1 files changed, 412 insertions, 0 deletions
diff --git a/comp1511/cs_beats/beats.c b/comp1511/cs_beats/beats.c
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+++ b/comp1511/cs_beats/beats.c
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+// Assignment 2 20T1 COMP1511: CS bEats
+// beats.c
+//
+// The purpose of this program is to categorise music input.
+//
+// Version 1.0.0: Assignment released.
+// Version 1.0.1: Fix default return value of add_musical_note_to_beat.
+
+#include <assert.h>
+#include <ctype.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "beats.h"
+
+struct track {
+    struct beat *head;
+    struct beat *cur;
+};
+
+struct beat {
+    struct note *notes;
+    struct beat *next;
+};
+
+struct note {
+    int oct;
+    int key;
+    struct note *next;
+};
+
+////////////////////////////////////////////////////////////////////////
+//                       User Defined Functions                       //
+////////////////////////////////////////////////////////////////////////
+
+// Returns a value representing the pitch.
+static int get_pitch(const int octave, const int key) {
+    return (octave * 12) + (key);
+}
+
+// Return a malloced beat with fields initialised.
+struct beat *create_beat() {
+    Beat new_beat = malloc(sizeof(struct beat));
+    assert(new_beat != NULL);
+
+    new_beat->next = NULL;
+    new_beat->notes = NULL;
+
+    return new_beat;
+}
+
+// Returns the tail of a note linked list.
+static struct note *get_note_tail(struct note *nhead) {
+    if (nhead == NULL) {
+        return NULL;
+    }
+    struct note *ret = nhead;
+    while (ret->next != NULL) {
+        ret = ret->next;
+    }
+    return ret;
+}
+
+// Returns the tail of a beat linked list.
+static struct beat *get_beat_tail(struct beat *bhead) {
+    if (bhead == NULL) {
+        return NULL;
+    }
+    struct beat *ret = bhead;
+    while (ret->next != NULL) {
+        ret = ret->next;
+    }
+    return ret;
+}
+
+// Returns a malloced Note with fields initialised.
+static struct note *create_note() {
+    struct note *ret = malloc(sizeof(struct note));
+    assert(ret != NULL);
+
+    ret->oct = 0;
+    ret->key = 0;
+    ret->next = NULL;
+    return ret;
+}
+
+// Inserts a note into a linked list of notes before the target note.
+static void insert_note_before(struct beat *beat, struct note *note,
+                        struct note *target) {
+    if (beat->notes == target) {
+        beat->notes = note;
+        note->next = target;
+        return;
+    }
+    for (struct note *i = beat->notes; i != NULL; i = i->next) {
+        if (i->next == target) {
+            i->next = note;
+            note->next = target;
+            return;
+        }
+    }
+}
+
+////////////////////////////////////////////////////////////////////////
+//                         Stage 1 Functions                          //
+////////////////////////////////////////////////////////////////////////
+
+// Add a note to the end of a beat.
+int add_note_to_beat(struct beat *const beat, const int oct, const int key) {
+    if (oct < 0 || oct >= 10) {
+        return INVALID_OCTAVE;
+    }
+    if (key < 0 || key >= 12) {
+        return INVALID_KEY;
+    }
+
+    struct note *ntail = get_note_tail(beat->notes);
+    if (ntail != NULL) {
+        if (get_pitch(oct, key) <= get_pitch(ntail->oct, ntail->key)) {
+            return NOT_HIGHEST_NOTE;
+        }
+    }
+    struct note *new_note = create_note();
+    new_note->oct = oct;
+    new_note->key = key;
+    new_note->next = NULL;
+
+    if (ntail == NULL) {
+        beat->notes = new_note;
+    } else {
+        ntail->next = new_note;
+    }
+    return VALID_NOTE;
+}
+
+// Print the contents of a beat.
+void print_beat(struct beat *const beat) {
+    if (beat == NULL) {
+        return;
+    }
+    if (beat->notes == NULL) {
+        printf("\n");
+        return;
+    }
+    for (struct note *i = beat->notes; i != NULL; i = i->next) {
+        printf("%d ", i->oct);
+        if (i->key >= 10) {
+            printf("%d", i->key % 12);
+        } else {
+            printf("%d%d", i->key / 12, i->key % 12);
+        }
+        if (i->next) {
+            printf(" | ");
+        }
+    }
+    printf("\n");
+}
+
+// Count the number of notes in a beat that are in a given octave.
+int count_notes_in_octave(struct beat *const beat, int oct) {
+    if (beat->notes == NULL) {
+        return 0;
+    }
+    int notes = 0;
+    for (struct note *i = beat->notes; i != NULL; i = i->next) {
+        if (i->oct == oct) {
+            ++notes;
+        }
+    }
+    return notes;
+}
+
+////////////////////////////////////////////////////////////////////////
+//                         Stage 2 Functions                          //
+////////////////////////////////////////////////////////////////////////
+
+// Return a malloced track with fields initialized.
+struct track *create_track(void) {
+    struct track *ret = malloc(sizeof(struct track));
+    ret->head = NULL;
+    ret->cur = NULL;
+    return ret;
+}
+
+// Add a beat after the current beat in a track.
+void add_beat_to_track(struct track *track, struct beat *beat) {
+    if (track->cur != NULL) { // this behaviour may be unwanted
+        if (track->cur->next != NULL) {
+            beat->next = track->cur->next;
+            track->cur->next = beat;
+        } else {
+            track->cur->next = beat;
+        }
+    } else {
+        if (track->head == NULL) {
+            track->head = beat;
+        } else {
+            beat->next = track->head;
+            track->head = beat;
+        }
+    }
+}
+
+// Set a track's current beat to the next beat.
+int select_next_beat(struct track *track) {
+    if (track->cur == NULL) {
+        if (track->head == NULL) {
+            return TRACK_STOPPED;
+        } else {
+            track->cur = track->head;
+            return TRACK_PLAYING;
+        }
+    } else {
+        if (track->cur->next == NULL) {
+            track->cur = NULL;
+            return TRACK_STOPPED;
+        } else {
+            track->cur = track->cur->next;
+            return TRACK_PLAYING;
+        }
+    }
+}
+
+// Print the contents of a track.
+void print_track(struct track *track) {
+    if (track->head == NULL) {
+        return;
+    }
+    int count = 1;
+    for (struct beat *i = track->head; i != NULL; i = i->next) {
+        if (i == track->cur) {
+            printf(">");
+        } else {
+            printf(" ");
+        }
+        printf("[%d] ", count);
+        print_beat(i);
+        ++count;
+    }
+}
+
+// Count beats after the current beat in a track.
+int count_beats_left_in_track(struct track *track) {
+    int count = 0;
+    if (track == NULL || track->head == NULL) {
+        return count;
+    }
+    struct beat *i = track->cur;
+    if (i == NULL) {
+        i = track->head;
+    }
+    for (; i != NULL; i = i->next) {
+        ++count;
+    }
+    if (track->cur) {
+        --count;
+    }
+    return count;
+}
+
+////////////////////////////////////////////////////////////////////////
+//                         Stage 3 Functions                          //
+////////////////////////////////////////////////////////////////////////
+
+// Free the memory of a beat, and any memory it points to.
+void free_beat(struct beat *beat) {
+    if (beat == NULL) {
+        return;
+    }
+    if (beat->notes != NULL) {
+        struct note *i = beat->notes;
+        struct note *forwards = i->next;
+        while (i != NULL) {
+            forwards = i->next;
+            free(i);
+            i = forwards;
+        }
+    }
+    free(beat);
+}
+
+// Free the memory of a track, and any memory it points to.
+void free_track(struct track *track) {
+    if (track == NULL) {
+        return;
+    }
+    if (track->head != NULL) {
+        struct beat *i = track->head;
+        struct beat *forwards = i->next;
+        while (i != NULL) {
+            forwards = i->next;
+            free_beat(i);
+            i = forwards;
+        }
+    }
+    free(track);
+}
+
+// Remove the currently selected beat from a track.
+int remove_selected_beat(struct track *track) {
+    if (track->cur == NULL) {
+        return TRACK_STOPPED;
+    }
+    struct beat *backwards = NULL;
+    struct beat *forwards = NULL;
+    for (struct beat *i = track->head; i != NULL; i = i->next) {
+        if (i == track->cur) {
+            track->head = i->next;
+            forwards = i->next;
+            free_beat(track->cur);
+            break;
+        } else if (i->next == track->cur) {
+            backwards = i;
+            forwards = i->next->next;
+            free_beat(track->cur);
+            backwards->next = forwards;
+            break;
+        }
+    }
+    if (forwards == NULL) {
+        track->cur = NULL;
+        return TRACK_STOPPED;
+    } else {
+        track->cur = forwards;
+        return TRACK_PLAYING;
+    }
+}
+
+////////////////////////////////////////////////////////////////////////
+//                         Stage 4 Functions                          //
+////////////////////////////////////////////////////////////////////////
+
+// Add note to beat, given its 'musical notation'.
+int add_musical_note_to_beat(Beat beat, char *string) {
+    int oct = string[0] - '0';
+    if (oct < 0 || oct > 9) {
+        return INVALID_MUSICAL_NOTE;
+    }
+    int key = 0;
+    switch (string[1]) {
+    case 'A':
+        key = 0;
+        break;
+    case 'B':
+        key = 2;
+        break;
+    case 'C':
+        key = 3;
+        break;
+    case 'D':
+        key = 5;
+        break;
+    case 'E':
+        key = 7;
+        break;
+    case 'F':
+        key = 8;
+        break;
+    case 'G':
+        key = 10;
+        break;
+    default:
+        return INVALID_MUSICAL_NOTE;
+    }
+    for (char *c = string + 2; *c != '\0'; ++c) {
+        if (*c == '#') {
+            ++key;
+        } else {
+            return INVALID_MUSICAL_NOTE;
+        }
+    }
+    int pitch = get_pitch(oct, key);
+    oct = pitch / 12;
+    key = pitch % 12;
+    struct note *tail = get_note_tail(beat->notes);
+    if (tail == NULL || get_pitch(tail->oct, tail->key) < pitch) {
+        add_note_to_beat(beat, oct, key);
+        return VALID_NOTE;
+    }
+    struct note *higher = NULL;
+    for (struct note *i = beat->notes; i != NULL; i = i->next) {
+        int iter_pitch = get_pitch(i->oct, i->key);
+        if (iter_pitch == pitch) {
+            return INVALID_MUSICAL_NOTE;
+        } else if (iter_pitch > pitch) {
+            higher = i;
+            break;
+        }
+    }
+    struct note *note = create_note();
+    note->oct = oct;
+    note->key = key;
+    insert_note_before(beat, note, higher);
+    return VALID_NOTE;
+}
+
+////////////////////////////////////////////////////////////////////////
+//                         Stage 5 Functions                          //
+////////////////////////////////////////////////////////////////////////
+
+// Cut a range of beats to the end of a track.
+void cut_range_to_end(Track track, int range_length) {
+    printf("cut_range_to_end not implemented yet.");
+    return;
+}
+
+// Reverse a list of beats within a range of a track.
+int reverse_range(Track track, int range_length) {
+    printf("reverse_range not implemented yet.");
+    return 0;
+}