all: add a new package shaderprecomp

The current implementation is only for macOS so far.

Updates #2861

.gitignore

@@ -7,3 +7,6 @@
 .vscode
 go.work
 go.work.sum
+
+*.metallib
+!dummy.metallib

examples/shaderprecomp/defaultshader.go

@@ -0,0 +1,33 @@
+// Copyright 2020 The Ebiten Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build ignore
+
+//kage:unit pixels
+
+package main
+
+var Time float
+var Cursor vec2
+
+func Fragment(dstPos vec4, srcPos vec2, color vec4) vec4 {
+	pos := (dstPos.xy - imageDstOrigin()) / imageDstSize()
+	pos += Cursor / imageDstSize() / 4
+	clr := 0.0
+	clr += sin(pos.x*cos(Time/15)*80) + cos(pos.y*cos(Time/15)*10)
+	clr += sin(pos.y*sin(Time/10)*40) + cos(pos.x*sin(Time/25)*40)
+	clr += sin(pos.x*sin(Time/5)*10) + sin(pos.y*sin(Time/35)*80)
+	clr *= sin(Time/10) * 0.5
+	return vec4(clr, clr*0.5, sin(clr+Time/3)*0.75, 1)
+}

examples/shaderprecomp/main.go

@@ -0,0 +1,73 @@
+// Copyright 2024 The Ebitengine Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	_ "embed"
+	"log"
+
+	"github.com/hajimehoshi/ebiten/v2"
+	"github.com/hajimehoshi/ebiten/v2/ebitenutil"
+)
+
+//go:embed defaultshader.go
+var defaultShaderSourceBytes []byte
+
+type Game struct {
+	defaultShader *ebiten.Shader
+	counter       int
+}
+
+func (g *Game) Update() error {
+	g.counter++
+
+	if g.defaultShader == nil {
+		s, err := ebiten.NewShader(defaultShaderSourceBytes)
+		if err != nil {
+			return err
+		}
+		g.defaultShader = s
+	}
+	return nil
+}
+
+func (g *Game) Draw(screen *ebiten.Image) {
+	cx, cy := ebiten.CursorPosition()
+	w, h := screen.Bounds().Dx(), screen.Bounds().Dy()
+	op := &ebiten.DrawRectShaderOptions{}
+	op.Uniforms = map[string]interface{}{
+		"Time":   float32(g.counter) / float32(ebiten.TPS()),
+		"Cursor": []float32{float32(cx), float32(cy)},
+	}
+	screen.DrawRectShader(w, h, g.defaultShader, op)
+
+	msg := `This is a test for shader precompilation.
+Precompilation works only on macOS so far.
+Note that this example still works even without shader precompilation.`
+	ebitenutil.DebugPrint(screen, msg)
+}
+
+func (g *Game) Layout(outsideWidth, outsideHeight int) (screenWidth, screenHeight int) {
+	return outsideWidth, outsideHeight
+}
+
+func main() {
+	if err := registerPrecompiledShaders(); err != nil {
+		log.Fatal(err)
+	}
+	if err := ebiten.RunGame(&Game{}); err != nil {
+		log.Fatal(err)
+	}
+}

examples/shaderprecomp/metallib/dummy.metallib

@@ -0,0 +1 @@
+This is a dummy .metallib file to trick Go's embed package.

examples/shaderprecomp/metallib/gen.go

@@ -0,0 +1,103 @@
+// Copyright 2024 The Ebitengine Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build ignore
+
+// This is a program to generate precompiled Metal libraries.
+//
+// See https://developer.apple.com/documentation/metal/shader_libraries/building_a_shader_library_by_precompiling_source_files.
+package main
+
+import (
+	"os"
+	"os/exec"
+	"path/filepath"
+
+	"golang.org/x/sync/errgroup"
+
+	"github.com/hajimehoshi/ebiten/v2/shaderprecomp"
+)
+
+func main() {
+	if err := run(); err != nil {
+		panic(err)
+	}
+}
+
+func run() error {
+	tmpdir, err := os.MkdirTemp("", "")
+	if err != nil {
+		return err
+	}
+	defer os.RemoveAll(tmpdir)
+
+	srcs := shaderprecomp.AppendBuildinShaderSources(nil)
+
+	defaultSrcBytes, err := os.ReadFile(filepath.Join("..", "defaultshader.go"))
+	if err != nil {
+		return err
+	}
+	defaultSrc, err := shaderprecomp.NewShaderSource(defaultSrcBytes)
+	if err != nil {
+		return err
+	}
+	srcs = append(srcs, defaultSrc)
+
+	var wg errgroup.Group
+	for _, src := range srcs {
+		source := src
+		wg.Go(func() error {
+			return compile(source, tmpdir)
+		})
+	}
+	if err := wg.Wait(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func compile(source *shaderprecomp.ShaderSource, tmpdir string) error {
+	id := source.ID().String()
+
+	metalFilePath := filepath.Join(tmpdir, id+".metal")
+
+	f, err := os.Create(metalFilePath)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	if err := shaderprecomp.CompileToMSL(f, source); err != nil {
+		return err
+	}
+	if err := f.Sync(); err != nil {
+		return err
+	}
+
+	irFilePath := filepath.Join(tmpdir, id+".ir")
+	cmd := exec.Command("xcrun", "-sdk", "macosx", "metal", "-o", irFilePath, "-c", metalFilePath)
+	cmd.Stderr = os.Stderr
+	if err := cmd.Run(); err != nil {
+		return err
+	}
+
+	metallibFilePath := id + ".metallib"
+	cmd = exec.Command("xcrun", "-sdk", "macosx", "metallib", "-o", metallibFilePath, irFilePath)
+	cmd.Stderr = os.Stderr
+	if err := cmd.Run(); err != nil {
+		return err
+	}
+
+	return nil
+}

examples/shaderprecomp/metallib/generate.go

@@ -0,0 +1,17 @@
+// Copyright 2024 The Ebitengine Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:generate go run gen.go
+
+package metallib

examples/shaderprecomp/register_darwin.go

@@ -0,0 +1,52 @@
+// Copyright 2024 The Ebitengine Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"embed"
+	"errors"
+	"fmt"
+	"io/fs"
+	"os"
+
+	"github.com/hajimehoshi/ebiten/v2/shaderprecomp"
+)
+
+//go:embed metallib/*.metallib
+var metallibs embed.FS
+
+func registerPrecompiledShaders() error {
+	srcs := shaderprecomp.AppendBuildinShaderSources(nil)
+	defaultShaderSource, err := shaderprecomp.NewShaderSource(defaultShaderSourceBytes)
+	if err != nil {
+		return err
+	}
+	srcs = append(srcs, defaultShaderSource)
+
+	for _, src := range srcs {
+		name := src.ID().String() + ".metallib"
+		lib, err := metallibs.ReadFile("metallib/" + name)
+		if err != nil {
+			if errors.Is(err, fs.ErrNotExist) {
+				fmt.Fprintf(os.Stderr, "precompiled Metal library %s was not found. Run 'go generate' for 'metallib' directory to generate them\n", name)
+				continue
+			}
+			return err
+		}
+		shaderprecomp.RegisterMetalLibrary(src, lib)
+	}
+
+	return nil
+}

examples/shaderprecomp/register_others.go

@@ -0,0 +1,27 @@
+// Copyright 2024 The Ebitengine Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !darwin
+
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+func registerPrecompiledShaders() error {
+	fmt.Fprintf(os.Stderr, "precompiled shaders are not available in this environment.\n")
+	return nil
+}

internal/atlas/shader.go

@@ -104,13 +104,7 @@ func init() {
 		return nil
 	})
 	wg.Go(func() error {
-		ir, err := graphics.CompileShader([]byte(`//kage:unit pixels
-
-package main
-
-func Fragment(dstPos vec4, srcPos vec2, color vec4) vec4 {
-	return vec4(0)
-}`))
+		ir, err := graphics.CompileShader([]byte(builtinshader.ClearShaderSource))
 		if err != nil {
 			return fmt.Errorf("atlas: compiling the clear shader failed: %w", err)
 		}

internal/builtinshader/shader.go

@@ -188,3 +188,22 @@ func Fragment(dstPos vec4, srcPos vec2, color vec4) vec4 {
 	return mix(mix(c0, c1, rate.x), mix(c2, c3, rate.x), rate.y)
 }
 `)
+
+var ClearShaderSource = []byte(`//kage:unit pixels
+
+package main
+
+func Fragment(dstPos vec4, srcPos vec2, color vec4) vec4 {
+	return vec4(0)
+}
+`)
+
+func AppendShaderSources(sources [][]byte) [][]byte {
+	for filter := Filter(0); filter < FilterCount; filter++ {
+		for address := Address(0); address < AddressCount; address++ {
+			sources = append(sources, ShaderSource(filter, address, false), ShaderSource(filter, address, true))
+		}
+	}
+	sources = append(sources, ScreenShaderSource, ClearShaderSource)
+	return sources
+}

internal/graphics/shader.go

@@ -161,8 +161,8 @@ func __vertex(dstPos vec2, srcPos vec2, color vec4) (vec4, vec2, vec4) {
 	return shaderSuffix, nil
 }
 
-func CompileShader(src []byte) (*shaderir.Program, error) {
-	unit, err := shader.ParseCompilerDirectives(src)
+func completeShaderSource(fragmentSrc []byte) ([]byte, error) {
+	unit, err := shader.ParseCompilerDirectives(fragmentSrc)
 	if err != nil {
 		return nil, err
 	}
@@ -172,14 +172,23 @@ func CompileShader(src []byte) (*shaderir.Program, error) {
 	}
 
 	var buf bytes.Buffer
-	buf.Write(src)
+	buf.Write(fragmentSrc)
 	buf.WriteString(suffix)
 
+	return buf.Bytes(), nil
+}
+
+func CompileShader(fragmentSrc []byte) (*shaderir.Program, error) {
+	src, err := completeShaderSource(fragmentSrc)
+	if err != nil {
+		return nil, err
+	}
+
 	const (
 		vert = "__vertex"
 		frag = "Fragment"
 	)
-	ir, err := shader.Compile(buf.Bytes(), vert, frag, ShaderImageCount)
+	ir, err := shader.Compile(src, vert, frag, ShaderImageCount)
 	if err != nil {
 		return nil, err
 	}
@@ -193,3 +202,11 @@ func CompileShader(src []byte) (*shaderir.Program, error) {
 
 	return ir, nil
 }
+
+func CalcSourceHash(fragmentSrc []byte) (shaderir.SourceHash, error) {
+	src, err := completeShaderSource(fragmentSrc)
+	if err != nil {
+		return shaderir.SourceHash{}, err
+	}
+	return shaderir.CalcSourceHash(src), nil
+}

internal/graphicsdriver/metal/mtl/dispatch_darwin.go

@@ -0,0 +1,39 @@
+// Copyright 2024 The Ebiten Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mtl
+
+import (
+	"unsafe"
+
+	"github.com/ebitengine/purego"
+)
+
+var libSystem uintptr
+
+var (
+	dispatchDataCreate func(buffer unsafe.Pointer, size uint, queue uintptr, destructor uintptr) uintptr
+	dispatchRelease    func(obj uintptr)
+)
+
+func init() {
+	lib, err := purego.Dlopen("/usr/lib/libSystem.B.dylib", purego.RTLD_LAZY|purego.RTLD_GLOBAL)
+	if err != nil {
+		panic(err)
+	}
+	libSystem = lib
+
+	purego.RegisterLibFunc(&dispatchDataCreate, libSystem, "dispatch_data_create")
+	purego.RegisterLibFunc(&dispatchRelease, libSystem, "dispatch_release")
+}

internal/graphicsdriver/metal/mtl/mtl_darwin.go

@@ -493,6 +493,7 @@ var (
 	sel_supportsFeatureSet                                                                                                            = objc.RegisterName("supportsFeatureSet:")
 	sel_newCommandQueue                                                                                                               = objc.RegisterName("newCommandQueue")
 	sel_newLibraryWithSource_options_error                                                                                            = objc.RegisterName("newLibraryWithSource:options:error:")
+	sel_newLibraryWithData_error                                                                                                      = objc.RegisterName("newLibraryWithData:error:")
 	sel_release                                                                                                                       = objc.RegisterName("release")
 	sel_retain                                                                                                                        = objc.RegisterName("retain")
 	sel_new                                                                                                                           = objc.RegisterName("new")
@@ -652,6 +653,27 @@ func (d Device) MakeLibrary(source string, opt CompileOptions) (Library, error)
 	return Library{l}, nil
 }
 
+// MakeLibraryWithData creates a Metal library instance from a data instance that contains the functions in a precompiled Metal library.
+//
+// Reference: https://developer.apple.com/documentation/metal/mtldevice/1433391-makelibrary
+func (d Device) MakeLibraryWithData(buffer []byte) (Library, error) {
+	defer runtime.KeepAlive(buffer)
+
+	data := dispatchDataCreate(unsafe.Pointer(&buffer[0]), uint(len(buffer)), 0, 0)
+	defer dispatchRelease(data)
+
+	var err cocoa.NSError
+	l := d.device.Send(
+		sel_newLibraryWithData_error,
+		data,
+		unsafe.Pointer(&err),
+	)
+	if l == 0 {
+		return Library{}, errors.New(cocoa.NSString{ID: err.Send(sel_localizedDescription)}.String())
+	}
+	return Library{l}, nil
+}
+
 // MakeRenderPipelineState creates a render pipeline state object.
 //
 // Reference: https://developer.apple.com/documentation/metal/mtldevice/1433369-makerenderpipelinestate.

internal/graphicsdriver/metal/shader_darwin.go

@@ -16,6 +16,7 @@ package metal
 
 import (
 	"fmt"
+	"sync"
 
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver/metal/mtl"
@@ -23,6 +24,38 @@ import (
 	"github.com/hajimehoshi/ebiten/v2/internal/shaderir/msl"
 )
 
+type precompiledLibraries struct {
+	binaries map[shaderir.SourceHash][]byte
+	m        sync.Mutex
+}
+
+func (c *precompiledLibraries) put(hash shaderir.SourceHash, bin []byte) {
+	c.m.Lock()
+	defer c.m.Unlock()
+
+	if c.binaries == nil {
+		c.binaries = map[shaderir.SourceHash][]byte{}
+	}
+	if _, ok := c.binaries[hash]; ok {
+		panic(fmt.Sprintf("metal: the precompiled library for the hash %s is already registered", hash.String()))
+	}
+	c.binaries[hash] = bin
+}
+
+func (c *precompiledLibraries) get(hash shaderir.SourceHash) ([]byte, bool) {
+	c.m.Lock()
+	defer c.m.Unlock()
+
+	bin, ok := c.binaries[hash]
+	return bin, ok
+}
+
+var thePrecompiledLibraries precompiledLibraries
+
+func RegisterPrecompiledLibrary(hash shaderir.SourceHash, bin []byte) {
+	thePrecompiledLibraries.put(hash, bin)
+}
+
 type shaderRpsKey struct {
 	blend       graphicsdriver.Blend
 	stencilMode stencilMode
@@ -37,6 +70,8 @@ type Shader struct {
 	fs   mtl.Function
 	vs   mtl.Function
 	rpss map[shaderRpsKey]mtl.RenderPipelineState
+
+	libraryPrecompiled bool
 }
 
 func newShader(device mtl.Device, id graphicsdriver.ShaderID, program *shaderir.Program) (*Shader, error) {
@@ -61,24 +96,42 @@ func (s *Shader) Dispose() {
 	}
 	s.vs.Release()
 	s.fs.Release()
-	s.lib.Release()
+	// Do not release s.lib if this is precompiled. This is a shared precompiled library.
+	if !s.libraryPrecompiled {
+		s.lib.Release()
+	}
 }
 
 func (s *Shader) init(device mtl.Device) error {
-	src := msl.Compile(s.ir)
-	lib, err := device.MakeLibrary(src, mtl.CompileOptions{})
-	if err != nil {
-		return fmt.Errorf("metal: device.MakeLibrary failed: %w, source: %s", err, src)
+	var src string
+	if libBin, ok := thePrecompiledLibraries.get(s.ir.SourceHash); ok {
+		lib, err := device.MakeLibraryWithData(libBin)
+		if err != nil {
+			return err
+		}
+		s.lib = lib
+	} else {
+		src = msl.Compile(s.ir)
+		lib, err := device.MakeLibrary(src, mtl.CompileOptions{})
+		if err != nil {
+			return fmt.Errorf("metal: device.MakeLibrary failed: %w, source: %s", err, src)
+		}
+		s.lib = lib
 	}
-	s.lib = lib
 
 	vs, err := s.lib.MakeFunction(msl.VertexName)
 	if err != nil {
-		return fmt.Errorf("metal: lib.MakeFunction for vertex failed: %w, source: %s", err, src)
+		if src != "" {
+			return fmt.Errorf("metal: lib.MakeFunction for vertex failed: %w, source: %s", err, src)
+		}
+		return fmt.Errorf("metal: lib.MakeFunction for vertex failed: %w", err)
 	}
 	fs, err := s.lib.MakeFunction(msl.FragmentName)
 	if err != nil {
-		return fmt.Errorf("metal: lib.MakeFunction for fragment failed: %w, source: %s", err, src)
+		if src != "" {
+			return fmt.Errorf("metal: lib.MakeFunction for fragment failed: %w, source: %s", err, src)
+		}
+		return fmt.Errorf("metal: lib.MakeFunction for fragment failed: %w", err)
 	}
 	s.fs = fs
 	s.vs = vs

internal/shader/shader.go

@@ -202,6 +202,7 @@ func Compile(src []byte, vertexEntry, fragmentEntry string, textureCount int) (*
 		fragmentEntry: fragmentEntry,
 		unit:          unit,
 	}
+	s.ir.SourceHash = shaderir.CalcSourceHash(src)
 	s.global.ir = &shaderir.Block{}
 	s.parse(f)
 

internal/shaderir/program.go

@@ -16,8 +16,10 @@
 package shaderir
 
 import (
+	"encoding/hex"
 	"go/constant"
 	"go/token"
+	"hash/fnv"
 	"sort"
 	"strings"
 )
@@ -29,6 +31,21 @@ const (
 	Pixels
 )
 
+type SourceHash [16]byte
+
+func CalcSourceHash(source []byte) SourceHash {
+	h := fnv.New128a()
+	_, _ = h.Write(source)
+
+	var hash SourceHash
+	h.Sum(hash[:0])
+	return hash
+}
+
+func (s SourceHash) String() string {
+	return hex.EncodeToString(s[:])
+}
+
 type Program struct {
 	UniformNames []string
 	Uniforms     []Type
@@ -40,6 +57,8 @@ type Program struct {
 	FragmentFunc FragmentFunc
 	Unit         Unit
 
+	SourceHash SourceHash
+
 	uniformFactors []uint32
 }
 

shaderprecomp/shaderprecomp.go

@@ -0,0 +1,70 @@
+// Copyright 2024 The Ebitengine Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package shaderprecomp
+
+import (
+	"github.com/hajimehoshi/ebiten/v2/internal/builtinshader"
+	"github.com/hajimehoshi/ebiten/v2/internal/graphics"
+	"github.com/hajimehoshi/ebiten/v2/internal/shaderir"
+)
+
+// AppendBuildinShaderSources appends all the built-in shader sources to the given slice.
+//
+// Do not modify the content of the shader source.
+//
+// AppendBuildinShaderSources is concurrent-safe.
+func AppendBuildinShaderSources(sources []*ShaderSource) []*ShaderSource {
+	for _, s := range builtinshader.AppendShaderSources(nil) {
+		src, err := NewShaderSource(s)
+		if err != nil {
+			panic(err)
+		}
+		sources = append(sources, src)
+	}
+	return sources
+}
+
+// ShaderSource is an object encapsulating a shader source code.
+type ShaderSource struct {
+	source []byte
+	id     ShaderSourceID
+}
+
+// NewShaderSource creates a new ShaderSource object from the given source code.
+func NewShaderSource(source []byte) (*ShaderSource, error) {
+	hash, err := graphics.CalcSourceHash(source)
+	if err != nil {
+		return nil, err
+	}
+	return &ShaderSource{
+		source: source,
+		id:     ShaderSourceID(hash),
+	}, nil
+}
+
+// ID returns a unique identifier for the shader source.
+// The ShaderSourceID value must be the same for the same shader source and the same Ebitengine version.
+// There is no guarantee that the ShaderSourceID value is the same between different Ebitengine versions.
+func (s *ShaderSource) ID() ShaderSourceID {
+	return s.id
+}
+
+// ShaderSourceID is a uniuqe identifier for a shader source.
+type ShaderSourceID [16]byte
+
+// String returns a string representation of the shader source ID.
+func (s ShaderSourceID) String() string {
+	return shaderir.SourceHash(s).String()
+}

shaderprecomp/shaderprecomp_darwin.go

@@ -0,0 +1,47 @@
+// Copyright 2024 The Ebitengine Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package shaderprecomp
+
+import (
+	"io"
+
+	"github.com/hajimehoshi/ebiten/v2/internal/graphics"
+	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver/metal"
+	"github.com/hajimehoshi/ebiten/v2/internal/shaderir"
+	"github.com/hajimehoshi/ebiten/v2/internal/shaderir/msl"
+)
+
+// CompileToMSL compiles the shader source to Metal Shader Language, and writes the result to w.
+//
+// CompileToMSL is concurrent-safe.
+func CompileToMSL(w io.Writer, source *ShaderSource) error {
+	ir, err := graphics.CompileShader(source.source)
+	if err != nil {
+		return err
+	}
+	if _, err = w.Write([]byte(msl.Compile(ir))); err != nil {
+		return err
+	}
+	return nil
+}
+
+// RegisterMetalLibrary registers a precompiled Metal library for a shader source.
+// library must be the content of a .metallib file.
+// For more details, see https://developer.apple.com/documentation/metal/shader_libraries/building_a_shader_library_by_precompiling_source_files.
+//
+// RegisterMetalLibrary is concurrent-safe.
+func RegisterMetalLibrary(source *ShaderSource, library []byte) {
+	metal.RegisterPrecompiledLibrary(shaderir.SourceHash(source.ID()), library)
+}