[Scummvm-cvs-logs] CVS: scummvm/scumm player_v2.cpp,2.9,2.10

[Jochen Hoenicke]

Update of /cvsroot/scummvm/scummvm/scumm
In directory sc8-pr-cvs1:/tmp/cvs-serv32416

Modified Files:
	player_v2.cpp 
Log Message:
Synchronize channels playing the same frequency.  This prevents
interference effects.


Index: player_v2.cpp
===================================================================
RCS file: /cvsroot/scummvm/scummvm/scumm/player_v2.cpp,v
retrieving revision 2.9
retrieving revision 2.10
diff -u -d -r2.9 -r2.10
--- player_v2.cpp	1 Jun 2003 17:27:20 -0000	2.9
+++ player_v2.cpp	5 Jun 2003 08:45:24 -0000	2.10
@@ -35,7 +35,6 @@
 #define FB_WNOISE 0x12000       /* feedback for white noise */
 #define FB_PNOISE 0x08000       /* feedback for periodic noise */
 
-
 const uint8 note_lengths[] = {
 	0,  
 	0,  0,  2,
@@ -884,11 +883,31 @@
 }
 
 void Player_V2::generatePCjrSamples(int16 *data, int len) {
-	int i;
+	int i, j;
 	int freq, vol;
 
 	memset(data, 0, sizeof(int16) * len);
 	bool hasdata = false;
+
+	for (i = 1; i < 3; i++) {
+		freq = channels[i].d.freq >> 6;
+		if (channels[i].d.volume && channels[i].d.time_left) {
+			for (j = 0; j < i; j++) {
+				if (channels[j].d.volume
+				    && channels[j].d.time_left
+				    && freq == (channels[j].d.freq >> 6)) {
+					/* HACK: this channel is playing at
+					 * the same frequency as another.
+					 * Synchronize it to the same phase to
+					 * prevent interference. 
+					 */
+					_timer_count[i] = _timer_count[j];
+					_timer_output ^= (1 << i) &
+						(_timer_output ^ _timer_output << (i - j));
+				}
+			}
+		}
+	}
 
 	for (i = 0; i < 4; i++) {
 		freq = channels[i].d.freq >> 6;