Finally i found out how to make vanilla minecraft shaders, and this one is inspired by the game called Hotline Miami (google it). The shader may look horrible, but the main reason that i made this is so that people can understand and learn how to make their own shaders. Feel free to open the files inside the zip and learn from it. the only fil you need to change is the "~shader/spost/fxaa.json". This file tells minecraft what render passes to apply to the game, in what order, in what priority, and change options values in that render pass and it will work as a shader. The "json" files in the "~shaders/post/vanilla shaders" are the original shaders that you can access without any resourpack installed. The "json" files in "~shaders/program/"are the render passes thet you can apply in your shader. They have different variables that you can change in the "fxaa.json" file. You can see how that works in this example. The "fsh" and "vsh" files are also something with the different render passes, though i do not understand how they work. Also see the minecraft wiki

HOW TO INSTALL:

• Put the zip right into the resourcepack folder just like any resourcepack.
  

(It's %appdata%/.minecraft/resourcepacks/ for windows users that has not changed minecraft's game directory. If you dont know what that is, you probably haven't chanced it)

• Ingame; go to "options" and click on the "super secret settings" button to toggle the shader on and off.
  

TL;DR:
Makes the visual of the game druggy, pixelated and wierd. i was inspired by a game called hotline miami. You can install this the same way as most other resourcepacks, and can be toggeled with the "super secret settings" button.

NOTICE: does not work in 1.7.4 pre release. i dont think its my fault, just that mojang have changed something about how shaders works. there is not much i can do about it. it does work for 1.7.2 though.

Additional Notes

Please notice that the current version of schemagic (last time i checked) cannot view the shader functions. Use the actual minecraft instead.