Empty,

HLine,

VLine,

Cross,

Pixel,

Text(char),

Circle(bool),

fn to_char(self) -> char {

match self {

Self::Empty => ' ',

Self::HLine => '-',

Self::VLine => '|',

Self::Cross => '+',

Self::Pixel => '.',

Self::Text(c) => c,

Self::Circle(filled) => {

if filled {

'@'

} else {

'O'

}

}

}

}

fn update(&mut self, new_state: PixelState) {

let next_state = match (*self, new_state) {

(Self::HLine, Self::VLine) => Self::Cross,

(Self::VLine, Self::HLine) => Self::Cross,

(_, Self::Circle(what)) => Self::Circle(what),

(Self::Circle(what), _) => Self::Circle(what),

(_, Self::Pixel) => Self::Pixel,

(Self::Pixel, _) => Self::Pixel,

(_, new) => new,

};

*self = next_state;

}

type ErrorType = std::io::Error;

fn get_size(&self) -> (u32, u32) {

(100, 30)

}

fn ensure_prepared(&mut self) -> Result<(), DrawingErrorKind<std::io::Error>> {

Ok(())

}

fn present(&mut self) -> Result<(), DrawingErrorKind<std::io::Error>> {

for r in 0..30 {

let mut buf = String::new();

for c in 0..100 {

buf.push(self.0[r * 100 + c].to_char());

}

println!("{}", buf);

}

Ok(())

}

fn draw_pixel(

&mut self,

pos: (i32, i32),

color: BackendColor,

) -> Result<(), DrawingErrorKind<std::io::Error>> {

if color.alpha > 0.3 {

self.0[(pos.1 * 100 + pos.0) as usize].update(PixelState::Pixel);

}

Ok(())

}

fn draw_line<S: BackendStyle>(

&mut self,

from: (i32, i32),

to: (i32, i32),

style: &S,

) -> Result<(), DrawingErrorKind<Self::ErrorType>> {

if from.0 == to.0 {

let x = from.0;

let y0 = from.1.min(to.1);

let y1 = from.1.max(to.1);

for y in y0..y1 {

self.0[(y * 100 + x) as usize].update(PixelState::VLine);

}

return Ok(());

}

if from.1 == to.1 {

let y = from.1;

let x0 = from.0.min(to.0);

let x1 = from.0.max(to.0);

for x in x0..x1 {

self.0[(y * 100 + x) as usize].update(PixelState::HLine);

}

return Ok(());

}

plotters_backend::rasterizer::draw_line(self, from, to, style)

}

fn estimate_text_size<S: BackendTextStyle>(

&self,

text: &str,

_: &S,

) -> Result<(u32, u32), DrawingErrorKind<Self::ErrorType>> {

Ok((text.len() as u32, 1))

}

fn draw_text<S: BackendTextStyle>(

&mut self,

text: &str,

style: &S,

pos: (i32, i32),

) -> Result<(), DrawingErrorKind<Self::ErrorType>> {

let (width, height) = self.estimate_text_size(text, style)?;

let (width, height) = (width as i32, height as i32);

let dx = match style.anchor().h_pos {

HPos::Left => 0,

HPos::Right => -width,

HPos::Center => -width / 2,

};

let dy = match style.anchor().v_pos {

VPos::Top => 0,

VPos::Center => -height / 2,

VPos::Bottom => -height,

};

let offset = (pos.1 + dy).max(0) * 100 + (pos.0 + dx).max(0);

for (idx, chr) in (offset..).zip(text.chars()) {

self.0[idx as usize].update(PixelState::Text(chr));

}

Ok(())

}

b: DrawingArea<DB, plotters::coord::Shift>,

) -> Result<(), Box<dyn Error>>

DB::ErrorType: 'static,

let mut chart = ChartBuilder::on(&b)

.margin(1)

.caption("Sine and Cosine", ("sans-serif", (10).percent_height()))

.set_label_area_size(LabelAreaPosition::Left, (5i32).percent_width())

.set_label_area_size(LabelAreaPosition::Bottom, (10i32).percent_height())

.build_cartesian_2d(-std::f64::consts::PI..std::f64::consts::PI, -1.2..1.2)?;

chart

.configure_mesh()

.disable_x_mesh()

.disable_y_mesh()

.draw()?;

chart.draw_series(LineSeries::new(

(-314..314).map(|x| x as f64 / 100.0).map(|x| (x, x.sin())),

&RED,

))?;

chart.draw_series(LineSeries::new(

(-314..314).map(|x| x as f64 / 100.0).map(|x| (x, x.cos())),

&RED,

))?;

b.present()?;

Ok(())

draw_chart(TextDrawingBackend(vec![PixelState::Empty; 5000]).into_drawing_area())?;

let b = BitMapBackend::new(OUT_FILE_NAME, (1024, 768)).into_drawing_area();

b.fill(&WHITE)?;

draw_chart(b)?;

println!("Image result has been saved to {}", OUT_FILE_NAME);

Ok(())