Runtime material compilation & hot-reload (Phases 0-1)

examples/flutter/material_editor/.gitignore

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+# Miscellaneous
+*.class
+*.log
+*.pyc
+*.swp
+.DS_Store
+.atom/
+.build/
+.buildlog/
+.history
+.svn/
+.swiftpm/
+migrate_working_dir/
+
+# IntelliJ related
+*.iml
+*.ipr
+*.iws
+.idea/
+
+# The .vscode folder contains launch configuration and tasks you configure in
+# VS Code which you may wish to be included in version control, so this line
+# is commented out by default.
+#.vscode/
+
+# Flutter/Dart/Pub related
+**/doc/api/
+**/ios/Flutter/.last_build_id
+.dart_tool/
+.flutter-plugins
+.flutter-plugins-dependencies
+.pub-cache/
+.pub/
+/build/
+
+# Symbolication related
+app.*.symbols
+
+# Obfuscation related
+app.*.map.json
+
+# Android Studio will place build artifacts here
+/android/app/debug
+/android/app/profile
+/android/app/release

examples/flutter/material_editor/.metadata

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+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+  revision: "44a626f4f0027bc38a46dc68aed5964b05a83c18"
+  channel: "[user-branch]"
+
+project_type: app
+
+# Tracks metadata for the flutter migrate command
+migration:
+  platforms:
+    - platform: root
+      create_revision: 44a626f4f0027bc38a46dc68aed5964b05a83c18
+      base_revision: 44a626f4f0027bc38a46dc68aed5964b05a83c18
+    - platform: linux
+      create_revision: 44a626f4f0027bc38a46dc68aed5964b05a83c18
+      base_revision: 44a626f4f0027bc38a46dc68aed5964b05a83c18
+    - platform: macos
+      create_revision: 44a626f4f0027bc38a46dc68aed5964b05a83c18
+      base_revision: 44a626f4f0027bc38a46dc68aed5964b05a83c18
+    - platform: windows
+      create_revision: 44a626f4f0027bc38a46dc68aed5964b05a83c18
+      base_revision: 44a626f4f0027bc38a46dc68aed5964b05a83c18
+
+  # User provided section
+
+  # List of Local paths (relative to this file) that should be
+  # ignored by the migrate tool.
+  #
+  # Files that are not part of the templates will be ignored by default.
+  unmanaged_files:
+    - 'lib/main.dart'
+    - 'ios/Runner.xcodeproj/project.pbxproj'

examples/flutter/material_editor/README.md

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+# material_editor
+
+A Flutter project demonstrating **runtime material compilation and
+hot-reload** in Thermion: edit Filament `.mat` source in a text field and see
+the change on a live-rendered sphere, without restarting the app.
+
+The top half of the window is a `ViewerWidget` rendering a sphere; the bottom
+half is a plain `TextField` holding `.mat` source. Every edit (debounced, or
+via the **Apply** button) is compiled to a `.filamat` package *inside the
+running engine* and hot-swapped onto the sphere.
+
+## How it works
+
+Two APIs from `thermion_dart` drive the whole loop:
+
+1. **`FilamentApp.compileMaterial(source)`** (runtime compile) — parses and
+   compiles `.mat` source through the same `matp` + `filamat` pipeline the
+   offline `matc` tool uses, returning the compiled `.filamat` bytes. On
+   failure it throws `MaterialCompileException` with the compiler's message,
+   which the editor shows inline under the text field.
+
+2. **`FilamentApp.reloadMaterialFromBytes(material, bytes)`** (hot-reload) —
+   builds a new `Material` from the compiled bytes, creates a replacement
+   `MaterialInstance`, re-points every renderable that used the old instance,
+   replays recorded instance state (parameters like `baseTint` below) onto the
+   replacement, and destroys the old material. The sphere never leaves the
+   scene; only the material under it changes.
+
+Startup (`_onViewerAvailable`) compiles `materials/starter.mat` — a lit
+material with `baseTint` / `roughness` / `metallic` parameters — creates an
+instance, sets those parameters, and creates the sphere geometry with that
+instance. Subsequent compiles go through `reloadMaterialFromBytes`, so the
+parameter values set at startup survive every edit: change `shadingModel` to
+`unlit`, delete `prepareMaterial`, or introduce a syntax error — the sphere
+keeps rendering the last good material while the error is shown inline.
+
+The starter source is a good place to experiment:
+
+- change `material.baseColor = materialParams.baseTint;` to a constant
+  `float4(1.0, 0.3, 0.1, 1.0)`;
+- add `material.clearCoat = 1.0;` after `prepareMaterial(material);`;
+- set `shadingModel : unlit` (and drop the roughness/metallic lines) to see
+  flat unshaded color;
+- delete a `}` to see the inline error report.
+
+## Platform support
+
+Runtime compilation is linked into **desktop** engine builds only (Linux,
+macOS, Windows). On web `compileMaterial` throws `UnsupportedError`, and on
+Android/iOS the native engine reports "not supported" via
+`MaterialCompileException`. The example handles both: the sphere still
+renders with the default material and the status bar explains why.
+
+## Running
+
+```sh
+flutter pub get
+flutter run -d linux   # or -d macos / -d windows
+```
+
+The example targets desktop platforms only (runtime compilation is not
+available elsewhere).

examples/flutter/material_editor/analysis_options.yaml

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+# This file configures the analyzer, which statically analyzes Dart code to
+# check for errors, warnings, and lints.
+#
+# The issues identified by the analyzer are surfaced in the UI of Dart-enabled
+# IDEs (https://dart.dev/tools#ides-and-editors). The analyzer can also be
+# invoked from the command line by running `flutter analyze`.
+
+# The following line activates a set of recommended lints for Flutter apps,
+# packages, and plugins designed to encourage good coding practices.
+include: package:flutter_lints/flutter.yaml
+
+linter:
+  # The lint rules applied to this project can be customized in the
+  # section below to disable rules from the `package:flutter_lints/flutter.yaml`
+  # included above or to enable additional rules. A list of all available lints
+  # and their documentation is published at https://dart.dev/lints.
+  #
+  # Instead of disabling a lint rule for the entire project in the
+  # section below, it can also be suppressed for a single line of code
+  # or a specific dart file by using the `// ignore: name_of_lint` and
+  # `// ignore_for_file: name_of_lint` syntax on the line or in the file
+  # producing the lint.
+  rules:
+    # avoid_print: false  # Uncomment to disable the `avoid_print` rule
+    # prefer_single_quotes: true  # Uncomment to enable the `prefer_single_quotes` rule
+
+# Additional information about this file can be found at
+# https://dart.dev/guides/language/analysis-options