Speeds up font compilation by around 200%

Cython is used to compile some hot paths into native Python extensions.
These hot paths were identified through running ufocompile with the hotshot
profiler and then converting file by file to Cython, starting with the "hottest"
paths and continuing until returns were deminishing. This means that only a few
Python files were converted to Cython.

Closes #23
Closes #20 (really this time)

1 files changed, 102 insertions, 0 deletions

diff --git a/misc/pylib/fontbuild/convertCurves.pyx b/misc/pylib/fontbuild/convertCurves.pyx
new file mode 100644
index 000000000..b6efd5ca2
--- /dev/null
+++ b/misc/pylib/fontbuild/convertCurves.pyx
@@ -0,0 +1,102 @@
+#! /usr/bin/env python
+#
+# Copyright 2015 Google Inc. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+Converts a cubic bezier curve to a quadratic spline with 
+exactly two off curve points.
+
+"""
+
+import numpy
+from numpy import array,cross,dot
+from fontTools.misc import bezierTools
+from robofab.objects.objectsRF import RSegment
+
+def replaceSegments(contour, segments):
+    while len(contour):
+        contour.removeSegment(0)
+    for s in segments:
+        contour.appendSegment(s.type, [(p.x, p.y) for p in s.points], s.smooth)
+    
+def calcIntersect(a,b,c,d):
+    numpy.seterr(all='raise')
+    e = b-a
+    f = d-c
+    p = array([-e[1], e[0]])
+    try:
+        h = dot((a-c),p) / dot(f,p)
+    except:
+        print a,b,c,d
+        raise
+    return c + dot(f,h)
+
+def simpleConvertToQuadratic(p0,p1,p2,p3):
+    p = [array(i.x,i.y) for i in [p0,p1,p2,p3]]
+    off = calcIntersect(p[0],p[1],p[2],p[3])
+
+# OFFCURVE_VECTOR_CORRECTION = -.015
+OFFCURVE_VECTOR_CORRECTION = 0
+
+def convertToQuadratic(p0,p1,p2,p3):
+    # TODO: test for accuracy and subdivide further if needed
+    p = [(i.x,i.y) for i in [p0,p1,p2,p3]]
+    # if p[0][0] == p[1][0] and p[0][0] == p[2][0] and p[0][0] == p[2][0] and p[0][0] == p[3][0]:
+    #     return (p[0],p[1],p[2],p[3]) 
+    # if p[0][1] == p[1][1] and p[0][1] == p[2][1] and p[0][1] == p[2][1] and p[0][1] == p[3][1]:
+    #     return (p[0],p[1],p[2],p[3])     
+    seg1,seg2 = bezierTools.splitCubicAtT(p[0], p[1], p[2], p[3], .5)
+    pts1 = [array([i[0], i[1]]) for i in seg1]
+    pts2 = [array([i[0], i[1]]) for i in seg2]
+    on1 = seg1[0]
+    on2 = seg2[3]
+    try:
+        off1 = calcIntersect(pts1[0], pts1[1], pts1[2], pts1[3])
+        off2 = calcIntersect(pts2[0], pts2[1], pts2[2], pts2[3])
+    except:
+        return (p[0],p[1],p[2],p[3])
+    off1 = (on1 - off1) * OFFCURVE_VECTOR_CORRECTION + off1
+    off2 = (on2 - off2) * OFFCURVE_VECTOR_CORRECTION + off2
+    return (on1,off1,off2,on2)
+
+def cubicSegmentToQuadratic(c,sid):
+    
+    segment = c[sid]
+    if (segment.type != "curve"):
+        print "Segment type not curve"
+        return
+    
+    #pSegment,junk = getPrevAnchor(c,sid)
+    pSegment = c[sid-1] #assumes that a curve type will always be proceeded by another point on the same contour
+    points = convertToQuadratic(pSegment.points[-1],segment.points[0],
+                                segment.points[1],segment.points[2])
+    return RSegment(
+        'qcurve', [[int(i) for i in p] for p in points[1:]], segment.smooth)
+
+def glyphCurvesToQuadratic(g):
+
+    for c in g:
+        segments = []
+        for i in range(len(c)):
+            s = c[i]
+            if s.type == "curve":
+                try:
+                    segments.append(cubicSegmentToQuadratic(c, i))
+                except Exception:
+                    print g.name, i
+                    raise
+            else:
+                segments.append(s)
+        replaceSegments(c, segments)