Revert "internal/restorable: integrate the implementation into internal/atlas"

This reverts commit c404b448aa.

Updates #3083

internal/atlas/image.go

@@ -27,6 +27,7 @@ import (
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicscommand"
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
 	"github.com/hajimehoshi/ebiten/v2/internal/packing"
+	"github.com/hajimehoshi/ebiten/v2/internal/restorable"
 	"github.com/hajimehoshi/ebiten/v2/internal/shaderir"
 )
 
@@ -143,7 +144,7 @@ func (b *backend) extendIfNeeded(width, height int) {
 	graphics.QuadVerticesFromDstAndSrc(vs, 0, 0, float32(sw), float32(sh), 0, 0, float32(sw), float32(sh), 1, 1, 1, 1)
 	is := graphics.QuadIndices()
 	dr := image.Rect(0, 0, sw, sh)
-	newImg.DrawTriangles(srcs, vs, is, graphicsdriver.BlendCopy, dr, [graphics.ShaderSrcImageCount]image.Rectangle{}, NearestFilterShader.ensureShader(), nil, graphicsdriver.FillRuleFillAll)
+	newImg.DrawTriangles(srcs, vs, is, graphicsdriver.BlendCopy, dr, [graphics.ShaderSrcImageCount]image.Rectangle{}, NearestFilterShader.ensureShader().Shader, nil, graphicsdriver.FillRuleFillAll)
 	b.image.Dispose()
 
 	b.image = newImg
@@ -168,7 +169,7 @@ func clearImage(i *graphicscommand.Image, region image.Rectangle) {
 	vs := make([]float32, 4*graphics.VertexFloatCount)
 	graphics.QuadVerticesFromDstAndSrc(vs, float32(region.Min.X), float32(region.Min.Y), float32(region.Max.X), float32(region.Max.Y), 0, 0, 0, 0, 0, 0, 0, 0)
 	is := graphics.QuadIndices()
-	i.DrawTriangles([graphics.ShaderSrcImageCount]*graphicscommand.Image{}, vs, is, graphicsdriver.BlendClear, region, [graphics.ShaderSrcImageCount]image.Rectangle{}, clearShader.ensureShader(), nil, graphicsdriver.FillRuleFillAll)
+	i.DrawTriangles([graphics.ShaderSrcImageCount]*graphicscommand.Image{}, vs, is, graphicsdriver.BlendClear, region, [graphics.ShaderSrcImageCount]image.Rectangle{}, restorable.ClearShader.Shader, nil, graphicsdriver.FillRuleFillAll)
 }
 
 func (b *backend) clearPixels(region image.Rectangle) {
@@ -520,7 +521,7 @@ func (i *Image) drawTriangles(srcs [graphics.ShaderSrcImageCount]*Image, vertice
 		imgs[i] = src.backend.image
 	}
 
-	i.backend.image.DrawTriangles(imgs, vertices, indices, blend, dstRegion, srcRegions, shader.ensureShader(), uniforms, fillRule)
+	i.backend.image.DrawTriangles(imgs, vertices, indices, blend, dstRegion, srcRegions, shader.ensureShader().Shader, uniforms, fillRule)
 
 	for _, src := range srcs {
 		if src == nil {

internal/atlas/shader.go

@@ -15,20 +15,15 @@
 package atlas
 
 import (
-	"fmt"
 	"runtime"
 
-	"golang.org/x/sync/errgroup"
+	"github.com/hajimehoshi/ebiten/v2/internal/restorable"
-
-	"github.com/hajimehoshi/ebiten/v2/internal/builtinshader"
-	"github.com/hajimehoshi/ebiten/v2/internal/graphics"
-	"github.com/hajimehoshi/ebiten/v2/internal/graphicscommand"
 	"github.com/hajimehoshi/ebiten/v2/internal/shaderir"
 )
 
 type Shader struct {
 	ir     *shaderir.Program
-	shader *graphicscommand.Shader
+	shader *restorable.Shader
 }
 
 func NewShader(ir *shaderir.Program) *Shader {
@@ -46,11 +41,11 @@ func (s *Shader) finalize() {
 	})
 }
 
-func (s *Shader) ensureShader() *graphicscommand.Shader {
+func (s *Shader) ensureShader() *restorable.Shader {
 	if s.shader != nil {
 		return s.shader
 	}
-	s.shader = graphicscommand.NewShader(s.ir)
+	s.shader = restorable.NewShader(s.ir)
 	runtime.SetFinalizer(s, (*Shader).finalize)
 	return s.shader
 }
@@ -75,43 +70,18 @@ func (s *Shader) deallocate() {
 	if s.shader == nil {
 		return
 	}
-	s.shader.Dispose()
+	s.shader.Shader.Dispose()
+	s.shader.Shader = nil
 	s.shader = nil
 }
 
 var (
-	NearestFilterShader *Shader
+	NearestFilterShader = &Shader{
-	LinearFilterShader  *Shader
+		shader: restorable.NearestFilterShader,
-	clearShader         *Shader
+		ir:     restorable.LinearFilterShaderIR,
-)
-
-func init() {
-	var wg errgroup.Group
-	wg.Go(func() error {
-		ir, err := graphics.CompileShader([]byte(builtinshader.ShaderSource(builtinshader.FilterNearest, builtinshader.AddressUnsafe, false)))
-		if err != nil {
-			return fmt.Errorf("atlas: compiling the nearest shader failed: %w", err)
-		}
-		NearestFilterShader = NewShader(ir)
-		return nil
-	})
-	wg.Go(func() error {
-		ir, err := graphics.CompileShader([]byte(builtinshader.ShaderSource(builtinshader.FilterLinear, builtinshader.AddressUnsafe, false)))
-		if err != nil {
-			return fmt.Errorf("atlas: compiling the linear shader failed: %w", err)
-		}
-		LinearFilterShader = NewShader(ir)
-		return nil
-	})
-	wg.Go(func() error {
-		ir, err := graphics.CompileShader([]byte(builtinshader.ClearShaderSource))
-		if err != nil {
-			return fmt.Errorf("atlas: compiling the clear shader failed: %w", err)
-		}
-		clearShader = NewShader(ir)
-		return nil
-	})
-	if err := wg.Wait(); err != nil {
-		panic(err)
 	}
-}
+	LinearFilterShader = &Shader{
+		shader: restorable.LinearFilterShader,
+		ir:     restorable.LinearFilterShaderIR,
+	}
+)

internal/restorable/doc.go

@@ -0,0 +1,22 @@
+// Copyright 2017 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 restorable used to offer an Image struct that stores image commands
+// and restores its pixel data from the commands when context lost happens.
+//
+// However, now Ebitengine doesn't handle context losts, and this package is
+// just a thin wrapper.
+//
+// TODO: Integrate this package into internal/atlas and internal/graphicscommand (#805).
+package restorable

internal/restorable/shader.go

@@ -0,0 +1,82 @@
+// 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.
+
+package restorable
+
+import (
+	"fmt"
+
+	"golang.org/x/sync/errgroup"
+
+	"github.com/hajimehoshi/ebiten/v2/internal/builtinshader"
+	"github.com/hajimehoshi/ebiten/v2/internal/graphics"
+	"github.com/hajimehoshi/ebiten/v2/internal/graphicscommand"
+	"github.com/hajimehoshi/ebiten/v2/internal/shaderir"
+)
+
+type Shader struct {
+	Shader *graphicscommand.Shader
+}
+
+func NewShader(ir *shaderir.Program) *Shader {
+	s := &Shader{
+		Shader: graphicscommand.NewShader(ir),
+	}
+	return s
+}
+
+var (
+	NearestFilterShader   *Shader
+	NearestFilterShaderIR *shaderir.Program
+	LinearFilterShader    *Shader
+	LinearFilterShaderIR  *shaderir.Program
+	ClearShader           *Shader
+)
+
+func init() {
+	var wg errgroup.Group
+	var nearestIR, linearIR, clearIR *shaderir.Program
+	wg.Go(func() error {
+		ir, err := graphics.CompileShader([]byte(builtinshader.ShaderSource(builtinshader.FilterNearest, builtinshader.AddressUnsafe, false)))
+		if err != nil {
+			return fmt.Errorf("restorable: compiling the nearest shader failed: %w", err)
+		}
+		nearestIR = ir
+		return nil
+	})
+	wg.Go(func() error {
+		ir, err := graphics.CompileShader([]byte(builtinshader.ShaderSource(builtinshader.FilterLinear, builtinshader.AddressUnsafe, false)))
+		if err != nil {
+			return fmt.Errorf("restorable: compiling the linear shader failed: %w", err)
+		}
+		linearIR = ir
+		return nil
+	})
+	wg.Go(func() error {
+		ir, err := graphics.CompileShader([]byte(builtinshader.ClearShaderSource))
+		if err != nil {
+			return fmt.Errorf("restorable: compiling the clear shader failed: %w", err)
+		}
+		clearIR = ir
+		return nil
+	})
+	if err := wg.Wait(); err != nil {
+		panic(err)
+	}
+	NearestFilterShaderIR = nearestIR
+	NearestFilterShader = NewShader(nearestIR)
+	LinearFilterShaderIR = linearIR
+	LinearFilterShader = NewShader(linearIR)
+	ClearShader = NewShader(clearIR)
+}