From ae73181466c7e32b0e5e9e814f5170310c20f263 Mon Sep 17 00:00:00 2001
From: Jochum van der Ploeg <jochum@vdploeg.net>
Date: Sat, 14 Dec 2024 13:35:46 +0100
Subject: [PATCH] feat!: Allow for custom shaders and materials (#3384)

Allows for custom materials and shaders.
---
 .../resources/material/spatial_material.dart  | 10 ++--
 .../lib/src/resources/shader/shader.dart      | 52 +++++++++++--------
 .../shader/uniform_binding_test.dart          |  1 +
 3 files changed, 37 insertions(+), 26 deletions(-)

diff --git a/packages/flame_3d/lib/src/resources/material/spatial_material.dart b/packages/flame_3d/lib/src/resources/material/spatial_material.dart
index eb3b088dfda..b15022767f0 100644
--- a/packages/flame_3d/lib/src/resources/material/spatial_material.dart
+++ b/packages/flame_3d/lib/src/resources/material/spatial_material.dart
@@ -12,8 +12,9 @@ class SpatialMaterial extends Material {
     this.roughness = 0.6,
   })  : albedoTexture = albedoTexture ?? Texture.standard,
         super(
-          vertexShader: Shader(
-            name: 'TextureVertex',
+          vertexShader: Shader.vertex(
+            asset:
+                'packages/flame_3d/assets/shaders/spatial_material.shaderbundle',
             slots: [
               UniformSlot.value('VertexInfo', {
                 'model',
@@ -26,8 +27,9 @@ class SpatialMaterial extends Material {
               ),
             ],
           ),
-          fragmentShader: Shader(
-            name: 'TextureFragment',
+          fragmentShader: Shader.fragment(
+            asset:
+                'packages/flame_3d/assets/shaders/spatial_material.shaderbundle',
             slots: [
               UniformSlot.sampler('albedoTexture'),
               UniformSlot.value('Material', {
diff --git a/packages/flame_3d/lib/src/resources/shader/shader.dart b/packages/flame_3d/lib/src/resources/shader/shader.dart
index a7e1bd5f4fa..30e645130e5 100644
--- a/packages/flame_3d/lib/src/resources/shader/shader.dart
+++ b/packages/flame_3d/lib/src/resources/shader/shader.dart
@@ -6,49 +6,53 @@ import 'package:flame_3d/graphics.dart';
 import 'package:flame_3d/resources.dart';
 import 'package:flutter_gpu/gpu.dart' as gpu;
 
-/// {@template shader}
+/// {@template shader_resource}
 ///
 /// {@endtemplate}
 class ShaderResource extends Resource<gpu.Shader> {
-  final Shader shader;
+  /// {@macro shader_resource}
+  factory ShaderResource.createFromAsset({
+    required String asset,
+    required String shaderName,
+    required List<UniformSlot> slots,
+  }) {
+    final library = gpu.ShaderLibrary.fromAsset(asset)!;
 
-  /// {@macro shader}
-  ShaderResource(
-    super.resource, {
-    required String name,
-    List<UniformSlot> slots = const [],
-  }) : shader = Shader(name: name, slots: slots) {
-    for (final slot in slots) {
-      slot.resource = resource.getUniformSlot(slot.name);
+    final shader = library[shaderName];
+    if (shader == null) {
+      throw StateError('Shader "$shaderName" not found in library "$asset"');
     }
+    return ShaderResource._(shader, slots: slots);
   }
 
-  factory ShaderResource.create({
-    required String name,
-    required List<UniformSlot> slots,
+  ShaderResource._(
+    super.resource, {
+    List<UniformSlot> slots = const [],
   }) {
-    final shader = _library[name];
-    if (shader == null) {
-      throw StateError('Shader "$name" not found in library');
+    for (final slot in slots) {
+      slot.resource = resource.getUniformSlot(slot.name);
     }
-    return ShaderResource(shader, name: name, slots: slots);
   }
-
-  static final _library = gpu.ShaderLibrary.fromAsset(
-    'packages/flame_3d/assets/shaders/spatial_material.shaderbundle',
-  )!;
 }
 
 class Shader {
+  final String asset;
   final String name;
   final List<UniformSlot> slots;
   final Map<String, UniformInstance> instances = {};
 
   Shader({
+    required this.asset,
     required this.name,
     required this.slots,
   });
 
+  Shader.vertex({required String asset, required List<UniformSlot> slots})
+      : this(asset: asset, name: 'TextureVertex', slots: slots);
+
+  Shader.fragment({required String asset, required List<UniformSlot> slots})
+      : this(asset: asset, name: 'TextureFragment', slots: slots);
+
   /// Set a [Texture] at the given [key] on the buffer.
   void setTexture(String key, Texture texture) => _setTypedValue(key, texture);
 
@@ -140,6 +144,10 @@ class Shader {
   }
 
   ShaderResource compile() {
-    return ShaderResource.create(name: name, slots: slots);
+    return ShaderResource.createFromAsset(
+      asset: asset,
+      shaderName: name,
+      slots: slots,
+    );
   }
 }
diff --git a/packages/flame_3d/test/resources/shader/uniform_binding_test.dart b/packages/flame_3d/test/resources/shader/uniform_binding_test.dart
index f628a34df6e..151dc97a24a 100644
--- a/packages/flame_3d/test/resources/shader/uniform_binding_test.dart
+++ b/packages/flame_3d/test/resources/shader/uniform_binding_test.dart
@@ -107,6 +107,7 @@ void main() {
 
 Shader _createShader(List<UniformSlot> slots) {
   return Shader(
+    asset: 'none',
     name: '-test-',
     slots: slots,
   );