Ticket #8058: cd-timer2.diff

scummvm/scumm/saveload.cpp

@@ -159 +159 @@
 
         initBGBuffers(_scrHeight);
 
+        if ((_features & GF_AUDIOTRACKS) && _vars[VAR_MI1_TIMER] > 0)
+                _sound->startCDTimer();
+
         CHECK_HEAP debug(1, "State loaded from '%s'", filename);
 
 

scummvm/scumm/scummvm.cpp

@@ -340 +340 @@
 
 int Scumm::scummLoop(int delta)
 {
-        static int counter = 0;
-
 #ifndef _WIN32_WCE
         if (_debugger)
                 _debugger->on_frame();
@@ -380 +378 @@
         _vars[VAR_MOUSE_Y] = mouse.y;
         _vars[VAR_DEBUGMODE] = _debugMode;
 
-        if (_features & GF_AUDIOTRACKS) {               
-                if (delta) {
-                        if (delta == 1) {
-                                // Better sync with the Loom CD intro
-                                _vars[VAR_MI1_TIMER]++;
-                        } else if (++counter != 2)
-                                _vars[VAR_MI1_TIMER] += 5;
-                        else {
-                                counter = 0;
-                                _vars[VAR_MI1_TIMER] += 6;
-                        }                               
-                }
+        if (_features & GF_AUDIOTRACKS) {
+                _vars[VAR_MI1_TIMER] = _sound->readCDTimer();
         } else if (_features & GF_OLD256) {
 
                 if(tempMusic == 3) {

scummvm/scumm/sound.cpp

@@ -667 +667 @@
 
         _soundsPaused = pause;
         _scumm->_mixer->pause(pause);   
+
+        if ((_scumm->_features & GF_AUDIOTRACKS) && _scumm->_vars[_scumm->VAR_MI1_TIMER] > 0) {
+                if (pause)
+                        stopCDTimer();
+                else
+                        startCDTimer();
+        }
+                
 }
 
 int Sound::startSfxSound(File *file, int file_size) {
@@ -1028 +1036 @@
         return -1;
 }
 
+// We use a real timer in an attempt to get better sync with CD tracks. This is
+// necessary for games like Loom CD.
+
+static void cd_timer_handler(void *ptr)
+{
+        Scumm *scumm = (Scumm *) ptr;
+
+        // Maybe I could simply update _vars[VAR_MI1_TIMER] directly here, but
+        // I don't feel comfortable just doing that from what might be a
+        // separate thread. If someone tells me it's safe, I'll make the
+        // change right away.
+        
+        // FIXME: Turn off the timer when it's no longer needed. In theory, it
+        // should be possible to check with pollCD(), but since CD sound isn't
+        // properly restarted when reloading a saved game, I don't dare to.
+
+        scumm->_sound->_cd_timer_value += 6;
+}
+
+int Sound::readCDTimer()
+{
+        return _cd_timer_value;
+}
+
+void Sound::startCDTimer()
+{
+        int timer_interval;
+
+        // The timer interval has been tuned for Loom CD and the Monkey 1
+        // intro. I have to use 100 for Loom, or there will be a nasty stutter
+        // when Chaos first appears, and I have to use 101 for Monkey 1 or the
+        // intro music will be cut short.
+
+        if (_scumm->_gameId == GID_LOOM256)
+                timer_interval = 100;
+        else 
+                timer_interval = 101;
+
+        _scumm->_timer->releaseProcedure(&cd_timer_handler);
+        _cd_timer_value = _scumm->_vars[_scumm->VAR_MI1_TIMER];
+        _scumm->_timer->installProcedure(&cd_timer_handler, timer_interval);
+}
+
+void Sound::stopCDTimer()
+{
+        _scumm->_timer->releaseProcedure(&cd_timer_handler);
+}
+
 void Sound::playCDTrack(int track, int num_loops, int start, int delay)
 {
 #ifdef COMPRESSED_SOUND_FILE
         if (playMP3CDTrack(track, num_loops, start, delay) == -1)
 #endif
                 _scumm->_system->play_cdrom(track, num_loops, start, delay);
+
+        // Start the timer after starting the track. Starting an MP3 track is
+        // almost instantaneous, but a CD player may take some time. Hopefully
+        // play_cdrom() will block during that delay.
+
+        startCDTimer();
 }
 
 void Sound::stopCD()
 {
+        stopCDTimer();
 #ifdef COMPRESSED_SOUND_FILE
         if (stopMP3CD() == -1)
 #endif

scummvm/scumm/sound.h

@@ -23 +23 @@
 
 #include "scummsys.h"
 #include "sound/mixer.h"
+#include "common/timer.h"
 
 class Scumm;
 class File;
@@ -88 +89 @@
 
 #endif
 
+        int _cd_timer_value;
         bool _soundsPaused;
         int16 _sound_volume_master, _sound_volume_music, _sound_volume_sfx;
         byte _sfxMode;
@@ -124 +126 @@
         int playSfxSound(void *sound, uint32 size, uint rate, bool isUnsigned);
         int playSfxSound_MP3(void *sound, uint32 size);
 
+        int readCDTimer();
+        void startCDTimer();
+        void stopCDTimer();
+
         void playCDTrack(int track, int num_loops, int start, int delay);
         void stopCD();
         int pollCD();