instance.go

package webgpu

import (
	"github.com/bluescreen10/webgpu-go/driver"
)

// These are options to be passed when creating an instance.
type InstanceOptions struct {
	// Prefer driver to be used.
	Driver string
}

// Instance is the main entry-point to interact with the GPU.
// Corresponds to https://www.w3.org/TR/webgpu/#gpu-interface.
type Instance struct {
	driver driver.Driver
}

// Returns the driver name
func (i *Instance) DriverName() string {
	return i.driver.Name()
}

// Creates a new surface using the configuration provide by the
// surface descriptor. This varies depending on the platform.
func (i *Instance) CreateSurface(desc SurfaceDescriptor) (*Surface, error) {
	driverSurface, err := i.driver.CreateSurface(desc)
	if err != nil {
		return nil, err
	}

	return &Surface{surface: driverSurface}, nil
}

// Returns an adapter. If options are provided they
// will be used to select from multiple adapters.
func (i *Instance) RequestAdapter(opts *RequestAdapterOptions) (*Adapter, error) {
	adapters := i.driver.EnumerateAdapters()
	if len(adapters) == 0 {
		return nil, ErrNoAdapter
	}

	// If options are provided they must be met
	if opts != nil && len(adapters) > 1 {
		var j int

		// TODO: implement feature filtering
		// for _, a := range adapters {
		// 	if opts.PowerPreference == LowPower && a.IsLowPower() &&
		// 		opts.ForceFallbackAdapter == a.Info().IsFallbackAdapter {
		// 		adapters[j] = a
		// 		j++
		// 	}
		// }

		adapters = adapters[:j]

		if len(adapters) > 0 {
			return &Adapter{adapter: adapters[0]}, nil
		} else {
			return nil, ErrNoAdapter
		}
	}

	return &Adapter{adapter: adapters[0]}, nil
}

// Returns an optimal GPUTextureFormat for displaying 8-bit depth.
func (i *Instance) GetPreferredCanvasFormat() TextureFormat {
	return i.driver.GetPreferredCanvasFormat()
}

// Releases the instance.
func (i *Instance) Release() {
	i.driver.Release()
}

// Creates a new instance. If specified, uses the
// instance descriptor to customize it.
func New(opts *InstanceOptions) *Instance {
	var name string

	if opts != nil {
		name = opts.Driver
	}

	driver := Get(name)
	return &Instance{driver: driver}
}