tutorial: fix a compilation error and remove now useless vector type casts.

test/tutorial/tut03.cpp

@@ -67,9 +67,8 @@ public:
         m_size = size;
         m_size.x = (m_size.x + 15) & ~15;
         m_size.y = (m_size.y + 15) & ~15;
-        /* FIXME: casts are necessary because of missing operators */
-        m_texel_settings = vec4(1.0, 1.0, 2.0, 2.0) / (vec4)m_size.xyxy;
-        m_screen_settings = vec4(1.0, 1.0, 0.5, 0.5) * (vec4)m_size.xyxy;
+        m_texel_settings = vec4(1.0, 1.0, 2.0, 2.0) / m_size.xyxy;
+        m_screen_settings = vec4(1.0, 1.0, 0.5, 0.5) * m_size.xyxy;
 
         /* Window size decides the world aspect ratio. For instance, 640×480
          * will be mapped to (-0.66,-0.5) - (0.66,0.5). */
@@ -83,8 +82,7 @@ public:
             m_window2world = 0.5 / m_window_size.y;
         else
             m_window2world = 0.5 / m_window_size.x;
-        m_texel2world = (vec2)m_window_size / (vec2)m_size
-                                            * (vec2)m_window2world;
+        m_texel2world = (vec2)m_window_size / m_size * m_window2world;
 
         m_oldmouse = ivec2(0, 0);
 
@@ -867,7 +865,7 @@ private:
 
 int main(int argc, char **argv)
 {
-    Application app("Tutorial 3: Fractal", ivec2(640, 480, 60.0f);
+    Application app("Tutorial 3: Fractal", ivec2(640, 480), 60.0f);
 
 #if defined _MSC_VER && !defined _XBOX
     _chdir("..");