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author | Akira Kakuto <kakuto@fuk.kindai.ac.jp> | 2015-12-28 12:09:41 +0000 |
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committer | Akira Kakuto <kakuto@fuk.kindai.ac.jp> | 2015-12-28 12:09:41 +0000 |
commit | 1fff76f0c267ade1406b5a8a9a8c48c7cab1ad4f (patch) | |
tree | 7701270ffe1ed4b8ec08208b9ccdf2afb0b5f957 /Build/source/libs/freetype2/freetype-src/src/tools/cordic.py | |
parent | 28d16176960e908983aaa3926faddc374209de78 (diff) |
freetype-2.6.2
git-svn-id: svn://tug.org/texlive/trunk@39211 c570f23f-e606-0410-a88d-b1316a301751
Diffstat (limited to 'Build/source/libs/freetype2/freetype-src/src/tools/cordic.py')
-rwxr-xr-x | Build/source/libs/freetype2/freetype-src/src/tools/cordic.py | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/Build/source/libs/freetype2/freetype-src/src/tools/cordic.py b/Build/source/libs/freetype2/freetype-src/src/tools/cordic.py new file mode 100755 index 00000000000..6742c90dfef --- /dev/null +++ b/Build/source/libs/freetype2/freetype-src/src/tools/cordic.py @@ -0,0 +1,33 @@ +# compute arctangent table for CORDIC computations in fttrigon.c +import sys, math + +#units = 64*65536.0 # don't change !! +units = 180 * 2**16 +scale = units/math.pi +shrink = 1.0 +comma = "" + +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 + + sys.stdout.write( comma + repr( int(angle2) ) ) + comma = ", " + + shrink /= math.sqrt( 1 + x*x ) + +print +print "shrink factor = " + repr( shrink ) +print "shrink factor 2 = " + repr( int( shrink * (2**32) ) ) +print "expansion factor = " + repr( 1/shrink ) +print "" + |