DebugDraw

Easy3D / Data & Batching / DebugDraw

Easy3D::DebugDraw queues debug primitives — line segments and axis-aligned boxes — for development overlays. Line()/Box() store one DebugLine/DebugBox per call; Lines()/Boxes() expose them so a future CPU-side vertex builder / CNA draw path can consume them. This class does no GPU work itself.

#include <Easy3D/DebugDraw.hpp>

namespace Easy3D
{
    struct DebugLine;
    struct DebugBox;
    class  DebugDraw;
}

Queueing is pure data storage, but constructing the CNA Vector3 values you pass in calls CNA's compiled constructors — so executables using this class link CNA in practice. See Building & CMake.

The primitive types

DebugLine

Field	Type	Meaning
`From`	`Vector3`	Segment start, world space.
`To`	`Vector3`	Segment end, world space.

DebugBox

Field	Type	Meaning
`Center`	`Vector3`	World-space center of the box.
`Size`	`Vector3`	Full extents along X/Y/Z; the box is axis-aligned.

Type aliases

Alias	Refers to
`DebugDraw::Vector3`	`Microsoft::Xna::Framework::Vector3`

API

void Clear() noexcept

Drop all queued primitives (both lines and boxes). Typically called once per frame before re-queueing.

void Line(const Vector3& from, const Vector3& to)

Queue a line segment.

void Box(const Vector3& center, const Vector3& size)

Queue an axis-aligned box.

[[nodiscard]] std::size_t LineCount() const noexcept
[[nodiscard]] std::size_t BoxCount() const noexcept
[[nodiscard]] std::size_t PrimitiveCount() const noexcept

Number of queued lines / boxes / both together (PrimitiveCount() == LineCount() + BoxCount()).

[[nodiscard]] const std::vector<DebugLine>& Lines() const noexcept
[[nodiscard]] const std::vector<DebugBox>& Boxes() const noexcept

The queued primitives, in call order — the hand-off point for a future vertex builder or your own overlay renderer.

Unlike the batches, DebugDraw has no Begin()/End() pair — debug primitives are not a "batch you flush" but a bag you Clear() whenever it suits your debugging flow (per frame, or accumulated across frames while paused).

Example — visualizing collision data

#include <Easy3D/DebugDraw.hpp>

using Vector3 = Easy3D::DebugDraw::Vector3;

Easy3D::DebugDraw debug;

// Each frame:
debug.Clear();

// Mark the player's bounding box.
debug.Box(player.Position, Vector3(0.8f, 1.6f, 0.8f));

// Draw the velocity vector.
debug.Line(player.Position, player.Position + player.Velocity);

// A little world-origin axis cross.
debug.Line(Vector3::Zero, Vector3(1, 0, 0));
debug.Line(Vector3::Zero, Vector3(0, 1, 0));
debug.Line(Vector3::Zero, Vector3(0, 0, 1));

// Later: iterate debug.Lines() / debug.Boxes() in your overlay renderer.

Scope

Deliberately minimal: no colors, no durations/timers, no spheres or text. Those may or may not arrive later — only if Galaxy Eggbert needs them (see Design Principles). Rendering the queued primitives is Roadmap Phase 3/4 work, same as the other batches.