[gdal-dev] Enabling GEOS with GDAL on Windows

[Alex Hagen-Zanker]

  >>would love to be able to access geos without any work arounds

Jay, I am not an expert and struggled to get it working as well. I took 
the following steps using nmake. If you don't have nmake, you can find 
instructions for getting it by Googling. It is also an option to get 
Visual Studio Express.

1. Download and compile latest version of GEOS (following their install 
instructions).
2. Make sure that the GEOS Environment Variables are correct (GEOS_DIR 
and GEOS_HEADERS, I suppose GEOS_DIR would be sufficient)
3. Modify GDAL's "nmake.opt" file  where it concerns GEOS, i.e. the 
following lines:

# Uncomment for GEOS support
#GEOS_DIR=C:/warmerda/geos
GEOS_CFLAGS = -I$(GEOS_DIR)/capi -I$(GEOS_DIR)/source/headers -DHAVE_GEOS
GEOS_LIB     = $(GEOS_DIR)/source/geos_c_i.lib

4. Build GDAL using nmake:

nmake /f makefile.vc clean
nmake /f makefile.vc
nmake /f makefile.vc install
nmake /f makefile.vc devinstall

5. Make sure that your GDAL uses the right geos.dll, e.g. by searching 
your computer for geos.dll and renaming all unused instances.

Good luck, Alex