use right field when dealing with joysticks. use enum instead of magic value (ny00123)

git-svn-id: http://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@4179 ed541006-0bf7-43e9-8c4d-6fc63c346d47

Author: qbix79

src/gui/sdl_mapper.cpp

@@ -712,7 +712,7 @@ class CStickBindGroup : public  CBindGroup {
 			if (abs(event->jaxis.value)<25000) return 0;
 			return CreateAxisBind(event->jaxis.axis,event->jaxis.value>0);
 		} else if (event->type==SDL_JOYBUTTONDOWN) {
-			if (event->button.which!=stick) return 0;
+			if (event->jbutton.which!=stick) return 0;
 #if defined (REDUCE_JOYSTICK_POLLING)
 			return CreateButtonBind(event->jbutton.button%button_wrap);
 #else
@@ -1690,7 +1690,7 @@ static void SetActiveEvent(CEvent * event) {
 }
 
 static void DrawButtons(void) {
-	SDL_FillRect(mapper.surface,0,0);
+	SDL_FillRect(mapper.surface,0,CLR_BLACK);
 	SDL_LockSurface(mapper.surface);
 	for (CButton_it but_it = buttons.begin();but_it!=buttons.end();but_it++) {
 		(*but_it)->Draw();