Include Eigen headers in Windows SDK to prevent people from having to grab the thirdparty packages

makepanda/makepanda.py

@@ -2676,6 +2676,11 @@ if (PkgSkip("PYTHON")==0 and os.path.isdir(GetThirdpartyBase()+"/Pmw")):
     CopyTree(GetOutputDir()+'/Pmw',         GetThirdpartyBase()+'/Pmw')
 ConditionalWriteFile(GetOutputDir()+'/include/ctl3d.h', '/* dummy file to make MAX happy */')
 
+# Since Eigen is included by all sorts of core headers, as a convenience
+# to C++ users on Windows, we include it in the Panda include directory.
+if not PkgSkip("EIGEN") and GetTarget() == "windows" and GetThirdpartyDir():
+    CopyTree(GetOutputDir()+'/include/Eigen', GetThirdpartyDir()+'eigen/include/Eigen')
+
 ########################################################################
 #
 # Copy header files to the built/include/parser-inc directory.