Detection of smoothness/Sluggish behavior of an UI operation via Auotmation

Hi, in this post i have tried to find out the solution of detecting the sluggish behavior while doing the operations on 3D objects via UI automation.
Before we start lets clear about what I meant by sluggish behavior - Sluggish behavior is something we found while dragging an object in an application from one point to another point and the dragging is not smooth OR mouse operation take some time to to show the effect in the application.
I thought of following steps to detect the above behavior visually via UI automation:
Steps (e.g. with dragging the object from one point to another point):
1. Set the position of mouse from and to Points for dragging.
2. Store the point of To (means end point) in above steps.
3. Store he color of the point in step2.
4. Perform the drag operation to end point.
5. Store the color of point on step 2 in a separate color variable.
6. Compare the Step 3 and Step 5 color values.
7. If Step 6 comparison result is same then there is sluggish behavior otherwise operation could be considered as smooth.

Example in C#:
Class Automation
{
//Set the cursor position
[DllImport("user32.dll", CharSet = CharSet.Auto)]
public static extern int SetCursorPos(int x, int y);

//Get the color
[DllImport("gdi32")]
public static extern uint GetPixel(IntPtr hDC, int XPos, int YPos);

[DllImport("User32.dll", CharSet = CharSet.Auto)]
public static extern IntPtr GetWindowDC(IntPtr hWnd);

//To perform Mouse drag
[DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
public static extern void mouse_event(long dwFlags, long dx, long dy, long cButtons, long dwExtraInfo);
//mouse button
public const UInt32 MOUSEEVENTF_MOVE = 0x00000001;
public const UInt32 MOUSEEVENTF_LEFTDOWN = 0x0002;
public const UInt32 MOUSEEVENTF_LEFTUP = 0x0004;

static void Main(string[] args)
{
//Set the start point on object to be drag
System.Drawing.Point startPoint = new Point(10, 10);
//Set the end point of drag to.
System.Drawing.Point endPoint = new Point(150, 100);

//Get the color of end point
IntPtr dc = GetWindowDC(IntPtr.Zero);
long colorBefore = GetPixel(dc, endPoint.X, endPoint.Y);

//Perform drag operation using mouse
SetCursorPos(startPoint.X, startPoint.Y);
System.Threading.Thread.Sleep(100);
mouse_event(MOUSEEVENTF_LEFTDOWN, 0, 0, 0, 0); //hold
SetCursorPos(endPoint.X, endPoint.Y);
mouse_event(MOUSEEVENTF_MOVE, 0, 0, 0, 0); //Drag
mouse_event(MOUSEEVENTF_LEFTUP, 0, 0, 0, 0); //Release

//Get the color of end point for comparison
long colorAfter = GetPixel(dc, endPoint.X, endPoint.Y);

if (colorAfter != colorBefore)
{
Console.WriteLine("Drag operation is SMOOTH");
}
else
{
//Sluggish behavior
Console.WriteLine("Drag operation was not SMOOTH");
}

}
}