metal

1:1 PHP bindings of Metal, CAMetalLayer and CAEDRMetadata, as classes named after their native counterparts. Version 0.10.0. macOS only.

A handle is one PHP object per native object, retained while PHP holds it. NSError and NSException become MetalException.

Requirements

• macOS with Metal
• PHP 8.4, NTS or ZTS

Install

Through PIE:

pie install php-io-extensions/metal

From a checkout of this repository:

./install-macos.sh

That builds into Homebrew php@8.4 and php@8.4-zts, ad-hoc signs the .so, and writes 30-metal.ini. Pass other PHP binaries as arguments to install those instead.

Names

• One PHP class per Metal type, one method per selector. Keywords are joined in camelCase: newLibraryWithSource:options:error: is newLibraryWithSourceOptionsError().
• Flag parameters take Enum|int. Enum cases are the C constant without its type prefix, in upper snake case: MTLPixelFormatRGBA8Unorm is MTLPixelFormat::RGBA8_UNORM.
• A descriptor's [[X alloc] init] is X::new(). A class factory keeps the selector name (MTLVertexDescriptor::vertexDescriptor(), CAMetalLayer::layer()). Properties are name() / setName(). isBlendingEnabled is blendingEnabled().
• pointer(): int and static fromPointer(int $pointer): static hand an object to another extension. fromPointer(0) throws MetalException. An address that is not the called class throws too. Any other address is trusted to hold an object.
• An NSError** is not a PHP argument. A nil result throws MetalException with the error's localizedDescription and code. The method name still ends in Error.
• A string|int byte argument is a PHP string or an address. 0 is refused. Any other address is trusted. A string shorter than the call's byte count throws ValueError.

Example

Clear a 2×2 texture to green and read one pixel back:

$texture = MTLTextureDescriptor::texture2DDescriptorWithPixelFormatWidthHeightMipmapped(
    MTLPixelFormat::RGBA8_UNORM, 2, 2, false
);
$texture->setStorageMode(MTLStorageMode::SHARED);
$texture->setUsage(MTLTextureUsage::RENDER_TARGET);
$texture = MTLCreateSystemDefaultDevice()->newTextureWithDescriptor($texture);

$pass = MTLRenderPassDescriptor::renderPassDescriptor();
$color = $pass->colorAttachments()->objectAtIndexedSubscript(0);
$color->setTexture($texture);
$color->setLoadAction(MTLLoadAction::CLEAR);
$color->setClearColor(new MTLClearColor(0.0, 1.0, 0.0, 1.0));
$color->setStoreAction(MTLStoreAction::STORE);

$commands = MTLCreateSystemDefaultDevice()->newCommandQueue()->commandBuffer();
$commands->renderCommandEncoderWithDescriptor($pass)->endEncoding();
$commands->commit();
$commands->waitUntilCompleted();

$pixel = $texture->getBytesBytesPerRowFromRegionMipmapLevel(
    null, 4, new MTLRegion(new MTLOrigin(1, 1, 0), new MTLSize(1, 1, 1)), 0
);
// $pixel is "\x00\xff\x00\xff"

Testing

composer install
php84 -d memory_limit=128M vendor/bin/pest
zhp -d memory_limit=128M vendor/bin/pest

php84 is Homebrew php@8.4. zhp is php@8.4-zts. Both must be green.