How do I correctly get control bound coordinates relitive to the control for mouse comparison? -

i presently learning c# , have chosen project write simple colour picker control ; things have changed substantially since last looked @ writing code , have struck problem.

i using mousedown event in control mouse coordinates point - working fine , returns expect - mouse coordinates relative control; when try , check against control location returned value point showing position of control relative form in cases mouse coordinates outside bounds of because values less relative start position of control i.e click @ pixel 1,1 in control - mouse position 1,1 because control located @ 9,9 relative form location of mouse less bounds of control - have absolutely no idea how fix this, have been attempting sort out pointtoclient , pointtoscreen no avail seem come outlandish values can please me out it's driving me insane.

i've managed sort out myself thought i'd post answer , can else. having problems getting point values relative same pixel origin : sorted it.

 private void colourpicker_mousedown(object sender, mouseeventargs e)  {   // being paranoid worried scaling issues, this.location      // return same result mess may not handle      // scaling <i haven't checked>      point controlcoord = this.pointtoclient(this.pointtoscreen(this.location));      int controlxstartposition = controlcoord.x;      int controlystartposition = controlcoord.y;      int controlxcalculatedwidth = ((rectanglecolumnscount + 1) * widthperblock ) + controlxstartposition;      int controlycalculatedheight = ((rectanglerowscount   + 1) * heightperblock) + controlystartposition;       // ensure mouse coordinates comparible control coordinates boundry checks.      point controlrelitivemousecoord  = this.parentform.pointtoclient(this.pointtoscreen(e.location));      int controlrelitivemousexcoord = controlrelitivemousecoord.x;      int controlrelitivemouseycoord = controlrelitivemousecoord.y;       // 0 relitive coordinates used caluculating selected block location      int zerorelitivexmousecoord = e.x;      int zerorelitiveymousecoord = e.y;       // ensure in calculated boundries of control control maybe bigger painted area on      // design time form , don't want use unpaited area in our calculations.      if((controlrelitivemousexcoord > controlxstartposition) && (controlrelitivemousexcoord < controlxcalculatedwidth))      {         if((controlrelitivemouseycoord > controlystartposition) && (controlrelitivemouseycoord < controlycalculatedheight))         {             setevaluatedcolourfromposition(zerorelitivexmousecoord, zerorelitiveymousecoord);         }      }   }