Examples: OpenGL2: Disabling/restoring GL_LIGHTING and GL_COLOR_MATERIAL to increase compatibility with legacy OpenGL applications. (#1996)

CHANGELOG.txt

@@ -75,6 +75,7 @@ Other Changes:
  - Examples: OpenGL3: Tweaked the imgui_impl_opengl3.cpp to work as-is with Emscripten + WebGL 2.0. (#1941). [@o-micron] 
  - Examples: OpenGL3: Made the example app default to GL 3.0 + GLSL 130 (instead of GL 3.2 + GLSL 150) unless on Mac.
  - Examples: OpenGL3: Added error output when shaders fail to compile/link.
+ - Examples: OpenGL2: Disabling/restoring GL_LIGHTING and GL_COLOR_MATERIAL to increase compatibility with legacy OpenGL applications. (#1996)
  - Examples: DirectX10, DirectX11: Fixed unreleased resources in Init and Shutdown functions. (#1944)
  - Examples: DirectX11: Querying for IDXGIFactory instead of IDXGIFactory1 to increase compatibility. (#1989) [@matt77hias]
  - Examples: Win32, Glfw, SDL: Added support for the ImGuiMouseCursor_Hand cursor.

examples/imgui_impl_opengl2.cpp

@@ -18,6 +18,7 @@
 
 // CHANGELOG 
 // (minor and older changes stripped away, please see git history for details)
+//  2018-08-03: OpenGL: Disabling/restoring GL_LIGHTING and GL_COLOR_MATERIAL to increase compatibility with legacy OpenGL applications.
 //  2018-06-08: Misc: Extracted imgui_impl_opengl2.cpp/.h away from the old combined GLFW/SDL+OpenGL2 examples.
 //  2018-06-08: OpenGL: Use draw_data->DisplayPos and draw_data->DisplaySize to setup projection matrix and clipping rectangle.
 //  2018-02-16: Misc: Obsoleted the io.RenderDrawListsFn callback and exposed ImGui_ImplGlfwGL2_RenderDrawData() in the .h file so you can call it yourself.
@@ -90,6 +91,8 @@ void ImGui_ImplOpenGL2_RenderDrawData(ImDrawData* draw_data)
     glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
     glDisable(GL_CULL_FACE);
     glDisable(GL_DEPTH_TEST);
+    glDisable(GL_LIGHTING);
+    glDisable(GL_COLOR_MATERIAL);
     glEnable(GL_SCISSOR_TEST);
     glEnableClientState(GL_VERTEX_ARRAY);
     glEnableClientState(GL_TEXTURE_COORD_ARRAY);