ShapesDrawer

The ShapesDrawer system provides a fire-and-forget immediate-mode drawing API built on top of the Shapes library. Game code calls static ShapesDrawer.Draw*() methods from any context (Update, Debug, etc.), and the system batches all requests into per-shape queues that are rendered once per camera per frame. Queues are automatically cleared each frame via a custom PlayerLoop injection.

Architecture

Rendering Pipeline

Key Concepts

Concept	Description
Fire-and-forget	Call ShapesDrawer.Draw*() from any code. The shape is queued and rendered at the end of the frame. No cleanup required.
Per-frame clearing	A custom PlayerLoopSystem injected at PRE_UPDATE clears all draw queues each frame. Shapes only persist for one frame.
Per-camera rendering	Draw commands are issued inside Draw.Command(cam) for each camera, supporting multi-camera setups.
Render pipeline support	Automatically hooks into either URP/HDRP (beginCameraRendering) or Built-in (Camera.onPreRender).
Shape structs	Each shape type is a readonly struct (e.g., LineDrawer.Line, ArcDrawer.Arc) stored in a List<TShape> queue for cache-friendly iteration.

Quick Start

Drawing Shapes

using Paragon.Core.ShapesDrawer;
using UnityEngine;

// Lines
ShapesDrawer.DrawLine(Vector3.zero, Vector3.forward, Color.red, thickness: 2f);
ShapesDrawer.DrawLine(start, end, Color.green, lineEndCap: LineEndCap.ROUND);

// Arcs
ShapesDrawer.DrawArc(pivot, Vector3.up, 0f, 90f, radius: 2f, Color.blue);

// Rings
ShapesDrawer.DrawRing(center, Vector3.up, radius: 3f, Color.yellow);

// Pies (filled arcs)
ShapesDrawer.DrawPie(center, Vector3.up, 0f, 45f, radius: 2f, Color.cyan);

// Spheres
ShapesDrawer.DrawSphere(center, radius: 1f, Color.magenta);
ShapesDrawer.DrawWireSphere(center, radius: 1f, Color.white);

// Cubes
ShapesDrawer.DrawCube(center, Quaternion.identity, Vector3.one, Color.green);
ShapesDrawer.DrawWireCube(center, rotation, size, Color.red);

Using in Debug Systems

public override void OnDebug()
{
    // Draw every frame while debug is enabled
    ShapesDrawer.DrawWireSphere(transform.position, detectionRadius, Color.yellow);
    ShapesDrawer.DrawLine(transform.position, target.position, Color.red);
}

Classes

Class	Description
ShapesDrawer	Singleton MonoBehaviour — static draw API, camera hooks, PlayerLoop injection
ShapeDrawer<TShape>	Abstract generic base for shape-specific drawers with queue and draw pattern
Shapes	Shape struct + drawer implementations (Line, Arc, Cube, etc.)

See Also

• Shapes Library — the underlying rendering library