fixed slideshow interval

.vscode/launch.json

@@ -8,7 +8,7 @@
       "mode": "auto",
       "program": "${workspaceFolder}/main.go",
       "env":{
-        "SLIDESHOW_INTERVAL": "10",
+        "SLIDESHOW_INTERVAL": "13",
         "SLIDESHOW_DIRECTORY": "/home/velvettear/images",
         "SLIDESHOW_RESOLUTION": "600x1024",
         "SLIDESHOW_LOGLEVEL": "debug"

internal/slideshow/slideshow.go

@@ -15,16 +15,11 @@ import (
 )
 
 // internal counter
-var counter int64
-
 // start the slideshow
 func Start() {
 	loggo.Info("starting the image slideshow...", "interval: "+strconv.FormatFloat(config.Interval.Seconds(), 'f', 0, 64)+" seconds")
+	var sleepTime time.Duration
 	for {
-		var sleepTime time.Duration
-		if counter > 0 {
-			sleepTime = time.Until(time.Now().Add(config.Interval))
-		}
 		var scaledImage string
 		image := watcher.GetRandomImage()
 		if len(config.Resolution) > 0 {
@@ -38,11 +33,11 @@ func Start() {
 		if sleepTime > 0 {
 			time.Sleep(sleepTime)
 		}
+		sleepTime = time.Until(time.Now().Add(config.Interval))
 		error := setBackground(image)
 		if error != nil {
 			loggo.Error("encountered an error setting the background image", "image: "+image, error.Error())
 		}
-		counter++
 		loggo.Info("set new background image", "image: "+image)
 		if len(scaledImage) > 0 {
 			error = os.Remove(scaledImage)