CS 3005: Programming in C++

Musical Staves

Introduction

In this assignment you will add a collection of musical staff objects. (The plural of staff is staves.) In addition you will add commands to the score editor to add, edit, and display staves. The score reader and score writer classes will also be updated to fully support staves.

Syntax in the .score file for staff

This format was designed to be read using the C++ standard library’s >> operator. All values are whitespace delimited. By context, your code should be able to determine whether the next value is a std::string or a double.

There is no new syntax to the .score file format. We already added the STAFF in the previous assignment. This assignment will make it so the score reader actually keeps each staff it reads, and the score writer will write out all of the staves in the score.

Notes on the ScoreReader::readScore method

• After reading the staff object, add it to the staves collection.

Notes on the ScoreWriter::writeScore method

• After writing out all instruments, write out all staves.

Assignment

Here are the new commands that are required in the score editor program for this assignment. Previous commands are still required.

Example Session

$ ./program-score-editor/score_editor 
Choice? score-add-waveform
Waveform name: w1
Waveform type: sine
Amplitude: 1.0
Choice? score-add-envelope
Envelope name: e1
Envelope type: AD
Maximum amplitude: 1.0
Attack seconds: 0.1
Choice? score-add-instrument
Instrument name: i1
Waveform name: w1
Envelope name: e1
Choice? score-add-staff
Staff name: s1
Instrument name: i1
Choice? score-list-staves
s1 i1
Choice? score-show-staff
Staff name: s1
s1 i1

Choice? score-staff-add-note
Staff name: s1
Start: 0.5 
Duration: q
Note: C4
Choice? score-show-staff
Staff name: s1
s1 i1
0.5 0.25 C4

Choice? score-add-staff
Staff name: s2
Instrument name: i1
Choice? score-staff-add-note
Staff name: s2
Start: 0.25
Duration: h
Note: G4
Choice? score-show-staff
Staff name: s2
s2 i1
0.25 0.5 G4

Choice? score-list-staves
s1 i1
s2 i1
Choice? score-render
Filename: foo.wav
Samples per second: 1000
Bits per sample: 16
Choice? score-add-waveform
Waveform name: w2
Waveform type: square
Amplitude: 0.9
Choice? score-add-instrument
Instrument name: i2
Waveform name: w2
Envelope name: e1
Choice? score-staff-set-instrument
Staff name: s1
Instrument name: i2
Choice? score-list-staves
s1 i2
s2 i1
Choice? score-render
Filename: bar.wav
Samples per second: 1000
Bits per sample: 16
Choice? quit

Programming Requirements

Create library-score/MusicalStaves.{h,cpp}

MusicalStaves Class

This class will represent a collection of staff objects, with the key being the name of the staff and the value being the staff.

protected Data Members:

• std::map<std::string, MusicalStaff> mStaves; Map of staff names to staff objects.

public Methods:

• MusicalStaves(); Does nothing.
• virtual ~MusicalStaves(); Empty destructor.
• void addStaff(const std::string& name, const MusicalStaff& staff); Uses the name as the key and the staff as the value to store in the map.
• MusicalStaff& getStaff(const std::string& name); If name is a key, return the value associated with that key. If not, return a statically allocated MusicalStaff object. This is similar to MenuData::getAction returning a static object if the key is not valid. Except, this is more simple because we don’t do any prefix matching.
• const MusicalStaff& getStaff(const std::string& name) const; Const version of getStaff.
• unsigned int size() const; Returns the number of items in the map.
• typedef std::map<std::string, MusicalStaff>::iterator iterator; Convenience typedef for iterator.
• typedef std::map<std::string, MusicalStaff>::const_iterator const_iterator; Convenience typedef for iterator.
• iterator begin(); Returns the beginning iterator of the map.
• const_iterator begin() const; Returns the beginning iterator of the map.
• iterator end(); Returns the ending iterator of the map.
• const_iterator end() const; Returns the ending iterator of the map.

Update library-score/MusicalScore.{h,cpp}

We will add to the MusicalScore class by adding the MusicalStaves collection.

MusicalScore Class

This class will store all of the information for a piece of music.

Data Members:

• A MusicalStaves collection object for storing all staff objects that may be used in the music.

public Methods:

• MusicalScore(); Allow the MusicalStaves object to be default constructed.
• MusicalScore(const TimeSignature& time_signature, const double tempo); Allow the MusicalStaves object to be default constructed.
• void addStaff(const MusicalStaff& staff); Adds staff to the collection of staves, using the staff’s name as a key.
• MusicalStaff& getStaff(const std::string& name); Returns the staff object with the given name, from the collection.
• const MusicalStaff& getStaff(const std::string& name) const; Returns the staff object with the given name, from the collection.
• MusicalStaves& getStaves(); Returns the data member.
• const MusicalStaves& getStaves() const; Returns the data member.
• void renderStaff(const MusicalStaff& staff, const int samples_per_second, AudioTrack& track) const; Uses the MusicalStaff render method to render the staff into the audio track.
• void renderStaves(const int samples_per_second, std::map<std::string, AudioTrack>& tracks) const; Renders each staff into a track, with the renderStaff method. Store each staff in the map, with the staff name as the key.
• void renderWavChannels(const int samples_per_second, std::vector<AudioTrack>& channels) const; Uses renderStaves to render all staves into a map of staves. Then adds all of the tracks to the channels vector, in the order obtained by looping over the map.

Update library-score-io/ScoreReader.{h,cpp}

We will update the ScoreReader class by adding the ability to read store staves it reads.

ScoreReader Class

This class will eventually read all of the information for a piece of music from the .score file format.

Data Members:

No data members are required.

public Methods:

• void readScore(std::istream& input_stream, MusicalScore& score) const; When a staff is read, store it in the staves.

Update library-score-io/ScoreWriter.{h,cpp}

We will update the ScoreWrite class by adding the ability to write all staves.

ScoreWriter Class

This class will eventually write all of the information for a piece of music from the .score file format.

Data Members:

No data members are required.

public Methods:

• void writeScore(std::ostream& os, const MusicalScore& score) const; After the instruments have been written, write all staves.

Create library-score-io/WavWriter.{h,cpp}

WavWriter Class

This class will render a score and save the rendered tracks to a WAV file.

protected Data Members:

None

public Methods:

• WavWriter(); Empty constructor.
• virtual ~WavWriter(); Empty destructor.
• void writeWavFromScore(const MusicalScore& score, const int samples_per_second, const int bits_per_sample, const std::string& wav_filename) const; Uses the renderWavChannels method on the MusicalScore object to render the score into channels. Uses a temporary WAVFile object to write the channels to a file.

Update library-commands/score_editor_aux.{h,cpp}

Commands created for the score editor program will go here. We’ll make a few more in this assignment.

Functions:

• int register_score_editor_commands(ApplicationData& app_data); Update to add the new commands specified for this assignment.
• void setStaffInstrumentUI(ApplicationData& app); Change the instrument assigned to a staff in the score. See example formatting above.
• void listScoreStavesUI(ApplicationData& app); List staves in the score. See example formatting above.
• void addStaffUI(ApplicationData& app); Add a staff to the score. See example formatting above.
• void showStaffUI(ApplicationData& app); Display the details of a staff. See example formatting above.
• void addStaffNoteUI(ApplicationData& app); Add a note to a staff. See example formatting above.
• void renderScoreUI(ApplicationData& app) Render the current score to a WAV file. Gathers required information from the user. Then uses a temporary WavWriter object to write a WAV file based on the score. See example formatting above.

Additional Documentation

Grading Instructions

To receive credit for this assignment:

• your code must be pushed to your repository for this class on GitHub
• all unit tests must pass
• all acceptance tests must pass
• all programs must build, run, and execute as described in the assignment descriptions.

Extra Challenges (Not Required)

TBA

Last Updated 04/22/2025