Interface IDebugDrawer

Namespace: Box3D

Assembly: Box3D.NET.dll

Receives the primitives Box3D emits while drawing a world.

public interface IDebugDrawer

Examples

A drawer that collects line segments for a renderer to upload:

struct SegmentCollector : IDebugDrawer
{
    public List<(Vector3, Vector3, DebugColor)> Lines;

    public void DrawSegment(Vector3 p1, Vector3 p2, DebugColor color)
        => Lines.Add((p1, p2, color));

    // ... the rest may be left empty; Box3D skips nothing, but a drawer may.
}

var collector = new SegmentCollector { Lines = lines };
world.Draw(ref collector, DebugDrawOptions.Default with { DrawJoints = true });

Remarks

Implement this over whatever renderer the application already has. Box3D.NET deliberately knows nothing about OpenGL, Vulkan, Unity or anything else: it hands over points, segments and boxes in world space and the application decides what a line looks like.

Every method is called synchronously from inside Box3D.PhysicsWorld.Draw``1(``0@,Box3D.DebugDrawOptions@), on the thread that called it, and none of them may touch the world being drawn. Reading or writing the simulation from here is the same race as doing it mid-step.

A frame's worth of drawing allocates nothing, provided the implementation does not allocate: the calls arrive through function pointers with no delegate, no closure and no boxing. Implementing this on a struct passed by ref keeps it that way and lets the JIT inline the calls.

Methods

DrawBounds(BoundingBox, DebugColor): Draws an axis-aligned bounding box.
DrawBox(Vector3, Vector3, Quaternion, DebugColor): Draws an oriented box.
DrawCapsule(Vector3, Vector3, float, DebugColor, float): Draws a capsule between two points.
DrawPoint(Vector3, float, DebugColor): Draws a point.
DrawSegment(Vector3, Vector3, DebugColor): Draws a line segment.
DrawShape(nint, Vector3, Quaternion, DebugColor): Draws a drawable built earlier by the shape factory.
DrawSphere(Vector3, float, DebugColor, float): Draws a sphere.
DrawString(Vector3, ReadOnlySpan<byte>, DebugColor): Draws text anchored to a world position.
DrawTransform(Vector3, Quaternion): Draws a coordinate frame, the application choosing the axis length.

Table of Contents

Interface IDebugDrawer

Examples

Remarks

Methods