1 files changed, 37 insertions, 40 deletions

diff --git a/apps/gui/pitchscreen.c b/apps/gui/pitchscreen.c
index a699d4a7b4..2d0412d822 100644
--- a/apps/gui/pitchscreen.c
+++ b/apps/gui/pitchscreen.c
@@ -80,43 +80,44 @@ enum
 
    All that math in each entry simply converts the float constant
    to an integer equal to PITCH_SPEED_PRECISION times the float value,
-   with as little precision loss as possible.
+   with as little precision loss as possible (i.e. correctly rounding
+   the last digit).
 */
-#define SEMITONE_VALUE(x) \
-    ( (int)(((x) + 0.5 / PITCH_SPEED_PRECISION) * PITCH_SPEED_PRECISION) )
+#define TO_INT_WITH_PRECISION(x) \
+    ( (int)(((x) * PITCH_SPEED_PRECISION * 10 + 5) / 10) )
     
 static const int semitone_table[] =
 {
-    SEMITONE_VALUE(50),
-    SEMITONE_VALUE(52.97315472),
-    SEMITONE_VALUE(56.12310242),
-    SEMITONE_VALUE(59.46035575),
-    SEMITONE_VALUE(62.99605249),
-    SEMITONE_VALUE(66.74199271),
-    SEMITONE_VALUE(70.71067812),
-    SEMITONE_VALUE(74.91535384),
-    SEMITONE_VALUE(79.3700526 ),
-    SEMITONE_VALUE(84.08964153),
-    SEMITONE_VALUE(89.08987181),
-    SEMITONE_VALUE(94.38743127),
-    SEMITONE_VALUE(100        ),
-    SEMITONE_VALUE(105.9463094),
-    SEMITONE_VALUE(112.2462048),
-    SEMITONE_VALUE(118.9207115),
-    SEMITONE_VALUE(125.992105 ),
-    SEMITONE_VALUE(133.4839854),
-    SEMITONE_VALUE(141.4213562),
-    SEMITONE_VALUE(149.8307077),
-    SEMITONE_VALUE(158.7401052),
-    SEMITONE_VALUE(168.1792831),
-    SEMITONE_VALUE(178.1797436),
-    SEMITONE_VALUE(188.7748625),
-    SEMITONE_VALUE(200        )
+    TO_INT_WITH_PRECISION(50.00000000), /* Octave lower */
+    TO_INT_WITH_PRECISION(52.97315472),
+    TO_INT_WITH_PRECISION(56.12310242),
+    TO_INT_WITH_PRECISION(59.46035575),
+    TO_INT_WITH_PRECISION(62.99605249),
+    TO_INT_WITH_PRECISION(66.74199271),
+    TO_INT_WITH_PRECISION(70.71067812),
+    TO_INT_WITH_PRECISION(74.91535384),
+    TO_INT_WITH_PRECISION(79.37005260),
+    TO_INT_WITH_PRECISION(84.08964153),
+    TO_INT_WITH_PRECISION(89.08987181),
+    TO_INT_WITH_PRECISION(94.38743127),
+    TO_INT_WITH_PRECISION(100.0000000), /* Normal sound */
+    TO_INT_WITH_PRECISION(105.9463094),
+    TO_INT_WITH_PRECISION(112.2462048),
+    TO_INT_WITH_PRECISION(118.9207115),
+    TO_INT_WITH_PRECISION(125.9921049),
+    TO_INT_WITH_PRECISION(133.4839854),
+    TO_INT_WITH_PRECISION(141.4213562),
+    TO_INT_WITH_PRECISION(149.8307077),
+    TO_INT_WITH_PRECISION(158.7401052),
+    TO_INT_WITH_PRECISION(168.1792831),
+    TO_INT_WITH_PRECISION(178.1797436),
+    TO_INT_WITH_PRECISION(188.7748625),
+    TO_INT_WITH_PRECISION(200.0000000)  /* Octave higher */
 };
 
 #define NUM_SEMITONES   ((int)(sizeof(semitone_table) / sizeof(int)))
-#define SEMITONE_START -12
-#define SEMITONE_END    12
+#define SEMITONE_END    (NUM_SEMITONES/2)
+#define SEMITONE_START  (-SEMITONE_END)
 
 /* A table of values for approximating the cent curve with 
    linear interpolation.  Multipy the next lowest semitone
@@ -126,19 +127,15 @@ static const int semitone_table[] =
    x(n) = 100 * 2^(n * 20/1200) 
 */
 
-#define CENT_INTERP(x) \
-    ( (int)(((x) + 0.5 / PITCH_SPEED_PRECISION) * PITCH_SPEED_PRECISION) )
-
-
 static const int cent_interp[] =
 {
-    PITCH_SPEED_100,
-    CENT_INTERP(101.1619440),
-    CENT_INTERP(102.3373892),
-    CENT_INTERP(103.5264924),
-    CENT_INTERP(104.7294123),
+    TO_INT_WITH_PRECISION(100.0000000),
+    TO_INT_WITH_PRECISION(101.1619440),
+    TO_INT_WITH_PRECISION(102.3373892),
+    TO_INT_WITH_PRECISION(103.5264924),
+    TO_INT_WITH_PRECISION(104.7294123),
     /* this one's the next semitone but we have it here for convenience */
-    CENT_INTERP(105.9463094),
+    TO_INT_WITH_PRECISION(105.9463094),
 };
 
 /* Number of cents between entries in the cent_interp table */