RFR: Update macOS version of the OpenGL sample to match the current state of OpenGL/Glut on Mac [v3]

[Athijegannathan Sundararajan]

On Thu, 30 May 2024 07:47:41 GMT, Ana Maria Mihalceanu <duke at openjdk.org> wrote:

>> Running the macOS instructions for the [OpenGL sample ](https://github.com/openjdk/jextract/tree/master/samples/opengl) results in failure as Apple discontinued official support for OpenGL (core) and the native `libGL.dylib` doesn't exist anymore. 
>> Below is the situation in details:
>> 
>> * running [compile.sh](https://github.com/openjdk/jextract/blob/master/samples/opengl/compile.sh) or [compilesource.sh](https://github.com/openjdk/jextract/blob/master/samples/opengl/compilesource.sh) will produce Java code that compiles.
>> * attempting to run [run.sh](https://github.com/openjdk/jextract/blob/master/samples/opengl/run.sh) will result in error 
>> 
>> Exception in thread "main" java.lang.ExceptionInInitializerError
>> 	at Teapot.main(Teapot.java:75)
>> Caused by: java.lang.IllegalArgumentException: Cannot open library: libGL.dylib
>> 	at java.base/java.lang.foreign.SymbolLookup.libraryLookup(SymbolLookup.java:314)
>> 	at java.base/java.lang.foreign.SymbolLookup.libraryLookup(SymbolLookup.java:266)
>> 	at opengl.glut_h_3.<clinit>(glut_h_3.java:58)
>> 	... 1 more
>> 
>> 
>> But OpenGL and Glut frameworks are still pre-installed with Apple development tools. This PR fixes the above error by referencing to the OpenGL and Glut frameworks available with Xcode:
>> * `jextract` finds the header files via [compile_flags.txt]([[compile.sh](https://github.com/openjdk/jextract/blob/master/samples/opengl/compile_flags.txt)](https://github.com/openjdk/jextract/blob/master/samples/opengl/compile_flags.txt)
>> * At runtime, the generated header class finds the shared libraries thanks to providing `-l :/System/Library/Frameworks/GLUT.framework/Versions/Current/GLUT` and `-l -l :/System/Library/Frameworks/OpenGL.framework/Versions/Current/OpenGL` to `jextract` command.
>> *  A small side effect: the `Teapot.java` class is updated to use generated `glutDisplayFunc$func` and `glutIdleFunc$func`classes. Generated code varies depending on OpenGL/Glut distribution used. 
>> 
>> - [x] Tested locally on macOS Sonoma 14.4.1 with JDK 22 and using [jextract binaries](https://jdk.java.net/jextract/).
>> - [ ] The code from `Teapot.java` is common for all the operating systems. Additional tests should be done on Windows/Linux.
>> 
>> **Reviewers**
>> [Athijegannathan Sundararajan](https://openjdk.org/census#sundar) (@sundararajana - Committer)
>
> Ana Maria Mihalceanu has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Add a newline at the end of file.

The -l paths in compilesource.sh may be changed as follows:

$ cat compilesource.sh
jextract -t opengl -l :/System/Library/Frameworks/GLUT.framework/GLUT \
  -l :/System/Library/Frameworks/OpenGL.framework/OpenGL \
  /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/GLUT.framework/Headers/glut.h

javac --source=22 -d . opengl/*.java

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PR Comment: https://git.openjdk.org/jextract/pull/245#issuecomment-2139550108