Vertex drawing

examples/cube.rs

@@ -3,37 +3,30 @@ pub mod components;
 use osmium::{renderer::Point, terminal};
 
 fn main() {
-    let (term_width, term_height) = crossterm::terminal::size().unwrap();
-    let a = term_height - 3;
-
     let engine = osmium::init();
 
-    let my_rect = engine.entity(|r| {
-        r.draw_rect(0, 0, 1, 2, 0xff0000);
-        r.draw_rect(1, 0, 1, 2, 0x00ff00);
-        r.draw_rect(2, 0, 1, 2, 0x0000ff);
-    });
+    engine.entity(|r| {
+        r.draw_vertex(
+            0,
+            0,
+            &[
+                Point { x: 0, y: 0 },
+                Point { x: 30, y: 0 },
+                Point { x: 15, y: 8 },
+            ],
+            0x0000ff,
+        );
 
-    my_rect.component(components::Velocity(Point { x: 0, y: 0 }));
-    my_rect.component(components::ZigZag(term_width - 3));
-
-    my_rect.set_position(0, term_height - 3);
-
-    components::threads::tick(&engine);
-    components::threads::key(&engine);
-
-    engine.on_event({
-        let my_rect = my_rect.clone();
-        move |e: &crossterm::event::Event| {
-            if let Some(key_event) = e.as_key_event() {
-                match key_event.code {
-                    crossterm::event::KeyCode::Char(' ') => {
-                        my_rect.component(components::Jumping(0, a));
-                    }
-                    _ => {}
-                }
-            }
-        }
+        r.draw_vertex_outline(
+            0,
+            0,
+            &[
+                Point { x: 0, y: 0 },
+                Point { x: 30, y: 0 },
+                Point { x: 15, y: 8 },
+            ],
+            0xff0000,
+        );
     });
 
     terminal::hide_cursor().unwrap();

src/renderer.rs

@@ -23,6 +23,108 @@ impl Renderer {
         print_liner(self.pos.x + x, self.pos.y + y, &hex_bg(color), &rect);
     }
 
+    pub fn draw_pixel(&self, x: u16, y: u16, color: u32) {
+        print_liner(self.pos.x + x, self.pos.y + y, &hex_bg(color), &" \x1b[0m");
+    }
+
+    pub fn draw_line(&self, x0: i16, y0: i16, x1: i16, y1: i16, color: u32) {
+        let dx = (x1 - x0).abs();
+        let sx = if x0 < x1 { 1 } else { -1 };
+        let dy = -(y1 - y0).abs();
+        let sy = if y0 < y1 { 1 } else { -1 };
+        let mut err = dx + dy;
+
+        let (mut x, mut y) = (x0, y0);
+
+        loop {
+            self.draw_pixel(x as u16, y as u16, color);
+
+            if x == x1 && y == y1 {
+                break;
+            }
+
+            let e2 = 2 * err;
+            if e2 >= dy {
+                err += dy;
+                x += sx;
+            }
+            if e2 <= dx {
+                err += dx;
+                y += sy;
+            }
+        }
+    }
+
+    pub fn draw_vertex_outline(&self, x: u16, y: u16, vertices: &[Point], color: u32) {
+        if vertices.len() < 2 {
+            return;
+        }
+
+        for i in 0..vertices.len() {
+            let p0 = &vertices[i];
+            let p1 = &vertices[(i + 1) % vertices.len()];
+
+            self.draw_line(
+                x as i16 + p0.x as i16,
+                y as i16 + p0.y as i16,
+                x as i16 + p1.x as i16,
+                y as i16 + p1.y as i16,
+                color,
+            );
+        }
+    }
+
+    pub fn draw_vertex(&self, x: u16, y: u16, vertices: &[Point], color: u32) {
+        if vertices.len() < 3 {
+            return;
+        }
+
+        self.draw_vertex_outline(x, y, vertices, color);
+
+        let pts: Vec<(i32, i32)> = vertices
+            .iter()
+            .map(|p| ((p.x + x) as i32, (p.y + y) as i32))
+            .collect();
+
+        let min_y = pts.iter().map(|(_, y)| *y).min().unwrap();
+        let max_y = pts.iter().map(|(_, y)| *y).max().unwrap();
+
+        for y in min_y..=max_y {
+            let mut intersections = Vec::<i32>::new();
+
+            for i in 0..pts.len() {
+                let (x1, y1) = pts[i];
+                let (x2, y2) = pts[(i + 1) % pts.len()];
+
+                // same edge test as your original
+                if (y1 <= y && y2 > y) || (y2 <= y && y1 > y) {
+                    let dy = y2 - y1;
+                    let dx = x2 - x1;
+
+                    let t = (y - y1) as f32 / dy as f32;
+                    let x = (x1 as f32 + t * dx as f32).round() as i32;
+                    intersections.push(x);
+                }
+            }
+
+            if intersections.len() < 2 {
+                continue;
+            }
+
+            intersections.sort_unstable();
+
+            // fill between pairs
+            for pair in intersections.chunks(2) {
+                if pair.len() < 2 {
+                    continue;
+                }
+                for x in pair[0]..=pair[1] {
+                    self.draw_pixel(x as u16, y as u16, color);
+                }
+            }
+        }
+    }
+
     pub fn set_position(&mut self, x: u16, y: u16) {
         self.pos.x = x;
         self.pos.y = y;