[gcode_macro M106]
rename_existing: G106
description: Compresses fan speeds into 10–30% range if bed temp ≥ 70°C

# === OVERVIEW ===
# This macro overrides the default M106 behavior to apply a thermal-aware fan speed limiter.
# When the bed temperature is at or above 70°C, it compresses the part cooling fan speed range
# into a safer 10–30% range (i.e., 26–76 PWM) to reduce warping or delamination in high-temp materials.
#
# === WHY USE THIS ===
# - Prevents excessive part cooling when printing materials like ABS, ASA, or PC.
# - Helps maintain stable chamber temperatures and reduce thermal shock.
# - Minimizes curling or layer splitting due to sudden cooling on hot beds.
#
# === HOW TO USE ===
# Simply use M106 S<value> as usual in your G-code or slicer.
# The macro will automatically adjust the fan speed if needed based on bed temperature.
#
# === NOTES ===
# - This logic only applies when the bed temperature is 70°C or higher.
# - Below 70°C, full-range fan control is allowed.
# - You can customize the input/output compression range if needed.

# === PARAMETERS ===
#   S: Standard fan speed in 0–255 (required by M106)

# Internal constants:
#   min_input  = 26  (10% of 255)
#   max_input  = 255 (100%)
#   min_output = 26  (10%)
#   max_output = 76  (30%)

gcode:
    {% set fan_speed = params.S|default(0)|int %}
    {% set bed_temp = printer["heater_bed"].temperature %}
    {% set min_input = 26 %}
    {% set max_input = 255 %}
    {% set min_output = 26 %}
    {% set max_output = 76 %}

    {% if bed_temp >= 70 %}
        # If below threshold, limit fan to the lower compressed range (10–30%)
        {% if fan_speed < min_input %}
            {% set compressed_speed = min_output %}
        {% else %}
            {% set compressed_speed = (min_output + ((fan_speed - min_input) * (max_output - min_output) / (max_input - min_input)))|int %}
        {% endif %}
        G106 S{compressed_speed}
    {% else %}
        # Below threshold, allow full fan speed as requested
        G106 S{fan_speed}
    {% endif %}