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-rw-r--r--engines/agos/midiparser_s1d.cpp207
1 files changed, 97 insertions, 110 deletions
diff --git a/engines/agos/midiparser_s1d.cpp b/engines/agos/midiparser_s1d.cpp
index 01690247f0..9ca87436fc 100644
--- a/engines/agos/midiparser_s1d.cpp
+++ b/engines/agos/midiparser_s1d.cpp
@@ -31,20 +31,22 @@ namespace AGOS {
/**
* Simon 1 Demo version of MidiParser.
- *
- * This parser is the result of eyeballing the one MUS file that's included
- * with simon1demo. So there might be some things missing. I've tried to notate
- * question-mark areas where they occur.
*/
class MidiParser_S1D : public MidiParser {
-protected:
+private:
byte *_data;
bool _no_delta;
+ struct Loop {
+ uint16 timer;
+ byte *start, *end;
+ } _loops[16];
+
+ uint32 readVLQ2(byte *&data);
+ void chainEvent(EventInfo &info);
protected:
void parseNextEvent(EventInfo &info);
void resetTracking();
- uint32 readVLQ2(byte * &data);
public:
MidiParser_S1D() : _data(0), _no_delta(false) {}
@@ -52,145 +54,128 @@ public:
bool loadMusic(byte *data, uint32 size);
};
+uint32 MidiParser_S1D::readVLQ2(byte *&data) {
+ uint32 delta = 0;
-// The VLQs for simon1demo seem to be
-// in Little Endian format.
-uint32 MidiParser_S1D::readVLQ2(byte * &data) {
- byte str;
- uint32 value = 0;
- int i;
-
- for (i = 0; i < 4; ++i) {
- str = data[0];
- ++data;
- value |= (str & 0x7F) << (i * 7);
- if (!(str & 0x80))
- break;
+ // LE format VLQ, which is 2 bytes long at max.
+ delta = *data++;
+ if (delta & 0x80) {
+ delta &= 0x7F;
+ delta |= *data++ << 7;
}
- return value;
+
+ return delta;
+}
+
+void MidiParser_S1D::chainEvent(EventInfo &info) {
+ // When we chain an event, we add up the old delta.
+ uint32 delta = info.delta;
+ parseNextEvent(info);
+ info.delta += delta;
}
void MidiParser_S1D::parseNextEvent(EventInfo &info) {
info.start = _position._play_pos;
+ info.length = 0;
info.delta = _no_delta ? 0 : readVLQ2(_position._play_pos);
-
_no_delta = false;
- info.event = *(_position._play_pos++);
- if (info.command() < 0x8) {
+
+ info.event = *_position._play_pos++;
+ if (!(info.event & 0x80)) {
_no_delta = true;
- info.event += 0x80;
+ info.event |= 0x80;
}
- switch (info.command()) {
- case 0x8:
- info.basic.param1 = *(_position._play_pos++);
- info.basic.param2 = 0;
- info.length = 0;
- break;
-
- case 0x9:
- info.basic.param1 = *(_position._play_pos++);
- info.basic.param2 = *(_position._play_pos++); // I'm ASSUMING this byte is velocity!
- info.length = 0;
- break;
-
- case 0xA:
- case 0xB:
- // I'm not sure what these are meant to do, or what the
- // parameter is. Elvira 1 needs them, though, and who am I to
- // argue with her?
- info.basic.param1 = *(_position._play_pos++);
- info.basic.param2 = 0;
- break;
-
- case 0xC:
- info.basic.param1 = *(_position._play_pos++);
- info.basic.param2 = 0;
- ++_position._play_pos; // I have NO IDEA what the second byte is for.
- break;
-
- case 0xD:
- // Triggered by MOD0/MOD1/MOD2/MOD3/MOD4/MOD6/MOD7/MOD8/MOD9 in Elvira 2
- // Triggered by MOD0/MOD2/MOD3/MOD5/MOD6/MOD7/MOD8/MOD9/MOD10/MOD12/MOD14/MOD15/MOD20 in Waxworks
- break;
-
- case 0xE:
- // Triggered by MOD9 in Elvira 1
- // Triggered by MOD3/MOD5 in Elvira 2
- // Triggered by MOD3/MOD7/MOD8/MOD13 in Waxworks
- break;
-
- case 0xF:
- switch (info.event & 0x0F) {
- case 0x0:
- // Trigged by MOD2/MOD6/MOD15 in Waxworks
- // Pure guesswork
- info.ext.type = *(_position._play_pos++);
- info.length = readVLQ(_position._play_pos);
- info.ext.data = _position._play_pos;
- break;
-
- case 0x3: // Not sure, Song Select?
- // Trigged by MOD1/MOD7/MOD10 in Elvira 1
- info.basic.param1 = *(_position._play_pos++);
+ if (info.event == 0xFC) {
+ // This means End of Track.
+ // Rewrite in SMF (MIDI transmission) form.
+ info.event = 0xFF;
+ info.ext.type = 0x2F;
+ } else {
+ switch (info.command()) {
+ case 0x8: // note off
+ info.basic.param1 = *_position._play_pos++;
info.basic.param2 = 0;
break;
- case 0x4:
- // Trigged by MOD8 in Elvira 1
- break;
-
- case 0x7:
- // Trigged by MOD6 in Elvira 2
- // Trigged by MOD5 in Waxworks
+ case 0x9: // note on
+ info.basic.param1 = *_position._play_pos++;
+ info.basic.param2 = *_position._play_pos++;
break;
- case 0x8: // Not sure, ?
- // Trigged by MOD19 in Waxworks
- info.basic.param1 = info.basic.param2 = 0;
+ case 0xA: { // loop control
+ // In case the stop mode(?) is set to 0x80 this will stop the
+ // track over here.
+
+ const int16 loopIterations = int8(*_position._play_pos++);
+ if (!loopIterations) {
+ _loops[info.channel()].start = _position._play_pos;
+ } else {
+ if (!_loops[info.channel()].timer) {
+ if (_loops[info.channel()].start) {
+ _loops[info.channel()].timer = uint16(loopIterations);
+ _loops[info.channel()].end = _position._play_pos;
+
+ // Go to the start of the loop
+ _position._play_pos = _loops[info.channel()].start;
+ }
+ } else {
+ if (_loops[info.channel()].timer)
+ _position._play_pos = _loops[info.channel()].start;
+ --_loops[info.channel()].timer;
+ }
+ }
+
+ // We need to read the next midi event here. Since we can not
+ // safely pass this event to the MIDI event processing.
+ chainEvent(info);
+ } break;
+
+ case 0xB: // auto stop marker(?)
+ // In case the stop mode(?) is set to 0x80 this will stop the
+ // track.
+
+ // We need to read the next midi event here. Since we can not
+ // safely pass this event to the MIDI event processing.
+ chainEvent(info);
break;
- case 0xA:
- // Trigged by MOD5 in Elvira 2
+ case 0xC: // program change
+ info.basic.param1 = *_position._play_pos++;
+ info.basic.param2 = 0;
break;
- case 0xC:
- // This means End of Track.
- // Rewrite in SMF (MIDI transmission) form.
- info.event = 0xFF;
- info.ext.type = 0x2F;
- info.length = 0;
- break;
+ case 0xD: // jump to loop end
+ if (_loops[info.channel()].end)
+ _position._play_pos = _loops[info.channel()].end;
- case 0xF: // Not sure, META event?
- // Trigged by MOD8/MOD9/MOD11/MOD12/MOD13 in Waxworks
- info.ext.type = *(_position._play_pos++);
- info.length = readVLQ(_position._play_pos);
- info.ext.data = _position._play_pos;
- _position._play_pos += info.length;
+ // We need to read the next midi event here. Since we can not
+ // safely pass this event to the MIDI event processing.
+ chainEvent(info);
break;
default:
- error("MidiParser_S1D: Unexpected type 0x%02X found", (int) info.event);
+ // The original called some other function from here, which seems
+ // not to be MIDI related.
+ warning("MidiParser_S1D: default case %d", info.channel());
+
+ // We need to read the next midi event here. Since we can not
+ // safely pass this event to the MIDI event processing.
+ chainEvent(info);
break;
}
- break;
- default:
- error("MidiParser_S1D: Unexpected event 0x%02X found", (int) info.command());
- break;
}
}
bool MidiParser_S1D::loadMusic(byte *data, uint32 size) {
unloadMusic();
+ // The original actually just ignores the first two bytes.
byte *pos = data;
if (*(pos++) != 0xFC)
debug(1, "Expected 0xFC header but found 0x%02X instead", (int) *pos);
- // The next 3 bytes MIGHT be tempo, but we skip them and use the default.
-// setTempo (*(pos++) | (*(pos++) << 8) | (*(pos++) << 16));
- pos += 3;
+ pos += 1;
// And now we're at the actual data. Only one track.
_num_tracks = 1;
@@ -208,7 +193,9 @@ bool MidiParser_S1D::loadMusic(byte *data, uint32 size) {
void MidiParser_S1D::resetTracking() {
MidiParser::resetTracking();
- _no_delta = false;
+ // The first event never contains any delta.
+ _no_delta = true;
+ memset(_loops, 0, sizeof(_loops));
}
MidiParser *MidiParser_createS1D() { return new MidiParser_S1D; }
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-23 14:01:04 +0000