Make SDL2 more responsive to expose/restore events -- see part 2 of #71.

sdl2/pdcdisp.c

@@ -556,6 +556,5 @@ void PDC_blink_text(void)
 
 void PDC_doupdate(void)
 {
-    PDC_update_rects();
-    SDL_Delay(1);
+    PDC_napms(1);
 }

sdl2/pdckbd.c

@@ -400,6 +400,19 @@ static int _process_mouse_event(void)
     return KEY_MOUSE;
 }
 
+int PDC_event_filter(void *userdata, SDL_Event *event)
+{
+    if (SDL_WINDOWEVENT == event->type &&
+        (SDL_WINDOWEVENT_RESTORED == event->window.event ||
+         SDL_WINDOWEVENT_EXPOSED == event->window.event))
+    {
+        SDL_UpdateWindowSurface(pdc_window);
+        return 0;
+    }
+
+    return 1;
+}
+
 /* return the next available key or mouse event */
 
 int PDC_get_key(void)
@@ -409,9 +422,8 @@ int PDC_get_key(void)
     case SDL_QUIT:
         exit(1);
     case SDL_WINDOWEVENT:
-        switch (event.window.event)
+        if (SDL_WINDOWEVENT_SIZE_CHANGED == event.window.event)
         {
-        case SDL_WINDOWEVENT_SIZE_CHANGED:
             pdc_screen = SDL_GetWindowSurface(pdc_window);
             pdc_sheight = pdc_screen->h - pdc_xoffset;
             pdc_swidth = pdc_screen->w - pdc_yoffset;
@@ -424,10 +436,6 @@ int PDC_get_key(void)
                 SP->key_code = TRUE;
                 return KEY_RESIZE;
             }
-            break;
-        case SDL_WINDOWEVENT_RESTORED:
-        case SDL_WINDOWEVENT_EXPOSED:
-            SDL_UpdateWindowSurface(pdc_window);
         }
         break;
     case SDL_MOUSEMOTION:

sdl2/pdcscrn.c

@@ -311,6 +311,8 @@ int PDC_scr_open(void)
 
     PDC_reset_prog_mode();
 
+    SDL_SetEventFilter(PDC_event_filter, NULL);
+
     return OK;
 }
 

sdl2/pdcsdl.h

@@ -32,4 +32,5 @@ extern bool pdc_own_window;          /* if pdc_window was not set
 PDCEX  void PDC_update_rects(void);
 PDCEX  void PDC_retile(void);
 
+extern int PDC_event_filter(void *, SDL_Event *);
 extern void PDC_blink_text(void);

sdl2/pdcutil.c

@@ -12,6 +12,12 @@ void PDC_napms(int ms)
     PDC_LOG(("PDC_napms() - called: ms=%d\n", ms));
 
     PDC_update_rects();
+    while (ms > 50)
+    {
+        SDL_PumpEvents();
+        SDL_Delay(50);
+        ms -= 50;
+    }
     SDL_PumpEvents();
     SDL_Delay(ms);
 }