Renderer

Wyrd.Ecs.Renderer draws entities through SDL_GPU: batched, frustum-culled, one draw call per (material, mesh) pair. AddRenderer needs AddWindow called somewhere in the same chain, it claims the window AddWindow opened - but not necessarily first, construction order doesn’t matter.

Setting up

using Wyrd.Ecs.Renderer;

var world = new WorldBuilder()
    .AddWindow("My Game", 1280, 720)
    .AddRenderer()
    .Build();

Cameras

var camera = world.Commands.CreateEntity();
world.Commands.AddComponent(camera, Transform.Identity);
world.Commands.AddComponent(camera, new OrthographicCamera(0, true, 10f, 0.1f, 100f));
world.ApplyCommands();

A camera is queried as (Transform, PerspectiveCamera) or (Transform, OrthographicCamera), an entity with no Transform simply never renders. Every active camera, of either kind, draws in Order sequence into the same swapchain target, so a 3D scene plus a 2D HUD is two camera entities, not a separate compositing pass:

var hud = world.Commands.CreateEntity();
world.Commands.AddComponent(hud, new Transform { Position = new Vector3(0, 0, -5), Rotation = Quaternion.Identity, Scale = Vector3.One });
world.Commands.AddComponent(hud, new PerspectiveCamera(Order: 1, ClearOnBegin: false, Angle.Deg(45), 0.1f, 100f));
world.ApplyCommands();

ClearOnBegin: false draws on top of whatever the first camera already put in the swapchain, instead of erasing it first.

Note

PerspectiveCamera.FieldOfView is a vertical Angle. OrthographicCamera.Size is half the vertical world-space extent.

Materials

world.Commands.AddComponent(entity, new Material(ShaderKind.UnlitSprite, textureHandle));

Material is pipeline-selecting state only, the shader, the texture, and the blend mode, the things that have to match for two entities to batch into one draw call. Per-instance data like tint lives on the drawable component instead, see Sprites and Meshes.

BlendMode

new Material(ShaderKind.UnlitSprite, textureHandle, BlendMode.Transparent)

BlendMode.Opaque, Material’s default, writes depth and tests it, draw order doesn’t matter. BlendMode.Transparent tests depth but doesn’t write it, and needs back-to-front draw order for correct compositing, the renderer sorts every transparent entity by depth for you each frame, across sprites and meshes together.

Note

The sprite/mesh shaders premultiply each pixel’s alpha before blending, so texture files stay ordinary straight-alpha PNGs.

Loading assets

Textures and meshes load through RendererSystem, returning a Handle<T>: a cheap-to-copy reference into an internal arena, not the asset itself. Loading is asynchronous, an entity can reference a Handle<T> before its asset finishes loading, RendererSystem draws a placeholder in its place until it’s ready.

Next

Sprites for the 2D path, Meshes for 3D.