Files
klubhaus-doorbell/libraries/FastLED/src/fl/rgbw.cpp
2026-02-12 00:45:31 -08:00

167 lines
4.6 KiB
C++

/// @file rgbw.cpp
/// Functions for red, green, blue, white (RGBW) output
#include "fl/stdint.h"
#define FASTLED_INTERNAL
#include "FastLED.h"
#include "rgbw.h"
namespace fl {
namespace {
inline uint8_t min3(uint8_t a, uint8_t b, uint8_t c) {
if (a < b) {
if (a < c) {
return a;
} else {
return c;
}
} else {
if (b < c) {
return b;
} else {
return c;
}
}
}
inline uint8_t divide_by_3(uint8_t x) {
uint16_t y = (uint16_t(x) * 85) >> 8;
return static_cast<uint8_t>(y);
}
} // namespace
// @brief Converts RGB to RGBW using a color transfer method
// from color channels to 3x white.
// @author Jonathanese
void rgb_2_rgbw_exact(uint16_t w_color_temperature, uint8_t r, uint8_t g,
uint8_t b, uint8_t r_scale, uint8_t g_scale,
uint8_t b_scale, uint8_t *out_r, uint8_t *out_g,
uint8_t *out_b, uint8_t *out_w) {
(void)w_color_temperature;
r = scale8(r, r_scale);
g = scale8(g, g_scale);
b = scale8(b, b_scale);
uint8_t min_component = min3(r, g, b);
*out_r = r - min_component;
*out_g = g - min_component;
*out_b = b - min_component;
*out_w = min_component;
}
void rgb_2_rgbw_max_brightness(uint16_t w_color_temperature, uint8_t r,
uint8_t g, uint8_t b, uint8_t r_scale,
uint8_t g_scale, uint8_t b_scale, uint8_t *out_r,
uint8_t *out_g, uint8_t *out_b, uint8_t *out_w) {
(void)w_color_temperature;
*out_r = scale8(r, r_scale);
*out_g = scale8(g, g_scale);
*out_b = scale8(b, b_scale);
*out_w = min3(r, g, b);
}
void rgb_2_rgbw_null_white_pixel(uint16_t w_color_temperature, uint8_t r,
uint8_t g, uint8_t b, uint8_t r_scale,
uint8_t g_scale, uint8_t b_scale,
uint8_t *out_r, uint8_t *out_g, uint8_t *out_b,
uint8_t *out_w) {
(void)w_color_temperature;
*out_r = scale8(r, r_scale);
*out_g = scale8(g, g_scale);
*out_b = scale8(b, b_scale);
*out_w = 0;
}
void rgb_2_rgbw_white_boosted(uint16_t w_color_temperature, uint8_t r,
uint8_t g, uint8_t b, uint8_t r_scale,
uint8_t g_scale, uint8_t b_scale, uint8_t *out_r,
uint8_t *out_g, uint8_t *out_b, uint8_t *out_w) {
(void)w_color_temperature;
r = scale8(r, r_scale);
g = scale8(g, g_scale);
b = scale8(b, b_scale);
uint8_t min_component = min3(r, g, b);
uint8_t w;
bool is_min = true;
if (min_component <= 84) {
w = 3 * min_component;
} else {
w = 255;
is_min = false;
}
uint8_t r_prime;
uint8_t g_prime;
uint8_t b_prime;
if (is_min) {
r_prime = r - min_component;
g_prime = g - min_component;
b_prime = b - min_component;
} else {
uint8_t w3 = divide_by_3(w);
r_prime = r - w3;
g_prime = g - w3;
b_prime = b - w3;
}
*out_r = r_prime;
*out_g = g_prime;
*out_b = b_prime;
*out_w = w;
}
rgb_2_rgbw_function g_user_function = rgb_2_rgbw_exact;
void set_rgb_2_rgbw_function(rgb_2_rgbw_function func) {
if (func == nullptr) {
g_user_function = rgb_2_rgbw_exact;
return;
}
g_user_function = func;
}
void rgb_2_rgbw_user_function(uint16_t w_color_temperature, uint8_t r,
uint8_t g, uint8_t b, uint8_t r_scale,
uint8_t g_scale, uint8_t b_scale, uint8_t *out_r,
uint8_t *out_g, uint8_t *out_b, uint8_t *out_w) {
g_user_function(w_color_temperature, r, g, b, r_scale, g_scale, b_scale,
out_r, out_g, out_b, out_w);
}
void rgbw_partial_reorder(EOrderW w_placement, uint8_t b0, uint8_t b1,
uint8_t b2, uint8_t w, uint8_t *out_b0,
uint8_t *out_b1, uint8_t *out_b2, uint8_t *out_b3) {
uint8_t out[4] = {b0, b1, b2, 0};
switch (w_placement) {
// unrolled loop for speed.
case W3:
out[3] = w;
break;
case W2:
out[3] = out[2]; // memmove and copy.
out[2] = w;
break;
case W1:
out[3] = out[2];
out[2] = out[1];
out[1] = w;
break;
case W0:
out[3] = out[2];
out[2] = out[1];
out[1] = out[0];
out[0] = w;
break;
}
*out_b0 = out[0];
*out_b1 = out[1];
*out_b2 = out[2];
*out_b3 = out[3];
}
} // namespace fl