need tutorial

What I know so far

uniform is a way to get variables from outside the shader, into the shader. so I can make lua variables and then send them to it. I think it can also make variables inside the shader too, but i’m not sure

there’s no way to easily get debugging information, no print (x), no console.out, etc

attribute is only existing in the vertex shader portion

varying gets attributes out of the vertex shader and into the fragment shader

texCoord is between 0.0 and 1.0

// how the hell do you get the x, y of a texCoord.

there’s certain standard variables in glsl that are already defined. i don’t know that many of them.

codea uses GLSL 2.0?

Do you know any really good tutorials? I don’t have access to a mac, i only found one codea tutorial but i could have sworn there was more…? I did check google but every time i looked i got lost.

current goal: make a pretty button shader that has a light source, light/dark shadows on the top/bottom edges, outset/inset if necessary (e.g. for slider), and is brighter on top/darker towards the bottom (technically whatever side has the lightsource is brighter… lighting is pretty stuff) etc. basically I like pretty things :smile:

This might help: https://coolcodea.wordpress.com/2013/06/01/72-shaders-what-are-they/

thx

@xThomas shaders aren’t supposed to be used for those kind of things. They modify the appearance of a surface or pixel. Regardless, check out shadertoy.com and my favorite, thebookofshaders.com