feat(dsl): add builder pattern for all render struct types

Add create + withX pipeline builders following Material3D/Camera3D pattern:

2D: SpriteState, TextState, Particle2D, AmbientLight2D, DirectionalLight2D,
    PointLight2D, Occluder2D
3D: AmbientLight3D, DirectionalLight3D, PointLight3D, SpotLight3D

Each module provides create (required args, sensible defaults) and
withX modifiers for optional fields. Enables ergonomic pipelines:

  PointLight3D.create (pos, 6.0f)
  |> PointLight3D.withColor (Color(255uy, 200uy, 120uy))
  |> Draw3D.addPointLight

Author: AngelMunoz

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Added
 
+- Builder DSL for all render struct types: `create` + `withX` pipeline for `SpriteState`, `TextState`, `Particle2D`, `AmbientLight2D`, `DirectionalLight2D`, `PointLight2D`, `Occluder2D`, `AmbientLight3D`, `DirectionalLight3D`, `PointLight3D`, `SpotLight3D`. Follows `Material3D` / `Camera3D` pattern.
 - 3D rendering pipeline with CSM shadow maps (4-layer architecture: Renderer3D → Pipeline → Context → Commands).
 - `ClusteredForwardPipeline` with Cook-Torrance PBR shading, CSM shadow mapping, and material caching.
 - `Material3D` struct with PBR fields (albedo, roughness, metallic, normal, emission, opacity, tiling) and `fromRaylibMaterial` conversion.

src/Mibo.Raylib/Graphics2D/Command2D.fs

@@ -566,3 +566,77 @@ module Command2D =
 
   let inline clear (layer: int<RenderLayer>) (color: Color) =
     Command2D.Clear(color, layer)
+
+/// <summary>Convenience builders for <see cref="T:Mibo.Elmish.Graphics2D.Command2D.SpriteState"/>.</summary>
+module SpriteState =
+
+  /// <summary>Creates a sprite state with required fields. Defaults: Origin=Zero, Rotation=0, Color=White, Layer=0.</summary>
+  let create
+    (texture: Texture2D, dest: Rectangle, source: Rectangle)
+    : Command2D.SpriteState =
+    {
+      Texture = texture
+      Dest = dest
+      Source = source
+      Origin = Vector2.Zero
+      Rotation = 0.0f
+      Color = Color.White
+      Layer = 0<RenderLayer>
+    }
+
+  let inline withOrigin (v: Vector2) (s: Command2D.SpriteState) = {
+    s with
+        Origin = v
+  }
+
+  let inline withRotation (v: float32) (s: Command2D.SpriteState) = {
+    s with
+        Rotation = v
+  }
+
+  let inline withColor (v: Color) (s: Command2D.SpriteState) = {
+    s with
+        Color = v
+  }
+
+  let inline withLayer (v: int<RenderLayer>) (s: Command2D.SpriteState) = {
+    s with
+        Layer = v
+  }
+
+/// <summary>Convenience builders for <see cref="T:Mibo.Elmish.Graphics2D.Command2D.TextState"/>.</summary>
+module TextState =
+
+  /// <summary>Creates a text state with required fields. Defaults: FontSize=20, Spacing=1, Color=White, Layer=0.</summary>
+  let create
+    (font: Font, text: string, position: Vector2)
+    : Command2D.TextState =
+    {
+      Font = font
+      Text = text
+      Position = position
+      FontSize = 20.0f
+      Spacing = 1.0f
+      Color = Color.White
+      Layer = 0<RenderLayer>
+    }
+
+  let inline withFontSize (v: float32) (s: Command2D.TextState) = {
+    s with
+        FontSize = v
+  }
+
+  let inline withSpacing (v: float32) (s: Command2D.TextState) = {
+    s with
+        Spacing = v
+  }
+
+  let inline withColor (v: Color) (s: Command2D.TextState) = {
+    s with
+        Color = v
+  }
+
+  let inline withLayer (v: int<RenderLayer>) (s: Command2D.TextState) = {
+    s with
+        Layer = v
+  }

src/Mibo.Raylib/Graphics2D/Lighting/LightTypes.fs

@@ -57,3 +57,65 @@ type Occluder2D = {
   /// <summary>End point of the occluder segment in world space.</summary>
   P2: Vector2
 }
+
+/// <summary>Convenience builders for <see cref="T:Mibo.Elmish.Graphics2D.Lighting.AmbientLight2D"/>.</summary>
+module AmbientLight2D =
+
+  /// <summary>Creates an ambient light with the given color.</summary>
+  let create(color: Color) : AmbientLight2D = { Color = color }
+
+/// <summary>Convenience builders for <see cref="T:Mibo.Elmish.Graphics2D.Lighting.DirectionalLight2D"/>.</summary>
+module DirectionalLight2D =
+
+  /// <summary>Creates a directional light. Defaults: Color=White, Intensity=1, CastsShadows=true.</summary>
+  let create(direction: Vector2) : DirectionalLight2D = {
+    Direction = direction
+    Color = Color.White
+    Intensity = 1.0f
+    CastsShadows = true
+  }
+
+  let inline withColor (v: Color) (l: DirectionalLight2D) = { l with Color = v }
+
+  let inline withIntensity (v: float32) (l: DirectionalLight2D) = {
+    l with
+        Intensity = v
+  }
+
+  let inline withCastsShadows (v: bool) (l: DirectionalLight2D) = {
+    l with
+        CastsShadows = v
+  }
+
+/// <summary>Convenience builders for <see cref="T:Mibo.Elmish.Graphics2D.Lighting.PointLight2D"/>.</summary>
+module PointLight2D =
+
+  /// <summary>Creates a point light. Defaults: Color=White, Intensity=1, Falloff=2, CastsShadows=false.</summary>
+  let create(position: Vector2, radius: float32) : PointLight2D = {
+    Position = position
+    Color = Color.White
+    Intensity = 1.0f
+    Radius = radius
+    Falloff = 2.0f
+    CastsShadows = false
+  }
+
+  let inline withColor (v: Color) (l: PointLight2D) = { l with Color = v }
+
+  let inline withIntensity (v: float32) (l: PointLight2D) = {
+    l with
+        Intensity = v
+  }
+
+  let inline withFalloff (v: float32) (l: PointLight2D) = { l with Falloff = v }
+
+  let inline withCastsShadows (v: bool) (l: PointLight2D) = {
+    l with
+        CastsShadows = v
+  }
+
+/// <summary>Convenience builders for <see cref="T:Mibo.Elmish.Graphics2D.Lighting.Occluder2D"/>.</summary>
+module Occluder2D =
+
+  /// <summary>Creates an occluder from two endpoints.</summary>
+  let create(p1: Vector2, p2: Vector2) : Occluder2D = { P1 = p1; P2 = p2 }

src/Mibo.Raylib/Graphics2D/Lighting/ParticleTypes.fs

@@ -25,3 +25,24 @@ type Particle2D = {
   /// <summary>Tint color. Alpha controls transparency.</summary>
   Color: Color
 }
+
+/// <summary>Convenience builders for <see cref="T:Mibo.Elmish.Graphics2D.Lighting.Particle2D"/>.</summary>
+module Particle2D =
+
+  /// <summary>Creates a particle with required fields. Defaults: Rotation=0, SourceRect=empty, Color=White.</summary>
+  let create(position: Vector2, size: Vector2) : Particle2D = {
+    Position = position
+    Size = size
+    Rotation = 0.0f
+    SourceRect = Rectangle(0.0f, 0.0f, 0.0f, 0.0f)
+    Color = Color.White
+  }
+
+  let inline withRotation (v: float32) (p: Particle2D) = { p with Rotation = v }
+
+  let inline withSourceRect (v: Rectangle) (p: Particle2D) = {
+    p with
+        SourceRect = v
+  }
+
+  let inline withColor (v: Color) (p: Particle2D) = { p with Color = v }

src/Mibo.Raylib/Graphics3D/Light3D.fs

@@ -12,6 +12,20 @@ type AmbientLight3D = {
   Intensity: float32
 }
 
+/// <summary>Convenience builders for <see cref="T:Mibo.Elmish.Graphics3D.AmbientLight3D"/>.</summary>
+module AmbientLight3D =
+
+  /// <summary>Creates an ambient light. Defaults: Intensity=1.</summary>
+  let create(color: Color) : AmbientLight3D = {
+    Color = color
+    Intensity = 1.0f
+  }
+
+  let inline withIntensity (v: float32) (l: AmbientLight3D) = {
+    l with
+        Intensity = v
+  }
+
 /// <summary>Directional light configuration for 3D scenes.</summary>
 [<Struct>]
 type DirectionalLight3D = {
@@ -32,6 +46,29 @@ type DirectionalLight3D = {
   CastsShadows: bool
 }
 
+/// <summary>Convenience builders for <see cref="T:Mibo.Elmish.Graphics3D.DirectionalLight3D"/>.</summary>
+module DirectionalLight3D =
+
+  /// <summary>Creates a directional light. Defaults: Color=White, Intensity=1, CastsShadows=true.</summary>
+  let create(direction: Vector3) : DirectionalLight3D = {
+    Direction = direction
+    Color = Color.White
+    Intensity = 1.0f
+    CastsShadows = true
+  }
+
+  let inline withColor (v: Color) (l: DirectionalLight3D) = { l with Color = v }
+
+  let inline withIntensity (v: float32) (l: DirectionalLight3D) = {
+    l with
+        Intensity = v
+  }
+
+  let inline withCastsShadows (v: bool) (l: DirectionalLight3D) = {
+    l with
+        CastsShadows = v
+  }
+
 /// <summary>Point light configuration for 3D scenes.</summary>
 [<Struct>]
 type PointLight3D = {
@@ -61,6 +98,30 @@ type PointLight3D = {
   ShadowBias: float32 voption
 }
 
+/// <summary>Convenience builders for <see cref="T:Mibo.Elmish.Graphics3D.PointLight3D"/>.</summary>
+module PointLight3D =
+
+  /// <summary>Creates a point light. Defaults: Color=White, CastsShadows=false, ShadowBias=None.</summary>
+  let create(position: Vector3, radius: float32) : PointLight3D = {
+    Position = position
+    Color = Color.White
+    Radius = radius
+    CastsShadows = false
+    ShadowBias = ValueNone
+  }
+
+  let inline withColor (v: Color) (l: PointLight3D) = { l with Color = v }
+
+  let inline withCastsShadows (v: bool) (l: PointLight3D) = {
+    l with
+        CastsShadows = v
+  }
+
+  let inline withShadowBias (v: float32) (l: PointLight3D) = {
+    l with
+        ShadowBias = ValueSome v
+  }
+
 /// <summary>Spot light configuration for cone-shaped lights with distance attenuation.</summary>
 [<Struct>]
 type SpotLight3D = {
@@ -97,3 +158,45 @@ type SpotLight3D = {
   /// </remarks>
   ShadowBias: float32 voption
 }
+
+/// <summary>Convenience builders for <see cref="T:Mibo.Elmish.Graphics3D.SpotLight3D"/>.</summary>
+module SpotLight3D =
+
+  /// <summary>Creates a spot light. Defaults: Color=White, Intensity=1, InnerCutoff=0.5, OuterCutoff=0.7, CastsShadows=false, ShadowBias=None.</summary>
+  let create
+    (position: Vector3, direction: Vector3, radius: float32)
+    : SpotLight3D =
+    {
+      Position = position
+      Direction = direction
+      Color = Color.White
+      Intensity = 1.0f
+      Radius = radius
+      InnerCutoff = 0.5f
+      OuterCutoff = 0.7f
+      CastsShadows = false
+      ShadowBias = ValueNone
+    }
+
+  let inline withColor (v: Color) (l: SpotLight3D) = { l with Color = v }
+
+  let inline withIntensity (v: float32) (l: SpotLight3D) = {
+    l with
+        Intensity = v
+  }
+
+  let inline withCutoff (inner: float32) (outer: float32) (l: SpotLight3D) = {
+    l with
+        InnerCutoff = inner
+        OuterCutoff = outer
+  }
+
+  let inline withCastsShadows (v: bool) (l: SpotLight3D) = {
+    l with
+        CastsShadows = v
+  }
+
+  let inline withShadowBias (v: float32) (l: SpotLight3D) = {
+    l with
+        ShadowBias = ValueSome v
+  }