diff --git a/Makefile.pl b/Makefile.pl
index 0357735..9adda2a 100755
--- a/Makefile.pl
+++ b/Makefile.pl
@@ -119,13 +119,16 @@ print("Target : " . $target . "\n");
 
 my @l = ();
 foreach my $e (param_list()) {
+    if (not(param_get($e))) {
+        next;
+    }
     if (($e eq "vulkan-string-helper") and param_get("vulkan")) {
         push(@l, $e);
     }
     elsif (($e eq "xrender") and ($backend eq "x11")) {
         push(@l, $e);
     }
-    elsif (not($e eq "vulkan-string-helper") and not($e eq "xrender") and param_get($e)) {
+    elsif (not($e eq "vulkan-string-helper") and not($e eq "xrender")) {
         push(@l, $e);
     }
 }
diff --git a/pl/ostype/NetBSD.pl b/pl/ostype/NetBSD.pl
index e38abf5..74ff8d5 100644
--- a/pl/ostype/NetBSD.pl
+++ b/pl/ostype/NetBSD.pl
@@ -1,6 +1,7 @@
 # $Id$
 add_incdir("-I/usr/X11R7/include -I/usr/pkg/include");
-add_libdir("-L/usr/X11R7/lib -Wl,-R/usr/X11R7/lib -L/usr/pkg/lib -Wl,-R/usr/pkg/lib");
+add_libdir(
+    "-L/usr/X11R7/lib -Wl,-R/usr/X11R7/lib -L/usr/pkg/lib -Wl,-R/usr/pkg/lib");
 use_backend("x11");
 
 1;
diff --git a/pl/ostype/Windows.pl b/pl/ostype/Windows.pl
index bed4f3b..98f6f4d 100644
--- a/pl/ostype/Windows.pl
+++ b/pl/ostype/Windows.pl
@@ -1,8 +1,8 @@
 # $Id$
-$library_prefix = "";
-$library_suffix = ".dll";
+$library_prefix    = "";
+$library_suffix    = ".dll";
 $executable_suffix = ".exe";
-$math = "";
+$math              = "";
 add_ldflags("-Wl,--out-implib,src/libMw.a -static-libgcc");
 use_backend("gdi");
 
diff --git a/pl/rules.pl b/pl/rules.pl
index 93aba1f..4a577a6 100644
--- a/pl/rules.pl
+++ b/pl/rules.pl
@@ -3,39 +3,41 @@ new_object("src/*.c");
 
 my $gl_libs = "";
 
-if($backend eq "x11"){
-	add_cflags("-DUSE_X11");
-	new_object("src/backend/x11.c");
-	add_libs("-lX11 -lXrender -lXcursor");
+if ($backend eq "x11") {
+    add_cflags("-DUSE_X11");
+    new_object("src/backend/x11.c");
+    add_libs("-lX11 -lXrender -lXcursor");
 
-	$gl_libs = "-lGL -lGLU";
-}elsif($backend eq "gdi"){
-	add_cflags("-DUSE_GDI");
-	new_object("src/backend/gdi.c");
-	add_libs("-lgdi32");
+    $gl_libs = "-lGL -lGLU";
+}
+elsif ($backend eq "gdi") {
+    add_cflags("-DUSE_GDI");
+    new_object("src/backend/gdi.c");
+    add_libs("-lgdi32");
 
-	$gl_libs = "-lopengl32 -lglu32";
-}elsif($backend eq "darwin"){
-	add_cflags("-DUSE_DARWIN");
-	new_object("src/backend/mac/*.c");
-	add_ldflags("-framework Carbon");
+    $gl_libs = "-lopengl32 -lglu32";
+}
+elsif ($backend eq "darwin") {
+    add_cflags("-DUSE_DARWIN");
+    new_object("src/backend/mac/*.c");
+    add_ldflags("-framework Carbon");
 }
 
-if(param_get("stb-image")){
-	add_cflags("-DUSE_STB_IMAGE");
+if (param_get("stb-image")) {
+    add_cflags("-DUSE_STB_IMAGE");
 }
-if(param_get("stb-truetype")){
-	add_cflags("-DUSE_STB_TRUETYPE");
+if (param_get("stb-truetype")) {
+    add_cflags("-DUSE_STB_TRUETYPE");
 }
-if(param_get("freetype2")){
-	add_cflags("-DUSE_FREETYPE2");
-	if(not($cross)){
-		add_cflags(`pkg-config --cflags freetype2`);
-		add_libs(`pkg-config --libs freetype2`);
-	}
+if (param_get("freetype2")) {
+    add_cflags("-DUSE_FREETYPE2");
+    if (not($cross)) {
+        add_cflags(`pkg-config --cflags freetype2`);
+        add_libs(`pkg-config --libs freetype2`);
+    }
 }
-if(param_get("xrender")){
-	add_cflags("-DUSE_XRENDER");
+if (param_get("xrender")) {
+    add_cflags("-DUSE_XRENDER");
 }
 
 new_object("src/icon/*.c");
@@ -57,11 +59,12 @@ new_object("src/widget/scrollbar.c");
 new_object("src/widget/submenu.c");
 new_object("src/widget/viewport.c");
 new_object("src/widget/window.c");
-if(param_get("opengl")){
-	new_object("src/widget/opengl.c");
+
+if (param_get("opengl")) {
+    new_object("src/widget/opengl.c");
 }
-if(param_get("vulkan")){
-	new_object("src/widget/vulkan.c");
+if (param_get("vulkan")) {
+    new_object("src/widget/vulkan.c");
 }
 
 new_object("src/dialog/*.c");
@@ -70,7 +73,6 @@ new_object("src/abstract/*.c");
 
 new_object("external/*.c");
 
-
 new_example("examples/basic/example");
 new_example("examples/basic/rotate");
 new_example("examples/basic/image");
@@ -83,17 +85,17 @@ new_example("examples/basic/listbox");
 new_example("examples/basic/progressbar");
 new_example("examples/basic/colorpicker");
 
-if(param_get("opengl")){
-	new_example("examples/gldemos/boing", $gl_libs);
-	new_example("examples/gldemos/clock", $gl_libs);
-	new_example("examples/gldemos/cube", $gl_libs);
-	new_example("examples/gldemos/gears", $gl_libs);
-	new_example("examples/gldemos/triangle", $gl_libs);
-	new_example("examples/gldemos/tripaint", $gl_libs);
+if (param_get("opengl")) {
+    new_example("examples/gldemos/boing",    $gl_libs);
+    new_example("examples/gldemos/clock",    $gl_libs);
+    new_example("examples/gldemos/cube",     $gl_libs);
+    new_example("examples/gldemos/gears",    $gl_libs);
+    new_example("examples/gldemos/triangle", $gl_libs);
+    new_example("examples/gldemos/tripaint", $gl_libs);
 }
 
-if(param_get("vulkan")){
-	new_example("examples/vkdemos/vulkan");
+if (param_get("vulkan")) {
+    new_example("examples/vkdemos/vulkan");
 }
 
 1;
diff --git a/pl/utils.pl b/pl/utils.pl
index a5bf654..236d544 100644
--- a/pl/utils.pl
+++ b/pl/utils.pl
@@ -1,73 +1,75 @@
 # $Id$
 sub add_incdir {
-	my $input = $_[0];
-	$input =~ s/\r?\n/ /g;
+    my $input = $_[0];
+    $input =~ s/\r?\n/ /g;
 
-	$incdir = "${incdir} ${input}";
+    $incdir = "${incdir} ${input}";
 }
 
 sub add_cflags {
-	my $input = $_[0];
-	$input =~ s/\r?\n/ /g;
+    my $input = $_[0];
+    $input =~ s/\r?\n/ /g;
 
-	$cflags = "${cflags} ${input}";
+    $cflags = "${cflags} ${input}";
 }
 
 sub add_libdir {
-	my $input = $_[0];
-	$input =~ s/\r?\n/ /g;
+    my $input = $_[0];
+    $input =~ s/\r?\n/ /g;
 
-	$libdir = "${libdir} ${input}";
+    $libdir = "${libdir} ${input}";
 }
 
 sub add_ldflags {
-	my $input = $_[0];
-	$input =~ s/\r?\n/ /g;
+    my $input = $_[0];
+    $input =~ s/\r?\n/ /g;
 
-	$ldflags = "${ldflags} ${input}";
+    $ldflags = "${ldflags} ${input}";
 }
 
 sub add_libs {
-	my $input = $_[0];
-	$input =~ s/\r?\n/ /g;
+    my $input = $_[0];
+    $input =~ s/\r?\n/ /g;
 
-	$libs = "${libs} ${input}";
+    $libs = "${libs} ${input}";
 }
 
 sub new_example {
-	if(@_ == 2){
-		$examples_libs{"$_[0]${executable_suffix}"} = $_[1];
-	}
-	push(@examples_targets, "${_[0]}${executable_suffix}");
+    if (@_ == 2) {
+        $examples_libs{"$_[0]${executable_suffix}"} = $_[1];
+    }
+    push(@examples_targets, "${_[0]}${executable_suffix}");
 }
 
 sub new_object {
-	my @l = glob($_[0]);
-	foreach my $e (@l){
-		$e =~ s/\.c$/$object_suffix/;
-		push(@library_targets, $e);
-	}
+    my @l = glob($_[0]);
+    foreach my $e (@l) {
+        $e =~ s/\.c$/$object_suffix/;
+        push(@library_targets, $e);
+    }
 }
 
 sub use_backend {
-	$backend = $_[0];
+    $backend = $_[0];
 }
 
 our %params = ();
+
 sub param_set {
-	$params{$_[0]} = $_[1];
+    $params{ $_[0] } = $_[1];
 }
 
 sub param_get {
-	if(not(defined($params{$_[0]}))){
-		return 0;
-	}else{
-		return $params{$_[0]};
-	}
+    if (not(defined($params{ $_[0] }))) {
+        return 0;
+    }
+    else {
+        return $params{ $_[0] };
+    }
 }
 
 sub param_list {
-	return sort(keys(%params));
+    return sort(keys(%params));
 }
 
 1;