feat: add example for point_in_poly2d

crates/parry2d/examples/point_in_poly2d.rs

@@ -0,0 +1,110 @@
+use macroquad::prelude::*;
+use nalgebra::{Point2, UnitComplex, Vector2};
+use parry2d::shape::Ball;
+use parry2d::transformation::polygons_intersection_points;
+use parry2d::utils::point_in_poly2d;
+
+const RENDER_SCALE: f32 = 30.0;
+
+#[macroquad::main("parry2d::utils::point_in_poly2d")]
+async fn main() {
+    let mut spikes = spikes_polygon();
+    let test_points = grid_points();
+
+    let animation_rotation = UnitComplex::new(0.02);
+    let spikes_render_pos = Point2::new(screen_width() / 2.0, screen_height() / 2.0);
+
+    for i in 0.. {
+        clear_background(BLACK);
+
+        /*
+         * Compute polygon intersections.
+         */
+        spikes
+            .iter_mut()
+            .for_each(|pt| *pt = animation_rotation * *pt);
+        draw_polygon(&spikes, RENDER_SCALE, spikes_render_pos, BLUE);
+
+        for point in &test_points {
+            if point_in_poly2d(point, &spikes) {
+                draw_point(*point, RENDER_SCALE, spikes_render_pos, RED);
+            } else {
+                draw_point(*point, RENDER_SCALE, spikes_render_pos, GREEN);
+            }
+        }
+
+        next_frame().await
+    }
+}
+
+fn spikes_polygon() -> Vec<Point2<f32>> {
+    let teeths = 3;
+    let width = 15.0;
+    let height = 7.5;
+    let tooth_width = width / (teeths as f32);
+    let center = Vector2::new(width / 2.0, height / 2.0);
+
+    let mut polygon = vec![
+        Point2::new(width, 0.0) - center,
+        Point2::new(width, height) - center,
+        Point2::new(0.0, height) - center,
+    ];
+
+    for i in 0..teeths {
+        let x = i as f32 * tooth_width;
+        polygon.push(Point2::new(x, 0.0) - center);
+        polygon.push(Point2::new(x + tooth_width / 2.0, height * 1.5) - center);
+    }
+
+    polygon
+}
+
+fn grid_points() -> Vec<Point2<f32>> {
+    let count = 40;
+    let spacing = 0.6;
+    let mut pts = vec![];
+    for i in 0..count {
+        for j in 0..count {
+            pts.push(Point2::new(
+                (i as f32 - count as f32 / 2.0) * spacing,
+                (j as f32 - count as f32 / 2.0) * spacing,
+            ));
+        }
+    }
+    pts
+}
+
+fn draw_polygon(polygon: &[Point2<f32>], scale: f32, shift: Point2<f32>, color: Color) {
+    for i in 0..polygon.len() {
+        let a = polygon[i];
+        let b = polygon[(i + 1) % polygon.len()];
+        draw_line(
+            a.x * scale + shift.x,
+            a.y * scale + shift.y,
+            b.x * scale + shift.x,
+            b.y * scale + shift.y,
+            2.0,
+            color,
+        );
+    }
+}
+
+fn draw_point(point: Point2<f32>, scale: f32, shift: Point2<f32>, color: Color) {
+    let edge_len = 0.15;
+    draw_line(
+        (point.x - edge_len) * scale + shift.x,
+        point.y * scale + shift.y,
+        (point.x + edge_len) * scale + shift.x,
+        point.y * scale + shift.y,
+        2.0,
+        color,
+    );
+    draw_line(
+        point.x * scale + shift.x,
+        (point.y - edge_len) * scale + shift.y,
+        point.x * scale + shift.x,
+        (point.y + edge_len) * scale + shift.y,
+        2.0,
+        color,
+    );
+}