glsl versions throw error trying to use in webgl

[thisispete]

I'm seeing an error in the matrix derivative line here:

128:     vec3 derivative = -8.0 * mat4x3(d1, d2, d3, d4) * (aa * a * extrapolations)
^^^ ERROR: '=' : cannot convert from 'highp 4-component vector of float' to 'highp 3-component vector of float'

129:         + mat4x3(g1, g2, g3, g4) * aaaa;
^^^ ERROR: 'mat4x3' : no matching overloaded function found

I know WebGL is an older version of GLSL, maybe too old for this specific implementation?

Maybe a fix is out of scope for your library, or maybe the error I'm seeing has to do with my specific webGL wrapper - possible I'm missing something.

[thisispete]

probably relevant https://stackoverflow.com/a/27163095