Cleanup the canvas backend

Author: 38

examples/wasm-demo/Cargo.toml

@@ -8,8 +8,9 @@ edition = "2018"
 crate-type=["cdylib"]
 
 [dependencies]
-plotters = {path = "../.."}
-wasm-bindgen = "0.2.62"
+plotters = {path = "../..", default_features = false, features = ["line_series"]  }
+plotters-canvas = "0.1.*"
+wasm-bindgen = "0.2"
 wee_alloc = "0.4.5"
 web-sys = { version = "0.3.39", features = ["HtmlCanvasElement"] }
 

examples/wasm-demo/src/func_plot.rs

@@ -1,5 +1,6 @@
 use crate::DrawResult;
 use plotters::prelude::*;
+use plotters_canvas::CanvasBackend;
 
 /// Draw power function f(x) = x^power.
 pub fn draw(canvas_id: &str, power: i32) -> DrawResult<impl Fn((i32, i32)) -> Option<(f32, f32)>> {

examples/wasm-demo/src/mandelbrot.rs

@@ -1,8 +1,10 @@
 use crate::DrawResult;
-use plotters::prelude::*;
 use std::ops::Range;
 use web_sys::HtmlCanvasElement;
 
+use plotters::prelude::*;
+use plotters_canvas::CanvasBackend;
+
 /// Draw Mandelbrot set
 pub fn draw(element: HtmlCanvasElement) -> DrawResult<impl Fn((i32, i32)) -> Option<(f64, f64)>> {
     let backend = CanvasBackend::with_canvas_object(element).unwrap();