From 8ae2fef8176145e5921fd888de1e466463726567 Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Tue, 16 Jul 2019 02:48:49 +0900
Subject: [PATCH] restorable: Refactoring: Do not have to update basePixels in
 some cases

If there is no draw-traiangles command, the image can keep its
basePixels.
---
 internal/restorable/image.go | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/internal/restorable/image.go b/internal/restorable/image.go
index 32bd33089..795c19150 100644
--- a/internal/restorable/image.go
+++ b/internal/restorable/image.go
@@ -563,14 +563,16 @@ func (i *Image) restore() error {
 		}
 		gimg.DrawTriangles(c.image.image, c.vertices, c.indices, c.colorm, c.mode, c.filter, c.address)
 	}
-	i.image = gimg
 
-	// TODO: Can we avoid getting pixels here? (#897)
-	pix := gimg.Pixels()
-	i.basePixels = &Pixels{
-		pixels: pix,
-		length: len(pix),
+	if len(i.drawTrianglesHistory) > 0 {
+		pix := gimg.Pixels()
+		i.basePixels = &Pixels{
+			pixels: pix,
+			length: len(pix),
+		}
 	}
+
+	i.image = gimg
 	i.drawTrianglesHistory = nil
 	i.stale = false
 	return nil