[DedeHai]

micro optimisation, remove some (implicit) double floats.
on a C3 this saves almost 1k of flash, about half of that on classic ESP32.

@softhack007 you did look into these things in the past, please review, especially the function call changes or if any of them were intentionally double floats for higher precision

Summary by CodeRabbit

• Bug Fixes
  • Improved consistency in distance and launch-speed calculations for Lava Lamp and particle fireworks effects.
  • Refined Loxone color and brightness handling, including color-temperature adjustments.
  • Improved color calculations for supported color-control integrations.
  • Updated coordinate checks used in sunrise and sunset calculations.

[coderabbitai]

Walkthrough

Math, effect, time, and color-conversion calculations now use float-specific functions or constants. The Loxone Lumitech conversion also normalizes brightness before applying it to color channels.

Changes

Float calculations

Layer / File(s)	Summary
Math and effect calculations wled00/wled_math.cpp, usermods/user_fx/user_fx.cpp, wled00/FX.cpp, wled00/ntp.cpp	Math helpers and effect calculations use float-specific functions or constants. The NTP coordinate-presence check uses 10.0f.
Color conversions wled00/lx_parser.cpp, wled00/src/dependencies/espalexa/EspalexaDevice.cpp	Loxone conversions use float-suffixed scaling and normalize Lumitech brightness before applying it to color channels. Espalexa calculations use float constants and floorf.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Refactor

Suggested reviewers: softhack007

Merge Risk: ⚪ Minimal · up to 5af21

No new merge-blocking risk was introduced by this PR.

Pre-merge checks: 4 · 1

Failed checks: 1 warning

Check name	Status	Explanation	Resolution
Docstring Coverage		Docstring coverage is 55.56% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 9 functions across 6 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

Passed checks: 4 passed

Check name	Status	Explanation
Description Check		Check skipped - CodeRabbit’s high-level summary is enabled.
Title check		The title clearly describes the main change: replacing unnecessary double-precision floating-point operations with float operations.
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.

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Actionable comments posted: 1

---

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Inline comments:
Review comments at @wled00/src/dependencies/espalexa/EspalexaDevice.cpp:
- Around line 233-235: In setColorXY, clamp each scaled RGB channel to the
inclusive range 0–255 before converting it to byte and assigning it to rgb.

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📒 Files selected for processing: 6

• usermods/user_fx/user_fx.cpp
• wled00/FX.cpp
• wled00/lx_parser.cpp
• wled00/ntp.cpp
• wled00/src/dependencies/espalexa/EspalexaDevice.cpp
• wled00/wled_math.cpp

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• GitHub Check: wled_build / Build Environments (esp32dev_hub75_forum_pinout)
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⚙️ CodeRabbit configuration file

Files:

• wled00/src/dependencies/espalexa/EspalexaDevice.cpp
• wled00/lx_parser.cpp
• wled00/ntp.cpp
• wled00/FX.cpp
• wled00/wled_math.cpp

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⚙️ CodeRabbit configuration file

Files:

• usermods/user_fx/user_fx.cpp
• wled00/src/dependencies/espalexa/EspalexaDevice.cpp
• wled00/lx_parser.cpp
• wled00/ntp.cpp
• wled00/FX.cpp
• wled00/wled_math.cpp

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Files:

• usermods/user_fx/user_fx.cpp
• wled00/src/dependencies/espalexa/EspalexaDevice.cpp
• wled00/lx_parser.cpp
• wled00/ntp.cpp
• wled00/FX.cpp
• wled00/wled_math.cpp

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Files:

• usermods/user_fx/user_fx.cpp
• wled00/src/dependencies/espalexa/EspalexaDevice.cpp
• wled00/lx_parser.cpp
• wled00/ntp.cpp
• wled00/FX.cpp
• wled00/wled_math.cpp

Source excerpt: Follow the existing style in the file you are editing Source excerpt: Avoid unexplained "magic numbers".

📄 CodeRabbit inference engine (AGENTS.md)

Files:

• usermods/user_fx/user_fx.cpp
• wled00/src/dependencies/espalexa/EspalexaDevice.cpp
• wled00/lx_parser.cpp
• wled00/ntp.cpp
• wled00/FX.cpp
• wled00/wled_math.cpp

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🔇 Additional comments: 6

wled00/wled_math.cpp: 1

124-124: LGTM!

Also applies to: 127-127, 131-131, 146-147, 149-149, 157-157, 173-173, 188-188

usermods/user_fx/user_fx.cpp: 1

484-484: LGTM!

wled00/FX.cpp: 1

9857-9857: LGTM!

wled00/ntp.cpp: 1

526-526: LGTM!

wled00/lx_parser.cpp: 1

19-21: LGTM!

Also applies to: 25-25, 29-29, 34-36

wled00/src/dependencies/espalexa/EspalexaDevice.cpp: 1

145-145: LGTM!

Also applies to: 150-150, 154-154, 156-158, 160-162, 166-168

[DedeHai]

@coderabbitai do any of the changes introduce a loss in precision that has real consequences?

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🧩 Analysis chain

🏁 Script executed:

#!/bin/bash
gh pr diff 5925 --repo wled/WLED
ast-grep outline usermods/user_fx/user_fx.cpp --match '.*' --type function
ast-grep outline wled00/FX.cpp --match mode_particleFireworks1D
ast-grep outline wled00/lx_parser.cpp
ast-grep outline wled00/ntp.cpp --match calculateSunriseAndSunset
ast-grep outline wled00/src/dependencies/espalexa/EspalexaDevice.cpp
ast-grep outline wled00/wled_math.cpp

Length of output: 12138

---

🏁 Script executed:

#!/bin/bash
sed -n '1,85p' wled00/lx_parser.cpp
sed -n '117,204p' wled00/wled_math.cpp
sed -n '125,240p' wled00/src/dependencies/espalexa/EspalexaDevice.cpp
sed -n '9818,9865p' wled00/FX.cpp
sed -n '520,570p' wled00/ntp.cpp
sed -n '460,490p' usermods/user_fx/user_fx.cpp
rg -n -C2 'float (longitude|latitude)|#define round|#define sqrt|#define constrain' wled00
python - <<'PY'
import struct, math
f=lambda x: struct.unpack('f',struct.pack('f',x))[0]
rnd=lambda x: math.floor(x+0.5)
print("RGB percent conversions: input, double product, float product, rounded double, rounded float")
for x in range(101):
    a=x*2.55
    b=f(f(x)*f(2.55))
    if rnd(a)!=rnd(b):
        print(x,repr(a),repr(b),rnd(a),rnd(b))
print("Presence check near 0.1 degrees:")
for x in [0.1, -0.1]:
    x=f(x)
    print(x,int(x*10.0),int(f(x*f(10.0))))
print("Float pi constant absolute error:",f(math.pi)-math.pi)
print("Float pi/2 constant absolute error:",f(math.pi/2)-math.pi/2)
PY

Length of output: 15657

---

@DedeHai I found small numerical differences, but no precision loss that appears consequential for these uses. The changes are not guaranteed to produce identical output.

• Loxone RGB: A channel can change by one count out of 255 at a rounding boundary. For example, an independent IEEE-754 calculation gives 50 * 2.55 ≈ 127.49999999999999, but float multiplication gives 127.5. With standard round semantics, the result changes from 127 to 128. The float result is closer to the intended percentage conversion in this case.

• Espalexa: The color-temperature constants and final XY-to-RGB multiplication lose some intermediate precision. Near an integer boundary, this can change an 8-bit channel by one count. I found no indication of a larger color error from these changes.

• Trigonometric approximations: The float π constant differs from π by about 8.7e-8 radians. The arithmetic changes introduce errors on the float-rounding scale. These are much smaller than the documented 6.7e-5 approximation error of acos_t. I see no practical reason to retain double precision here.

• Particle effects: The Lava Lamp calculation already stores the distance as float. Using sqrtf fits that precision. The fireworks calculation converts the result to an integer and caps it at 127. Below that cap, the integer square-root boundaries are sufficiently separated that float precision is adequate.

• Sunrise/sunset and Lumitech: The coordinate change affects only the “coordinates are set” check, not the sunrise calculation. Removing floor in Lumitech does not lose precision because the division already uses integer operands. Moving brightness normalization earlier preserves the float calculation.

My assessment: the flash saving is worthwhile. The relevant compatibility difference is a possible one-count RGB change, not a meaningful reduction in calculation accuracy.

I inspected the changed expressions and checked representative rounding cases independently. I did not run firmware or compare LED output on hardware.

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[softhack007]

looks good for me :-)

wled_math was always intended as "fast/smaller, maybe less accurate" so I don't think anything there was intended to be double.

ntp sunrise/sunset calc has its own accuracy problems, but these are much bigger than the difference between double and float.

Can't say much for Loxone or Alexa, but it should be OK, both modules target colored lamps.