template and guide to writing first shaders

[cyberboy666]

this is partially already documented in conjur repo , but might be a bit highlevel for someone interested in writing their first shader, it should include:

• how to set up a shader deving environment (using glslviewer etc)
• template shader explaining the basics , lines to uncomment and see the changes etc
• basic concepts for creating simple gen-shaders
• template shader for texture input (colour and position) with basic concepts for creating simple pro-shaders
• maybe how to dev on ur mac/windows machine ?

[sebiik]

I'm curious where you'd want to set up the shader deving environment. Add an option in recur to start glslviewer mode on the pi so you could connect a USB keyboard and develop from there?

[cyberboy666]

@sebiik , yeah - i was thinking basically some instructions on how to edit a shader on the pi, (probably dont need a option to start glslviewer from within recur at first although that would be cool!), something like:

• plug in a usb-keybboard
• press . to exit recur
• open termit from start-menu, type glslViewer ~/Shaders/my_new_shader.frag -l
• open my_new_shader.frag in gedit and try changing these values ...
• do this to load in a image-texture to be processed , try changing these values ...

do you have any ideas on how to ease the entry for people customising there own video-effects etc ?

[averagehat]

If using ssh #110 works well;

One thing about just using glslViewer is that you have to supply something for the (midi) param values or else a lot of the shaders won't really work.

By being connected to the pi, I can use my own editing environment on a different machine (and even use glslViewer there as a single-shader preview, though there is still the param values problem) and get good live feedback for learning, especially helpful with the 2-input shaders which I don't even know how to create with glslViewer or anything else.

I will make a special effort to document my learning and if it works out I can put together some documentation about editing environment, ssh setup, glsl, whatever.

There is already a bit of documentation and templating here: https://github.com/langolierz/r_e_c_u_r/blob/9935f1a98bf308b1563e54ca8551ac16854bda9e/Shaders/2-input/mix_lumaKey.frag

[konsumer]

On this angle, I added these (discussed in #152 )

• glsl_sandbox - basically just some knobs for native glslviewer.
• recurweb a web-based editor, that has support for video and inputs. (visit here)

While working on these I also:

• expanded, normalized & cleaned-up shader collection
• created a simple template that uses standard uniforms and u_x* instead of fparams (which follows glslviewer and others)

Feel free to use these here (let me know, and I will make a PR for shaders.)