PyObjC: MetalPerformanceShaders Framework

Warnings

• breaking `pyobjc-framework-metalperformanceshaders` version 12.0 dropped support for Python 3.9. Version 11.0 dropped support for Python 3.8. Ensure your Python version meets the `pyobjc` requirements (currently Python >=3.10).
  Fix: Upgrade to Python 3.10 or later for PyObjC 12.x, or Python 3.9 or later for PyObjC 11.x.
• breaking PyObjC 10.3 introduced changes to how `__init__` and `__new__` methods are handled when subclassing Objective-C classes in Python. While a partial revert in 10.3.1 allowed `__init__` when a user-defined `__new__` exists, it can still break code relying on the old behavior where `__init__` was called regardless. The recommended pattern is to use `SomeClass.alloc().init()` or the more Pythonic `SomeClass(...)` (introduced in PyObjC 10.3) for object initialization.
  Fix: Review custom Python subclasses of Objective-C classes and adapt initialization logic to use `SomeClass.alloc().init()` or `SomeClass(...)`. If providing a custom `__new__`, ensure `__init__` is correctly called if desired.
• gotcha PyObjC framework bindings, including `pyobjc-framework-metalperformanceshaders`, do not include their own documentation. Users must refer to Apple's official Objective-C and Swift documentation for the MetalPerformanceShaders framework to understand the available APIs and their usage.
  Fix: Consult Apple's Metal Performance Shaders documentation for API specifics and usage examples.
• gotcha Installing PyObjC from source (e.g., using `pip install --no-binary :all: pyobjc`) requires a full Xcode installation or the Xcode Command Line Tools to be present, along with a sufficiently new macOS SDK. Building with an older SDK can lead to compilation errors due to missing protocol declarations or other API changes.
  Fix: Ensure Xcode and its Command Line Tools are installed and updated (`xcode-select --install`). For binary wheels, this is usually not an issue.
• deprecated The `isAlloc` attribute of `objc.selector` is deprecated and will be removed in PyObjC 12. While this change is primarily internal to the bridge, users with highly specialized code that directly inspects `objc.selector` attributes should be aware.
  Fix: Avoid direct reliance on the `isAlloc` attribute of `objc.selector`. Consult PyObjC documentation for alternative approaches if needed.

Install

• pip install pyobjc-framework-metalperformanceshaders Install latest version

Imports

• MetalPerformanceShaders

  import MetalPerformanceShaders

  All classes and functions from the MetalPerformanceShaders framework are exposed under the `MetalPerformanceShaders` module.

Quickstart

This quickstart demonstrates how to import the `MetalPerformanceShaders` framework through PyObjC and access a basic class like `MPSKernel`. Real-world usage of this framework is highly dependent on Apple's Metal API, requiring a Metal device, command queue, and texture management for actual GPU-accelerated operations.

import objc
from Foundation import NSObject # Often implicitly imported or used by other frameworks
import MetalPerformanceShaders

# Accessing a basic class from the framework
# MPSKernel is a base class for many Metal Performance Shaders operations.
try:
    # Simply accessing the class confirms the import and binding are working.
    _ = MetalPerformanceShaders.MPSKernel
    print("Successfully imported MetalPerformanceShaders and accessed MPSKernel.")

    # Note: Full usage of MetalPerformanceShaders (e.g., creating a blur filter, 
    # running a neural network, or performing ray tracing) is complex. 
    # It requires setting up a Metal device, command queue, and textures.
    # For example:
    # from Metal import MTLCreateSystemDefaultDevice
    # device = MTLCreateSystemDefaultDevice()
    # commandQueue = device.newCommandQueue()
    # # ... then create MPSImageGaussianBlur, encode to command buffer, etc.
    print("Note: Actual usage of MetalPerformanceShaders requires a Metal context (device, command queue, textures). Refer to Apple's Metal Performance Shaders documentation for details.")

except objc.nosuchmethod_error as e:
    print(f"Error accessing MetalPerformanceShaders.MPSKernel: {e}")
    print("This might indicate an issue with the framework bindings or an incompatible macOS version.")
except ImportError as e:
    print(f"Error importing MetalPerformanceShaders: {e}")
except Exception as e:
    print(f"An unexpected error occurred: {e}")