evas/wayland_shm: Add evas_swapper_reconfigure().

This can be used to reconfigure a swapper to another size, without the
need to destroy the swapper itself.

Although the shm pool is not being reused even when reconfiguring to a
smaller size, it could easily be.

This change is done right now only to keep the dx and dy offsets of a
previously requested swapper, which were not still used.

src/modules/evas/engines/wayland_shm/evas_swapbuf.c

@@ -110,8 +110,15 @@ evas_swapbuf_reconfigure(Outbuf *ob, int x, int y, int w, int h, unsigned int ro
    /* check for valid swapper */
    if (ob->priv.swapper)
      {
-        /* free existing swapper */
-        evas_swapper_free(ob->priv.swapper);
+        if ((ob->rotation == 0) || (ob->rotation == 180))
+          ob->priv.swapper = evas_swapper_reconfigure(ob->priv.swapper,
+                                                      x, y, w, h, depth,
+                                                      alpha);
+        else if ((ob->rotation == 90) || (ob->rotation == 270))
+          ob->priv.swapper = evas_swapper_reconfigure(ob->priv.swapper,
+                                                      x, y, h, w, depth,
+                                                      alpha);
+        return;
      }
 
    /* create new swapper */

src/modules/evas/engines/wayland_shm/evas_swapper.c

@@ -116,6 +116,56 @@ evas_swapper_setup(int dx, int dy, int w, int h, Outbuf_Depth depth, Eina_Bool a
    return ws;
 }
 
+Wl_Swapper *
+evas_swapper_reconfigure(Wl_Swapper *ws, int dx, int dy, int w, int h, Outbuf_Depth depth, Eina_Bool alpha)
+{
+   int i = 0;
+
+   LOGFN(__FILE__, __LINE__, __FUNCTION__);
+
+   if (!ws)
+     {
+        ERR("No swapper to reconfigure.");
+        return NULL;
+     }
+
+   /* loop the swapper's buffers and free them */
+   for (i = 0; i < ws->buff_num; i++)
+     _evas_swapper_buffer_free(&(ws->buff[i]));
+
+   /* free the shm pool */
+   _evas_swapper_shm_pool_free(ws);
+
+   ws->dx += dx;
+   ws->dy += dy;
+   ws->w = w;
+   ws->h = h;
+   ws->depth = depth;
+   ws->alpha = alpha;
+
+   /* create the shm pool */
+   if (!_evas_swapper_shm_pool_new(ws))
+     {
+        ERR("Could not allocate new shm pool.");
+        evas_swapper_free(ws);
+        return NULL;
+     }
+
+   for (i = 0; i < ws->buff_num; i++)
+     {
+        /* try to create new internal Wl_Buffer */
+        if (!_evas_swapper_buffer_new(ws, &(ws->buff[i])))
+          {
+             ERR("failed to create wl_buffer. free the swapper.");
+             evas_swapper_free(ws);
+             return NULL;
+          }
+     }
+
+   /* return reconfigured swapper */
+   return ws;
+}
+
 void 
 evas_swapper_swap(Wl_Swapper *ws, Eina_Rectangle *rects, unsigned int count)
 {
@@ -307,6 +357,8 @@ _evas_swapper_shm_pool_free(Wl_Swapper *ws)
 
    /* destroy the shm pool */
    wl_shm_pool_destroy(ws->pool);
+
+   ws->pool_size = 0;
 }
 
 static Eina_Bool 

src/modules/evas/engines/wayland_shm/evas_swapper.h

@@ -6,6 +6,7 @@
 typedef struct _Wl_Swapper Wl_Swapper;
 
 Wl_Swapper *evas_swapper_setup(int dx, int dy, int w, int h, Outbuf_Depth depth, Eina_Bool alpha, struct wl_shm *shm, struct wl_surface *surface);
+Wl_Swapper *evas_swapper_reconfigure(Wl_Swapper *ws, int dx, int dy, int w, int h, Outbuf_Depth depth, Eina_Bool alpha);
 void evas_swapper_swap(Wl_Swapper *ws, Eina_Rectangle *rects, unsigned int count);
 void evas_swapper_free(Wl_Swapper *ws);
 void *evas_swapper_buffer_map(Wl_Swapper *ws);