Add a `Plot` type for plotting 2D functions?

[mitchmindtree]

I've come across a few cases where it'd be nice to be able to draw straight from some generic FnMut, i.e.

let f = |x: f64| x.sin() * 20.0;
let rect = ...;
Plot::new(...).draw(f, rect, draw_state, transform, g);

where f is the function used to plot the line, rect is the bounds for the plot and x is the x Scalar distance from the left rect edge.

Some use-cases (with rough pseudocode):

• Easier drawing for envelopes: |x: f64| env.y(x)
• Drawing audio waveforms:

|x: f64| {
    let idx = (x / width) * waveform.len();
    let amp = waveform[idx];
    amp * 30.0
};

• Other kinds of mathematical functions.

I imagine it'd have builder params like line thickness, color etc.

Would be very useful for a Plot widget in conrod, which could then be used as a part of a more flexible EnvelopeEditor, WaveformDisplay, etc widgets.

Due to my graphics newbie-ness I'm unsure how to implement this myself, any help would be appreciated! Would certainly be interested in following along if someone does decide to implement this.

[mitchmindtree]

@bvssvni after having a look, it looks like this would require adding another required method to the Graphics trait - is that correct? I'm curious to get your thoughts on the feasibility of this when you get the chance :smile:

[mitchmindtree]

I guess another alternative is to use the Image type by rendering the "plot" to a texture?

[bvssvni]

You could also pass a Line to a function that renders the graph.

[mitchmindtree]

Yeah I'd considered using Line, but I thought it might be really inefficient for super detailed plots like waveforms? Maybe it's not though, I haven't even tried yet! Guess I'll see how that goes first :+1: