Add getCursorPos (#176)

src/DearImGui.hs

@@ -110,6 +110,7 @@ module DearImGui
   , Raw.endGroup
 
   , setCursorPos
+  , Raw.getCursorPos
   , Raw.alignTextToFramePadding
 
     -- * ID stack

src/DearImGui/Raw.hs

@@ -90,6 +90,7 @@ module DearImGui.Raw
   , popItemWidth
   , beginGroup
   , endGroup
+  , getCursorPos
   , setCursorPos
   , getCursorScreenPos
   , alignTextToFramePadding
@@ -1671,6 +1672,20 @@ setCursorPos :: (MonadIO m) => Ptr ImVec2 -> m ()
 setCursorPos posPtr = liftIO do
   [C.exp| void { SetCursorPos(*$(ImVec2* posPtr)) } |]
 
+-- | Get cursor position in window-local coordinates.
+--
+-- Useful to overlap draw using 'setCursorPos'.
+--
+-- Wraps @ImGui::SetCursorPos()@
+getCursorPos :: (MonadIO m) => m ImVec2
+getCursorPos = liftIO do
+  C.withPtr_ \ptr ->
+    [C.block|
+      void {
+        *$(ImVec2 * ptr) = GetCursorPos();
+      }
+    |]
+
 -- | Cursor position in absolute coordinates.
 --
 -- Useful to work with 'DrawList' API.