From c5f3eaf92579a0f38517ff90f82bdb4f1885e4e9 Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Tue, 26 Jul 2016 12:28:05 +0900
Subject: [PATCH] graphics: Refactoring

---
 image.go                  | 14 +++++++-------
 imageimpl.go              |  4 ++--
 internal/pixels/pixels.go | 12 +-----------
 3 files changed, 10 insertions(+), 20 deletions(-)

diff --git a/image.go b/image.go
index c8e9c30c7..c5c0c28a1 100644
--- a/image.go
+++ b/image.go
@@ -74,11 +74,11 @@ func (i *images) ensurePixels(context *opengl.Context) error {
 	return nil
 }
 
-func (i *images) resetPixelsIfNeeded(target *Image, context *opengl.Context) error {
+func (i *images) resetPixelsIfDependingOn(target *Image, context *opengl.Context) error {
 	i.m.Lock()
 	defer i.m.Unlock()
 	for img := range i.images {
-		if err := img.resetPixelsIfNeeded(target.impl, context); err != nil {
+		if err := img.resetPixelsIfDependingOn(target.impl, context); err != nil {
 			return err
 		}
 	}
@@ -152,7 +152,7 @@ func (i *Image) Size() (width, height int) {
 //
 // This function is concurrent-safe.
 func (i *Image) Clear() error {
-	if err := theImagesForRestoring.resetPixelsIfNeeded(i, glContext()); err != nil {
+	if err := theImagesForRestoring.resetPixelsIfDependingOn(i, glContext()); err != nil {
 		return err
 	}
 	return i.impl.Fill(color.Transparent)
@@ -162,7 +162,7 @@ func (i *Image) Clear() error {
 //
 // This function is concurrent-safe.
 func (i *Image) Fill(clr color.Color) error {
-	if err := theImagesForRestoring.resetPixelsIfNeeded(i, glContext()); err != nil {
+	if err := theImagesForRestoring.resetPixelsIfDependingOn(i, glContext()); err != nil {
 		return err
 	}
 	return i.impl.Fill(clr)
@@ -185,7 +185,7 @@ func (i *Image) Fill(clr color.Color) error {
 //
 // This function is concurrent-safe.
 func (i *Image) DrawImage(image *Image, options *DrawImageOptions) error {
-	if err := theImagesForRestoring.resetPixelsIfNeeded(i, glContext()); err != nil {
+	if err := theImagesForRestoring.resetPixelsIfDependingOn(i, glContext()); err != nil {
 		return err
 	}
 	return i.impl.DrawImage(image, options)
@@ -223,7 +223,7 @@ func (i *Image) At(x, y int) color.Color {
 //
 // This function is concurrent-safe.
 func (i *Image) Dispose() error {
-	if err := theImagesForRestoring.resetPixelsIfNeeded(i, glContext()); err != nil {
+	if err := theImagesForRestoring.resetPixelsIfDependingOn(i, glContext()); err != nil {
 		return err
 	}
 	if i.impl.isDisposed() {
@@ -240,7 +240,7 @@ func (i *Image) Dispose() error {
 //
 // This function is concurrent-safe.
 func (i *Image) ReplacePixels(p []uint8) error {
-	if err := theImagesForRestoring.resetPixelsIfNeeded(i, glContext()); err != nil {
+	if err := theImagesForRestoring.resetPixelsIfDependingOn(i, glContext()); err != nil {
 		return err
 	}
 	return i.impl.ReplacePixels(p)
diff --git a/imageimpl.go b/imageimpl.go
index 5f4a2ae87..669139b5e 100644
--- a/imageimpl.go
+++ b/imageimpl.go
@@ -214,7 +214,7 @@ func (i *imageImpl) ensurePixels(context *opengl.Context) error {
 	return nil
 }
 
-func (i *imageImpl) resetPixelsIfNeeded(target *imageImpl, context *opengl.Context) error {
+func (i *imageImpl) resetPixelsIfDependingOn(target *imageImpl, context *opengl.Context) error {
 	i.m.Lock()
 	defer i.m.Unlock()
 	if i == target {
@@ -231,7 +231,7 @@ func (i *imageImpl) resetPixelsIfNeeded(target *imageImpl, context *opengl.Conte
 	}
 	// target is an image begin tried to mutate.
 	// If pixels object is related to that image, the pixels must be reset.
-	if !i.pixels.NeedsReset(target.image) {
+	if !i.pixels.DependsOn(target.image) {
 		return nil
 	}
 	if context == nil {
diff --git a/internal/pixels/pixels.go b/internal/pixels/pixels.go
index fb278b27f..1e1bec0ad 100644
--- a/internal/pixels/pixels.go
+++ b/internal/pixels/pixels.go
@@ -96,7 +96,7 @@ func (p *Pixels) At(idx int, context *opengl.Context) (color.Color, error) {
 	return color.RGBA{r, g, b, a}, nil
 }
 
-func (p *Pixels) hasHistoryWith(target *graphics.Image) bool {
+func (p *Pixels) DependsOn(target *graphics.Image) bool {
 	for _, c := range p.drawImageHistory {
 		if c.image == target {
 			return true
@@ -116,16 +116,6 @@ func (p *Pixels) Reset(context *opengl.Context) error {
 	return nil
 }
 
-func (p *Pixels) NeedsReset(target *graphics.Image) bool {
-	if p.drawImageHistory == nil {
-		return false
-	}
-	if !p.hasHistoryWith(target) {
-		return false
-	}
-	return true
-}
-
 func (p *Pixels) HasHistory() bool {
 	return p.drawImageHistory != nil
 }