Resolve "SDL2 module"

Closes #29 (closed)

• create a working sdl module
• using only async commands with mpv
• put the sdl module in its own thread
• make the thing working

src/module/module_sdl2.c

@@ -36,6 +36,7 @@ struct module_sdl2_window {
     pthread_mutex_t mtx;
     struct lkt_thread self;
     volatile int launched;
+    volatile int mpv_wakeup;
 };
 
 /* Thread related functions */
@@ -51,8 +52,8 @@ sdl_thread__(struct lkt_thread_arg *arg)
     int w, h;
     free(arg);
     (void) self;
-    if (sdl2 == NULL)
-        return false;
+    RETURN_UNLESS(sdl2, "Big nope here, the sdl window pointer is NULL", NULL);
+    fprintf(stderr, " * Started SDL thread\n");
 
     /* SDL events won't change the database, only the mpv one's will.
        Do this to be able to put the SDL stuff inside a thread and don't change
@@ -96,6 +97,8 @@ loop:
             flags = mpv_render_context_update(sdl2->mpv_gl);
             if (flags & MPV_RENDER_UPDATE_FRAME)
                 redraw = 1;
+            if (event.type == wakeup_on_mpv_events)
+                sdl2->mpv_wakeup = 1;
         }
         /* Handle mpv events are not done here. */
     }
@@ -217,8 +220,8 @@ module_sdl2_new(struct lkt_win *const win)
 
     if (sdl2 == NULL) {
         sdl2 = calloc(1, sizeof(struct module_sdl2_window));
-        memset(sdl2, 0, sizeof(struct module_sdl2_window));
         RETURN_UNLESS(sdl2, "Out of memory", false);
+        memset(sdl2, 0, sizeof(struct module_sdl2_window));
 
         /* Yeah, this is how it is done. */
         pthread_mutex_t mtx = PTHREAD_MUTEX_INITIALIZER;
@@ -259,19 +262,21 @@ module_sdl2_new(struct lkt_win *const win)
     /* Init mpv_gl here */
     RETURN_IF(init_mpv_gl__(sdl2->mpv, &sdl2->mpv_gl, params), "Failed to init mpv_gl", false);
 
+    /* Finish */
+    SDL_SetWindowTitle(sdl2->window, "Lektord");
+    SDL_DisableScreenSaver();
+    win->window = sdl2;
+
     /* Start the SDL thread */
     if (!sdl2->launched) {
         struct lkt_thread_arg *arg = calloc(1, sizeof(struct lkt_thread_arg));
         RETURN_UNLESS(arg, "Out of memory", false);
         arg->args = win;
+        sdl2->launched = 1;
         RETURN_IF(lkt_th_new(&sdl2->self, LKT_DEFAULT_LIST_SIZE, sdl_thread__, arg),
                 "Failed to launch the SDL thread", false);
     }
 
-    /* Finish */
-    SDL_SetWindowTitle(sdl2->window, "Lektord");
-    SDL_DisableScreenSaver();
-    win->window = sdl2;
     return true;
 }
 
@@ -338,7 +343,12 @@ module_sdl2_handle_events(struct lkt_win *const win, sqlite3 *db, enum mpd_idle_
 {
     struct module_sdl2_window *sdl2 = win->window;
     RETURN_UNLESS(sdl2, "Can't handle events from a NULL window", false);
-    return ! lmpv_handle(win, sdl2->mpv, db, mpd_idle_events,
-                         (int *) &sdl2->mpv_time_pos,
-                         (int *) &sdl2->mpv_duration);
+    if (sdl2->mpv_wakeup) {
+        sdl2->mpv_wakeup = 0;
+        return ! lmpv_handle(win, sdl2->mpv, db, mpd_idle_events,
+                             (int *) &sdl2->mpv_time_pos,
+                             (int *) &sdl2->mpv_duration);
+    }
+    else
+        return true;
 }