Optimize shaders

Signed-off-by: Hans Kokx <hans.d.kokx@gmail.com>

README.md

@@ -14,8 +14,7 @@ It exposes two widget layers:
 - Position-driven rendering: visuals respond to tilt/input position with no internal time animation
 - Generic wrapper API for any widget via `Shiny(child: ...)`
 - Card API with `background`, `foreground`, `shape`, and drag tilt via `ShinyCard`
-- Built-in sparkle presets including `none` (default), 8-point star, 5-point star, rectangle, diamond, hexagon, random polygon, and confetti
-- Custom sparkle shapes via parameterized `SparkleShapeSpec` factories
+- Four specialized material profiles backed by dedicated shader assets
 - Global shader opacity control via `opacity`
 - Cross-platform Flutter support (mobile, web, desktop)
 
@@ -62,7 +61,7 @@ ShinyCard(
   controller: controller,
   background: Container(color: const Color(0xFF1B2D4B)),
   foreground: const Center(child: Text('HOLO')),
-  sparkleShape: SparkleShapeSpec.none,
+  profile: ShinyProfile.crackedIce,
   opacity: 1.0,
 )
 ```
@@ -78,37 +77,17 @@ Shiny(
 )
 ```
 
-## Sparkle Shapes
+## Profiles
 
-Use built-in sparkle presets:
+Choose a precompiled material profile:
 
 ```dart
 ShinyCard(
-  sparkleShape: SparkleShapeSpec.none,
+  profile: ShinyProfile.holographicSilver,
 )
 
 ShinyCard(
-  sparkleShape: SparkleShapeSpec.hexagon,
-)
-```
-
-Or create your own parameterized shapes:
-
-```dart
-ShinyCard(
-  sparkleShape: SparkleShapeSpec.customStar(
-    points: 7,
-    innerRatio: 0.36,
-  ),
-)
-
-Shiny(
-  sparkleShape: SparkleShapeSpec.customPolygon(
-    sides: 8,
-    aspectRatio: 1.2,
-    rotation: 0.2,
-  ),
-  child: const SizedBox(width: 240, height: 120),
+  profile: ShinyProfile.superGoldVinyl,
 )
 ```
 
@@ -123,13 +102,13 @@ final ShinyController controller = ShinyController(tiltStream: input.stream);
 
 - `Shiny`: generic effect wrapper
 - `ShinyCard`: shape + rotation + composition convenience widget
-- `SparkleShapeSpec`: built-in and custom sparkle silhouette configuration
+- `ShinyProfile`: specialized material presets mapped to dedicated shader assets
 - `ShinyController`: optional source selection for tilt
 - `SensorTiltController`: low-level sensor fusion stream utility
 
 Important defaults:
 
-- `sparkleShape` defaults to `SparkleShapeSpec.none` (no sparkles)
+- `profile` defaults to `ShinyProfile.crackedIce`
 - `opacity` defaults to `1.0`
 
 ## Platform Notes
@@ -147,8 +126,7 @@ See the package example app in `example/` for:
 - Sensor-driven motion
 - External stream override
 - Custom card shape/background/foreground composition
-- Built-in sparkle shape toggles in the demo UI
-- User-defined sparkle shape presets using `SparkleShapeSpec`
+- Profile switching in the demo UI
 
 ## Publishing Notes