diff --git a/src/kaleidoscope/plugin/LED-Stalker.cpp b/src/kaleidoscope/plugin/LED-Stalker.cpp index e18598f0..9a59f93f 100644 --- a/src/kaleidoscope/plugin/LED-Stalker.cpp +++ b/src/kaleidoscope/plugin/LED-Stalker.cpp @@ -105,27 +105,32 @@ cRGB Haunt::compute(uint8_t *step) { // BlazingTrail BlazingTrail::BlazingTrail(void) { } +constexpr uint8_t hue_start = 50.0 / 360 * 0xff; +constexpr uint8_t hue_end = 0; cRGB BlazingTrail::compute(uint8_t *step) { cRGB color; - if (*step >= 0xff - 30) { - color = hsvToRgb(0xff - *step, 255, 255); - } else { - color = hsvToRgb(30, 255, 255); + // Get the position in the animation, where 0 is start and 0xff is end + uint8_t pos255 = 0xff - *step; - color.r = min(*step * color.r / 255, 255); - color.g = min(*step * color.g / 255, 255); - } + // Fade hue linearly from orange to red + uint8_t hue = hue_start + (pos255 * (hue_end - hue_start) >> 8); - if (*step >= 0xff - 30) - *step -= 1; - else if (*step >= 0x40) - *step -= 16; - else if (*step >= 32) - *step -= 32; - else + // Fade value from full following a 1-x^4 curve + uint8_t val = + 0xff // Maximum brightness + - ((uint32_t) pos255 * pos255 * pos255 * pos255 // Animation position to 4th power + >> 24) // ...pulled down to 8-bit range (but this has a maximum of 0xfc rather than 0xff) + - pos255 / (0x100 / 4); // Correction to bring the end result into a full 0 to 0xff range + + color = hsvToRgb(hue, 0xff, val); + + if (*step < 4) { *step = 0; + } else { + *step -= 4; + } return color; }