No OpenVG in Raspbian Stretch Lite? Solved

[g8gkq]

I (and about 200 others) have been using OpenVG graphics on a headless RPi running Jessie Lite with a touchscreen to control a Digital Amateur Television Transmitter for a year or so. We realise that sooner or later we are going to have to migrate to Stretch and I have started testing.

I can't seem to find the components that I need for OpenVG in either the Desktop or Lite versions of Stretch (we will end up using the Lite version). One cause of the problem appears to be that libOpenVG.so and a number of other files are not included in /opt/vc/lib/. This means that when I come to compile I get errors such as :

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libshapes.o: In function `loadfont':
libshapes.c:(.text+0x1c0): undefined reference to `vgCreatePath'
libshapes.c:(.text+0x1e4): undefined reference to `vgAppendPathData'

I have already changed the makefile to use -lbrcmEGL -lbrcmGLESv2 rather than -lEGL and -lGLESv2

Is there a package that I can load to install the OpenVG library files? Or am I missing something else obvious?

Thanks for any suggestions

Dave
Project Lead for the Portsdown DATV Transmitter: https://github.com/BritishAmateurTelevisionClub/rpidatv

[topguy]

Small tips on how to solve similar problems...

Step 1: Which header file defines the function we are missing ?

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pi@raspberrypi:/ $ cd /opt/vc/include/
pi@raspberrypi:/opt/vc/include $ rgrep vgCreatePath .
./VG/openvg.h:VG_API_CALL VGPath VG_API_ENTRY vgCreatePath(VGint pathFormat,
pi@raspberrypi:/opt/vc/include $

Ok, so "openvg.h" it is..

Step 2: Which library file can be suitable ?

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pi@raspberrypi:/opt/vc/include $ cd /opt/vc/lib/
pi@raspberrypi:/opt/vc/lib $ ls
libbcm_host.so    libdebug_sym.so        libGLESv1_CM.so        libmmal_core.so       libvcfiled_check.a  libWFC.so
libbrcmEGL.so     libdebug_sym_static.a  libGLESv2.so           libmmal.so            libvchiq_arm.so     plugins
libbrcmGLESv2.so  libdtovl.so            libGLESv2_static.a     libmmal_util.so       libvchostif.a
libbrcmOpenVG.so  libEGL.so              libkhrn_client.a       libmmal_vc_client.so  libvcilcs.a
libbrcmWFC.so     libEGL_static.a        libkhrn_static.a       libopenmaxil.so       libvcos.so
libcontainers.so  libelftoolchain.so     libmmal_components.so  libOpenVG.so          libvcsm.so

hmm.. this libOpenVG looks promising considering the name of the headerfile...

Step 3 : Can we check which functions are in a library ?

Yes we can.

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pi@raspberrypi:/opt/vc/lib $ nm libOpenVG.so | grep vgCreatePath
00008ac0 T vgCreatePath

So I would make sure that "-L/opt/vc/lib -lOpenVG" is part of my compiler options.

Also tip if you are unsure which package a file belongs to:

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pi@raspberrypi:/opt/vc/lib $ dpkg -S libOpenVG.so
libraspberrypi0: /opt/vc/lib/libOpenVG.so
pi@raspberrypi:/opt/vc/lib $ dpkg -l | grep libraspberrypi0
ii  libraspberrypi0                1.20170703-1                      armhf        EGL/GLES/OpenVG/etc. libraries for the Raspberry Pi's VideoCore IV

[g8gkq]

@topguy Thanks very much - you led me to the solution:

libOpenVG.so is not included in Raspbian Stretch, but I did notice a file called libbrcmOpenVG.so in /opt/vc/lib. Running:

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pi@raspberrypi:/opt/vc/lib $ nm libbrcmOpenVG.so | grep vgCreatePath
00008ac8 T vgCreatePath

showed that this file was promising.

In another post, I found that someone had solved a similar issue by creating a symlink of /usr/lib/arm-linux-gnueabihf/libOpenVG.so to this file. So I ran

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pi@raspberrypi:/usr/lib/arm-linux-gnueabihf $ sudo ln -s /opt/vc/lib/libbrcmOpenVG.so libOpenVG.so

.
I also changed all the lines in my makefile that read

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LIBFLAGS=-L/opt/vc/lib -lEGL -lGLESv2 -ljpeg

to

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LIBFLAGS=-L/opt/vc/lib -lbrcmEGL -lbrcmGLESv2 -ljpeg

With those changes, the compile ran without errors and the touchscreen OpenVG graphics are now working.

Thanks again

Dave

[topguy]

I was pretty sure I was running on Raspbian Stretch Lite too and when I look back at my I see I have both "libbrcmOpenVG.so" and "libOpenVG.so" in the directory. So I had already made that symlink at some point but just didn't realise it.

[g8gkq]

Thanks

Is your symlink in the /opt/vc/lib/ folder or the /usr/lib/arm-linux-gnueabihf folder?

Dave

[topguy]

NO links to anything in "/usr/lib/arm-linux-gnueabihf" from "/opt/vc", that will very quickly break stuff. (IMO)
Its also possibly the reason they renamed the libs to include "brcm" because it caused confusion with duplicate named Mesa libraries.

[g8gkq]

Thanks! I'll change it.

Dave