added a stepped ramp calculator for Anduril,

because people keep asking

1 files changed, 51 insertions, 0 deletions

diff --git a/spaghetti-monster/anduril/steps.py b/spaghetti-monster/anduril/steps.py
new file mode 100755
index 0000000..9056ea3
--- /dev/null
+++ b/spaghetti-monster/anduril/steps.py
@@ -0,0 +1,51 @@
+#!/usr/bin/env python
+
+"""steps.py: Calculate the stepped ramp levels used by Anduril.
+Usage: steps.py floor ceiling num_steps
+For example:
+    > ./steps.py 1 150 3
+    1: 1
+    2: 75
+    3: 150
+"""
+
+def main(args):
+    floor, ceil, steps = [int(x) for x in args[:3]]
+    for i in range(steps):
+        guess = floor + (i * (float(ceil-floor)/(steps-1)))
+        this = nearest_level(guess, floor, ceil, steps)
+        #print('%i: %i (guess: %i)' % (i+1, this, guess))
+        print('%i: %i' % (i+1, this))
+
+
+def nearest_level(target, floor, ceil, steps):
+    """Copied/adapted from anduril.c"""
+    # bounds check
+    # using int16_t here saves us a bunch of logic elsewhere,
+    # by allowing us to correct for numbers < 0 or > 255 in one central place
+    mode_min = floor;
+    mode_max = ceil;
+
+    if (target < mode_min): return mode_min;
+    if (target > mode_max): return mode_max;
+    # the rest isn't relevant for smooth ramping
+    #if (! ramp_style): return target;
+
+    ramp_range = ceil - floor;
+    ramp_discrete_step_size = ramp_range / (steps-1);
+    this_level = floor;
+
+    for i in range(steps):
+        this_level = floor + (i * int(ramp_range) / (steps-1));
+        diff = int(target - this_level);
+        if (diff < 0): diff = -diff;
+        if (diff <= (ramp_discrete_step_size>>1)):
+            return this_level;
+
+    return this_level;
+
+
+if __name__ == "__main__":
+    import sys
+    main(sys.argv[1:])
+