call find-gl-context to ensure context is set during graft/ungraft in GL demos

extra/bunny/bunny.factor

@@ -1,6 +1,7 @@
 USING: accessors arrays bunny.cel-shaded bunny.fixed-pipeline
 bunny.model bunny.outlined destructors kernel math opengl.demo-support
-opengl.gl sequences ui ui.gadgets ui.gestures ui.render words ;
+opengl.gl sequences ui ui.gadgets ui.gadgets.worlds ui.gestures
+ui.render words ;
 IN: bunny
 
 TUPLE: bunny-gadget < demo-gadget model-triangles geom draw-seq draw-n ;
@@ -18,6 +19,7 @@ TUPLE: bunny-gadget < demo-gadget model-triangles geom draw-seq draw-n ;
     >>draw-n relayout-1 ;
 
 M: bunny-gadget graft* ( gadget -- )
+    dup find-gl-context
     GL_DEPTH_TEST glEnable
     dup model-triangles>> <bunny-geom> >>geom
     dup
@@ -29,6 +31,7 @@ M: bunny-gadget graft* ( gadget -- )
     drop ;
 
 M: bunny-gadget ungraft* ( gadget -- )
+    dup find-gl-context
     [ geom>> [ dispose ] when* ]
     [ draw-seq>> [ [ dispose ] when* ] each ] bi ;
 

extra/spheres/spheres.factor

@@ -1,6 +1,6 @@
 USING: kernel opengl.demo-support opengl.gl opengl.shaders opengl.framebuffers
 opengl multiline ui.gadgets accessors sequences ui.render ui math locals
-arrays generalizations combinators opengl.capabilities ;
+arrays generalizations combinators opengl.capabilities ui.gadgets.worlds ;
 IN: spheres
 
 STRING: plane-vertex-shader
@@ -162,6 +162,7 @@ M: spheres-gadget distance-step ( gadget -- dz )
     3array <gl-program> check-gl-program ;
 
 M: spheres-gadget graft* ( gadget -- )
+    dup find-gl-context
     "2.0" { "GL_ARB_shader_objects" } require-gl-version-or-extensions
     { "GL_EXT_framebuffer_object" } require-gl-extensions
     (plane-program) >>plane-program
@@ -173,6 +174,7 @@ M: spheres-gadget graft* ( gadget -- )
     drop ;
 
 M: spheres-gadget ungraft* ( gadget -- )
+    dup find-gl-context
     {
         [ reflection-framebuffer>> [ delete-framebuffer ] when* ]
         [ reflection-depthbuffer>> [ delete-renderbuffer ] when* ]