Prevent "Return to Level Editor" from working, if no levelsubset is loaded. This...

[supertux.git] / src / screen.cpp

diff --git a/src/screen.cpp b/src/screen.cpp
index d323c3f..df1b53f 100644 (file)
--- a/src/screen.cpp
+++ b/src/screen.cpp
@@ -95,6 +95,48 @@ void drawgradient(Color top_clr, Color bot_clr)
 #endif
 }
 
+/* --- FADE IN --- */
+
+/** Fades the given surface into a black one. If fade_out is true, it will fade out, else
+it will fade in */
+
+void fade(Surface *surface, int seconds, bool fade_out);
+
+void fade(const std::string& surface, int seconds, bool fade_out)
+{
+Surface* sur = new Surface(datadir + surface, IGNORE_ALPHA);
+fade(sur, seconds, fade_out);
+delete sur;
+}
+
+void fade(Surface *surface, int seconds, bool fade_out)
+{
+float alpha;
+if (fade_out)
+  alpha = 0;
+else
+  alpha = 255;
+
+  int cur_time, old_time;
+  cur_time = SDL_GetTicks();
+
+  while(alpha >= 0 && alpha < 256)
+    {
+    surface->draw(0,0,(int)alpha);
+    flipscreen();
+
+    old_time = cur_time;
+    cur_time = SDL_GetTicks();
+
+    /* Calculate the next alpha value */
+    float calc = (float) ((cur_time - old_time) / seconds);
+    if(fade_out)
+      alpha += 255 * calc;
+    else
+      alpha -= 255 * calc;
+    }
+}
+
 /* 'Stolen' from the SDL documentation.
  * Set the pixel at (x, y) to the given value
  * NOTE: The surface must be locked before calling this!