Improved osmesa module load when enabled

Remove the symlink, use swig module load to detect osmesa context
requested and load the correct module that way, should fix #111

Author: OKaluza

Makefile

@@ -256,8 +256,9 @@ endif
 
 .PHONY: swig
 swig : $(INC) src/LavaVuPython.i | paths
+	#NOTE: bug in swig requires pip install swig==4.2 until fixed
 	swig -v -Wextra -python -py3 -ignoremissing -O -c++ -DSWIG_DO_NOT_WRAP -outdir $(PREFIX) src/LavaVuPython.i
-	cd $(PREFIX)/osmesa; ln -sf ../LavaVuPython.py; touch __init__.py
+	cd $(PREFIX)/osmesa; touch __init__.py
 
 $(SWIGLIB) : $(LIBRARY) $(SWIGOBJ)
 	-rm -f $(PREFIX)/_LavaVuPython.*

lavavu/LavaVuPython.py

@@ -5,12 +5,14 @@
 # the SWIG interface file instead.
 
 from sys import version_info as _swig_python_version_info
-# Import the low-level C/C++ module
-if __package__ or "." in __name__:
-    from . import _LavaVuPython
+
+import os
+if 'osmesa' in os.environ.get('LV_CONTEXT', ''):
+    from osmesa import _LavaVuPython
 else:
     import _LavaVuPython
 
+
 try:
     import builtins as __builtin__
 except ImportError:

lavavu/lavavu.py

@@ -102,19 +102,14 @@
                 context = 'moderngl'
             except Exception as e:
                 context = 'osmesa'
-
-        if context == 'osmesa':
-            #OSMesa fallback, CPU only, multicore
-            from osmesa import LavaVuPython
+            os.environ['LV_CONTEXT'] = context
 
 #Default module if none already loaded
 try:
     LavaVuPython
 except:
     import LavaVuPython
 
-os.environ['LV_CONTEXT'] = context
-
 version = LavaVuPython.version
 server_ports = []
 

lavavu/osmesa/LavaVuPython.py

@@ -1,7 +1,22 @@
 /*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*
 * LavaVu python interface
 **~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*/
-%module LavaVuPython
+#%module LavaVuPython
+#%module(package="mypackage") LavaVuPython
+#%module(package="LavaVuPython", moduleimport="import $module") foo
+#%module(moduleimport="from osmesa import _LavaVuPython") foo
+
+%define MODULEIMPORT
+"
+import os
+if 'osmesa' in os.environ.get('LV_CONTEXT', ''):
+    from osmesa import $module
+else:
+    import $module
+"
+%enddef
+
+%module(moduleimport=MODULEIMPORT) LavaVuPython
 
 %{
 #define SWIG_FILE_WITH_INIT