Pass other textures to 2Dfilter shaders?

I’ve been poking around with GLSL shaders for a bit and I am wondering how (if I can) I go about passing other textures in the game engine as a uniform sampler2D to the fragment program? I know the properties of the controller can be passed to the program but I am failing to figure out or find a way to get access to other textures for sampling.

I want to experiment with various repeating patterns to shade the entire image, maybe like different line strokes and cross-hatching patterns in comics or crazy stuff like repeating symbols.

im a little confused on what you are looking to do. you can control how textures are tiled in the texture properties. unless you are looking to avoid the standard tiling grid

AFAIK, I think’s that not possible with the actual 2d filter system. But I’m not sure.

What I am looking to do is be able to sample the color / value that is on screen and sample a corresponding “fill” pattern from one or more textures that I supply. So I could replace whatever color / value I want with a pattern. For instance, maybe I want everything that is full red [1.0, 0.0, 0.0, 1.0] to be replaced with a pattern of repeating smiley faces from a texture. That is the sort of thing I am looking to do or maybe an easy cross fade from one camera to another just in the filter shader by accessing the a texture that is being rendered by another camera and weighting and multiplying the values together.