🎉 Add initial KWin port of the doom effect

kwin/doom/onSettingsChanged.js

@@ -0,0 +1,12 @@
+// This part is automatically included in the effect's source during the build process.
+// The code below is called whenever the user changes something in the configuration of
+// the effect.
+
+// I have not yet found a way to scaling the actor canvas on KWin. So this effect cannot
+// look as good as on GNOME.
+effect.setUniform(this.shader, 'uActorScale', 1.0);
+
+effect.setUniform(this.shader, 'uHorizontalScale',
+                  effect.readConfig('HorizontalScale', 1.0));
+effect.setUniform(this.shader, 'uVerticalScale', effect.readConfig('VerticalScale', 1.0));
+effect.setUniform(this.shader, 'uPixelSize', effect.readConfig('PixelSize', 1.0));