From 146c1e5846ad74b707064686211063bf67d91eb6 Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Sun, 3 Jul 2016 18:56:32 +0900
Subject: [PATCH] graphics: Refactoring: Remove graphicsContext.Draw and flush

---
 graphicscontext.go   | 47 ++++++++++++++++----------------------------
 internal/loop/run.go | 11 ++---------
 2 files changed, 19 insertions(+), 39 deletions(-)

diff --git a/graphicscontext.go b/graphicscontext.go
index a001fa117..b745ce5de 100644
--- a/graphicscontext.go
+++ b/graphicscontext.go
@@ -124,9 +124,14 @@ func (c *graphicsContext) drawToDefaultRenderTarget(context *opengl.Context) err
 	if err := drawWithFittingScale(c.screen, c.offscreen2); err != nil {
 		return err
 	}
-	if err := c.flush(context); err != nil {
+	// TODO: imageM is necessary to call graphics functions. Move this to graphics package.
+	imageM.Lock()
+	defer imageM.Unlock()
+	if err := graphics.FlushCommands(context); err != nil {
 		return err
 	}
+	// Call glFlush to prevent black flicking (especially on Android (#226) and iOS).
+	context.Flush()
 	return nil
 }
 
@@ -143,43 +148,25 @@ func (c *graphicsContext) UpdateAndDraw(context *opengl.Context, updateCount int
 			return err
 		}
 	}
-	if err := c.offscreen2.Clear(); err != nil {
-		return err
-	}
-	if err := drawWithFittingScale(c.offscreen2, c.offscreen); err != nil {
-		return err
+	if 0 < updateCount {
+		if err := c.offscreen2.Clear(); err != nil {
+			return err
+		}
+		if err := drawWithFittingScale(c.offscreen2, c.offscreen); err != nil {
+			return err
+		}
 	}
 	if err := c.drawToDefaultRenderTarget(context); err != nil {
 		return err
 	}
-	if err := theImages.savePixels(context); err != nil {
-		return err
+	if 0 < updateCount {
+		if err := theImages.savePixels(context); err != nil {
+			return err
+		}
 	}
 	return nil
 }
 
-func (c *graphicsContext) Draw(context *opengl.Context) error {
-	if err := c.initializeIfNeeded(context); err != nil {
-		return err
-	}
-	if err := c.drawToDefaultRenderTarget(context); err != nil {
-		return err
-	}
-	return nil
-}
-
-func (c *graphicsContext) flush(context *opengl.Context) error {
-	// TODO: imageM is necessary to call graphics functions. Move this to graphics package.
-	imageM.Lock()
-	defer imageM.Unlock()
-	if err := graphics.FlushCommands(context); err != nil {
-		return err
-	}
-	// Call glFlush to prevent black flicking (especially on Android (#226) and iOS).
-	context.Flush()
-	return nil
-}
-
 func (c *graphicsContext) restore(context *opengl.Context) error {
 	imageM.Lock()
 	defer imageM.Unlock()
diff --git a/internal/loop/run.go b/internal/loop/run.go
index 94360a258..995724a00 100644
--- a/internal/loop/run.go
+++ b/internal/loop/run.go
@@ -81,7 +81,6 @@ func (c *runContext) updateFPS(fps float64) {
 type GraphicsContext interface {
 	SetSize(width, height int, scale float64) error
 	UpdateAndDraw(context *opengl.Context, updateCount int) error
-	Draw(context *opengl.Context) error
 }
 
 func Run(g GraphicsContext, width, height int, scale float64, title string, fps int) error {
@@ -155,14 +154,8 @@ func (c *runContext) render(g GraphicsContext) error {
 	if tt == 0 && (int64(time.Second)/int64(fps)-int64(5*time.Millisecond)) < t {
 		tt = 1
 	}
-	if 1 <= tt {
-		if err := g.UpdateAndDraw(ui.GLContext(), tt); err != nil {
-			return err
-		}
-	} else {
-		if err := g.Draw(ui.GLContext()); err != nil {
-			return err
-		}
+	if err := g.UpdateAndDraw(ui.GLContext(), tt); err != nil {
+		return err
 	}
 	if err := ui.CurrentUI().SwapBuffers(); err != nil {
 		return err