commit f2073adf91ee59c0293b4a2e4ea3d15b1ed54fb4
author elmar <ktye78@gmail.com> Wed Jan 18 21:52:16 2017 +0100
committer Alex Brainman <alex.brainman@gmail.com> Fri Jan 20 06:22:47 2017 +0000
tree c968e7171c4cb38e9beafe77c7c9135dd111290a
parent f43f8d06a5464fa233a7ed4cd9630a2b3a4633ae

shiny/driver/internal/win32: use relative coordinates for mouse wheel events

Windows mouse wheel events report the cursor position in
absolute screen coordinates, while other mouse event's positions
are relative to the window.
This adds ScreenToClient to syscall_windows.go and converts the
event's position for mouse wheel events.

Fixes golang/go#18695

Change-Id: Ic086033e435cf4699c7ff0aad90e1a1ce233bb02
Reviewed-on: https://go-review.googlesource.com/35412
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>