Crate lunar_render 

rendering subsystem via wgpu

decoupled from game logic. handles 2D sprite and text rendering.

rendering model

game code does not touch the GPU directly. two paths feed the renderer:

1. components (preferred) — spawn entities with Sprite or Text alongside a Transform. built-in systems enqueue them automatically every frame.
2. immediate mode (HUD / debug / one-shots) — call draw_sprite, draw_rect, draw_line, draw_text on RenderQueue from inside a system. useful when the thing you’re drawing isn’t a persistent entity.

[DrawCommand] / [DrawKind] / RenderQueue::push are internal plumbing and not part of the public contract — they’re hidden from rustdoc.

example: component-driven

use lunar::prelude::*;

fn spawn_player(mut commands: Commands, mut assets: ResMut<AssetServer>) {
    commands.spawn((
        Transform::from_xy(100.0, 100.0),
        Sprite::new(assets.load_texture("player.png")),
    ));
}

example: immediate mode

fn draw_hud(mut queue: ResMut<RenderQueue>) {
    queue.draw_rect(Vec2::ZERO, Vec2::new(200.0, 40.0), Color::rgba(0.0, 0.0, 0.0, 0.6));
}

Modules

atlas

texture atlas integration for the render system.

layers

built-in layer constants for common rendering needs. lower values are drawn first (behind), higher values are drawn last (in front).

textbox

textbox component for rendering text with typewriter animation

Structs

Camera

camera resource, affects how the render queue is projected.

CameraFollow2d

drives the camera to track a target entity each frame.

ColorTint

draws a semi-transparent colored overlay each frame.

DebugOverlay

debug overlay for displaying runtime stats.

DrawContext

drawing context for immediate mode rendering.

PostProcessStack

ordered stack of post-processing effects applied each frame after the main render.

RenderConfig

rendering configuration.

RenderEngine

render engine resource, owns all GPU rendering state.

RenderInfo

render info resource, tracks rendering statistics.

RenderPlugin

render plugin, registers render systems and resources.

RenderQueue

render queue resource, collects draw commands each frame.

RenderTargetId

opaque identifier for an offscreen render target created by RenderEngine::create_render_target.

RenderTargetStore

maps RenderTargetId → Handle<Texture> so game code can retrieve the drawable texture handle for a render target without keeping it separately.

ScreenFlash

draws a fullscreen colored overlay each frame.

ScreenShake

camera shake state. insert as a resource to enable shaking.

Sprite

renderable 2D sprite component.

SpriteParams

parameters for drawing a transformed sprite. used with RenderQueue::draw_sprite_transformed_on_layer to avoid too many function arguments.

Text

renderable text component.

YSort

marker component that opts a sprite into y-sort ordering.

Traits

PostEffect

trait for a custom post-processing effect applied each frame after the main render.

RenderPass

trait for custom render passes that can be executed by the render engine.