bitmap backend implemented

Author: lisanhu

Cargo.toml

@@ -1,3 +1,124 @@
+<<<<<<< HEAD
 [workspace]
 members = ["plotters", "plotters-backend", "plotters-bitmap", "plotters-svg"]
 default-members = ["plotters"]
+=======
+[package]
+name = "plotters"
+version = "0.3.1"
+authors = ["Hao Hou <[email protected]>"]
+edition = "2018"
+license = "MIT"
+description = "A Rust drawing library focus on data plotting for both WASM and native applications"
+repository = "https://github.com/38/plotters"
+homepage = "https://plotters-rs.github.io/"
+keywords = ["WebAssembly", "Visualization", "Plotting", "Drawing"]
+categories = ["visualization", "wasm"]
+readme = "README.md"
+exclude = ["doc-template/*"]
+
+[dependencies]
+num-traits = "0.2.14"
+chrono = { version = "0.4.19", optional = true }
+plotters-svg = {version = "^0.3.*", optional = true}
+base64 = "*"
+
+[dependencies.plotters-backend]
+version = "^0.3"
+
+[dependencies.plotters-bitmap]
+version = "^0.3"
+optional = true
+default_features = false
+
+[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
+ttf-parser = { version = "0.12.0", optional = true }
+lazy_static = { version = "1.4.0", optional = true }
+pathfinder_geometry = { version = "0.5.1", optional = true }
+font-kit = { version = "0.10.0", optional = true }
+
+[target.'cfg(not(target_arch = "wasm32"))'.dependencies.image]
+version = "0.23.14"
+optional = true
+default-features = false
+features = ["jpeg", "png", "bmp"]
+
+[target.'cfg(target_arch = "wasm32")'.dependencies.wasm-bindgen]
+version = "0.2.62"
+
+[target.'cfg(target_arch = "wasm32")'.dependencies.web-sys]
+version = "0.3.51"
+features = [
+         "Document",
+         "DomRect",
+         "Element",
+         "HtmlElement",
+         "Node",
+         "Window",
+         "HtmlCanvasElement",
+         "CanvasRenderingContext2d",
+]
+
+[features]
+default = [
+        "bitmap_backend", "bitmap_encoder", "bitmap_gif",
+        "svg_backend",
+        "chrono",
+        "ttf",
+        "image",
+        "deprecated_items",  "all_series", "all_elements",
+        "full_palette"
+]
+all_series = ["area_series", "line_series", "point_series", "surface_series"]
+all_elements = ["errorbar", "candlestick", "boxplot", "histogram"]
+
+# Tier 1 Backends
+bitmap_backend = ["plotters-bitmap", "ttf"]
+bitmap_encoder = ["plotters-bitmap/image_encoder"]
+bitmap_gif = ["plotters-bitmap/gif_backend"]
+svg_backend = ["plotters-svg"]
+
+# Colors
+full_palette = []
+
+# Elements
+errorbar = []
+candlestick = []
+boxplot = []
+
+# Series
+histogram = []
+area_series = []
+line_series = []
+point_series = []
+surface_series = []
+
+# Font implemnetation
+ttf = ["font-kit", "ttf-parser", "lazy_static", "pathfinder_geometry"]
+
+# Misc
+datetime = ["chrono"]
+evcxr = ["svg_backend", "bitmap_backend", "image"]
+deprecated_items = [] # Keep some of the deprecated items for backward compatibility
+
+[dev-dependencies]
+itertools = "0.10.0"
+criterion = "0.3.4"
+rayon = "1.5.1"
+serde_json = "1.0.64"
+serde = "1.0.126"
+serde_derive = "1.0.126"
+
+[target.'cfg(not(target_arch = "wasm32"))'.dev-dependencies]
+rand = "0.8.3"
+rand_distr = "0.4.0"
+rand_xorshift = "0.3.0"
+
+[target.'cfg(target_arch = "wasm32")'.dev-dependencies]
+wasm-bindgen-test = "0.3.24"
+
+[[bench]]
+name = "benchmark"
+harness = false
+path = "benches/main.rs"
+>>>>>>> 6bd0da5 (bitmap backend implemented)

plotters/src/evcxr.rs

@@ -1,6 +1,8 @@
 use crate::coord::Shift;
 use crate::drawing::{DrawingArea, IntoDrawingArea};
 use base64;
+use image::{png::PngEncoder, ImageBuffer, ImageError, Pixel, RgbImage, Rgb};
+use std::ops::Deref;
 use plotters_svg::SVGBackend;
 use plotters_bitmap::BitMapBackend;
 
@@ -43,9 +45,9 @@ pub fn evcxr_figure<
     SVGWrapper(buffer, "".to_string())
 }
 
-pub struct BitmapWrapper(String, String);
+pub struct BitMapWrapper(String, String);
 
-impl BitmapWrapper {
+impl BitMapWrapper {
     pub fn evcxr_display(&self) {
         println!("{:?}", self);
     }
@@ -56,7 +58,7 @@ impl BitmapWrapper {
     }
 }
 
-impl std::fmt::Debug for BitmapWrapper {
+impl std::fmt::Debug for BitMapWrapper {
     fn fmt(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
         let svg = self.0.as_str();
         write!(
@@ -67,19 +69,34 @@ impl std::fmt::Debug for BitmapWrapper {
     }
 }
 
+fn encode_png<P, Container>(img: &ImageBuffer<P, Container>) -> Result<Vec<u8>, ImageError>
+where
+    P: Pixel<Subpixel = u8> + 'static,
+    Container: Deref<Target = [P::Subpixel]>,
+{
+    let mut buf = Vec::new();
+    let encoder = PngEncoder::new(&mut buf);
+    encoder.encode(img, img.width(), img.height(), P::COLOR_TYPE)?;
+    Ok(buf)
+}
+
 /// Start drawing an evcxr figure
 pub fn evcxr_bitmap_figure<
     Draw: FnOnce(DrawingArea<BitMapBackend, Shift>) -> Result<(), Box<dyn std::error::Error>>,
 >(
     size: (u32, u32),
     draw: Draw,
-) -> SVGWrapper {
-    let pixel_size = plotters_bitmap::bitmap_pixel::RGBPixel::PIXEL_SIZE;
-    let mut buf = [u8; (size.0 as usize) * (size.1 as usize) * pixel_size];
-    let root = BitMapBackend::with_buffer(&buf, size).into_drawing_area();
-    let buffer = base64::encode(&buf);
+) -> BitMapWrapper {
+    let pixel_size = 3;
+    let mut buf = Vec::new();
+    buf.resize((size.0 as usize) * (size.1 as usize) * pixel_size, 0);
+    let root = BitMapBackend::with_buffer(&mut buf, size).into_drawing_area();
     draw(root).expect("Drawing failure");
-    BitmapWrapper(buffer, "".to_string())
+    let img = RgbImage::from_raw(size.0, size.1, buf).unwrap();
+    let enc_buf = encode_png(&img).unwrap();
+    let buffer = base64::encode(&enc_buf);
+    BitMapWrapper(buffer, "".to_string())
+    // todo!()
 }
 
 pub fn evcxr_animation<