RFR: 8271024: Implement macOS Metal Rendering Pipeline [v6]

[Andy Goryachev]

On Wed, 2 Jul 2025 07:53:24 GMT, Ambarish Rapte <arapte at openjdk.org> wrote:

>> ### Description
>> This is the implementation of new graphics rendering pipeline for JavaFX using Metal APIs on MacOS.
>> We released two Early Access (EA) builds and have reached a stage where it is ready to be integrated.
>> Default rendering pipeline on macOS has not been changed by this PR. OpenGL still stays as the default rendering pipeline and Metal rendering pipeline is optional to choose (by providing  `-Dprism.order=mtl`)
>> The `-Dprism.verbose=true` option can be used to verify the rendering pipeline in use.
>> 
>> ### Details about the changes
>> 
>> **Shader changes**
>> - MSLBackend class: This is the primary class that parses (Prism and Decora) jsl shaders into Metal shaders(msl)
>> - There are a few additional Metal shader files added under directory : modules/javafx.graphics/src/main/native-prism-mtl/msl
>> 
>> **Build changes** - There are new tasks added to build.gradle for
>> - Generation/ Compilation/ linking of Metal shaders
>> - Compilation of Prism Java and Objective C files
>> 
>> **Prism** - Prism is the rendering engine of JavaFX.
>> - Added Metal specific Java classes and respective native implementation which use Metal APIs
>> - Java side changes:
>>   - New Metal specific classes: Classes prefixed with MTL, are added here : modules/javafx.graphics/src/main/java/com/sun/prism/mtl 
>>   - Modification to Prism common classes: A few limited changes were required in Prism common classes to support Metal classes. 
>> - Native side changes:
>>   - New Metal specific Objective C implementation is added here: modules/javafx.graphics/src/main/native-prism-mtl
>> 
>> **Glass** - Glass is the windowing toolkit of JavaFX
>> - Existing Glass classes are refactored to support both OpenGL and Metal pipelines
>> - Added Metal specific Glass implementation.
>> 
>> ### Testing
>> - Testing performed on different hardware and macOS versions.
>>   - HW - macBooks with Intel, Intel with discrete graphics card, Apple Silicon (M1, M2 and M4)
>>   - macOS versions - macOS 13, macOS 14 and macOS 15
>> - Functional Testing:
>>   - All headful tests pass with Metal pipeline.
>>   - Verified samples applications: Ensemble and toys
>> - Performance Testing:
>>   - Tested with RenderPerfTest: Almost all tests match/exceed es2 performance except a few that fall a little short on different hardwares. These will be addressed separately (there are open bugs already filed)
>> 
>> ### Note to reviewers :
>> - Providing `-Dprism.order=mtl` option is a must for testing the Metal pipeline
>> - It woul...
>
> Ambarish Rapte has updated the pull request incrementally with one additional commit since the last revision:
> 
>   add @Override

Did a bit more digging in Eclipse:

1. the resource is in `javafx.graphics.jar` under correct path `com/sun/prism/mtl/msl/jfxshaders.metallib`
2. the class loader fails to locate it in BuildinClassLoader:findResourceAsStream() L293
because it tries to load the stream from the file system, not a jar.

Even after I add the dir with the resource to the `java.library.path`

-Djava.library.path="/Users/angorya/Projects/jfx3/jfx/rt/build/sdk/lib:/Users/angorya/Projects/jfx3/jfx/rt/build/modular-sdk/modules/javafx.graphics/com/sun/prism/mtl"


The reason is that eclipse is looking for the resources for the graphics module in
`rt/modules/javafx.graphics/bin` where the module classes are compiled to, and not in other places.

-------------

PR Comment: https://git.openjdk.org/jfx/pull/1824#issuecomment-3049869591