RFR: 8271024: Implement macOS Metal Rendering Pipeline [v15]

[Kevin Rushforth]

On Fri, 1 Aug 2025 17:09:58 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:
> 
>   kcr: review: crash regression fix

I ran a full set of automated headless tests using the MTL pipeline on my M1 running macOS 14 and everything passes now.

Andy has valid points for his follow-up questions about dispose. They should either be addressed or documented, since the usual pattern is to unconditionally call `super.dispose()` at the end of the `dispose()` method.

There is one other issue that needs to be addressed, and then I'll get back to reviewing the code. This PR branch is a few commits behind master, which is usually OK unless there have been changes that conflict semantically with the PR.

When testing a PR, I merge master into my local review branch to make sure I'm testing what would be the state of the repo if the PR were integrated then. This reveals a problem, namely that the Headless glass platform needs the same change to the `HeadlessView::_getNativeFrameBuffer` method as you did for all other subclasses of View to avoid the following compilation error:


modules/javafx.graphics/src/main/java/com/sun/glass/ui/headless/HeadlessView.java:32: error: HeadlessView is not abstract and does not override abstract method _getNativeFrameBuffer(long) in View
public class HeadlessView extends View {
       ^
modules/javafx.graphics/src/main/java/com/sun/glass/ui/headless/HeadlessView.java:87: error: _getNativeFrameBuffer(long) in HeadlessView cannot override _getNativeFrameBuffer(long) in View
    protected int _getNativeFrameBuffer(long ptr) {
                  ^
  return type int is not compatible with long


So you will need to merge the latest master into your PR branch and make the needed change.

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PR Comment: https://git.openjdk.org/jfx/pull/1824#issuecomment-3145700979
PR Comment: https://git.openjdk.org/jfx/pull/1824#issuecomment-3145702499