ui/viewgfx.cpp: Added ability to restrict tiles to integer scale factors. (#9783)

Also encapsulated things a bit more and made the UI manager hold onto the storage rather than keeping it in file statics.

docs/source/usingmame/defaultkeys.rst

@@ -35,8 +35,8 @@ and saving/loading save states.
 
     If you are running with -debug, this key sends a ‘break’ in emulation.
 
-    When the on-screen display is visible, you can use the following
-    keys to control it:
+    When a slider control is visible, you can use the following keys to control
+    it:
 
     * **Up** - select previous parameter to modify.
     * **Down** - select next parameter to modify.
@@ -115,8 +115,10 @@ and saving/loading save states.
     * **Home**/**End** - move to top/bottom of list.
     * **Left**/**Right** - change color displayed.
     * **R** - rotate tiles 90 degrees clockwise.
-    * **-**/**+** - increase/decrease the number of tiles per row.
-    * **0** - restore the default number of tiles per row.
+    * **-**/**+** - increase/decrease the number of tiles per row (hold Shift to
+      restrict to integer scale factors).
+    * **0** - restore the default number of tiles per row (hold Shift to
+      restrict to integer scale factors).
     * **Enter** - switch to tilemap viewer.
 
     Tilemap mode:

src/frontend/mame/ui/ui.cpp

@@ -203,8 +203,6 @@ void mame_ui_manager::init()
 	ui::system_list::instance().cache_data(options());
 
 	// initialize the other UI bits
-	ui_gfx_init(machine());
-
 	m_ui_colors.refresh(options());
 
 	// update font row info from setting

src/frontend/mame/ui/viewgfx.h

@@ -20,12 +20,6 @@
     FUNCTION PROTOTYPES
 ***************************************************************************/
 
-// initialization
-void ui_gfx_init(running_machine &machine);
-
-// returns 'true' if the internal graphics viewer has relevance
-bool ui_gfx_is_relevant(running_machine &machine);
-
 // master handler
 uint32_t ui_gfx_ui_handler(render_container &container, mame_ui_manager &mui, bool uistate);