From 0b33acc92acb31f477703f8900a420d15f386335 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emmanuel=20Beno=C3=AEt?= <tseeker@nocternity.net>
Date: Wed, 22 Nov 2017 08:48:43 +0100
Subject: [PATCH] UI - Fixed mouse behaviour when the pointer exits the window

---
 imgui_impl_sdl.cc | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/imgui_impl_sdl.cc b/imgui_impl_sdl.cc
index c089c6f..7484480 100644
--- a/imgui_impl_sdl.cc
+++ b/imgui_impl_sdl.cc
@@ -257,13 +257,15 @@ void ImGui_ImplSdl_NewFrame(SDL_Window *window ,
     // (we already got mouse wheel, keyboard keys & characters from SDL_PollEvent())
     int mx, my;
     Uint32 mouseMask = SDL_GetMouseState(&mx, &my);
+    static ImVec2 prevMouse{ -FLT_MAX , -FLT_MAX };
     if ( mouseLock ) {
         io.MousePos = mousePos;
     } else {
-        if (SDL_GetWindowFlags(window) & SDL_WINDOW_MOUSE_FOCUS)
+        if (SDL_GetWindowFlags(window) & SDL_WINDOW_MOUSE_FOCUS) {
             io.MousePos = ImVec2((float)mx, (float)my);   // Mouse position, in pixels (set to -1,-1 if no mouse / on another screen, etc.)
-        else
-            io.MousePos = ImVec2(-1,-1);
+	    prevMouse = io.MousePos;
+	} else
+            io.MousePos = prevMouse;
     }
 
     io.MouseDown[0] = g_MousePressed[0] || (mouseMask & SDL_BUTTON(SDL_BUTTON_LEFT)) != 0;		// If a mouse press event came, always pass it as "mouse held this frame", so we don't miss click-release events that are shorter than 1 frame.