logarithmic volume control

English.lproj/MainMenu.nib/classes.nib

@@ -79,6 +79,7 @@
                 playlistView = PlaylistView; 
                 positionSlider = TrackingSlider; 
                 timeField = NSTextField; 
+                volumeSlider = NSSlider; 
             }; 
             SUPERCLASS = NSObject; 
         }, 

English.lproj/MainMenu.nib/info.nib

@@ -3,7 +3,7 @@
 <plist version="1.0">
 <dict>
 	<key>IBDocumentLocation</key>
-	<string>19 350 617 240 0 0 1024 746 </string>
+	<string>-18 96 617 240 0 0 1024 746 </string>
 	<key>IBEditorPositions</key>
 	<dict>
 		<key>29</key>
@@ -28,11 +28,11 @@
 	<integer>3</integer>
 	<key>IBOpenObjects</key>
 	<array>
-		<integer>21</integer>
-		<integer>823</integer>
-		<integer>463</integer>
 		<integer>513</integer>
+		<integer>463</integer>
+		<integer>823</integer>
 		<integer>29</integer>
+		<integer>21</integer>
 	</array>
 	<key>IBSystem Version</key>
 	<string>8I127</string>

PlaybackController.h

@@ -14,6 +14,7 @@
 	IBOutlet PlaylistView *playlistView;
 	
 	IBOutlet TrackingSlider *positionSlider;
+	IBOutlet NSSlider *volumeSlider;
 	IBOutlet NSTextField *timeField;
 	IBOutlet NSTextField *lengthField;
 	IBOutlet NSTextField *bitrateField;

PlaybackController.m

@@ -23,6 +23,7 @@
 - (void)awakeFromNib
 {
 	currentVolume = 100.0;
+	[volumeSlider setDoubleValue:pow(10.0, log10(0.5)/4.0)*[volumeSlider maxValue]];
 }
 
 
@@ -157,16 +158,23 @@
 
 - (IBAction)changeVolume:(id)sender
 {
-	currentVolume = (float)[sender doubleValue];
+	float percent;
 	
-	//gravitates at the halfway mark
-	float v = ([sender frame].size.width/[sender maxValue])*(currentVolume-([sender maxValue]/2.0));
+	//Approximated log
+	percent = (float)[sender doubleValue]/[sender maxValue];
+	percent = percent * percent * percent * percent;
+
+	//gravitates at the 100% mark
+	float v = [sender frame].size.width - ([sender frame].size.width*(percent*[sender maxValue])/100.0);
 	if (fabs(v) < 10.0)
 	{
-		currentVolume = [sender maxValue]/2.0;
-		[sender setDoubleValue:currentVolume];
+		percent = 0.5;
+		v = pow(10.0, log10(percent)/4.0);
+		[sender setDoubleValue:v*[sender maxValue]];
 	}
 	
+	currentVolume = percent * [sender maxValue];
+	
 	[soundController  setVolume:currentVolume];
 }