This test program uses OpenGL (Mesa) to simulate camera input,
and writes decoded Data Matrix streams to STDOUT.

Right-click on the window to cycle through the test images.  To
add your own images for testing, just overwrite any image in the
"rotate_test/images" directory with another 256x256 PNG file.  If
you want to add brand new images then you will have to update the
gFilename[] and gFileCount variables at the top of rotate_test.c
to include them.