (0.0f == just pressed)
     float       KeysDownDurationPrev[512];  // Previous duration the key has been down