qmk-firmware/keyboards/ymdk_np21/breathing_custom.h

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/**
* Breathing effect code for PS2AVRGB boards (ATMEGA32A)
* Works in conjunction with `backlight.c`.
*
* Code adapted from `quantum.c` to register with the existing TIMER1 overflow
* handler in `backlight.c` instead of setting up its own timer.
* Kenneth A. (github.com/krusli | krusli.me)
*/
#ifdef BACKLIGHT_ENABLE
#ifdef BACKLIGHT_BREATHING
#include "backlight_custom.h"
#ifndef BREATHING_PERIOD
#define BREATHING_PERIOD 6
#endif
#define breathing_min() do {breathing_counter = 0;} while (0)
#define breathing_max() do {breathing_counter = breathing_period * 244 / 2;} while (0)
// TODO make this share code with quantum.c
#define BREATHING_NO_HALT 0
#define BREATHING_HALT_OFF 1
#define BREATHING_HALT_ON 2
#define BREATHING_STEPS 128
static uint8_t breathing_period = BREATHING_PERIOD;
static uint8_t breathing_halt = BREATHING_NO_HALT;
static uint16_t breathing_counter = 0;
static bool breathing = false;
bool is_breathing(void) {
return breathing;
}
// See http://jared.geek.nz/2013/feb/linear-led-pwm
static uint16_t cie_lightness(uint16_t v) {
if (v <= 5243) // if below 8% of max
return v / 9; // same as dividing by 900%
else {
uint32_t y = (((uint32_t) v + 10486) << 8) / (10486 + 0xFFFFUL); // add 16% of max and compare
// to get a useful result with integer division, we shift left in the expression above
// and revert what we've done again after squaring.
y = y * y * y >> 8;
if (y > 0xFFFFUL) // prevent overflow
return 0xFFFFU;
else
return (uint16_t) y;
}
}
void breathing_enable(void) {
breathing = true;
breathing_counter = 0;
breathing_halt = BREATHING_NO_HALT;
// interrupt already registered
}
void breathing_pulse(void) {
if (get_backlight_level() == 0)
breathing_min();
else
breathing_max();
breathing_halt = BREATHING_HALT_ON;
// breathing_interrupt_enable();
breathing = true;
}
void breathing_disable(void) {
breathing = false;
// backlight_set(get_backlight_level());
b_led_set(get_backlight_level()); // custom implementation of backlight_set()
}
void breathing_self_disable(void)
{
if (get_backlight_level() == 0)
breathing_halt = BREATHING_HALT_OFF;
else
breathing_halt = BREATHING_HALT_ON;
}
void breathing_toggle(void) {
if (is_breathing())
breathing_disable();
else
breathing_enable();
}
void breathing_period_set(uint8_t value)
{
if (!value)
value = 1;
breathing_period = value;
}
void breathing_period_default(void) {
breathing_period_set(BREATHING_PERIOD);
}
void breathing_period_inc(void)
{
breathing_period_set(breathing_period+1);
}
void breathing_period_dec(void)
{
breathing_period_set(breathing_period-1);
}
/* To generate breathing curve in python:
* from math import sin, pi; [int(sin(x/128.0*pi)**4*255) for x in range(128)]
*/
static const uint8_t breathing_table[BREATHING_STEPS] PROGMEM = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 17, 20, 24, 28, 32, 36, 41, 46, 51, 57, 63, 70, 76, 83, 91, 98, 106, 113, 121, 129, 138, 146, 154, 162, 170, 178, 185, 193, 200, 207, 213, 220, 225, 231, 235, 240, 244, 247, 250, 252, 253, 254, 255, 254, 253, 252, 250, 247, 244, 240, 235, 231, 225, 220, 213, 207, 200, 193, 185, 178, 170, 162, 154, 146, 138, 129, 121, 113, 106, 98, 91, 83, 76, 70, 63, 57, 51, 46, 41, 36, 32, 28, 24, 20, 17, 15, 12, 10, 8, 6, 5, 4, 3, 2, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
// Use this before the cie_lightness function.
static inline uint16_t scale_backlight(uint16_t v) {
return v / BACKLIGHT_LEVELS * get_backlight_level();
}
void custom_breathing_handler(void) {
uint16_t interval = (uint16_t) breathing_period * 244 / BREATHING_STEPS;
// resetting after one period to prevent ugly reset at overflow.
breathing_counter = (breathing_counter + 1) % (breathing_period * 244);
uint8_t index = breathing_counter / interval % BREATHING_STEPS;
if (((breathing_halt == BREATHING_HALT_ON) && (index == BREATHING_STEPS / 2)) ||
((breathing_halt == BREATHING_HALT_OFF) && (index == BREATHING_STEPS - 1)))
{
// breathing_interrupt_disable();
}
setPWM(cie_lightness(scale_backlight((uint16_t) pgm_read_byte(&breathing_table[index]) * 0x0101U)));
}
#endif // BACKLIGHT_BREATHING
#endif // BACKLIGHT_ENABLE