Add a basic lines-based debug-renderer

3 files changed, 86 insertions, 3 deletions

diff --git a/src_testbed/debug_render.rs b/src_testbed/debug_render.rs
new file mode 100644
index 0000000..135529f
--- /dev/null
+++ b/src_testbed/debug_render.rs
@@ -0,0 +1,81 @@
+use crate::harness::Harness;
+use bevy::prelude::*;
+use bevy_prototype_debug_lines::DebugLines;
+use rapier::math::{Point, Real, DIM};
+use rapier::pipeline::{
+    DebugRenderBackend, DebugRenderMode, DebugRenderObject, DebugRenderPipeline,
+};
+use std::fmt::Debug;
+
+pub struct RapierDebugRenderPlugin {
+    depth_test: bool,
+}
+
+impl Default for RapierDebugRenderPlugin {
+    fn default() -> Self {
+        Self {
+            depth_test: cfg!(feature = "dim3"),
+        }
+    }
+}
+
+impl RapierDebugRenderPlugin {
+    pub fn with_depth_test(enabled: bool) -> Self {
+        Self {
+            depth_test: enabled,
+        }
+    }
+}
+
+impl Plugin for RapierDebugRenderPlugin {
+    fn build(&self, app: &mut App) {
+        app.add_plugin(
+            bevy_prototype_debug_lines::DebugLinesPlugin::with_depth_test(self.depth_test),
+        )
+        .insert_resource(DebugRenderPipeline::new(
+            Default::default(),
+            !DebugRenderMode::RIGID_BODY_AXES,
+        ))
+        .add_system_to_stage(CoreStage::Update, debug_render_scene);
+    }
+}
+
+struct BevyLinesRenderBackend<'a> {
+    lines: &'a mut DebugLines,
+}
+
+impl<'a> DebugRenderBackend for BevyLinesRenderBackend<'a> {
+    #[cfg(feature = "dim2")]
+    fn draw_line(&mut self, _: DebugRenderObject, a: Point<Real>, b: Point<Real>, color: [f32; 4]) {
+        self.lines.line_colored(
+            [a.x, a.y, 1.0e-8].into(),
+            [b.x, b.y, 1.0e-8].into(),
+            0.0,
+            Color::hsla(color[0], color[1], color[2], color[3]),
+        )
+    }
+    #[cfg(feature = "dim3")]
+    fn draw_line(&mut self, _: DebugRenderObject, a: Point<Real>, b: Point<Real>, color: [f32; 4]) {
+        self.lines.line_colored(
+            [a.x, a.y, a.z].into(),
+            [b.x, b.y, b.z].into(),
+            0.0,
+            Color::hsla(color[0], color[1], color[2], color[3]),
+        )
+    }
+}
+
+fn debug_render_scene(
+    mut pipeline: ResMut<DebugRenderPipeline>,
+    harness: NonSend<Harness>,
+    mut lines: ResMut<DebugLines>,
+) {
+    let mut backend = BevyLinesRenderBackend { lines: &mut *lines };
+    pipeline.render(
+        &mut backend,
+        &harness.physics.bodies,
+        &harness.physics.colliders,
+        &harness.physics.impulse_joints,
+        &harness.physics.multibody_joints,
+    );
+}
diff --git a/src_testbed/lib.rs b/src_testbed/lib.rs
index bbf2d2f..881e05d 100644
--- a/src_testbed/lib.rs
+++ b/src_testbed/lib.rs
@@ -19,6 +19,7 @@ mod box2d_backend;
 mod camera2d;
 #[cfg(feature = "dim3")]
 mod camera3d;
+mod debug_render;
 mod graphics;
 pub mod harness;
 pub mod objects;
diff --git a/src_testbed/testbed.rs b/src_testbed/testbed.rs
index 1bb30eb..2c40cf2 100644
--- a/src_testbed/testbed.rs
+++ b/src_testbed/testbed.rs
@@ -5,7 +5,7 @@ use bevy::prelude::*;
 
 use crate::physics::{PhysicsEvents, PhysicsSnapshot, PhysicsState};
 use crate::plugin::TestbedPlugin;
-use crate::ui;
+use crate::{debug_render, ui};
 use crate::{graphics::GraphicsManager, harness::RunState};
 
 use na::{self, Point2, Point3, Vector3};
@@ -17,7 +17,7 @@ use rapier::geometry::{ColliderHandle, ColliderSet, NarrowPhase};
 #[cfg(feature = "dim3")]
 use rapier::geometry::{InteractionGroups, Ray};
 use rapier::math::{Real, Vector};
-use rapier::pipeline::PhysicsHooks;
+use rapier::pipeline::{DebugRenderMode, PhysicsHooks};
 
 #[cfg(all(feature = "dim2", feature = "other-backends"))]
 use crate::box2d_backend::Box2dWorld;
@@ -380,7 +380,8 @@ impl TestbedApp {
             .add_plugins(DefaultPlugins)
             .add_plugin(OrbitCameraPlugin)
             .add_plugin(WireframePlugin)
-            .add_plugin(bevy_egui::EguiPlugin);
+            .add_plugin(bevy_egui::EguiPlugin)
+            .add_plugin(debug_render::RapierDebugRenderPlugin::default());
 
             #[cfg(target_arch = "wasm32")]
             app.add_plugin(bevy_webgl2::WebGL2Plugin);