Use perceptual volume scale for volume bars

Display volume bars using a perceptual scale instead of the
linear dB scale. This makes adjusting volume with the bar a
lot more usable on touchscreen targets.

Change-Id: I2db010486e6ba17f9d08202ee74a0b509f2cb434

2 files changed, 9 insertions, 4 deletions

diff --git a/apps/gui/skin_engine/skin_display.c b/apps/gui/skin_engine/skin_display.c
index 9cc9e8c74d..913bdcfbc4 100644
--- a/apps/gui/skin_engine/skin_display.c
+++ b/apps/gui/skin_engine/skin_display.c
@@ -185,8 +185,13 @@ void draw_progressbar(struct gui_wps *gwps, struct skin_viewport* skin_viewport,
     {
         int minvol = sound_min(SOUND_VOLUME);
         int maxvol = sound_max(SOUND_VOLUME);
-        length = maxvol-minvol;
-        end = global_settings.volume-minvol;
+#if defined(HAVE_PERCEPTUAL_VOLUME) || defined(HAVE_TOUCHSCREEN)
+        length = 1000;
+        end = to_normalized_volume(global_settings.volume, minvol, maxvol, length);
+#else
+        length = maxvol - minvol;
+        end = global_settings.volume - minvol;
+#endif
     }
     else if (pb->type == SKIN_TOKEN_BATTERY_PERCENTBAR)
     {
diff --git a/apps/gui/wps.c b/apps/gui/wps.c
index fe656034b9..d35a5ac6d2 100644
--- a/apps/gui/wps.c
+++ b/apps/gui/wps.c
@@ -182,8 +182,8 @@ static int skintouch_to_wps(void)
             const int min_vol = sound_min(SOUND_VOLUME);
             const int max_vol = sound_max(SOUND_VOLUME);
             const int step_vol = sound_steps(SOUND_VOLUME);
-            global_settings.volume = (offset * (max_vol - min_vol)) / 1000;
-            global_settings.volume += min_vol;
+
+            global_settings.volume = from_normalized_volume(offset, min_vol, max_vol, 1000);
             global_settings.volume -= (global_settings.volume % step_vol);
             setvol();
         }