From 1b2b20988d335ac1580a456a9c35de72d40d57cd Mon Sep 17 00:00:00 2001 From: Albert Y <76888457+filterpaper@users.noreply.github.com> Date: Tue, 6 Jun 2023 19:27:32 +0800 Subject: [PATCH] Use unsigned integer for kinetic speed The current kinetic mouse key function uses resource intensive floating point to compute the quadratic curve speed. But the result is returned as an unsigned 8-bit integer value. The code line where fractional accuracy is important is at the division of `speed = (uint8_t)(speed / (1000.0f / mk_interval));` This change uses 16-bit integers for the quadratic calculation variables, which are less resource-intensive. The output acceleration curve is almost unchanged with the default `MOUSEKEY_INTERVAL` value. Truncation is used to round division output to an integer. With higher `MOUSEKEY_INTERVAL` values, rounding appears more accurate using 16-bit integer versus floating point. Example: `mk_interval = 30` | speed | (uint8_t)(speed / (1000.0f / mk_interval)) | (uint8_t)(speed / (1000U / mk_interval)) | |------|----|----| | 292 | 8 | 9 | | 484 | 14 | 15 | | 1060 | 31 | 32 | | 1660 | 49 | 50 | --- quantum/mousekey.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/quantum/mousekey.c b/quantum/mousekey.c index df8aa613bea4..ede055dc8f82 100644 --- a/quantum/mousekey.c +++ b/quantum/mousekey.c @@ -74,7 +74,7 @@ uint8_t mk_time_to_max = MOUSEKEY_TIME_TO_MAX; uint8_t mk_wheel_delay = MOUSEKEY_WHEEL_DELAY / 10; /* milliseconds between repeated motion events (0-255) */ # ifdef MK_KINETIC_SPEED -float mk_wheel_interval = 1000.0f / MOUSEKEY_WHEEL_INITIAL_MOVEMENTS; +uint16_t mk_wheel_interval = 1000U / MOUSEKEY_WHEEL_INITIAL_MOVEMENTS; # else uint8_t mk_wheel_interval = MOUSEKEY_WHEEL_INTERVAL; # endif @@ -190,37 +190,37 @@ const uint16_t mk_decelerated_speed = MOUSEKEY_DECELERATED_SPEED; const uint16_t mk_initial_speed = MOUSEKEY_INITIAL_SPEED; static uint8_t move_unit(void) { - float speed = mk_initial_speed; + uint16_t speed = mk_initial_speed; if (mousekey_accel & ((1 << 0) | (1 << 2))) { speed = mousekey_accel & (1 << 2) ? mk_accelerated_speed : mk_decelerated_speed; } else if (mousekey_repeat && mouse_timer) { - const float time_elapsed = timer_elapsed(mouse_timer) / 50; - speed = mk_initial_speed + MOUSEKEY_MOVE_DELTA * time_elapsed + MOUSEKEY_MOVE_DELTA * 0.5 * time_elapsed * time_elapsed; + const uint16_t time_elapsed = timer_elapsed(mouse_timer) / 50; + speed = mk_initial_speed + MOUSEKEY_MOVE_DELTA * time_elapsed + MOUSEKEY_MOVE_DELTA * 0.5 * time_elapsed * time_elapsed; speed = speed > mk_base_speed ? mk_base_speed : speed; } /* convert speed to USB mouse speed 1 to 127 */ - speed = (uint8_t)(speed / (1000.0f / mk_interval)); + speed = (uint8_t)(speed / (1000U / mk_interval)); speed = speed < 1 ? 1 : speed; return speed > MOUSEKEY_MOVE_MAX ? MOUSEKEY_MOVE_MAX : speed; } static uint8_t wheel_unit(void) { - float speed = MOUSEKEY_WHEEL_INITIAL_MOVEMENTS; + uint16_t speed = MOUSEKEY_WHEEL_INITIAL_MOVEMENTS; if (mousekey_accel & ((1 << 0) | (1 << 2))) { speed = mousekey_accel & (1 << 2) ? MOUSEKEY_WHEEL_ACCELERATED_MOVEMENTS : MOUSEKEY_WHEEL_DECELERATED_MOVEMENTS; } else if (mousekey_wheel_repeat && mouse_timer) { if (mk_wheel_interval != MOUSEKEY_WHEEL_BASE_MOVEMENTS) { - const float time_elapsed = timer_elapsed(mouse_timer) / 50; - speed = MOUSEKEY_WHEEL_INITIAL_MOVEMENTS + 1 * time_elapsed + 1 * 0.5 * time_elapsed * time_elapsed; + const uint16_t time_elapsed = timer_elapsed(mouse_timer) / 50; + speed = MOUSEKEY_WHEEL_INITIAL_MOVEMENTS + 1 * time_elapsed + 1 * 0.5 * time_elapsed * time_elapsed; } speed = speed > MOUSEKEY_WHEEL_BASE_MOVEMENTS ? MOUSEKEY_WHEEL_BASE_MOVEMENTS : speed; } - mk_wheel_interval = 1000.0f / speed; + mk_wheel_interval = 1000U / speed; return (uint8_t)speed > MOUSEKEY_WHEEL_INITIAL_MOVEMENTS ? 2 : 1; }