build system update

bin/dev

@@ -20,6 +20,7 @@ WAIT_FOR_PROCESS = "wait_for_process"
 class DevHelper:
     SHADER_EXTENSIONS = (".vert", ".frag", ".comp", ".geom", ".tesc", ".tese")
     PROJECT_NAME = "sophia"
+    DEFAULT_PRESET = "debug"
 
     def __init__(self):
         self.last_exit_status = 0
@@ -39,9 +40,29 @@ class DevHelper:
             return method(*rest, **kwargs)
 
     # Primary command wrappers
+
+    ##
+    # Configures and builds a CMake preset (see CMakePresets.json).
+    #   dev build [preset] [--fresh]
+    # The preset defaults to debug and builds into build/<preset>. --fresh
+    # discards the preset's CMake cache before configuring.
     def build(self, *args, **kwargs):
-        command = f"rm -rf build && cmake -S . -B build -DCMAKE_BUILD_TYPE=Debug"
-        self._exec_in_root(command, replace=True)
+        preset, fresh = self._parse_preset_args(args, "build")
+        self._build_preset(preset, fresh)
+
+    ##
+    # Builds the debug preset (incrementally), then runs the testbed from
+    # build/debug. Any arguments are passed through to the testbed.
+    #   dev testbed [args...]
+    def testbed(self, *args, **kwargs):
+        preset = self.DEFAULT_PRESET
+        self._build_preset(preset, fresh=False)
+
+        preset_dir = os.path.join(self._project_root(), "build", preset)
+        binary = os.path.join(preset_dir, "bin", "testbed")
+        print(f"Running: {shlex.join([binary, *args])}")
+        os.chdir(preset_dir)
+        os.execv(binary, [binary, *args])
 
     ##
     # Checks out a branch named after a Gitea issue URL.
@@ -149,6 +170,52 @@ class DevHelper:
             if not name.startswith("_") and name != "call" and callable(getattr(DevHelper, name))
         )
 
+    def _parse_preset_args(self, args, command):
+        preset = None
+        fresh = False
+        for arg in args:
+            if arg == "--fresh":
+                fresh = True
+            elif arg.startswith("-"):
+                raise ValueError(f"Unknown option: {arg}")
+            elif preset is None:
+                preset = arg
+            else:
+                raise ValueError(f"Usage: dev {command} [preset] [--fresh]")
+
+        preset = preset or self.DEFAULT_PRESET
+        presets = self._configure_presets()
+        if preset not in presets:
+            raise ValueError(f"Unknown preset: {preset} (available: {', '.join(presets)})")
+        return preset, fresh
+
+    def _configure_presets(self):
+        with open(os.path.join(self._project_root(), "CMakePresets.json")) as f:
+            presets = json.load(f)["configurePresets"]
+        return [preset["name"] for preset in presets if not preset.get("hidden")]
+
+    def _build_preset(self, preset, fresh):
+        configure = ["cmake", "--preset", preset]
+        if fresh:
+            configure.append("--fresh")
+        self._run_in_root(configure)
+        self._copy_compile_commands(preset)
+        self._run_in_root(["cmake", "--build", "--preset", preset])
+
+    # Editor tooling reads build/compile_commands.json, so point it at the
+    # most recently configured preset.
+    def _copy_compile_commands(self, preset):
+        build_dir = os.path.join(self._project_root(), "build")
+        source = os.path.join(build_dir, preset, "compile_commands.json")
+        if os.path.isfile(source):
+            shutil.copyfile(source, os.path.join(build_dir, "compile_commands.json"))
+
+    def _run_in_root(self, command):
+        print(f"Running: {shlex.join(command)}")
+        result = subprocess.run(command, cwd=self._project_root())
+        if result.returncode != 0:
+            sys.exit(result.returncode)
+
     def _parse_issue_url(self, url):
         match = re.match(r"^(https?://[^/]+)/([^/]+)/([^/]+)/issues/(\d+)", url)
         if match is None: