build OpenJFX using Yocto for embedded system - javafx

Question

Here's what I need: A working OpenJFX 14 environment with hardware acceleration.
I have a i.MX 8M ARMv8 embedded system for which I'm trying to get OpenJFX 14 or latest running. The chipset has a Vivante GC7000UL GPU. The current Yocto build I did has galcore module loaded. The X window environment works fine and it has libEGL.so, libGLESv2.so and libGL.so in /usr/lib. I am a java engineer, not an OpenGL expert so I don't know if anymore libraries are needed for OpenGL APIs.
I have looked at the prebuilt versions from LibericaFX and Azul zulu. The latter does not have a ARM build. The former has aarch64 build but it is does not have monocle implementation. They have the prism ES2 implementation but unfortunately it needs GLX v1.3 or higher which I don't seem to have.
I tried to compile OpenJFX myself for ARMv8 using a Yocto recipe based on armv6hf.gradle. I managed to compile successfully and able to run it. But it does not render using the hardware pipeline.
Prism pipeline init order: es2 sw
Using Double Precision Marlin Rasterizer
Using dirty region optimizations
Not using texture mask for primitives
Not forcing power of 2 sizes for textures
Using hardware CLAMP_TO_ZERO mode
Opting in for HiDPI pixel scaling
Prism pipeline name = com.sun.prism.es2.ES2Pipeline
Loading ES2 native library ... prism_es2_monocle
GraphicsPipeline.createPipeline failed for com.sun.prism.es2.ES2Pipeline
java.lang.UnsatisfiedLinkError: /usr/lib/jni/libprism_es2_monocle.so: /usr/lib/jni/libprism_es2_monocle.so: undefined symbol: getNativeDisplayType
at java.base/java.lang.ClassLoader$NativeLibrary.load0(Native Method)
...
at java.base/java.lang.Thread.run(Thread.java:832)
*** Fallback to Prism SW pipeline
Prism pipeline name = com.sun.prism.sw.SWPipeline
(X) Got class = class com.sun.prism.sw.SWPipeline
Initialized prism pipeline: com.sun.prism.sw.SWPipeline
Which makes sense because getNativeDisplayType() method is defined in eglWrapper.c which is not included as a part of prism_es2_monocle linking.
Ok. Cool. Let me add that file to the compilation step.
Now the compilation fails with this error.
jfx-14.0.2.1-1/modules/javafx.graphics/src/main/native-prism-es2/eglWrapper/eglWrapper
.c:71:1: error: unknown type name 'PrismNativePort'
71 | PrismNativePort prismPort;
| ^~~~~~~~~~~~~~~
This is where my journey ends. I cannot find PrismNativePort mentioned anywhere other than this file (I've searched entire internet with Google).
Has anybody tried to compile OpenJFX other than Android or Linux x86? Can anyone tell me if I can try anything to make it work with hardware acceleration? Thank you.
This is what I use to start the sample application.
java --module-path /opt/openjfx/jfx-14 \
--add-modules javafx.controls \
-Djava.library.path=/usr/lib/jni \
-Dembedded=monocle \
-Dprism.verbose=true \
ColorfulCircles
Update: I found the PrismNativePort defined in a very old version of JFX code from 2016. Looks like a component called LensPort was decommissioned but eglWrapper still has links to the deleted code.

Answer 1

Not a real answer, but just an idea. OpenJFX 16-ea has more improvements for Raspberry Pi, so maybe also for your use-case. I'm starting my app with following commands on the Raspberry Pi 3 B (gtk instead of monocle):
java -Dglass.platform=gtk \
-Dprism.verbose=true \
-Djavafx.verbose=true \
-p /opt/arm32fb-sdk/lib \
--add-modules javafx.controls \
-jar /home/pi/APP.jar

Answer 2

You have to tell Glass to use monocle :
-Dglass.platform=Monocle
Here is my full command line to start app :
java --module-path ./dist/libARMv8/ --add-modules javafx.controls,javafx.fxml \
-Dembedded=monocle \
-Dglass.platform=Monocle \
-Dmonocle.platform=MX8 \
-Dprism.order=es2 \
-Dprism.verbose=true \
-Djavafx.verbose=true \
-Dcom.sun.javafx.isEmbedded=true -Dcom.sun.javafx.touch=true -Dcom.sun.javafx.virtualKeyboard=javafx \
-jar ./dist/JavaFXTestApp4.jar
I made a build of javaFX for iMX8. The hardware acceleration work but there is some blinking issue : for example, when I click in textField to show the virtual keyboard the display start blinking. Same issues with comboBox.
This blinking issue does not happen in software rendering mode.
I'm not an openGL expert either, so no more ideas for now.... It is maybe an issue with the Vivante openGL driver.
I can share my build script and give more details if someone is interested in it.
edit : to avoid blinking issue with hardware acceleration, add this to the command line :
-Dprism.forceUploadingPainter=true
Best regards,