# HG changeset patch
# User Matti Hamalainen <ccr@tnsp.org>
# Date 1349667875 -10800
# Node ID e65fed571d7a7796d26d9861da192a1cd565857b
# Parent  585e0a95be36f00c7ee46ad025e1c29e20490e5f
Improve vibrato implementation. Might not work in Amiga periods mode, tho.

diff -r 585e0a95be36 -r e65fed571d7a jssplr.c
--- a/jssplr.c	Mon Oct 08 03:01:30 2012 +0300
+++ b/jssplr.c	Mon Oct 08 06:44:35 2012 +0300
@@ -10,8 +10,13 @@
 
 /* Miscellaneous tables
  */
-#define jmpNSineTable    (256)
-static int *jmpSineTable = NULL;
+static const Uint8 jmpSineTab[32] =
+{
+      0,  24,  49,  74,  97, 120, 141, 161,
+    180, 197, 212, 224, 235, 244, 250, 253,
+    255, 253, 250, 244, 235, 224, 212, 197,
+    180, 161, 141, 120,  97,  74,  49,  24
+};
 
 
 static const Sint16 jmpXMAmigaPeriodTab[13 * 8] = {
@@ -251,20 +256,6 @@
 {
     JSSPlayer *mp;
     
-    // Initialize global tables
-    if (jmpSineTable == NULL)
-    {
-        int i;
-        if ((jmpSineTable = dmMalloc(jmpNSineTable * sizeof(int))) == NULL)
-            JSSERROR(DMERR_MALLOC, NULL, "Could not allocate memory for sinus table.\n");
-    
-        for (i = 0; i < 256; i++)
-        {
-            float f = ((float) i * M_PI * 2.0f) / 256.0f;
-            jmpSineTable[i] = (int) (sin(f) * 2048.0f);
-        }
-    }
-
     // Allocate a player structure
     mp = dmMalloc0(sizeof(JSSPlayer));
     if (mp == NULL)
@@ -649,41 +640,37 @@
  */
 static void jmpDoTremolo(JSSPlayer * mp, JSSPlayerChannel *chn, int channel)
 {
-    int delta, pos, depth;
+    (void) channel;
     
-    // Check settings
-    if (chn->tremolo.depth == 0 || chn->tremolo.speed == 0)
-        return;
-
-    // Get position of tremolo waveform
-    pos = chn->tremolo.pos & 255;
-    depth = chn->tremolo.depth;
-
-    switch (chn->tremolo.wc & 3)
+    if (chn->tremolo.depth != 0 && chn->tremolo.speed != 0)
     {
-        case 0:    // Sine-wave
-            delta = (jmpSineTable[pos] * depth) / 2048;
-            break;
+        int delta, tmp = chn->tremolo.pos & 31;
 
-        case 1:    // Ramp down
-            delta = ((pos - 128) * depth) / 128;
-            break;
-
-        case 2:    // Square
-            delta = (((pos & 128) - 64) * depth) / 64;
-            break;
+        switch (chn->tremolo.wc & 3)
+        {
+            case 0:
+                delta = jmpSineTab[tmp];
+                break;
+            case 1:
+                tmp <<= 3;
+                delta = (chn->tremolo.pos < 0) ? 255 - tmp : tmp;
+                break;
+            case 2:
+                delta = 255;
+                break;
+            case 3:
+                delta = jmpSineTab[tmp];
+                break;
+        }
 
-        default:
-            return;
-    }
+        delta = (delta * chn->tremolo.depth) >> 6;
+
+//        jmpCSetVolume(mp, chn, channel, chn->volume + (chn->tremolo.pos >= 0 ? ), FALSE);
 
-    // Set the new volume
-    jmpCSetVolume(mp, chn, channel, chn->volume + delta, FALSE);
-
-    // Advance tremolo waveform position
-    chn->tremolo.pos += chn->tremolo.speed;
-    if (chn->tremolo.pos > 255)
-        chn->tremolo.pos = 0;
+        chn->tremolo.pos += chn->tremolo.speed;
+        if (chn->tremolo.pos > 31)
+            chn->tremolo.pos -= 64;
+    }
 }
 
 
@@ -691,41 +678,37 @@
  */
 static void jmpDoVibrato(JSSPlayer * mp, JSSPlayerChannel *chn, int channel)
 {
-    int delta, pos, depth;
+    (void) channel;
 
-    // Check settings
-    if (chn->vibrato.depth == 0 || chn->vibrato.speed == 0)
-        return;
-    
-    // Get position of vibrato waveform
-    pos = chn->vibrato.pos & 255;
-    depth = chn->vibrato.depth;
-
-    switch (chn->vibrato.wc & 3)
+    if (chn->vibrato.depth != 0 && chn->vibrato.speed != 0)
     {
-        case 0:    // Sine-wave
-            delta = (jmpSineTable[pos] * depth) / 2048;
-            break;
+        int delta, tmp = chn->vibrato.pos & 31;
 
-        case 1:    // Ramp down
-            delta = ((pos - 128) * depth) / 16;
-            break;
-
-        case 2:    // Square
-            delta = (((pos & 128) - 64) * depth) / 8;
-            break;
+        switch (chn->vibrato.wc & 3)
+        {
+            case 0:
+                delta = jmpSineTab[tmp];
+                break;
+            case 1:
+                tmp <<= 3;
+                delta = (chn->vibrato.pos < 0) ? 255 - tmp : tmp;
+                break;
+            case 2:
+                delta = 255;
+                break;
+            case 3:
+                delta = jmpSineTab[tmp];
+                break;
+        }
 
-        default:
-            return;
-    }
+        delta = ((delta * chn->vibrato.depth) >> 7) << 2;
+        chn->freq = chn->cfreq + (chn->vibrato.pos >= 0 ? delta : -delta);
+        JMPSETNDFLAGS(cdfNewFreq);
 
-    // Set the new frequency
-    jmpCSetPitch(mp, chn, chn->pitch + delta);
-
-    // Advance vibrato waveform position
-    chn->vibrato.pos += chn->vibrato.speed;
-    if (chn->vibrato.pos > 255)
-        chn->vibrato.pos = 0;
+        chn->vibrato.pos += chn->vibrato.speed;
+        if (chn->vibrato.pos > 31)
+            chn->vibrato.pos -= 64;
+    }
 }