text overlay positions preset

cmd/mxl-pattern/main.go

@@ -35,6 +35,7 @@ type appArgs struct {
 	textOverlay string
 	overlayX    int
 	overlayY    int
+	overlayPos  string
 
 	videoWidth  uint
 	videoHeight uint
@@ -277,9 +278,26 @@ func flagSetAddFlags(fs *pflag.FlagSet, args *appArgs) {
 	fs.StringVarP(&args.pattern, "pattern", "p", "bars", "Video pattern type")
 	fs.BoolVar(&args.listPatterns, "list-patterns", false, "List video available video patterns and exit")
 
-	fs.StringVarP(&args.textOverlay, "text", "t", "", "Text overlay above video pattern")
-	fs.IntVar(&args.overlayX, "text-x", 0, "Text overlay X position in px")
-	fs.IntVar(&args.overlayY, "text-y", 0, "Text overlay Y position in px")
+	fs.StringVarP(&args.textOverlay, "text", "t", "", "Text overlay above video pattern. Ignored if text-pos set")
+	fs.IntVar(&args.overlayX, "text-x", 0, "Text overlay X position in px. Ignored if text-pos set")
+	fs.IntVar(
+		&args.overlayY,
+		"text-y",
+		0,
+		"Text overlay Y position in px")
+	fs.StringVar(
+		&args.overlayPos,
+		"text-pos",
+		"",
+		"Text overlay position with pre-defined values:\n"+
+			"tl - top-left corner\n"+
+			"tc - top-center\n"+
+			"tr - top-right corner\n"+
+			"cc - center of the frame\n"+
+			"bl - bottom-left corner\n"+
+			"bc - bottom-center\n"+
+			"br - bottom-right corner",
+	)
 
 	fs.UintVar(&args.videoWidth, "width", 1920, "Video pattern width")
 	fs.UintVar(&args.videoHeight, "height", 1080, "Video pattern height")
@@ -376,7 +394,7 @@ func main() {
 			args.overlayX > int(vi.width) ||
 			args.overlayY < 0 ||
 			args.overlayY > int(vi.height) {
-			log.Fatalf("Overlay X/Y pos can't be negative or greater, than video width/height")
+			log.Fatalf("overlay X/Y pos can't be negative or greater, than video width/height")
 		}
 		overlay, err = generator.NewTextOverlay(
 			args.textOverlay,
@@ -384,6 +402,7 @@ func main() {
 			int(vi.height),
 			args.overlayX,
 			args.overlayY,
+			args.overlayPos,
 			face,
 		)
 		if err != nil {