pcsound: Extend frequency table to 128 entries.

Extend from 96 to the full 128 entries found in the frequency table in
the Vanilla .exes. This was helpfully posted by Gez to the Doom wiki:

  http://doomwiki.org/wiki/Talk:PC_speaker_sound_effects

Change from the current scheme of storing frequency values to using
the timer divisor values used by the Vanilla .exes; divide into the PC
timer frequency to calculate the frequencies to play.

Thanks to Gez for dumping the full list of frequencies; this fixes #336.

1 files changed, 23 insertions, 15 deletions

diff --git a/src/i_pcsound.c b/src/i_pcsound.c
index 907aeb54..655f5a8b 100644
--- a/src/i_pcsound.c
+++ b/src/i_pcsound.c
@@ -36,6 +36,8 @@
 
 #include "pcsound.h"
 
+#define TIMER_FREQ 1193181 /* hz */
+
 static boolean pcs_initialized = false;
 
 static SDL_mutex *sound_lock;
@@ -47,18 +49,24 @@ static unsigned int current_sound_remaining = 0;
 static int current_sound_handle = 0;
 static int current_sound_lump_num = -1;
 
-static const float frequencies[] = {
-    0.0f, 175.00f, 180.02f, 185.01f, 190.02f, 196.02f, 202.02f, 208.01f, 214.02f, 220.02f,
-    226.02f, 233.04f, 240.02f, 247.03f, 254.03f, 262.00f, 269.03f, 277.03f, 285.04f,
-    294.03f, 302.07f, 311.04f, 320.05f, 330.06f, 339.06f, 349.08f, 359.06f, 370.09f,
-    381.08f, 392.10f, 403.10f, 415.01f, 427.05f, 440.12f, 453.16f, 466.08f, 480.15f,
-    494.07f, 508.16f, 523.09f, 539.16f, 554.19f, 571.17f, 587.19f, 604.14f, 622.09f,
-    640.11f, 659.21f, 679.10f, 698.17f, 719.21f, 740.18f, 762.41f, 784.47f, 807.29f,
-    831.48f, 855.32f, 880.57f, 906.67f, 932.17f, 960.69f, 988.55f, 1017.20f, 1046.64f,
-    1077.85f, 1109.93f, 1141.79f, 1175.54f, 1210.12f, 1244.19f, 1281.61f, 1318.43f,
-    1357.42f, 1397.16f, 1439.30f, 1480.37f, 1523.85f, 1569.97f, 1614.58f, 1661.81f,
-    1711.87f, 1762.45f, 1813.34f, 1864.34f, 1921.38f, 1975.46f, 2036.14f, 2093.29f,
-    2157.64f, 2217.80f, 2285.78f, 2353.41f, 2420.24f, 2490.98f, 2565.97f, 2639.77f,
+static const uint16_t divisors[] = {
+    0,
+    6818, 6628, 6449, 6279, 6087, 5906, 5736, 5575,
+    5423, 5279, 5120, 4971, 4830, 4697, 4554, 4435,
+    4307, 4186, 4058, 3950, 3836, 3728, 3615, 3519,
+    3418, 3323, 3224, 3131, 3043, 2960, 2875, 2794,
+    2711, 2633, 2560, 2485, 2415, 2348, 2281, 2213,
+    2153, 2089, 2032, 1975, 1918, 1864, 1810, 1757,
+    1709, 1659, 1612, 1565, 1521, 1478, 1435, 1395,
+    1355, 1316, 1280, 1242, 1207, 1173, 1140, 1107,
+    1075, 1045, 1015,  986,  959,  931,  905,  879,
+     854,  829,  806,  783,  760,  739,  718,  697,
+     677,  658,  640,  621,  604,  586,  570,  553,
+     538,  522,  507,  493,  479,  465,  452,  439,
+     427,  415,  403,  391,  380,  369,  359,  348,
+     339,  329,  319,  310,  302,  293,  285,  276,
+     269,  261,  253,  246,  239,  232,  226,  219,
+     213,  207,  201,  195,  190,  184,  179,
 };
 
 static void PCSCallbackFunc(int *duration, int *freq)
@@ -72,7 +80,7 @@ static void PCSCallbackFunc(int *duration, int *freq)
         *freq = 0;
         return;
     }
-    
+
     if (current_sound_lump != NULL && current_sound_remaining > 0)
     {
         // Read the next tone
@@ -83,9 +91,9 @@ static void PCSCallbackFunc(int *duration, int *freq)
         // for a full discussion of this.
         // Check we don't overflow the frequency table.
 
-        if (tone < arrlen(frequencies))
+        if (tone < arrlen(divisors) && divisors[tone] != 0)
         {
-            *freq = (int) frequencies[tone];
+            *freq = (int) (TIMER_FREQ / divisors[tone]);
         }
         else
         {