shader core

[mattdesl]

shader

see dev branch for progress

• largely inspired by gl-shader, try to share code where possible e.g. gl-shader-extract
• only have a single program handle, no caching
• keep reloading in mind for live-reload
• provide the best possible UX for error logs, maybe using gl-shader-errors at some point
• glGetUniform calls should be more opaque so the dev doesn't accidentally query GL state
• KISS; avoid initial shader compile etc
• evaluate the gl-shader uniform wrapper approach and whether something else is more suitable

[mattdesl]

will log to console.error by default unless quiet: true (for unit tests etc)

though console.warn looks nice too

[mattdesl]

looking into this a bit more. the shader wrapper that stackgl uses is quite nice since it allows for a clean way of handling structs and arrays:

shader.uniforms.lights[0] = {
   position: ...
}

Compare with string-based access.

The downside is that you end up very easily calling glGetUniform which can destroy framerate, and also it doesn't behave like you would expect. Generally using getter/setter to perform a complex action can lead to surprises IMHO.

//does not work as expected
vec3.add(shader.uniforms.lightPosition, aVec, bVec)

EDIT:

Alternative syntax where the discrete uniforms are functions:

//query current uniform looks like this
var pos = shader.uniforms.lights[0].position()

//set uniform, no ambiguity here since it's a function
vec3.add(tmp, aVec, bVec)
shader.uniforms.lights[0].position(tmp)

Or more verbose:

shader.uniforms.lights[0].position.set(tmp)
shader.uniforms.lights[0].position.get()

[mikolalysenko]

I actually think that maybe it is worth killing gl-shader long term. A more ideal solution would be to have a "draw command" that could take the shader source as a string argument, along with all uniforms that need to be set. Then these could be grouped using some "draw list" that would combine and reorder draw commands so that the number of shader state changes and uniform updates are minimized.

[mattdesl]

Interesting idea. Definitely going to think about it and how it could all look for the end-user.