Use uname to detect the platform

src/Makefile.am

@@ -9,6 +9,7 @@ spek_SOURCES = \
 
 INCLUDES = \
 	-include config.h \
+	-include sys/utsname.h \
 	$(SPEK_CFLAGS) \
 	$(IGE_MAC_CFLAGS) \
 	-DLOCALEDIR=\""$(localedir)"\" \
@@ -16,7 +17,7 @@ INCLUDES = \
 	-DPKGLIBDIR=\""$(pkglibdir)"\"
 
 VALAFLAGS = \
-	--vapidir=$(srcdir)/../vapi --pkg config \
+	--vapidir=$(srcdir)/../vapi --pkg config --pkg sys \
 	$(IGE_MAC_VALA) \
 	@SPEK_PACKAGES@
 

src/spek-spectrogram.vala

@@ -20,6 +20,7 @@ using Cairo;
 using Gdk;
 using Gtk;
 using Pango;
+using Sys;
 
 namespace Spek {
 	class Spectrogram : DrawingArea {
@@ -40,14 +41,14 @@ namespace Spek {
 		private const int BPAD = 40;
 		private const int GAP = 10;
 		private const int RULER = 10;
-		private const double FONT_SCALE = 
-#if MAC_INTEGRATION
-			1.5; // Pango/Quartz fonts are smaller than on X.
-#else
-			1.0;
-#endif
+		private double FONT_SCALE;
 
 		public Spectrogram () {
+			// Pango/Quartz fonts are smaller than on X.
+			var name = UtsName ();
+			uname (ref name);
+			FONT_SCALE = name.sysname == "Darwin" ? 1.5 : 1.0;
+
 			// Pre-draw the palette.
 			palette = new ImageSurface (Format.RGB24, RULER, BANDS);
 			for (int y = 0; y < BANDS; y++) {

vapi/Makefile.am

@@ -1,5 +1,6 @@
 noinst_DATA = \
-	config.vapi
+	config.vapi \
+	sys.vapi
 
 EXTRA_DIST = \
 	$(noinst_DATA)

vapi/sys.vapi

@@ -0,0 +1,14 @@
+[CCode (cheader_filename = "sys/utsname.h")]
+namespace Sys {
+	[CCode (cname = "struct utsname")]
+	public struct UtsName {
+		public weak string sysname;
+		public weak string nodename;
+		public weak string release;
+		public weak string version;
+		public weak string machine;
+		public weak string domainname;
+	}
+	[CCode (cname = "uname")]
+	public int uname (ref UtsName name);
+}