Add timing functions.

Artefact2 · Oct 24, 2014 · c9b5bba · c9b5bba
1 parent b95ae54
commit c9b5bba
Show file tree

Hide file tree

Showing 5 changed files with 82 additions and 10 deletions.
diff --git a/README.md b/README.md
@@ -3,7 +3,7 @@ libxm
 
 A small XM (FastTracker II Extended Module) player library. Designed
 for easy integration in demos and such, and provides timing functions
-for easy sync (well, not yet, but it's planned).
+for easy sync against specific instruments, samples or channels.
 
 Written in C11 and released under the WTFPL license, version 2.
 

diff --git a/include/xm.h b/include/xm.h
@@ -63,19 +63,30 @@ const char* xm_get_tracker_name(xm_context_t*);
 
 
 
+/** Get the number of channels. */
+uint16_t xm_get_number_of_channels(xm_context_t*);
+
 /** Get the module length (in patterns). */
 uint16_t xm_get_module_length(xm_context_t*);
 
 /** Get the number of patterns. */
 uint16_t xm_get_number_of_patterns(xm_context_t*);
 
-/** Get the number of rows of a pattern. */
+/** Get the number of rows of a pattern.
+ *
+ * @note Pattern numbers go from 0 to
+ * xm_get_number_of_patterns(...)-1.
+ */
 uint16_t xm_get_number_of_rows(xm_context_t*, uint16_t);
 
 /** Get the number of instruments. */
 uint16_t xm_get_number_of_instruments(xm_context_t*);
 
-/** Get the number of samples of an instrument. */
+/** Get the number of samples of an instrument.
+ *
+ * @note Instrument numbers go from 1 to
+ * xm_get_number_of_instruments(...).
+ */
 uint16_t xm_get_number_of_samples(xm_context_t*, uint16_t);
 
 
@@ -89,13 +100,43 @@ void xm_get_playing_speed(xm_context_t*, uint16_t* bpm, uint16_t* tempo);
 
 /** Get the current position in the module being played.
  *
- * @param pattern_index will receive the current pattern index in the
- * POT (pattern order table)
- * @param pattern will receive the current pattern number
- * @param row will receive the current row
- * @param samples will receive the total number of generated samples
- * (divide by sample rate to get seconds of generated audio)
+ * @param pattern_index if not NULL, will receive the current pattern
+ * index in the POT (pattern order table)
+ * 
+ * @param pattern if not NULL, will receive the current pattern number
+ * 
+ * @param row if not NULL, will receive the current row
+ * 
+ * @param samples if not NULL, will receive the total number of
+ * generated samples (divide by sample rate to get seconds of
+ * generated audio)
  */
 void xm_get_position(xm_context_t*, uint8_t* pattern_index, uint8_t* pattern, uint8_t* row, uint64_t* samples);
 
+/** Get the latest time (in number of generated samples) when a
+ * particular instrument was triggered in any channel.
+ *
+ * @note Instrument numbers go from 1 to
+ * xm_get_number_of_instruments(...).
+ */
+uint64_t xm_get_latest_trigger_of_instrument(xm_context_t*, uint16_t);
+
+/** Get the latest time (in number of generated samples) when a
+ * particular sample was triggered in any channel.
+ *
+ * @note Instrument numbers go from 1 to
+ * xm_get_number_of_instruments(...).
+ *
+ * @note Sample numbers go from 0 to
+ * xm_get_nubmer_of_samples(...,instr)-1.
+ */
+uint64_t xm_get_latest_trigger_of_sample(xm_context_t*, uint16_t instr, uint16_t sample);
+
+/** Get the latest time (in number of generated samples) when any
+ * instrument was triggered in a given channel.
+ *
+ * @note Channel numbers go from 1 to xm_get_number_of_channels(...).
+ */
+uint64_t xm_get_latest_trigger_of_channel(xm_context_t*, uint16_t);
+
 #endif
diff --git a/src/context.c b/src/context.c
@@ -86,6 +86,12 @@ const char* xm_get_tracker_name(xm_context_t* ctx) {
 	return ctx->module.trackername;
 }
 
+
+
+uint16_t xm_get_number_of_channels(xm_context_t* ctx) {
+	return ctx->module.num_channels;
+}
+
 uint16_t xm_get_module_length(xm_context_t* ctx) {
 	return ctx->module.length;
 }
@@ -103,9 +109,11 @@ uint16_t xm_get_number_of_instruments(xm_context_t* ctx) {
 }
 
 uint16_t xm_get_number_of_samples(xm_context_t* ctx, uint16_t instrument) {
-	return ctx->module.instruments[instrument].num_samples;
+	return ctx->module.instruments[instrument - 1].num_samples;
 }
 
+
+
 void xm_get_playing_speed(xm_context_t* ctx, uint16_t* bpm, uint16_t* tempo) {
 	if(bpm) *bpm = ctx->bpm;
 	if(tempo) *tempo = ctx->tempo;
@@ -117,3 +125,15 @@ void xm_get_position(xm_context_t* ctx, uint8_t* pattern_index, uint8_t* pattern
 	if(row) *row = ctx->current_row;
 	if(samples) *samples = ctx->generated_samples;
 }
+
+uint64_t xm_get_latest_trigger_of_instrument(xm_context_t* ctx, uint16_t instr) {
+	return ctx->module.instruments[instr - 1].latest_trigger;
+}
+
+uint64_t xm_get_latest_trigger_of_sample(xm_context_t* ctx, uint16_t instr, uint16_t sample) {
+	return ctx->module.instruments[instr - 1].samples[sample].latest_trigger;
+}
+
+uint64_t xm_get_latest_trigger_of_channel(xm_context_t* ctx, uint16_t chn) {
+	return ctx->channels[chn - 1].latest_trigger;
+}
diff --git a/src/play.c b/src/play.c
@@ -793,6 +793,14 @@ static void xm_trigger_note(xm_context_t* ctx, xm_channel_context_t* ch, unsigne
 		ch->period = xm_period(ctx, ch->note);
 		xm_update_frequency(ctx, ch);
 	}
+
+	ch->latest_trigger = ctx->generated_samples;
+	if(ch->instrument != NULL) {
+		ch->instrument->latest_trigger = ctx->generated_samples;
+	}
+	if(ch->sample != NULL) {
+		ch->sample->latest_trigger = ctx->generated_samples;
+	}
 }
 
 static void xm_cut_note(xm_channel_context_t* ch) {

diff --git a/src/xm_internal.h b/src/xm_internal.h
@@ -95,6 +95,7 @@ struct xm_sample_s {
 	xm_loop_type_t loop_type;
 	float panning;
 	int8_t relative_note;
+	uint64_t latest_trigger;
 
 	float* data;
  };
@@ -111,6 +112,7 @@ struct xm_sample_s {
 	 uint8_t vibrato_depth;
 	 uint8_t vibrato_rate;
 	 uint16_t volume_fadeout;
+	 uint64_t latest_trigger;
 
 	 xm_sample_t* samples;
  };
@@ -208,6 +210,7 @@ struct xm_sample_s {
 
 	 unsigned long frame_count;
 	 float end_of_previous_sample[XM_SAMPLE_RAMPING_POINTS];
+	 uint64_t latest_trigger;
 
 	 float actual_panning;
 	 float target_panning;