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Fixes potential wpm sampling overflow, along with code comment fixes (#15277)

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Co-authored-by: Trevor Powell <trevor@vectorstorm.com.au>
This commit is contained in:
vectorstorm 2021-12-27 11:52:56 +11:00 committed by GitHub
parent 6e40dfa022
commit 0391801267
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GPG key ID: 4AEE18F83AFDEB23
3 changed files with 45 additions and 34 deletions
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2
docs/feature_wpm.md
View file

@ -16,7 +16,7 @@ For split keyboards using soft serial, the computed WPM score will be available
| `WPM_ALLOW_COUNT_REGRESSION` | _Not defined_ | If defined allows the WPM to be decreased when hitting Delete or Backspace |
| `WPM_UNFILTERED` | _Not defined_ | If undefined (the default), WPM values will be smoothed to avoid sudden changes in value |
| `WPM_SAMPLE_SECONDS` | `5` | This defines how many seconds of typing to average, when calculating WPM |
| `WPM_SAMPLE_PERIODS` | `50` | This defines how many sampling periods to use when calculating WPM |
| `WPM_SAMPLE_PERIODS` | `25` | This defines how many sampling periods to use when calculating WPM |
| `WPM_LAUNCH_CONTROL` | _Not defined_ | If defined, WPM values will be calculated using partial buffers when typing begins |
'WPM_UNFILTERED' is potentially useful if you're filtering data in some other way (and also because it reduces the code required for the WPM feature), or if reducing measurement latency to a minimum is important for you.

75
quantum/wpm.c
View file

@ -22,33 +22,37 @@
// 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.
* then adjust for how much time is captured by our ring buffer. The size
* of the ring buffer can be configured using the keymap configuration
* value `WPM_SAMPLE_PERIODS`.
*
* 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 int16_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;
/* LATENCY is used as part of filtering, and controls how quickly the reported
* WPM trails behind our actual instantaneous measured WPM value, and is
* defined in milliseconds. So for LATENCY == 100, the displayed WPM is
* smoothed out over periods of 0.1 seconds. This results in a nice,
* smoothly-moving reported WPM value which nevertheless is never more than
* 0.1 seconds behind the typist's actual current WPM.
*
* LATENCY is not used if WPM_UNFILTERED is defined.
*/
# define LATENCY (100)
static uint32_t smoothing_timer = 0;
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; }
@ -71,7 +75,7 @@ __attribute__((weak)) bool wpm_keycode_user(uint16_t keycode) {
return false;
}
#ifdef WPM_ALLOW_COUNT_REGRESSION
#if defined(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);
@ -95,12 +99,12 @@ __attribute__((weak)) uint8_t wpm_regress_count(uint16_t keycode) {
// Outside 'raw' mode we smooth results over time.
void update_wpm(uint16_t keycode) {
if (wpm_keycode(keycode)) {
if (wpm_keycode(keycode) && period_presses[current_period] < INT16_MAX) {
period_presses[current_period]++;
}
#ifdef WPM_ALLOW_COUNT_REGRESSION
#if defined(WPM_ALLOW_COUNT_REGRESSION)
uint8_t regress = wpm_regress_count(keycode);
if (regress) {
if (regress && period_presses[current_period] > INT16_MIN) {
period_presses[current_period]--;
}
#endif
@ -116,32 +120,41 @@ void decay_wpm(void) {
}
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;
int32_t wpm_now = (60000 * presses) / (duration * WPM_ESTIMATED_WORD_SIZE);
if (wpm_now < 0) // set some reasonable WPM measurement limits
wpm_now = 0;
if (wpm_now > 240) wpm_now = 240;
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; */
/* } */
wpm_timer = timer_read32();
}
if (presses < 2) // don't guess high WPM based on a single keypress.
wpm_now = 0;
#if defined WPM_LAUNCH_CONTROL
#if defined(WPM_LAUNCH_CONTROL)
/*
* If the `WPM_LAUNCH_CONTROL` option is enabled, then whenever our WPM
* drops to absolute zero due to no typing occurring within our sample
* ring buffer, we reset and start measuring fresh, which lets our WPM
* immediately reach the correct value even before a full sampling buffer
* has been filled.
*/
if (presses == 0) {
current_period = 0;
periods = 0;
wpm_now = 0;
current_period = 0;
periods = 0;
wpm_now = 0;
period_presses[0] = 0;
}
#endif // WPM_LAUNCH_CONTROL
#ifndef WPM_UNFILTERED
#if defined(WPM_UNFILTERED)
current_wpm = wpm_now;
#else
int32_t latency = timer_elapsed32(smoothing_timer);
if (latency > LATENCY) {
smoothing_timer = timer_read32();
@ -150,7 +163,5 @@ void decay_wpm(void) {
}
current_wpm = prev_wpm + (latency * ((int)next_wpm - (int)prev_wpm) / LATENCY);
#else
current_wpm = wpm_now;
#endif
}

2
quantum/wpm.h
View file

@ -26,7 +26,7 @@
# define WPM_SAMPLE_SECONDS 5
#endif
#ifndef WPM_SAMPLE_PERIODS
# define WPM_SAMPLE_PERIODS 50
# define WPM_SAMPLE_PERIODS 25
#endif
bool wpm_keycode(uint16_t keycode);