summaryrefslogtreecommitdiff
path: root/keyboards/ymdk/melody96/keymaps/zunger/keymap.c
blob: d0d2698b7a106af88a3493e0e22900a3e811e9af (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
/* Copyright 2019 Yonatan Zunger
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#include QMK_KEYBOARD_H
#include <assert.h>

// This keymap is designed to make it easy to type in a wide variety of languages, as well as
// generate mathematical symbols (à la Space Cadet).
//
// LAYER MAGIC (aka, typing in many alphabets)
//   This keyboard has three "base" layers: QWERTY, GREEK, and CADET. The GREEK and CADET layers
// are actually full of Unicode points, and so which point they generate depends on things like
// whether the shift key is down. To handle this, each of those layers is actually *two* layers, one
// with and one without shift. In our main loop, we manage modifier state detection, as well as
// layer switch detection, and pick the right layer on the fly.
//   Layers are selected with a combination of three keys. The "Greek" and "Cadet" keys act like
// modifiers: When held down, they transiently select the indicated base layer. The "Layer Lock" key
// locks the value of the base layer at whatever is currently held; so e.g., if you hold Greek +
// Layer Lock, you'll stay in Greek mode until you hit Layer Lock again without any of the mods
// held.
//   TODO: This system of layer selection is nice for math, but it's not very nice for actually
// typing in multiple languages. It seems like a better plan will be to reserve one key for each
// base layer -- maybe fn + F(n) -- which can either be held as a modifier or tapped to switch
// layers. That will open up adding some more languages, like Yiddish, but to do this effectively
// we'll need to find a good UI with which to show the currently selected layer. Need to check what
// the melody96 has in the way of outputs (LEDs, sound, etc).
//
// ACCENT MAGIC (aka, typing conveniently in Romance languages)
//   We want to support easy typing of diacritical marks. We can't rely on the host OS for this,
// because (e.g.) on MacOS, to make any of the other stuff work, we need to be using the Unicode
// input method at the OS level, which breaks all the normal accent stuff on that end. So we do it
// ourselves. Accents can actually be invoked in two different ways: one fast and very compatible,
// one very versatile but with occasional compatibility problems.
//
//   THE MAIN WAY: You can hit one of the "accent request" key patterns immediately *before* typing
//   a letter to be accented. It will emit the corresponding accented Unicode. For example, you can
//   hit fn-e to request an acute accent, followed by i, and it will output í, U+00ED LATIN SMALL
//   LETTER I WITH ACUTE. These "combined characters" are in Unicode normal form C (NFKC), which is
//   important because many European websites and apps, in particular, tend to behave very badly
//   (misunderstanding and/or crashing) when presented with characters in other forms! The catch is
//   that this only works for the various combinations of letters and accents found in the Latin-1
//   supplement block of Unicode -- basically, things you need for Western European languages.
//
//   (NB: If you make an accent request followed by a letter which can't take the corresponding
//   accent, it will output the uncombined form of the accent followed by whatever you typed; so
//   e.g., if you hit fn-e followed by f, it will output ´f, U+00B4 ACUTE ACCENT followed by an
//   ordinary f. This is very similar to the default behavior of MacOS.)
//
//   THE FLEXIBLE WAY: If you hit the accent request with a shift -- e.g., fn-shift-e -- it will
//   instead immediately output the corresponding *combining* Unicode accent mark, which will modify
//   the *previous* character you typed. For example, if you type i followed by fn-shift-e, it will
//   generate í. But don't be fooled by visual similarity: unlike the previous example, this one is
//   an ordinary i followed by U+0301 COMBINING ACUTE ACCENT. It's actually *two symbols*, and this
//   is Unicode normal form D (NFKD). Unlike NFKC, there are NFKD representations of far more
//   combinations of letters and accents, and it's easy to add more of these if you need. (The NFKC
//   representation of such combinations is identical to their NFKD representation)
//
//   Programs that try to compare Unicode strings *should* first normalize them by converting them
//   all into one normal form or another, and there are functions in every programming language to
//   do this -- e.g., JavaScript's string.normalize() -- but lots of programmers fail to understand
//   this, and so write code that massively freaks out when it encounters the wrong form.
//
// The current accent request codes are modeled on the ones in MacOS.
//
//    fn+`    Grave accent (`)
//    fn+e    Acute accent (´)
//    fn+i    Circumflex (^)
//    fn+u    Diaresis / umlaut / trema (¨)
//    fn+c    Cedilla (¸)
//    fn+n    Tilde (˜)
//
// Together, these functions make for a nice "polyglot" keyboard: one that can easily type in a wide
// variety of languages, which is very useful for people who, well, need to type in a bunch of
// languages.
//
// The major TODOs are:
//   - Update the layer selection logic (and add visible layer cues);
//   - Factor the code below so that the data layers are more clearly separated from the code logic,
//     so that other users of this keymap can easily add whichever alphabets they need without
//     having to deeply understand the implementation.


enum custom_keycodes {
  // We provide special layer management keys:
  //    GREEK triggers the Greek (aka "Front") layer, or the SHIFTGREEK layer when shift is held.
  //          (Because we use Unicode, we need to implement shift-handling at the firmware level,
  //          rather than the OS level like we do in the QWERTY layer)
  //    CADET or GREEK+ALT triggers the Cadet (aka "Top") layer, or the SHIFTCADET layer when
  //          shift is held.
  //    LAYER_LOCK locks the "base" layer (i.e., QWERTY, GREEK, or CADET) to the value which is
  //          pressed at the moment that it is being released. When a layer lock is set, the
  //          analogous layer modifier key is reversed; e.g., if you lock the GREEK layer, then the
  //          GREEK button bounces you back to QWERTY.
  //
  // We also parse the shift, alt, and caps lock keys to provide management of those which is
  // compatible with these various layers.
  KC_GREEK = SAFE_RANGE,
  KC_CADET,
  KC_LAYER_LOCK,

  // These are the keycodes generated by the various "accent request" keystrokes.
  KC_ACCENT_START,
  KC_CGRV = KC_ACCENT_START,  // Grave accent
  KC_CAGU,  // Acute accent
  KC_CDIA,  // Diaresis / umlaut / trema
  KC_CCIR,  // Circumflex
  KC_CCED,  // Cedilla
  KC_CTIL,  // Tilde
  KC_ACCENT_END,
};

enum layers_keymap {
  _QWERTY = 0,
  _FUNCTION,

  _GREEK,
  _SHIFTGREEK,
  _CADET,
  _SHIFTCADET,
};

// This is so that H(xxxx) has the same width as _______, which makes the grids more legible.
#define H(x) UC(0x##x)
#define MO_FN MO(_FUNCTION)
#define KC_LLCK KC_LAYER_LOCK


const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
  // NB: Using GESC for escape in the QWERTY layer as a temporary hack because I messed up the
  // switch on the KC_GRV key; change back to KC_ESC once this is fixed.
	[_QWERTY] = LAYOUT_hotswap(
    KC_GESC, KC_F1,   KC_F2,   KC_F3,   KC_F4,   KC_F5,   KC_F6,   KC_F7,   KC_F8,   KC_F9,   KC_F10,  KC_F11,  KC_F12,  KC_HOME, KC_END,  KC_PGUP, KC_PGDN, KC_MPLY, KC_BRK,
    KC_GRV,  KC_1,    KC_2,    KC_3,    KC_4,    KC_5,    KC_6,    KC_7,    KC_8,    KC_9,    KC_0,    KC_MINS, KC_EQL,           KC_BSPC, KC_LLCK, KC_PSLS, KC_PAST, KC_PMNS,
    KC_TAB,  KC_Q,    KC_W,    KC_E,    KC_R,    KC_T,    KC_Y,    KC_U,    KC_I,    KC_O,    KC_P,    KC_LBRC, KC_RBRC,          KC_BSLS, KC_P7,   KC_P8,   KC_P9,
    KC_LCTL, KC_A,    KC_S,    KC_D,    KC_F,    KC_G,    KC_H,    KC_J,    KC_K,    KC_L,    KC_SCLN, KC_QUOT,                   KC_ENT,  KC_P4,   KC_P5,   KC_P6,   KC_PPLS,
    KC_LSFT,          KC_Z,    KC_X,    KC_C,    KC_V,    KC_B,    KC_N,    KC_M,    KC_COMM, KC_DOT,  KC_SLSH, KC_RSFT,          KC_UP,   KC_P1,   KC_P2,   KC_P3,
    KC_LCTL, KC_LALT, KC_LGUI,                            KC_SPC,                             MO_FN,   KC_GREEK,KC_CADET,KC_LEFT, KC_DOWN, KC_RGHT, KC_P0,   KC_PDOT, KC_PENT),
  /* The Greek layers. Shown here are the QWERTY layer (for visual reference) and the two Greek
   * layers.
   * ,----------------------------------------------------------------------------
   * | ` |F1 |F2 |F3 |F4 |F5 |F6 |F7 |F8 |F9 |F10|F11|F12|HOM|END|PGU|PGD|MUT|BRK|  QWERTY
   * | ` | ₁ | ₂ | ₃ | ₄ | ₅ | ₆ | ₇ | ₈ | ₉ | ₀ | ₋ | ₊ | ₍ | ₎ |   |   |   |   |  SHIFTGREEK
   * | ` | ¹ | ² | ³ | ⁴ | ⁵ | ⁶ | ⁷ | ⁸ | ⁹ | ⁰ | ⁻ | ⁺ | ⁽ | ⁾ |   |   |   |   |  GREEK
   * |---------------------------------------------------------------------------|
   * | ` | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 0 | - | + | BKSPC |LCK| / | * | - |
   * | ` | ¿ |   | € |   |   |   |   |   |   |   |   | ≁ | BKSPC |LCK|   | ⊗ |   |
   * |   |   |   |   |   |   |   |   |   |   |   | ∝ | ∼ | BKSPC |LCK| ⊘ | ⊙ | ⊖ |
   * |---------------------------------------------------------------------------|
   * | TAB  | Q | W | E | R | T | Y | U | I | O | P | [ | ] |  \ | 7 | 8 | 9 |   |
   * |      | Θ | Ω | Ε | Ρ | Τ | Ψ | Υ | Ι | Ο | Π |   |   |    |   |   |   |   |
   * |      | θ | ω | ε | ρ | τ | ψ | υ | ι | ο | π |   |   |    |   |   |   |   |
   * |-----------------------------------------------------------------------| + |
   * | CTRL   | A | S | D | F | G | H | J | K | L | ; | ' |  RET | 4 | 5 | 6 | ⊕ |
   * | CTRL   | Α | Σ | Δ | Φ | Γ | Η |   | Κ | Λ | … | ∴ |  RET |   |   |   |   |
   * | CTRL   | α | σ | δ | φ | γ | η | ϑ | κ | λ | ⋯ | ⋅ |  RET |   |   |   |   |
   * |-----------------------------------------------------------------------|---|
   * | SHIFT   | Z | X | C | V | B | N | M | , | . | / |SHFT | ↑ | 1 | 2 | 3 |   |
   * | SHIFT   | Ζ | Ξ | Χ | ✔ | Β | Ν | Μ | ≲ | ≳ |   |SHFT |   |   |   |   |   |
   * | SHIFT   | ζ | ξ | χ | ς | β | ν | μ | ≪ | ≫ | ∫ |SHFT |   |   |   |   |   |
   * |-----------------------------------------------------------------------|ENT|
   * | CTL | ALT| CMD|         SPACE         | α | β | γ | ← | ↓ | → | 0 | . |   |
   * | CTL | ALT| CMD|         SPACE         | α | β | γ |   |   |   |   |   |   |
   * | CTL | ALT| CMD|         SPACE         | α | β | γ |   |   |   |   |   |   |
   * `---------------------------------------------------------------------------'
   */
	[_GREEK] = LAYOUT_hotswap(
    KC_GRV,  H(00b9), H(00b2), H(00b3), H(2074), H(2075), H(2076), H(2077), H(2078), H(2079), H(2070), H(207b), H(207a), H(207d), H(207e), XXXXXXX, XXXXXXX, XXXXXXX, _______,
    KC_GRV,  _______, _______, _______, _______, _______, _______, _______, H(00b0), _______, _______, H(221d), H(223c),          _______, _______, H(2298), H(2299), H(2296),
    _______, H(03b8), H(03c9), H(03b5), H(03c1), H(03c4), H(03c8), H(03c5), H(03b9), H(03bf), H(03c0), KC_LBRC, KC_RBRC,          KC_BSLS, KC_P7,   KC_P8,   KC_P9,
    _______, H(03b1), H(03c3), H(03b4), H(03c6), H(03b3), H(03b7), H(03d1), H(03ba), H(03bb), H(22ef), H(22c5),                   _______, KC_P4,   KC_P5,   KC_P6,   H(2295),
    _______,          H(03b6), H(03be), H(03c7), H(03c2), H(03b2), H(03bd), H(03bc), H(226a), H(226b), H(222b), _______,          _______, KC_P1,   KC_P2,   KC_P3,
    _______, _______, _______,                            _______,                            _______, _______, _______, _______, _______, _______, KC_P0,   KC_PDOT, KC_PENT),
	[_SHIFTGREEK] = LAYOUT_hotswap(
    KC_GRV,  H(2081), H(2082), H(2083), H(2084), H(2085), H(2086), H(2087), H(2088), H(2089), H(2080), H(208b), H(208a), H(208d), H(208e), XXXXXXX, XXXXXXX, XXXXXXX, _______,
    KC_GRV,  H(00bf), _______, H(20ac), _______, _______, _______, _______, _______, _______, _______, XXXXXXX, H(2241),          _______, _______, XXXXXXX, H(2297), XXXXXXX,
    _______, H(0398), H(03a9), H(0395), H(03a1), H(03a4), H(03a8), H(03a5), H(0399), H(039f), H(03a0), KC_LBRC, KC_RBRC,          KC_BSLS, KC_P7,   KC_P8,   KC_P9,
    _______, H(0391), H(03a3), H(0394), H(03a6), H(0393), H(0397), XXXXXXX, H(039a), H(039b), H(2026), H(2234),                   _______, KC_P4,   KC_P5,   KC_P6,   H(2295),
    _______,          H(0396), H(039e), H(03a7), H(2714), H(0392), H(039d), H(039c), H(2272), H(2273), XXXXXXX, _______,          _______, KC_P1,   KC_P2,   KC_P3,
    _______, _______, _______,                            _______,                            _______, _______, _______, _______, _______, _______, KC_P0,   KC_PDOT, KC_PENT),
  /* The Cadet layers. Again, we show the QWERTY layer and the two cadet layers.
   * ,----------------------------------------------------------------------------
   * | ` |F1 |F2 |F3 |F4 |F5 |F6 |F7 |F8 |F9 |F10|F11|F12|HOM|END|PGU|PGD|MUT|BRK|  QWERTY
   * | ∅ |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |  SHIFTCADET
   * | ¬ |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |  CADET
   * |---------------------------------------------------------------------------|
   * | ` | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 0 | - | + | BKSPC |LCK| / | * | - |
   * | ` | ¡ |   | £ |   |   |   |   | ° |   |   | * | ∓ | BKSPC |LCK|   |   |   |
   * |   |   |   |   |   |   |   |   |   |   |   |   | ± | BKSPC |LCK|   | × |   |
   * |---------------------------------------------------------------------------|
   * | TAB  | Q | W | E | R | T | Y | U | I | O | P | [ | ] |  \ | 7 | 8 | 9 |   |
   * |      | ℚ |   |   | ℝ | ⊆ | ⊇ |   | ℵ | ∄ |   | ∉ |   |    | * | * | * |   |
   * |      | ∧ | ∨ | ∩ | ∪ | ⊂ | ⊃ | ∀ | ∞ | ∃ | ∂ | ∈ |   |    | * | * | * |   | [1]
   * |-----------------------------------------------------------------------| + |
   * | CTRL   | A | S | D | F | G | H | J | K | L | ; | ' |  RET | 4 | 5 | 6 | ⊕ |
   * | CTRL   | Å |   | ∇ |   | ⇑ | ⇓ | ⇐ | ⇒ | ⇔ |   |   |  RET | * | * | * |   |
   * | CTRL   | ⟘ | ⊤ | ⊢ | ⊣ | ↑ | ↓ | ← | → | ↔ |   |   |  RET | * | * | * |   | [1]
   * |-----------------------------------------------------------------------|---|
   * | SHIFT   | Z | X | C | V | B | N | M | , | . | / |SHFT | ↑ | 1 | 2 | 3 |   |
   * | SHIFT   | ℤ | ℂ |   | ≉ | ≢ | ℕ |   |   |   |   |SHFT |   | * | * | * |   |
   * | SHIFT   |   | ≠ |   | ≈ | ≡ | ≤ | ≥ |   |   | ÷ |SHFT |   | * | * | * |   | [1]
   * |-----------------------------------------------------------------------|ENT|
   * | CTL | ALT| CMD|         SPACE         | α | β | γ | ← | ↓ | → | 0 | . |   |
   * | CTL | ALT| CMD|         SPACE         | α | β | γ |   |   |   |   |   |   |
   * | CTL | ALT| CMD|         SPACE         | α | β | γ |   |   |   |   |   |   |
   * `---------------------------------------------------------------------------'
   * [1] CADET + numpad moves the mouse. SHIFT+CADET+NUMPAD moves it more quickly. CADET+5
   * clicks the mouse, and SHIFT+CADET+FIVE right-clicks.
   */
	[_CADET] = LAYOUT_hotswap(
    H(00AC), KC_F1,   KC_F2,   KC_F3,   KC_F4,   KC_F5,   KC_F6,   KC_F7,   KC_F8,   KC_F9,   KC_F10,  KC_F11,  KC_F12,  XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, _______,
    KC_GRV,  XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, H(00b1),          _______, _______, XXXXXXX, H(00d7), XXXXXXX,
    _______, H(2227), H(2228), H(2229), H(222a), H(2282), H(2283), H(2200), H(221e), H(2203), H(2202), H(2208), XXXXXXX,          XXXXXXX, KC_P7,   KC_P8,   KC_P9,
    _______, H(22a5), H(22a4), H(22a2), H(22a3), H(2191), H(2193), H(2190), H(2192), H(2194), XXXXXXX, XXXXXXX,                   _______, KC_P4,   KC_P5,   KC_P6,   XXXXXXX,
    _______,          XXXXXXX, H(2260), XXXXXXX, H(2248), H(2261), H(2264), H(2265), XXXXXXX, XXXXXXX, H(00f7), _______,          _______, KC_P1,   KC_P2,   KC_P3,
    _______, _______, _______,                            _______,                            _______, _______, _______, _______, _______, _______, KC_P0,   KC_PDOT, KC_PENT),
	[_SHIFTCADET] = LAYOUT_hotswap(
    H(2205), KC_F1,   KC_F2,   KC_F3,   KC_F4,   KC_F5,   KC_F6,   KC_F7,   KC_F8,   KC_F9,   KC_F10,  KC_F11,  KC_F12,  XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, _______,
    KC_GRV,  H(00a1), XXXXXXX, H(00a3), XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, H(2213),          _______, _______, XXXXXXX, XXXXXXX, XXXXXXX,
    _______, H(211a), XXXXXXX, XXXXXXX, H(211d), H(2286), H(2287), XXXXXXX, H(2135), H(2204), XXXXXXX, H(2209), XXXXXXX,          XXXXXXX, KC_P7,   KC_P8,   KC_P9,
    _______, H(212b), XXXXXXX, H(2207), XXXXXXX, H(21d1), H(21d3), H(21d0), H(21d2), H(21d4), XXXXXXX, XXXXXXX,                   _______, KC_P4,   KC_P5,   KC_P6,   XXXXXXX,
    _______,          H(2124), H(2102), XXXXXXX, H(2249), H(2262), H(2115), XXXXXXX, XXXXXXX, XXXXXXX, H(00f7), _______,          _______, KC_P1,   KC_P2,   KC_P3,
    _______, _______, _______,                            _______,                            _______, _______, _______, _______, _______, _______, KC_P0,   KC_PDOT, KC_PENT),

  // Function layer is mostly for keyboard meta-control operations, but also contains the combining
  // accent marks. These are deliberately placed to match where the analogous controls go on Mac OS.
	[_FUNCTION] = LAYOUT_hotswap(
    KC_CGRV, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, KC_MUTE, KC_VOLD, KC_VOLU, _______, _______, RESET,
    KC_CGRV, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______,          _______, _______, _______, _______, _______,
    _______, _______, _______, KC_CAGU, _______, _______, _______, KC_CDIA, KC_CCIR, _______, _______, _______, _______,          _______, _______, _______, _______,
    _______, _______, _______, UC_M_OS, UC_M_LN, UC_M_WI, UC_M_BS, UC_M_WC, _______, _______, _______, _______,                   _______, _______, _______, _______, _______,
    _______,          _______, _______, KC_CCED, _______, _______, KC_CTIL, _______, _______, _______, _______, _______,          _______, _______, _______, _______,
    _______, _______, _______,                            _______,                            _______, _______, _______, _______, _______, _______, _______, _______, _______),
};

////////////////////////////////////////////////////////////////////////////////////////////////////
// Accent implementation
//
// In the body of process_record_user, we store an "accent_request", which is the accent keycode if
// one was just selected, or zero otherwise. When the *next* key is hit, we look up whether the
// accent request plus that next keycode (plus the state of the shift key) together amount to an
// interesting combined (NFKC) character, and if so, emit it; otherwise, we emit the accent as a
// separate character and then process the next key normally. The resulting UI behavior is similar
// to that of the combining accent keys in MacOS.
//
// We store two arrays, depending on whether shift is or isn't held. Each is two-dimensional, with
// its outer key by the next keycode struck, and the inner key by the accent requested. The outer
// array has KC_Z + 1 as its upper bound, so that we can save memory by only coding alphabetic keys.
// The contents are either Unicode code points, or zero to indicate that we don't have a point for
// this combination.

#define KC_NUM_ACCENTS (KC_ACCENT_END - KC_ACCENT_START)
#define KC_NUM_SLOTS (KC_Z + 1)

const uint16_t PROGMEM unshifted_accents[KC_NUM_SLOTS][KC_NUM_ACCENTS] = {
  //         KC_CGRV, KC_CAGU, KC_CDIA, KC_CCIR, KC_CCED, KC_CTIL
  [KC_A] = { 0x00e0,  0x00e1,  0x00e4,  0x00e2,  0,       0x00e3 },
  [KC_E] = { 0x00e8,  0x00e9,  0x00eb,  0x00ea,  0,       0      },
  [KC_I] = { 0x00ec,  0x00ed,  0x00ef,  0x00ee,  0,       0      },
  [KC_O] = { 0x00f2,  0x00f3,  0x00f6,  0x00f4,  0,       0x00f5 },
  [KC_U] = { 0x00f9,  0x00fa,  0x00fc,  0x00fb,  0,       0      },
  [KC_Y] = { 0,       0,       0x00ff,  0,       0,       0      },
  [KC_N] = { 0,       0,       0,       0,       0,       0x00f1 },
  [KC_C] = { 0,       0,       0,       0,       0x00e7,  0      },
};

const uint16_t PROGMEM shifted_accents[KC_NUM_SLOTS][KC_NUM_ACCENTS] = {
  //         KC_CGRV, KC_CAGU, KC_CDIA, KC_CCIR, KC_CCED, KC_CTIL
  [KC_A] = { 0x00c0,  0x00c1,  0x00c4,  0x00c2,  0,       0x00c3 },
  [KC_E] = { 0x00c8,  0x00c9,  0x00cb,  0x00ca,  0,       0      },
  [KC_I] = { 0x00cc,  0x00cd,  0x00cf,  0x00ce,  0,       0      },
  [KC_O] = { 0x00d2,  0x00d3,  0x00d6,  0x00d4,  0,       0x00d5 },
  [KC_U] = { 0x00d9,  0x00da,  0x00dc,  0x00db,  0,       0      },
  [KC_Y] = { 0,       0,       0x00df,  0,       0,       0      },
  [KC_N] = { 0,       0,       0,       0,       0,       0x00d1 },
  [KC_C] = { 0,       0,       0,       0,       0x00c7,  0      },
};

// The uncombined and combined forms of the accents, for when we want to emit them as single
// characters.
const uint16_t PROGMEM uncombined_accents[KC_NUM_ACCENTS] = {
  [KC_CGRV - KC_ACCENT_START] = 0x0060,
  [KC_CAGU - KC_ACCENT_START] = 0x00b4,
  [KC_CDIA - KC_ACCENT_START] = 0x00a8,
  [KC_CCIR - KC_ACCENT_START] = 0x005e,
  [KC_CCED - KC_ACCENT_START] = 0x00b8,
  [KC_CTIL - KC_ACCENT_START] = 0x02dc,
};

const uint16_t PROGMEM combined_accents[KC_NUM_ACCENTS] = {
  [KC_CGRV - KC_ACCENT_START] = 0x0300,
  [KC_CAGU - KC_ACCENT_START] = 0x0301,
  [KC_CDIA - KC_ACCENT_START] = 0x0308,
  [KC_CCIR - KC_ACCENT_START] = 0x0302,
  [KC_CCED - KC_ACCENT_START] = 0x0327,
  [KC_CTIL - KC_ACCENT_START] = 0x0303,
};

// This function manages keypresses that happen after an accent has been selected by an earlier
// keypress.
// Args:
//   accent_key: The accent key which was earlier selected. This must be in the range
//     [KC_ACCENT_START, KC_ACCENT_END).
//   keycode: The keycode which was just pressed.
//   is_shifted: The current shift state (as set by a combination of shift and caps lock)
//   force_no_accent: If true, we're in a situation where we want to force there to be no
//     accent combination -- if e.g. we're in a non-QWERTY layer, or if other modifier keys
//     are held.
//
// Returns true if the keycode has been completely handled by this function (and so should not be
// processed further by process_record_user) or false otherwise.
bool process_key_after_accent(
    uint16_t accent_key,
    uint16_t keycode,
    bool is_shifted,
    bool force_no_accent
) {
  assert(accent_key >= KC_ACCENT_START);
  assert(accent_key < KC_ACCENT_END);
  const int accent_index = accent_key - KC_ACCENT_START;

  // If the keycode is outside A..Z, or force_no_accent is set, we know we shouldn't even bother
  // with a table lookup.
  if (keycode <= KC_Z && !force_no_accent) {
    // Pick the correct array. Because this is progmem, we're going to need to do the
    // two-dimensional array indexing by hand, and so we just cast it to a single-dimensional array.
    const uint16_t *points = (const uint16_t*)(is_shifted ? shifted_accents : unshifted_accents);
    const uint16_t code_point = pgm_read_word_near(points + KC_NUM_ACCENTS * keycode + accent_index);
    if (code_point) {
      register_unicode(code_point);
      return true;
    }
  }

  // If we get here, there was no accent match. Emit the accent as its own character, and then let
  // the caller figure out what to do next.
  register_unicode(pgm_read_word_near(uncombined_accents + accent_index));
  return false;
}

// Layer bitfields.
#define GREEK_LAYER (1UL << _GREEK)
#define SHIFTGREEK_LAYER (1UL << _SHIFTGREEK)
#define CADET_LAYER (1UL << _CADET)
#define SHIFTCADET_LAYER (1UL << _SHIFTCADET)
// The layers we don't touch.
#define LAYER_MASK ~(GREEK_LAYER|SHIFTGREEK_LAYER|CADET_LAYER|SHIFTCADET_LAYER)

bool process_record_user(uint16_t keycode, keyrecord_t *record) {
  // We track these persistent globals and manage them on our own, rather than trying to rely on
  // get_mods or the like, because this function is called *before* that's updated!
  static bool shift_held = false;
  static bool alt_held = false;
  static bool ctrl_held = false;
  static bool super_held = false;
  static bool greek_held = false;
  static bool cadet_held = false;

  // These are where we remember the values of lock states.
  static bool shift_lock = false;
  static int layer_lock = _QWERTY;

  // The accent request, or zero if there isn't one.
  static uint16_t accent_request = 0;

  // If this is set to true, don't trigger any handling of pending accent requests. That's what we
  // want to do if e.g. the user just hit the shift key or something.
  bool ignore_accent_change = !record->event.pressed;

  // Step 1: Process any modifier key state changes, so we can maintain that state.
  if (keycode == KC_LSHIFT || keycode == KC_RSHIFT) {
    shift_held = record->event.pressed;
    ignore_accent_change = true;
  } else if (keycode == KC_LALT || keycode == KC_RALT) {
    alt_held = record->event.pressed;
    ignore_accent_change = true;
  } else if (keycode == KC_LCTRL || keycode == KC_RCTRL) {
    ctrl_held = record->event.pressed;
    ignore_accent_change = true;
  } else if (keycode == KC_LGUI || keycode == KC_RGUI) {
    super_held = record->event.pressed;
    ignore_accent_change = true;
  } else if (keycode == KC_GREEK) {
    greek_held = record->event.pressed;
    ignore_accent_change = true;
  } else if (keycode == KC_CADET) {
    cadet_held = record->event.pressed;
    ignore_accent_change = true;
  }

  // Step 2: Figure out which layer we're supposed to be in, by transforming all the prior stuff
  // into layer requests.
  const bool greek_request = (greek_held && !alt_held);
  const bool cadet_request = (cadet_held || (greek_held && alt_held));

  // Now, handle the lock keys. We store next_layer_lock in a local variable so that we can
  // determine the layer to pick right now before we update layer_lock.
  int next_layer_lock = layer_lock;
  if (keycode == KC_CAPS) {
    // If we're in QWERTY mode, caps lock is already going to be managed by the host OS, but by
    // tracking it ourselves we can also usefully apply it to the GREEK and CADET layers.
    if (record->event.pressed) {
      shift_lock = !shift_lock;
    }
  } else if (keycode == KC_LAYER_LOCK) {
    if (record->event.pressed) {
      if (cadet_request) {
        next_layer_lock = _CADET;
      } else if (greek_request) {
        next_layer_lock = _GREEK;
      } else {
        next_layer_lock = _QWERTY;
      }
    }
  }

  // OK! Now we know which buttons are being held, and the current and upcoming states of the locks.
  // We can compute our new base layer. Remember that the CADET and GREEK keys act as their own
  // antonyms if they match the layer lock -- e.g., if you have CADET locked, then CADET+X generates
  // QWERTY-X.
  int base_layer;
  if (cadet_request) {
    base_layer = (layer_lock == _CADET ? _QWERTY : _CADET);
  } else if (greek_request) {
    base_layer = (layer_lock == _GREEK ? _QWERTY : _GREEK);
  } else {
    base_layer = layer_lock;
  }

  const bool shifted = (shift_held != shift_lock);
  int actual_layer;
  if (base_layer == _CADET) {
    actual_layer = (shifted ? _SHIFTCADET : _CADET);
  } else if (base_layer == _GREEK) {
    actual_layer = (shifted ? _SHIFTGREEK : _GREEK);
  } else {
    // We don't do shifting for the QWERTY layer, since for that we emit USB HID codes and shifting
    // is managed by the host OS.
    actual_layer = _QWERTY;
  }

  // And now we can update the layer lock and the actual firmware layer selector.
  layer_lock = next_layer_lock;
  layer_state_t new_layer_state = (layer_state & LAYER_MASK) | (1UL << actual_layer);
  if (new_layer_state != layer_state) {
    layer_state_set(new_layer_state);
  }

  // Step 3: Handle accents. If there's a pending accent request, process it. If what the user just
  // hit creates a new accent request, update the pending state for the next keypress.
  if (!ignore_accent_change && accent_request && record->event.pressed) {
    // Only do the accent stuff if we're in the QWERTY layer and we aren't modifying something.
    const bool force_no_accent = (
        actual_layer != _QWERTY ||
        ctrl_held ||
        super_held ||
        alt_held
    );
    const uint16_t old_accent = accent_request;
    accent_request = 0;
    if (process_key_after_accent(old_accent, keycode, shifted, force_no_accent)) {
      return false;
    }
  }

  // And if a new accent request just arrived, update accent_request.
  if (keycode >= KC_ACCENT_START && keycode < KC_ACCENT_END && record->event.pressed) {
    if (shifted) {
      // Shift + accent request generates the combining accent key, and leaves accent_request alone.
      register_unicode(pgm_read_word_near(combined_accents + keycode - KC_ACCENT_START));
      return false;
    } else {
      accent_request = keycode;
    }
  }

  return true;
}