Add shape helpers

Cargo.toml

@@ -7,6 +7,7 @@ edition = "2021"
 crate-type = ["cdylib", "rlib"]
 
 [dependencies]
+glam = "^0.21"
 wee_alloc = "^0.4"
 
 [profile.release]

src/lib.rs

@@ -1,3 +1,5 @@
+use glam::Vec2;
+
 #[global_allocator]
 static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;
 
@@ -30,8 +32,8 @@ macro_rules! handle_event_at {
         pub extern "C" fn $event(id: u32, x: f32, y: f32) {
             unsafe {
                 let panel = &mut PANEL_IMPLS[id as usize];
-                let point = Point { x, y };
-                (&mut *panel).$event(point);
+                let at = Vec2::new(x, y);
+                (&mut *panel).$event(at);
             }
         }
     };
@@ -45,10 +47,10 @@ handle_event_at!(on_deselect);
 #[allow(unused)]
 pub trait PanelImpl {
     fn update(&mut self, dt: f32) {}
-    fn on_hover(&mut self, at: Point) {}
-    fn on_select(&mut self, at: Point) {}
-    fn on_drag(&mut self, at: Point) {}
-    fn on_deselect(&mut self, at: Point) {}
+    fn on_hover(&mut self, at: Vec2) {}
+    fn on_select(&mut self, at: Vec2) {}
+    fn on_drag(&mut self, at: Vec2) {}
+    fn on_deselect(&mut self, at: Vec2) {}
 }
 
 pub struct DummyPanel {
@@ -63,10 +65,9 @@ impl DummyPanel {
 
 impl PanelImpl for DummyPanel {
     fn update(&mut self, _dt: f32) {
-        self.panel.draw_triangle(
-            &Point { x: 0.0, y: 0.0 },
-            &Point { x: 0.1, y: 0.0 },
-            &Point { x: 0.0, y: 0.1 },
+        self.panel.draw_rect(
+            &Vec2 { x: 0.0, y: 0.0 },
+            &Vec2 { x: 0.5, y: 0.5 },
             &Color {
                 r: 1.0,
                 g: 0.0,
@@ -99,13 +100,6 @@ extern "C" {
     );
 }
 
-#[repr(C)]
-#[derive(Copy, Clone, Debug)]
-pub struct Point {
-    pub x: f32,
-    pub y: f32,
-}
-
 #[repr(C)]
 #[derive(Copy, Clone, Debug)]
 pub struct Color {
@@ -139,11 +133,61 @@ impl UiPanel {
         unsafe { UiPanel_setColor(self.0, color.r, color.g, color.b, color.a) }
     }
 
-    pub fn draw_triangle(&mut self, v1: &Point, v2: &Point, v3: &Point, color: &Color) {
+    pub fn draw_triangle(&mut self, v1: &Vec2, v2: &Vec2, v3: &Vec2, color: &Color) {
         unsafe {
             UiPanel_drawTriangle(
                 self.0, v1.x, v1.y, v2.x, v2.y, v3.x, v3.y, color.r, color.g, color.b, color.a,
             )
         }
     }
+
+    pub fn draw_circle(&mut self, center: &Vec2, radius: f32, color: &Color) {
+        use std::f32::consts::PI;
+
+        let delta = PI / 16.0;
+        let limit = PI * 2.0 + delta;
+
+        let mut last_spoke = Vec2::new(radius + center.x, center.y);
+        let mut theta = delta;
+        while theta < limit {
+            let new_spoke = Vec2::from_angle(theta) * radius + *center;
+            self.draw_triangle(&center, &last_spoke, &new_spoke, &color);
+            last_spoke = new_spoke;
+            theta += delta;
+        }
+    }
+
+    pub fn draw_ring(&mut self, center: &Vec2, radius: f32, thickness: f32, color: &Color) {
+        use std::f32::consts::PI;
+
+        let delta = PI / 64.0;
+        let limit = PI * 2.0 + delta;
+
+        let mut last_spoke = glam::Vec2::new(radius + center.x, center.y);
+        let mut last_theta = 0.0;
+        let mut theta = delta;
+        while theta < limit {
+            let angle = Vec2::from_angle(theta);
+            let new_spoke = angle * radius + *center;
+            let new_spoke2 = angle * (radius + thickness) + *center;
+            let last_spoke2 = Vec2::from_angle(last_theta) * (radius + thickness) + *center;
+
+            self.draw_triangle(&new_spoke2, &last_spoke, &new_spoke, &color);
+            self.draw_triangle(&new_spoke2, &last_spoke2, &last_spoke, &color);
+
+            last_spoke = new_spoke;
+            last_theta = theta;
+            theta += delta;
+        }
+    }
+
+    pub fn draw_rect(&mut self, xy: &Vec2, size: &Vec2, color: &Color) {
+        let v1 = *xy;
+        let v2 = v1 + Vec2::new(size.x, 0.0);
+        let v3 = v1 + Vec2::new(0.0, size.y);
+        let v4 = v1 + *size;
+
+        self.draw_triangle(&v1, &v2, &v3, &color);
+        self.draw_triangle(&v2, &v3, &v4, &color);
+    }
 }