Some improvements, added cutscene stub

resources/shaders/cutscene_black_desktop.fragment

@@ -0,0 +1,7 @@
+uniform float uAlpha;
+varying vec2 texCoord;
+
+void main()
+{
+    gl_FragColor = vec4(0.0, 0.0, 0.0, uAlpha);
+}

resources/shaders/cutscene_black_web.fragment

@@ -0,0 +1,8 @@
+precision mediump float;
+uniform float uAlpha;
+varying vec2 texCoord;
+
+void main()
+{
+    gl_FragColor = vec4(0.0, 0.0, 0.0, uAlpha);
+}