Primitives and Buffers¶

Primitive type mapping¶

Primitives in WebGPU are mapped to Kotlin primitive types directly, ensuring type safety and performance efficiency. The mapping follows a platform-agnostic strategy to maintain consistency across all target platforms.

Basic type mappings¶

WebGPU Type	Kotlin Type	Example
`unsigned long`	`UInt`	`GPUSize32`, `GPUIndex32`
`long`	`Int`	`GPUSignedOffset32`, `GPUDepthBias`
`unsigned long long`	`ULong`	`GPUSize64`
`float`	`Float`	Parameters in `setViewport`
`double`	`Double`	`GPUColor` properties, `GPUPipelineConstantValue`
`boolean`	`Boolean`	Various boolean properties
`DOMString`	`String`	Labels, shader code

Examples from the codebase¶

The core module defines type aliases for WebGPU-specific types:

// From typealiases.kt
typealias GPUBufferDynamicOffset = UInt
typealias GPUStencilValue = UInt
typealias GPUSampleMask = UInt
typealias GPUDepthBias = Int
typealias GPUSize64 = ULong
typealias GPUIntegerCoordinate = UInt
typealias GPUIndex32 = UInt
typealias GPUSize32 = UInt
typealias GPUSignedOffset32 = Int

In the web-specific implementation, the same values are exposed to JavaScript through the generated bindings:

// From types.kt in webgpu-web-bindings
external interface WGPUColor : JsAny {
    var r: JsNumber /* double */
    var g: JsNumber /* double */
    var b: JsNumber /* double */
    var a: JsNumber /* double */
}

Buffer types¶

ArrayBuffer¶

ArrayBuffer is mapped differently depending on the target platform:

In browser environments (JavaScript and WebAssembly), it is mapped to the JavaScript ArrayBuffer type.
On the JVM, it wraps a MemorySegment through ArrayBuffer.wrap(segment).
On Kotlin/Native targets, it wraps a raw pointer through ArrayBuffer.wrap(pointer, size).
On Android, it wraps a direct ByteBuffer through ArrayBuffer.wrap(buffer), or — for memory a native library lends the caller, such as a GPU-mapped range between map and unmap — the borrowed range itself through ArrayBuffer.wrap(address, size). The borrowed view reads and writes that memory in place, in the platform's native byte order, and never frees it: the caller keeps owning the memory and must keep it valid for the view's whole lifetime.

AllowSharedBufferSource¶

AllowSharedBufferSource is mapped to the ArrayBuffer type across all platforms, which simplifies the API while maintaining compatibility with the WebGPU standard.