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, 308 insertions, 0 deletions

diff --git a/misc/pylib/fontbuild/italics.pyx b/misc/pylib/fontbuild/italics.pyx
new file mode 100644
index 000000000..522336197
--- /dev/null
+++ b/misc/pylib/fontbuild/italics.pyx
@@ -0,0 +1,308 @@
+# 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.
+
+
+import math
+
+from fontTools.misc.transform import Transform
+import numpy as np
+from numpy.linalg import norm
+from scipy.sparse.linalg import cg
+from scipy.ndimage.filters import gaussian_filter1d as gaussian
+from scipy.cluster.vq import vq, whiten
+
+from fontbuild.alignpoints import alignCorners
+from fontbuild.curveFitPen import fitGlyph, segmentGlyph
+
+
+def italicizeGlyph(f, g, angle=10, stemWidth=185, meanYCenter=-825, narrowAmount=1):
+    unic = g.unicode #save unicode
+
+    glyph = f[g.name]
+    slope = np.tanh(math.pi * angle / 180)
+
+    # determine how far on the x axis the glyph should slide
+    # to compensate for the slant.
+    # meanYCenter:
+    #   -600 is a magic number that assumes a 2048 unit em square,
+    #   and -825 for a 2816 unit em square. (UPM*0.29296875)
+    m = Transform(1, 0, slope, 1, 0, 0)
+    xoffset, junk = m.transformPoint((0, meanYCenter))
+    m = Transform(narrowAmount, 0, slope, 1, xoffset, 0)
+
+    if len(glyph) > 0:
+        g2 = italicize(f[g.name], angle, xoffset=xoffset, stemWidth=stemWidth)
+        f.insertGlyph(g2, g.name)
+
+    transformFLGlyphMembers(f[g.name], m)
+
+    if unic > 0xFFFF: #restore unicode
+        g.unicode = unic
+
+
+def italicize(glyph, angle=12, stemWidth=180, xoffset=-50):
+    CURVE_CORRECTION_WEIGHT = .03
+    CORNER_WEIGHT = 10
+
+    # decompose the glyph into smaller segments
+    ga, subsegments = segmentGlyph(glyph,25)
+    va, e  = glyphToMesh(ga)
+    n = len(va)
+    grad = mapEdges(lambda a, pn: normalize(pn[0]-a), va, e)
+    cornerWeights = mapEdges(lambda a, pn: normalize(pn[0]-a).dot(normalize(a-pn[1])), grad, e)[:,0].reshape((-1,1))
+    smooth = np.ones((n,1)) * CURVE_CORRECTION_WEIGHT
+
+    controlPoints = findControlPointsInMesh(glyph, va, subsegments)
+    smooth[controlPoints > 0] = 1
+    smooth[cornerWeights < .6] = CORNER_WEIGHT
+    # smooth[cornerWeights >= .9999] = 1
+
+    out = va.copy()
+    hascurves = False
+    for c in glyph.contours:
+        for s in c.segments:
+            if s.type == "curve":
+                hascurves = True
+                break
+        if hascurves:
+            break
+    if stemWidth > 100:
+        outCorrected = skewMesh(recompose(skewMesh(out, angle * 1.6), grad, e, smooth=smooth), -angle * 1.6)
+        # out = copyMeshDetails(va, out, e, 6)
+    else:
+        outCorrected = out
+
+    # create a transform for italicizing
+    normals = edgeNormals(out, e)
+    center = va + normals * stemWidth * .4
+    if stemWidth > 130:
+        center[:, 0] = va[:, 0] * .7 + center[:,0] * .3
+    centerSkew = skewMesh(center.dot(np.array([[.97,0],[0,1]])), angle * .9)
+
+    # apply the transform
+    out = outCorrected + (centerSkew - center)
+    out[:,1] = outCorrected[:,1]
+
+    # make some corrections
+    smooth = np.ones((n,1)) * .1
+    out = alignCorners(glyph, out, subsegments)
+    out = copyMeshDetails(skewMesh(va, angle), out, e, 7, smooth=smooth)
+    # grad = mapEdges(lambda a,(p,n): normalize(p-a), skewMesh(outCorrected, angle*.9), e)
+    # out = recompose(out, grad, e, smooth=smooth)
+
+    out = skewMesh(out, angle * .1)
+    out[:,0] += xoffset
+    # out[:,1] = outCorrected[:,1]
+    out[va[:,1] == 0, 1] = 0
+    gOut = meshToGlyph(out, ga)
+    # gOut.width *= .97
+    # gOut.width += 10
+    # return gOut
+
+    # recompose the glyph into original segments
+    return fitGlyph(glyph, gOut, subsegments)
+
+
+def transformFLGlyphMembers(g, m, transformAnchors = True):
+    # g.transform(m)
+    g.width = g.width * m[0]
+    p = m.transformPoint((0,0))
+    for c in g.components:
+        d = m.transformPoint(c.offset)
+        c.offset = (d[0] - p[0], d[1] - p[1])
+    if transformAnchors:
+        for a in g.anchors:
+                aa = m.transformPoint((a.x,a.y))
+                a.x  = aa[0]
+                # a.x,a.y = (aa[0] - p[0], aa[1] - p[1])
+                # a.x = a.x - m[4]
+
+
+def glyphToMesh(g):
+    points = []
+    edges = {}
+    offset = 0
+    for c in g.contours:
+        if len(c) < 2:
+            continue
+        for i,prev,next in rangePrevNext(len(c)):
+            points.append((c[i].points[0].x, c[i].points[0].y))
+            edges[i + offset] = np.array([prev + offset, next + offset], dtype=int)
+        offset += len(c)
+    return np.array(points), edges
+
+
+def meshToGlyph(points, g):
+    g1 = g.copy()
+    j = 0
+    for c in g1.contours:
+        if len(c) < 2:
+            continue
+        for i in range(len(c)):
+            c[i].points[0].x = points[j][0]
+            c[i].points[0].y = points[j][1]
+            j += 1
+    return g1
+
+
+def quantizeGradient(grad, book=None):
+    if book == None:
+        book = np.array([(1,0),(0,1),(0,-1),(-1,0)])
+    indexArray = vq(whiten(grad), book)[0]
+    out = book[indexArray]
+    for i,v in enumerate(out):
+        out[i] = normalize(v)
+    return out
+
+
+def findControlPointsInMesh(glyph, va, subsegments):
+    controlPointIndices = np.zeros((len(va),1))
+    index = 0
+    for i,c in enumerate(subsegments):
+        segmentCount = len(glyph.contours[i].segments) - 1
+        for j,s in enumerate(c):
+            if j < segmentCount:
+                if glyph.contours[i].segments[j].type == "line":
+                    controlPointIndices[index] = 1
+            index += s[1]
+    return controlPointIndices
+
+
+def recompose(v, grad, e, smooth=1, P=None, distance=None):
+    n = len(v)
+    if distance == None:
+        distance = mapEdges(lambda a, pn: norm(pn[0] - a), v, e)
+    if (P == None):
+        P = mP(v,e)
+        P += np.identity(n) * smooth
+    f = v.copy()
+    for i,(prev,next) in e.iteritems():
+        f[i] = (grad[next] * distance[next] - grad[i] * distance[i])
+    out = v.copy()
+    f += v * smooth
+    for i in range(len(out[0,:])):
+        out[:,i] = cg(P, f[:,i])[0]
+    return out
+
+
+def mP(v,e):
+    n = len(v)
+    M = np.zeros((n,n))
+    for i, edges in e.iteritems():
+        w = -2 / float(len(edges))
+        for index in edges:
+            M[i,index] = w
+        M[i,i] = 2
+    return M
+
+
+def normalize(v):
+    n = np.linalg.norm(v)
+    if n == 0:
+        return v
+    return v/n
+
+
+def mapEdges(func,v,e,*args):
+    b = v.copy()
+    for i, edges in e.iteritems():
+        b[i] = func(v[i], [v[j] for j in edges], *args)
+    return b
+
+
+def getNormal(a,b,c):
+    "Assumes TT winding direction"
+    p = np.roll(normalize(b - a), 1)
+    n = -np.roll(normalize(c - a), 1)
+    p[1] *= -1
+    n[1] *= -1
+    # print p, n, normalize((p + n) * .5)
+    return normalize((p + n) * .5)
+
+
+def edgeNormals(v,e):
+    "Assumes a mesh where each vertex has exactly least two edges"
+    return mapEdges(lambda a, pn : getNormal(a,pn[0],pn[1]),v,e)
+
+
+def rangePrevNext(count):
+    c = np.arange(count,dtype=int)
+    r = np.vstack((c, np.roll(c, 1), np.roll(c, -1)))
+    return r.T
+
+
+def skewMesh(v,angle):
+    slope = np.tanh([math.pi * angle / 180])
+    return v.dot(np.array([[1,0],[slope,1]]))
+
+
+def labelConnected(e):
+    label = 0
+    labels = np.zeros((len(e),1))
+    for i,(prev,next) in e.iteritems():
+        labels[i] = label
+        if next <= i:
+            label += 1
+    return labels
+
+
+def copyGradDetails(a,b,e,scale=15):
+    n = len(a)
+    labels = labelConnected(e)
+    out = a.astype(float).copy()
+    for i in range(labels[-1]+1):
+        mask = (labels==i).flatten()
+        out[mask,:] = gaussian(b[mask,:], scale, mode="wrap", axis=0) + a[mask,:] - gaussian(a[mask,:], scale, mode="wrap", axis=0)
+    return out
+
+
+def copyMeshDetails(va,vb,e,scale=5,smooth=.01):
+    gradA = mapEdges(lambda a, pn: normalize(pn[0]-a), va, e)
+    gradB = mapEdges(lambda a, pn: normalize(pn[0]-a), vb, e)
+    grad = copyGradDetails(gradA, gradB, e, scale)
+    grad = mapEdges(lambda a, pn: normalize(a), grad, e)
+    return recompose(vb, grad, e, smooth=smooth)
+
+
+def condenseGlyph(glyph, scale=.8, stemWidth=185):
+    ga, subsegments = segmentGlyph(glyph, 25)
+    va, e  = glyphToMesh(ga)
+    n = len(va)
+
+    normals = edgeNormals(va,e)
+    cn = va.dot(np.array([[scale, 0],[0,1]]))
+    grad = mapEdges(lambda a, pn: normalize(pn[0]-a), cn, e)
+    # ograd = mapEdges(lambda a,(p,n): normalize(p-a), va, e)
+
+    cn[:,0] -= normals[:,0] * stemWidth * .5 * (1 - scale)
+    out = recompose(cn, grad, e, smooth=.5)
+    # out = recompose(out, grad, e, smooth=.1)
+    out = recompose(out, grad, e, smooth=.01)
+
+    # cornerWeights = mapEdges(lambda a,(p,n): normalize(p-a).dot(normalize(a-n)), grad, e)[:,0].reshape((-1,1))
+    #     smooth = np.ones((n,1)) * .1
+    #     smooth[cornerWeights < .6] = 10
+    #
+    #     grad2 = quantizeGradient(grad).astype(float)
+    #     grad2 = copyGradDetails(grad, grad2, e, scale=10)
+    #     grad2 = mapEdges(lambda a,e: normalize(a), grad2, e)
+    #     out = recompose(out, grad2, e, smooth=smooth)
+    out[:,0] += 15
+    out[:,1] = va[:,1]
+    # out = recompose(out, grad, e, smooth=.5)
+    gOut = meshToGlyph(out, ga)
+    gOut = fitGlyph(glyph, gOut, subsegments)
+    for i,seg in enumerate(gOut):
+        gOut[i].points[0].y = glyph[i].points[0].y
+    return gOut