diff --git a/wled00/FX.cpp b/wled00/FX.cpp index d60c525261..47e5a2c700 100644 --- a/wled00/FX.cpp +++ b/wled00/FX.cpp @@ -2952,20 +2952,25 @@ static uint16_t spots_base(uint16_t threshold) if (SEGLEN <= 1) return mode_static(); if (!SEGMENT.check2) SEGMENT.fill(SEGCOLOR(1)); - unsigned maxZones = SEGLEN >> 2; - unsigned zones = 1 + ((SEGMENT.intensity * maxZones) >> 8); - unsigned zoneLen = SEGLEN / zones; - unsigned offset = (SEGLEN - zones * zoneLen) >> 1; + // constants for fixed point scaling + constexpr uint8_t ZONELEN_FP_SHIFT = 3; + constexpr uint32_t ZONELEN_FP_SCALE = 1U << ZONELEN_FP_SHIFT; + + unsigned maxZones = max(1U, SEGLEN >> 2); // prevents "0 zones" + unsigned zones = 1U + ((uint32_t(SEGMENT.intensity) * maxZones) >> 8); + unsigned zoneLen = SEGLEN / zones; + unsigned zoneLen8 = (SEGLEN * ZONELEN_FP_SCALE) / zones; // zoneLength * 8 (fixed‑point) -> avoids gaps at right/left sides + unsigned offset = (SEGLEN - ((zones * zoneLen8) >> ZONELEN_FP_SHIFT)) >> 1; for (unsigned z = 0; z < zones; z++) { - unsigned pos = offset + z * zoneLen; + unsigned pos = offset + ((z * zoneLen8) >> ZONELEN_FP_SHIFT); for (unsigned i = 0; i < zoneLen; i++) { unsigned wave = triwave16((i * 0xFFFF) / zoneLen); if (wave > threshold) { - unsigned index = 0 + pos + i; - unsigned s = (wave - threshold)*255 / (0xFFFF - threshold); + unsigned index = pos + i; + unsigned s = ((wave - threshold)*255 / (0xFFFF - threshold)) & 0xFF; // & 0xFF prevents overflow in next line SEGMENT.setPixelColor(index, color_blend(SEGMENT.color_from_palette(index, true, PALETTE_SOLID_WRAP, 0), SEGCOLOR(1), uint8_t(255-s))); } } @@ -2991,7 +2996,7 @@ uint16_t mode_spots_fade() unsigned tr = (t >> 1) + (t >> 2); return spots_base(tr); } -static const char _data_FX_MODE_SPOTS_FADE[] PROGMEM = "Spots Fade@Spread,Width,,,,,Overlay;!,!;!"; +static const char _data_FX_MODE_SPOTS_FADE[] PROGMEM = "Spots Fade@Speed,Width,,,,,Overlay;!,!;!"; //each needs 12 bytes typedef struct Ball {