mirrors/keychron_qmk_firmware
mirrors/keychron_qmk_firmware
0
0
Fork 0
mirror of https://github.com/Keychron/qmk_firmware.git synced 2024-11-22 16:37:58 +06:00
Code Issues Packages Projects Releases Wiki Activity

Remove floating point calculation in mouse move. Saves approx 650 bytes if no other floating point used.

Browse Source
This commit is contained in:
Martin Sandiford 2017-08-15 10:38:29 +09:30 committed by Jack Humbert
parent b7d43ee253
commit c622423668
1 changed files with 11 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
tmk_core/common/mousekey.c
View File

@ -55,6 +55,14 @@ uint8_t mk_wheel_time_to_max = MOUSEKEY_WHEEL_TIME_TO_MAX;
static uint16_t last_timer = 0;
inline int8_t times_inv_sqrt2(int8_t x)
{
// 181/256 is pretty close to 1/sqrt(2)
// 0.70703125 0.707106781
// 1 too small for x=99 and x=198
// This ends up being a mult and discard lower 8 bits
return (x * 181) >> 8;
}
static uint8_t move_unit(void)
{
@ -111,10 +119,10 @@ void mousekey_task(void)
if (mouse_report.y > 0) mouse_report.y = move_unit();
if (mouse_report.y < 0) mouse_report.y = move_unit() * -1;
/* diagonal move [1/sqrt(2) = 0.7] */
/* diagonal move [1/sqrt(2)] */
if (mouse_report.x && mouse_report.y) {
mouse_report.x *= 0.7;
mouse_report.y *= 0.7;
mouse_report.x = times_inv_sqrt2(mouse_report.x);
mouse_report.y = times_inv_sqrt2(mouse_report.y);
}
if (mouse_report.v > 0) mouse_report.v = wheel_unit();