[setup] add 'setupEnvironment' for setting-up standalone configuration

* setup environment vars to work in a prebuilt, standalone configuration
* call 'setupEnvironment' at the beginning of executables

meshroom/__init__.py

@@ -1,14 +1,96 @@
 __version__ = "2018.1"
 
+import logging
 from enum import Enum
 
+
 class Backend(Enum):
     STANDALONE = 1
     PYSIDE = 2
 
+
 backend = Backend.STANDALONE
 
+
 def useUI():
     global backend
     backend = Backend.PYSIDE
 
+
+def setupEnvironment():
+    """
+    Setup environment for Meshroom to work in a prebuilt, standalone configuration.
+
+    Use 'MESHROOM_INSTALL_DIR' to simulate standalone configuration with a path to a Meshroom installation folder.
+
+    # Meshroom standalone structure
+
+    - Meshroom/
+       - aliceVision/
+           - bin/    # runtime bundled binaries (exe + libs)
+           - share/  # resource files
+               - COPYING.md         # AliceVision COPYING file
+               - cameraSensors.db   # sensor database
+               - vlfeat_K80L3.tree  # voctree file
+       - lib/      # Python lib folder
+       - qtPlugins/
+       Meshroom    # main executable
+       COPYING.md  # Meshroom COPYING file
+    """
+
+    import os
+    import sys
+
+    def addToEnvPath(var, val, index=-1):
+        """
+        Add paths to the given environment variable.
+
+        Args:
+            var (str): the name of the variable to add paths to
+            val (str or list of str): the path(s) to add
+            index (int): insertion index
+        """
+        paths = os.environ.get(var, "").split(os.pathsep)
+
+        if not isinstance(val, (list, tuple)):
+            val = [val]
+
+        paths[index:index] = val
+        os.environ[var] = os.pathsep.join(paths)
+
+    # detect if this is a frozen environment based on executable name
+    isStandalone = "python" not in os.path.basename(sys.executable).lower()
+    # setup root directory (override possible by setting "MESHROOM_INSTALL_DIR" environment variable)
+    rootDir = os.path.dirname(sys.executable) if isStandalone else os.environ.get("MESHROOM_INSTALL_DIR", None)
+
+    if rootDir:
+        os.environ["MESHROOM_INSTALL_DIR"] = rootDir
+
+        aliceVisionDir = os.path.join(rootDir, "aliceVision")
+        # default directories
+        aliceVisionBinDir = os.path.join(aliceVisionDir, "bin")
+        aliceVisionShareDir = os.path.join(aliceVisionDir, "share")
+        qtPluginsDir = os.path.join(rootDir, "qtPlugins")
+        sensorDBPath = os.path.join(aliceVisionShareDir, "cameraSensors.db")
+        voctreePath = os.path.join(aliceVisionShareDir, "vlfeat_K80L3.tree")
+
+        env = {
+            'PATH': aliceVisionBinDir,
+            'LD_LIBRARY_PATH': aliceVisionBinDir,
+            'QT_PLUGIN_PATH': [qtPluginsDir],
+            'QML2_IMPORT_PATH': [os.path.join(qtPluginsDir, "qml")]
+        }
+
+        for key, value in env.items():
+            logging.info("Add to {}: {}".format(key, value))
+            addToEnvPath(key, value, 0)
+
+        variables = {
+            "ALICEVISION_SENSOR_DB": sensorDBPath,
+            "ALICEVISION_VOCTREE": voctreePath
+        }
+
+        for key, value in variables.items():
+            if key not in os.environ and os.path.exists(value):
+                logging.info("Set {}: {}".format(key, value))
+                os.environ[key] = value