scale images after setting a new wallpaper for improved performance

internal/slideshow/slideshow.go

@@ -18,15 +18,23 @@ import (
 func Start() {
 	loggo.Info("starting the image slideshow...", "interval: "+strconv.FormatFloat(config.Interval.Seconds(), 'f', 0, 64)+" seconds")
 	var sleepTime time.Duration
+	scaleImages := config.IsResolutionSet()
 	for {
+		var data []byte
 		image := watcher.GetRandomImage()
-		if config.IsResolutionSet() {
-			data, error := scale(image)
+		if scaleImages {
+			tmp, error := scale(image)
 			if error != nil {
 				loggo.Error("encountered an error scaling an image", "image: "+image, error.Error())
 				continue
 			}
-			error = setBackgroundPiped(data)
+			data = tmp
+		}
+		if sleepTime > 0 {
+			time.Sleep(sleepTime)
+		}
+		if scaleImages {
+			error := setBackgroundPiped(data)
 			if error != nil {
 				loggo.Error("encountered an error setting the background via pipe to feh's stdin", error.Error())
 			}
@@ -38,9 +46,6 @@ func Start() {
 			}
 			loggo.Info("set new background image", "image: "+image)
 		}
-		if sleepTime > 0 {
-			time.Sleep(sleepTime)
-		}
 		sleepTime = time.Until(time.Now().Add(config.Interval))
 	}
 }