Momentum-Apps/util.c

#include "util.h"

void set_note(TrackerSongPatternStep* step, uint8_t note)
{
	step->note &= 0x80;
	step->note |= (note & 0x7f);
}

void set_instrument(TrackerSongPatternStep* step, uint8_t inst)
{
	step->note &= 0x7f;
	step->inst_vol &= 0x0f;

	step->note |= ((inst & 0x10) << 3);
	step->inst_vol |= ((inst & 0xf) << 4);
}

void set_volume(TrackerSongPatternStep* step, uint8_t vol)
{
	step->command &= 0x7fff;
	step->inst_vol &= 0xf0;

	step->command |= ((vol & 0x10) << 11);
	step->inst_vol |= (vol & 0xf);
}

void set_command(TrackerSongPatternStep* step, uint16_t command)
{
	step->command &= 0x8000;
	step->command |= command & (0x7fff);
}

void play_song(FlizzerTrackerApp* tracker, bool from_cursor)
{
	tracker->tracker_engine.playing = true;
	tracker->was_editing = tracker->editing;
	tracker->editing = false;

	if(!(from_cursor))
	{
		tracker->tracker_engine.pattern_position = 0;
	}

	play();
}

void stop_song(FlizzerTrackerApp* tracker)
{
	tracker->tracker_engine.playing = false;
	tracker->editing = tracker->was_editing;
	stop();
}

bool is_pattern_empty(TrackerSong* song, uint8_t pattern)
{
	TrackerSongPattern song_pattern = song->pattern[pattern];

	for(int i = 0; i < song->pattern_length; i++)
	{
		TrackerSongPatternStep* step = &song_pattern.step[i];

		if(tracker_engine_get_note(step) != MUS_NOTE_NONE ||
		tracker_engine_get_instrument(step) != MUS_NOTE_INSTRUMENT_NONE ||
		tracker_engine_get_volume(step) != MUS_NOTE_VOLUME_NONE ||
		tracker_engine_get_command(step) != 0)
		{
			return false;
		}
	}

	return true;
}

void set_empty_pattern(TrackerSong* song, uint8_t pattern)
{
	TrackerSongPattern song_pattern = song->pattern[pattern];

	for(int i = 0; i < song->pattern_length; i++)
	{
		TrackerSongPatternStep* step = &song_pattern.step[i];

		set_note(step, MUS_NOTE_NONE);
		set_instrument(step, MUS_NOTE_INSTRUMENT_NONE);
		set_volume(step, MUS_NOTE_VOLUME_NONE);
		set_command(step, 0);
	}
}

bool check_and_allocate_pattern(TrackerSong* song, uint8_t pattern)
{
	if(pattern < song->num_patterns) //we can set this pattern since it already exists
	{
		return true;
	}

	else
	{
		if(song->pattern[pattern - 1].step == NULL) return false; //if we hop through several patterns (e.g. editing upper digit)

		if(!(is_pattern_empty(song, pattern - 1))) //don't let the user flood the song with empty patterns
		{
			song->pattern[pattern].step = malloc(sizeof(TrackerSongPatternStep) * song->pattern_length);
			set_empty_pattern(song, pattern);
			song->num_patterns++;
			return true;
		}

		else
		{
			return false;
		}
	}
}