opensteno_qmk/quantum/wpm.c
vectorstorm c9fd698711
Reimplements WPM feature to be smaller & precise (#13902)
* Reimplements WPM feature.

 - Now calculates exact WPM over the last up to three seconds of typing.
 - WPM_SMOOTHING removed, as it's no longer needed.
 - WPM_SAMPLE_SECONDS added, to specify how long a period to average WPM
   over, set to 5 seconds by default.
 - WPM_SAMPLE_PERIODS added, to specify how many sampling buffers we'll
   use.  Each one uses one extra byte of space.  Having more will lead
   to smoother decay of WPM values.  Defaults to 50 (we're saving so
   many bytes of firmware space I felt like being extravagent, and this
   change is still a big size saving overall)
 - WPM_UNFILTERED option added (defaults to unset), which disables all
   filtering within the WPM feature.  This saves some space in the
   firmware and also reduces latency between typing and the WPM
   calculation measuring it.  (saves 70 bytes in my tests)
 - WPM_LAUNCH_CONTROL added (defaults to unset).  When typing begins
   while the current displayed WPM value is zero, the WPM calculation
   only considers the time elapsed since typing began, not the whole
   WPM_SAMPLE_SECONDS buffer.  The result of this is that the displayed
   WPM value much more rapidly reaches an accurate WPM value, even when
   results are being filtered. (costs 22 bytes in my tests)
 - Updates documentation to reflect changed options.

Saves about 900 bytes, in my tests, compared against the previous implementation,
with default settings.

* Apply suggestions from code review

Co-authored-by: Sergey Vlasov <sigprof@gmail.com>

Co-authored-by: Trevor Powell <trevor@vectorstorm.org>
Co-authored-by: Nick Brassel <nick@tzarc.org>
Co-authored-by: Sergey Vlasov <sigprof@gmail.com>
2021-11-16 05:40:52 +11:00

156 lines
5.4 KiB
C

/*
* Copyright 2020 Richard Sutherland (rich@brickbots.com)
*
* 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 "wpm.h"
#include <math.h>
// WPM Stuff
static uint8_t current_wpm = 0;
static uint32_t wpm_timer = 0;
#ifndef WPM_UNFILTERED
static uint32_t smoothing_timer = 0;
#endif
/* The WPM calculation works by specifying a certain number of 'periods' inside
* a ring buffer, and we count the number of keypresses which occur in each of
* those periods. Then to calculate WPM, we add up all of the keypresses in
* the whole ring buffer, divide by the number of keypresses in a 'word', and
* then adjust for how much time is captured by our ring buffer. Right now
* the ring buffer is hardcoded below to be six half-second periods, accounting
* for a total WPM sampling period of up to three seconds of typing.
*
* Whenever our WPM drops to absolute zero due to no typing occurring within
* any contiguous three seconds, we reset and start measuring fresh,
* which lets our WPM immediately reach the correct value even before a full
* three second sampling buffer has been filled.
*/
#define MAX_PERIODS (WPM_SAMPLE_PERIODS)
#define PERIOD_DURATION (1000 * WPM_SAMPLE_SECONDS / MAX_PERIODS)
#define LATENCY (100)
static int8_t period_presses[MAX_PERIODS] = {0};
static uint8_t current_period = 0;
static uint8_t periods = 1;
#if !defined(WPM_UNFILTERED)
static uint8_t prev_wpm = 0;
static uint8_t next_wpm = 0;
#endif
void set_current_wpm(uint8_t new_wpm) { current_wpm = new_wpm; }
uint8_t get_current_wpm(void) { return current_wpm; }
bool wpm_keycode(uint16_t keycode) { return wpm_keycode_kb(keycode); }
__attribute__((weak)) bool wpm_keycode_kb(uint16_t keycode) { return wpm_keycode_user(keycode); }
__attribute__((weak)) bool wpm_keycode_user(uint16_t keycode) {
if ((keycode >= QK_MOD_TAP && keycode <= QK_MOD_TAP_MAX) || (keycode >= QK_LAYER_TAP && keycode <= QK_LAYER_TAP_MAX) || (keycode >= QK_MODS && keycode <= QK_MODS_MAX)) {
keycode = keycode & 0xFF;
} else if (keycode > 0xFF) {
keycode = 0;
}
if ((keycode >= KC_A && keycode <= KC_0) || (keycode >= KC_TAB && keycode <= KC_SLASH)) {
return true;
}
return false;
}
#ifdef WPM_ALLOW_COUNT_REGRESSION
__attribute__((weak)) uint8_t wpm_regress_count(uint16_t keycode) {
bool weak_modded = (keycode >= QK_LCTL && keycode < QK_LSFT) || (keycode >= QK_RCTL && keycode < QK_RSFT);
if ((keycode >= QK_MOD_TAP && keycode <= QK_MOD_TAP_MAX) || (keycode >= QK_LAYER_TAP && keycode <= QK_LAYER_TAP_MAX) || (keycode >= QK_MODS && keycode <= QK_MODS_MAX)) {
keycode = keycode & 0xFF;
} else if (keycode > 0xFF) {
keycode = 0;
}
if (keycode == KC_DELETE || keycode == KC_BACKSPACE) {
if (((get_mods() | get_oneshot_mods()) & MOD_MASK_CTRL) || weak_modded) {
return WPM_ESTIMATED_WORD_SIZE;
} else {
return 1;
}
} else {
return 0;
}
}
#endif
// Outside 'raw' mode we smooth results over time.
void update_wpm(uint16_t keycode) {
if (wpm_keycode(keycode)) {
period_presses[current_period]++;
}
#ifdef WPM_ALLOW_COUNT_REGRESSION
uint8_t regress = wpm_regress_count(keycode);
if (regress) {
period_presses[current_period]--;
}
#endif
}
void decay_wpm(void) {
int32_t presses = period_presses[0];
for (int i = 1; i <= periods; i++) {
presses += period_presses[i];
}
if (presses < 0) {
presses = 0;
}
int32_t elapsed = timer_elapsed32(wpm_timer);
uint32_t duration = (((periods)*PERIOD_DURATION) + elapsed);
uint32_t wpm_now = (60000 * presses) / (duration * WPM_ESTIMATED_WORD_SIZE);
wpm_now = (wpm_now > 240) ? 240 : wpm_now;
if (elapsed > PERIOD_DURATION) {
current_period = (current_period + 1) % MAX_PERIODS;
period_presses[current_period] = 0;
periods = (periods < MAX_PERIODS - 1) ? periods + 1 : MAX_PERIODS - 1;
elapsed = 0;
/* if (wpm_timer == 0) { */
wpm_timer = timer_read32();
/* } else { */
/* wpm_timer += PERIOD_DURATION; */
/* } */
}
if (presses < 2) // don't guess high WPM based on a single keypress.
wpm_now = 0;
#if defined WPM_LAUNCH_CONTROL
if (presses == 0) {
current_period = 0;
periods = 0;
wpm_now = 0;
}
#endif // WPM_LAUNCH_CONTROL
#ifndef WPM_UNFILTERED
int32_t latency = timer_elapsed32(smoothing_timer);
if (latency > LATENCY) {
smoothing_timer = timer_read32();
prev_wpm = current_wpm;
next_wpm = wpm_now;
}
current_wpm = prev_wpm + (latency * ((int)next_wpm - (int)prev_wpm) / LATENCY);
#else
current_wpm = wpm_now;
#endif
}