From 63d13bb770e0b68450af4643bcd4f32cd5b84653 Mon Sep 17 00:00:00 2001
From: devil-ira <justthecooldude@gmail.com>
Date: Mon, 14 Nov 2022 23:33:46 +0100
Subject: [PATCH] linestrip

---
 crates/bevy_debug_draw/Cargo.toml        |  1 +
 crates/bevy_debug_draw/src/debug_draw.rs | 44 ++++++++++++++++++++++++
 examples/2d/2d_debug_draw.rs             | 23 +++++++++----
 examples/3d/3d_debug_draw.rs             | 14 ++++----
 4 files changed, 68 insertions(+), 14 deletions(-)

diff --git a/crates/bevy_debug_draw/Cargo.toml b/crates/bevy_debug_draw/Cargo.toml
index 8e305b8a120cae..10d21250ef442f 100644
--- a/crates/bevy_debug_draw/Cargo.toml
+++ b/crates/bevy_debug_draw/Cargo.toml
@@ -9,6 +9,7 @@ license = "MIT OR Apache-2.0"
 keywords = ["bevy"]
 
 [dependencies]
+# Bevy
 bevy_pbr = { path = "../bevy_pbr", version = "0.9.0-dev", optional = true }
 bevy_sprite = { path = "../bevy_sprite", version = "0.9.0-dev", optional = true }
 bevy_app = { path = "../bevy_app", version = "0.9.0-dev" }
diff --git a/crates/bevy_debug_draw/src/debug_draw.rs b/crates/bevy_debug_draw/src/debug_draw.rs
index 103a8af536b15d..3472f4e38e5f15 100644
--- a/crates/bevy_debug_draw/src/debug_draw.rs
+++ b/crates/bevy_debug_draw/src/debug_draw.rs
@@ -53,6 +53,36 @@ impl DebugDraw {
         ]);
     }
 
+    #[inline]
+    pub fn linestrip(&mut self, positions: impl IntoIterator<Item = Vec3>, color: Color) {
+        let mut count = 0;
+        let positions = positions
+            .into_iter()
+            .map(|value| {
+                count += 1;
+                value.to_array()
+            })
+            .chain(iter::once([f32::NAN; 3]));
+
+        self.strip_positions.extend(positions);
+        self.add_strip_color(color, count);
+    }
+
+    #[inline]
+    pub fn linestrip_gradient(&mut self, points: impl IntoIterator<Item = (Vec3, Color)>) {
+        let points = points.into_iter();
+        let (lower, _) = points.size_hint();
+        self.strip_colors.reserve(lower + 1);
+        self.strip_positions.reserve(lower + 1);
+
+        for (position, color) in points {
+            self.strip_positions.push(position.to_array());
+            self.strip_colors.push(color.as_linear_rgba_f32());
+        }
+        self.strip_positions.push([f32::NAN; 3]);
+        self.strip_colors.push([f32::NAN; 4]);
+    }
+
     /// Draw a line from `start` to `start + vector`.
     #[inline]
     pub fn ray(&mut self, start: Vec3, vector: Vec3, color: Color) {
@@ -152,6 +182,20 @@ impl DebugDraw {
         self.line_gradient(start.extend(0.), end.extend(0.), start_color, end_color);
     }
 
+    #[inline]
+    pub fn linestrip_2d(&mut self, positions: impl IntoIterator<Item = Vec2>, color: Color) {
+        self.linestrip(positions.into_iter().map(|vec2| vec2.extend(0.)), color);
+    }
+
+    #[inline]
+    pub fn linestrip_gradient_2d(&mut self, positions: impl IntoIterator<Item = (Vec2, Color)>) {
+        self.linestrip_gradient(
+            positions
+                .into_iter()
+                .map(|(vec2, color)| (vec2.extend(0.), color)),
+        );
+    }
+
     /// Draw a line from `start` to `start + vector`.
     #[inline]
     pub fn ray_2d(&mut self, start: Vec2, vector: Vec2, color: Color) {
diff --git a/examples/2d/2d_debug_draw.rs b/examples/2d/2d_debug_draw.rs
index f69cc4dfeff621..024c44d6c85571 100644
--- a/examples/2d/2d_debug_draw.rs
+++ b/examples/2d/2d_debug_draw.rs
@@ -15,19 +15,28 @@ fn setup(mut commands: Commands) {
 }
 
 fn system(mut draw: ResMut<DebugDraw>, time: Res<Time>) {
-    draw.line_2d(Vec2::ZERO, Vec2::new(-200., 300.), Color::RED);
-    draw.line_2d(Vec2::ZERO, Vec2::ONE * 300., Color::GREEN);
+    let sin = time.elapsed_seconds().sin() * 50.;
+    draw.line_2d(Vec2::Y * -sin, Vec2::splat(-80.), Color::RED);
+    draw.ray_2d(Vec2::Y * sin, Vec2::splat(80.), Color::GREEN);
+
+    // Triangle
+    draw.linestrip_gradient_2d([
+        (Vec2::Y * 300., Color::BLUE),
+        (Vec2::new(-255., -155.), Color::RED),
+        (Vec2::new(255., -155.), Color::GREEN),
+        (Vec2::Y * 300., Color::BLUE),
+    ]);
 
     draw.rect_2d(
         Vec2::ZERO,
-        time.elapsed_seconds(),
-        Vec2::ONE * 300.,
+        time.elapsed_seconds() / 3.,
+        Vec2::splat(300.),
         Color::BLACK,
     );
-    // The circles have 24 line-segments by default.
+    // The circles have 32 line-segments by default.
     draw.circle_2d(Vec2::ZERO, 120., Color::BLACK);
     // You may want to increase this for larger circles.
     draw.circle_segments = 64;
-    draw.circle_2d(Vec2::ZERO, 250., Color::NAVY);
-    draw.circle_segments = 24;
+    draw.circle_2d(Vec2::ZERO, 300., Color::NAVY);
+    draw.circle_segments = 32;
 }
diff --git a/examples/3d/3d_debug_draw.rs b/examples/3d/3d_debug_draw.rs
index db2a8de9edbdc3..b02a489c652711 100644
--- a/examples/3d/3d_debug_draw.rs
+++ b/examples/3d/3d_debug_draw.rs
@@ -29,23 +29,23 @@ fn system(mut draw: ResMut<DebugDraw>, time: Res<Time>) {
     draw.rect(
         Vec3::new(time.elapsed_seconds().cos() * 2.5, 1., 0.),
         Quat::from_rotation_y(PI / 2.),
-        Vec2::ONE * 2.,
+        Vec2::splat(2.),
         Color::GREEN,
     );
 
     draw.sphere(Vec3::new(1., 0.5, 0.), 0.5, Color::RED);
     let vector = Vec3::new(-3., (time.elapsed_seconds() * 3.).sin(), 0.);
-    draw.ray(Vec3::new(1., 0., 0.), vector, Color::BLUE);
-    draw.ray(Vec3::new(1., 0.5, 0.), vector, Color::BLUE);
-    draw.ray(Vec3::new(1., 1., 0.), vector, Color::BLUE);
+    for f in [0., 0.5, 1.] {
+        draw.ray(Vec3::new(1., f, 0.), vector, Color::BLUE);
+    }
 
-    // The circles have 24 line-segments by default.
+    // The circles have 32 line-segments by default.
     draw.circle(Vec3::ZERO, Vec3::Y, 3., Color::BLACK);
-    // You may want to increase this for larger circles/spheres.
+    // You may want to increase this for larger circles or spheres.
     draw.circle_segments = 64;
     draw.circle(Vec3::ZERO, Vec3::Y, 3.1, Color::NAVY);
     draw.sphere(Vec3::ZERO, 3.2, Color::BLACK);
-    draw.circle_segments = 24;
+    draw.circle_segments = 32;
 }
 
 fn rotate_camera(mut query: Query<&mut Transform, With<Camera>>, time: Res<Time>) {