Added initial implementation of scale mode

4 files changed, 111 insertions, 67 deletions

diff --git a/src/globals.c b/src/globals.c
index a971120..23012c8 100644
--- a/src/globals.c
+++ b/src/globals.c
@@ -189,63 +189,3 @@ typedef enum Prob {
     PROB_20,
     PROB_NUM,
 } Prob;
-
-typedef enum Scales {
-    SCALE_CHRM,
-    SCALE_MAJR,
-    SCALE_MINR,
-    SCALE_PMAJ,
-    SCALE_PMIN,
-    SCALE_BLUE,
-    SCALE_DORI,
-    SCALE_PHYR,
-    SCALE_LYDI,
-    SCALE_MIXO,
-    SCALE_LOCR,
-    SCALE_PERS,
-    SCALE_HMIN,
-    SCALE_IWAT,
-    SCALE_INSN,
-    SCALE_HIRA,
-    SCALE_NUM,
-} Scales;
-
-char *scale_short[] = {
-    "CHRM",
-    "MAJR",
-    "MINR",
-    "PMAJ",
-    "PMIN",
-    "BLUE",
-    "DORI",
-    "PHYR",
-    "LYDI",
-    "MIXO",
-    "LOCR",
-    "PERS",
-    "HMIN",
-    "IWAT",
-    "INSN",
-    "HIRA",
-};
-
-char *scale_long[] = {
-    "CHROMATIC",
-    "MAJOR",
-    "MINOR",
-    "PENTATONIC MAJOR",
-    "PENTATONIC MINOR",
-    "BLUES",
-    "DORIAN",
-    "PHYRGIAN",
-    "LYDIAN",
-    "MIXOLYDIAN",
-    "LOCRIAN",
-    "PERSIAN",
-    "HUNGARIAN MINOR",
-    "IWATO",
-    "IN-SEN",
-    "HIRAJOSHI",
-};
-
-int current_scale = SCALE_CHRM;
diff --git a/src/main.c b/src/main.c
index 6bc3578..fe3dba0 100644
--- a/src/main.c
+++ b/src/main.c
@@ -49,13 +49,14 @@ WITH REGARD TO THIS SOFTWARE.
 //    that it's clear it's affecting all triggers.
 //  + Fix keyboard note drawing bugs.
 //  + Fix stop button behaviour.
+//  + Scale mode for entering notes.
+//  - Shortcut to quickly exit/enter chain mode.
+//  - Make sure bank switching is queued like patterns.
+//
 //  - Improve SRAM saving to make room for longer patterns and/or more banks.
-//  - Scale mode for entering notes.
 //  - Higher resolution clock to allow for microtiming and more accurate tempo.
 //  - Multiple pattern chains per bank that we can toggle between, gotta study
 //    if they fit in the SRAM.
-//  - Shortcut to quickly exit/enter chain mode.
-//  - Make sure bank switching is queued like patterns.
 //  - Add settings for "performance mode" in which banks are not saved by
 //    default while changing patterns.
 //  - Make sure sync works with the same cable for in/out.
@@ -72,6 +73,7 @@ WITH REGARD TO THIS SOFTWARE.
 #include "globals.c"
 #include "settings.c"
 #include "dsound.c"
+#include "scale.c"
 #include "sequencer.c"
 
 #define PROF_ENABLE 0
diff --git a/src/scale.c b/src/scale.c
new file mode 100644
index 0000000..51d46fe
--- /dev/null
+++ b/src/scale.c
@@ -0,0 +1,102 @@
+typedef enum Scales {
+    SCALE_CHRM,
+    SCALE_MAJR,
+    SCALE_MINR,
+    SCALE_PMAJ,
+    SCALE_PMIN,
+    SCALE_BLUE,
+    SCALE_DORI,
+    SCALE_PHYR,
+    SCALE_LYDI,
+    SCALE_MIXO,
+    SCALE_LOCR,
+    SCALE_PERS,
+    SCALE_HMIN,
+    SCALE_IWAT,
+    SCALE_INSN,
+    SCALE_HIRA,
+    SCALE_NUM,
+} Scales;
+
+char *scale_short[] = {
+    "CHRM",
+    "MAJR",
+    "MINR",
+    "PMAJ",
+    "PMIN",
+    "BLUE",
+    "DORI",
+    "PHYR",
+    "LYDI",
+    "MIXO",
+    "LOCR",
+    "PERS",
+    "HMIN",
+    "IWAT",
+    "INSN",
+    "HIRA",
+};
+
+char *scale_long[] = {
+    "CHROMATIC",
+    "MAJOR",
+    "MINOR",
+    "PENTATONIC MAJOR",
+    "PENTATONIC MINOR",
+    "BLUES",
+    "DORIAN",
+    "PHYRGIAN",
+    "LYDIAN",
+    "MIXOLYDIAN",
+    "LOCRIAN",
+    "PERSIAN",
+    "HUNGARIAN MINOR",
+    "IWATO",
+    "IN-SEN",
+    "HIRAJOSHI",
+};
+
+typedef u8 Scale[12];
+Scale scales[] = {
+//   1  b2 2  b3 3  4 b5  5 b6  6 b7  7   <- Major
+    {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}, // CHRM
+    {1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1}, // MAJR
+    {1, 0, 1, 1, 0, 1, 0, 1, 1, 0, 1, 0}, // MINR
+    {1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 0}, // PMAJ
+    {1, 0, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0}, // PMIN
+    {1, 0, 0, 1, 0, 1, 1, 1, 0, 0, 1, 0}, // BLUE
+    {1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 1, 0}, // DORI
+    {1, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0}, // PHYR
+    {1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1}, // LYDI
+    {1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 1, 0}, // MIXO
+    {1, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0}, // LOCR
+    {1, 1, 0, 0, 1, 1, 1, 0, 1, 0, 0, 1}, // PERS
+    {1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1}, // HMIN
+    {1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 0}, // IWAT
+    {1, 1, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0}, // INSN
+    {1, 0, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0}, // HIRA
+};
+
+int current_scale = SCALE_CHRM;
+int current_scale_root = 0;
+
+s32
+scale_note(s32 current, s32 inc) {
+    if (inc > 1 || inc < -1) {
+        return CLAMP(current + inc, (s32)NOTE_C_2, (s32)NOTE_C_8 - 1);
+    }
+    s32 pos = current % 12;
+    s32 offset = 0;
+    for (int i = 1; i <= 12; i++) {
+        s32 k = (current_scale_root + pos + i * inc) % 12;
+        if (k < 0) {
+            k *= -1;
+            k = 12 - k;
+        }
+        offset += inc;
+        if (scales[current_scale][k] == 1) {
+            break;
+        }
+    }
+    return CLAMP(current + offset, (s32)NOTE_C_2, (s32)NOTE_C_8 - 1);
+}
diff --git a/src/sequencer.c b/src/sequencer.c
index ce09658..609ccee 100644
--- a/src/sequencer.c
+++ b/src/sequencer.c
@@ -406,7 +406,7 @@ handle_channel_selection(void) {
                 case 3: { trig = &pat->ch4.notes[i]; } break;
                 default: {trig = &pat->ch1.notes[i]; } break;
             }
-            trig->note = MAX((s32)trig->note + inc, (s32)NOTE_C_2);
+            trig->note = scale_note(trig->note, inc);
         }
         redraw_trigs = true;
     } else if (key_tap(KEY_R)) {
@@ -423,7 +423,7 @@ handle_channel_selection(void) {
                 case 3: { trig = &pat->ch4.notes[i]; } break;
                 default: {trig = &pat->ch1.notes[i]; } break;
             }
-            trig->note = MIN((s32)trig->note + inc, (s32)NOTE_C_8 - 1);
+            trig->note = scale_note(trig->note, inc);
         }
         redraw_trigs = true;
     }
@@ -1292,7 +1292,7 @@ handle_trigger_selection(void) {
         }
         // Decrease note.
         if (trig->active && !empty) {
-            trig->note = MAX((s32)trig->note + inc, (s32)NOTE_C_2);
+            trig->note = scale_note(trig->note, inc);
         }
         redraw_trigs = true;
         redraw_piano_note = true;
@@ -1303,7 +1303,7 @@ handle_trigger_selection(void) {
         }
         // Increase note.
         if (trig->active && !empty) {
-            trig->note = MIN((s32)trig->note + inc, (s32)NOTE_C_8 - 1);
+            trig->note = scale_note(trig->note, inc);
         }
         redraw_trigs = true;
         redraw_piano_note = true;