1 files changed, 32 insertions, 0 deletions
diff --git a/modules/freetype2/src/tools/cordic.py b/modules/freetype2/src/tools/cordic.py
new file mode 100644
index 0000000000..6511429889
--- /dev/null
+++ b/modules/freetype2/src/tools/cordic.py
@@ -0,0 +1,32 @@
+#!/usr/bin/env python3
+
+# compute arctangent table for CORDIC computations in fttrigon.c
+import math
+
+# units  = 64*65536.0   # don't change !!
+units = 180 * 2 ** 16
+scale = units / math.pi
+shrink = 1.0
+angles2 = []
+
+print("")
+print("table of arctan( 1/2^n ) for PI = " + repr(units / 65536.0) + " units")
+
+for n in range(1, 32):
+
+    x = 0.5 ** n  # tangent value
+
+    angle = math.atan(x)  # arctangent
+    angle2 = round(angle * scale)  # arctangent in FT_Angle units
+
+    if angle2 <= 0:
+        break
+
+    angles2.append(repr(int(angle2)))
+    shrink /= math.sqrt(1 + x * x)
+
+print(", ".join(angles2))
+print("shrink factor    = " + repr(shrink))
+print("shrink factor 2  = " + repr(int(shrink * (2 ** 32))))
+print("expansion factor = " + repr(1 / shrink))
+print("")