right and forward

src/main.rs

@@ -2,8 +2,18 @@ mod turtle;
 
 use turtle::Turtle;
 
+fn square(turtle: &mut turtle::Turtle) {
+    turtle.left(90.0);
+    turtle.forward(5);
+    for _ in 0..3 {
+        turtle.right(90.0);
+        turtle.forward(5);
+    }
+}
+
 fn main() {
     let mut turtle = Turtle::new();
-    turtle.draw_line((50, 50), (200, 200));
+    
+    square(&mut turtle);
     turtle.save("output.png").unwrap();
 }

src/turtle.rs

@@ -8,16 +8,18 @@ type ImgBufU8 = ImageBuffer<Rgb<u8>, Vec<u8>>;
 type Colour = Rgb<u8>;
 type Coord = (i32, i32);
 
-const DEFAULT_WIDTH: u32 = 800;
-const DEFAULT_HEIGHT: u32 = 800;
+const DEFAULT_WIDTH: u32 = 300;
+const DEFAULT_HEIGHT: u32 = 300;
 const DEFAULT_BACKGROUND_COLOUR: Colour = Rgb([255u8, 255u8, 255u8]);
 const DEFAULT_COLOUR: Colour = Rgb([0u8, 0u8, 0u8]);
+const DEFAULT_POS: Coord = ((DEFAULT_WIDTH as f64/2.0) as i32, (DEFAULT_HEIGHT as f64/2.0) as i32);
 
 pub struct Turtle {
     buf: ImgBufU8,
     colour: Colour,
     pos: Coord,
-    angle: f64,
+    step_length: u32,
+    angle: f64, // угол в радианах
 }
 
 impl Turtle {
@@ -30,7 +32,8 @@ impl Turtle {
         Turtle {
             buf,
             colour: DEFAULT_COLOUR,
-            pos: (0, 0),
+            pos: DEFAULT_POS,
+            step_length: 10,
             angle: 0.0,
         }
     }
@@ -39,13 +42,28 @@ impl Turtle {
         self.pos
     }
 
-    pub fn draw_line(&mut self, start: Coord, end: Coord) {
-        drawing::draw_line_segment_mut(
-            &mut self.buf,
-            (start.0 as f32, start.1 as f32),
-            (end.0 as f32, end.1 as f32),
-            self.colour
-        );
+    pub fn angle(&self) -> f64 {
+        self.angle.to_degrees()
+    }
+
+    pub fn forward(&mut self, steps_count: u32) {
+        let start_pos = self.pos;
+
+        let dy = self.angle.sin() * steps_count as f64 * self.step_length as f64;
+        let dx = self.angle.cos() * steps_count as f64 * self.step_length as f64;
+        
+        self.pos.0 += dx.round() as i32;
+        self.pos.1 += dy.round() as i32;
+        
+        self.draw_line(start_pos, self.pos);
+    }
+
+    pub fn right(&mut self, degrees: f64) {
+        self.angle += degrees.to_radians();
+    }
+
+    pub fn left(&mut self, degrees: f64) {
+        self.angle -= degrees.to_radians();
     }
 
     pub fn save<P>(&self, output_path: P) -> ImageResult<()> 
@@ -54,4 +72,13 @@ impl Turtle {
     {
         self.buf.save(output_path)
     }
+
+    fn draw_line(&mut self, start: Coord, end: Coord) {
+        drawing::draw_line_segment_mut(
+            &mut self.buf,
+            (start.0 as f32, start.1 as f32),
+            (end.0 as f32, end.1 as f32),
+            self.colour
+        );
+    }
 }