public/subjects/drawing/README.md

drawing

Instructions

The purpose of this exercise is to create an image in the example bellow:

For this exercise you will need to do the following:

• Copy the code in usage to your main.rs.

• Create a module called geometrical_shapes in another file.

This module will keep all the logic for creating and operating with the different geometrical shapes. You need to define two traits, Displayable and Drawable.

• Drawable which contains the methods draw and color.

• Displayable which contains the method display.

Define them according to the way they are called in the main.rs function.

In order to make the code in the main.rs compile and run, you have to define the following structures:

• Point
• Circle
• Line
• Rectangle
• Triangle

You are free to implement all the shapes with whatever internal structure you see fit, but you must provide an associated function new for all the shapes, which will be described below:

• Point: a new point should be created from two i32 values.

• Line: a new line should be created from references to two different points. Also it will define an associated function called random:

  • random: receives two arguments, the first is the maximum x value a point can have and the second is the maximum y value that a point can have.

• Triangle: a new triangle should be created from references to three different points.

• Rectangle: a new rectangle should be created from two references to different points. ??????????????????????????????

• Circle: a new circle should be created from a point representing the center and an i32 value representing the radius for the circle.

• The main function also requires a definition of an associated function called random for the types Line, Point and Circle. You should derive their signature from the usage.

Note: Don't forget to add the dependencies in your Cargo.toml.

Bonus

• Implement the possibility of drawing a pentagon (implement the structure Pentagon, and the trait needed to draw in the image)

• Implement the possibility of drawing a cube (implement the structure Cube, and the trait needed to draw in the image)

Usage

mod geometrical_shapes;

use geometrical_shapes as gs;
use gs::{Displayable, Drawable};
use raster::{Color, Image};

fn main() {
    let mut image = Image::blank(1000, 1000);

    gs::Line::random(image.width, image.height).draw(&mut image);

    gs::Point::random(image.width, image.height).draw(&mut image);

    let rectangle = gs::Rectangle::new(&gs::Point::new(150, 150), &gs::Point::new(50, 50));
    rectangle.draw(&mut image);

    let triangle = gs::Triangle::new (
            &gs::Point::new(500, 500),
            &gs::Point::new(250, 700),
            &gs::Point::new(700, 800),
    );
    triangle.draw(&mut image);

    for _ in 1..50 {
        gs::Circle::random(image.width, image.height).draw(&mut image);
    }

    raster::save(&image, "image.png").unwrap();
}

impl Displayable for Image {
    fn display(&mut self, x: i32, y: i32, color: Color) {
        if x >= 0 && x < self.width && y >= 0 && y < self.height {
            self.set_pixel(x, y, color).unwrap();
        }
    }
}

Note: The expected output is a png file: image.png

Notions

• Image processing library

• Traits