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Diffstat (limited to 'scripts/lib/fontbuild/alignpoints.py')
| -rw-r--r-- | scripts/lib/fontbuild/alignpoints.py | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/scripts/lib/fontbuild/alignpoints.py b/scripts/lib/fontbuild/alignpoints.py new file mode 100644 index 0000000..ed502ed --- /dev/null +++ b/scripts/lib/fontbuild/alignpoints.py @@ -0,0 +1,148 @@ + + +import numpy as np +from numpy.linalg import lstsq +import math + +def alignCorners(glyph, va, subsegments): + out = va.copy() + # for i,c in enumerate(subsegments): + # segmentCount = len(glyph.contours[i].segments) - 1 + # n = len(c) + # for j,s in enumerate(c): + # if j < segmentCount: + # seg = glyph.contours[i].segments[j] + # if seg.type == "line": + # subIndex = subsegmentIndex(i,j,subsegments) + # out[subIndex] = alignPoints(va[subIndex]) + + for i,c in enumerate(subsegments): + segmentCount = len(glyph.contours[i].segments) + n = len(c) + for j,s in enumerate(c): + if j < segmentCount - 1: + segType = glyph.contours[i].segments[j].type + segnextType = glyph.contours[i].segments[j+1].type + next = j+1 + elif j == segmentCount -1 and s[1] > 3: + segType = glyph.contours[i].segments[j].type + segNextType = "line" + next = j+1 + elif j == segmentCount: + segType = "line" + segnextType = glyph.contours[i].segments[1].type + if glyph.name == "J": + print s[1] + print segnextType + next = 1 + else: + break + if segType == "line" and segnextType == "line": + subIndex = subsegmentIndex(i,j,subsegments) + pts = va[subIndex] + ptsnext = va[subsegmentIndex(i,next,subsegments)] + # out[subIndex[-1]] = (out[subIndex[-1]] - 500) * 3 + 500 #findCorner(pts, ptsnext) + # print subIndex[-1], subIndex, subsegmentIndex(i,next,subsegments) + try: + out[subIndex[-1]] = findCorner(pts, ptsnext) + except: + pass + # print glyph.name, "Can't find corner: parallel lines" + return out + + +def subsegmentIndex(contourIndex, segmentIndex, subsegments): + # This whole thing is so dumb. Need a better data model for subsegments + + contourOffset = 0 + for i,c in enumerate(subsegments): + if i == contourIndex: + break + contourOffset += c[-1][0] + n = subsegments[contourIndex][-1][0] + # print contourIndex, contourOffset, n + startIndex = subsegments[contourIndex][segmentIndex-1][0] + segmentCount = subsegments[contourIndex][segmentIndex][1] + endIndex = (startIndex + segmentCount + 1) % (n) + + indices = np.array([(startIndex + i) % (n) + contourOffset for i in range(segmentCount + 1)]) + return indices + +def alignPoints(pts, start=None, end=None): + if start == None or end == None: + start, end = fitLine(pts) + out = pts.copy() + for i,p in enumerate(pts): + out[i] = nearestPoint(start, end, p) + return out + +def findCorner(pp, nn): + if len(pp) < 4 or len(nn) < 4: + assert 0, "line too short to fit" + pStart,pEnd = fitLine(pp) + nStart,nEnd = fitLine(nn) + prev = pEnd - pStart + next = nEnd - nStart + # print int(np.arctan2(prev[1],prev[0]) / math.pi * 180), + # print int(np.arctan2(next[1],next[0]) / math.pi * 180) + # if lines are parallel, return simple average of end and start points + if np.dot(prev / np.linalg.norm(prev), + next / np.linalg.norm(next)) > .999999: + # print "parallel lines", np.arctan2(prev[1],prev[0]), np.arctan2(next[1],next[0]) + # print prev, next + assert 0, "parallel lines" + return lineIntersect(pStart, pEnd, nStart, nEnd) + +def lineIntersect((x1,y1),(x2,y2),(x3,y3),(x4,y4)): + x12 = x1 - x2 + x34 = x3 - x4 + y12 = y1 - y2 + y34 = y3 - y4 + + det = x12 * y34 - y12 * x34 + if det == 0: + print "parallel!" + + a = x1 * y2 - y1 * x2 + b = x3 * y4 - y3 * x4 + + x = (a * x34 - b * x12) / det + y = (a * y34 - b * y12) / det + + return (x,y) + +def fitLineLSQ(pts): + "returns a line fit with least squares. Fails for vertical lines" + n = len(pts) + a = np.ones((n,2)) + for i in range(n): + a[i,0] = pts[i,0] + line = lstsq(a,pts[:,1])[0] + return line + +def fitLine(pts): + """returns a start vector and direction vector + Assumes points segments that already form a somewhat smooth line + """ + n = len(pts) + if n < 1: + return (0,0),(0,0) + a = np.zeros((n-1,2)) + for i in range(n-1): + v = pts[i] - pts[i+1] + a[i] = v / np.linalg.norm(v) + direction = np.mean(a[1:-1], axis=0) + start = np.mean(pts[1:-1], axis=0) + return start, start+direction + +def nearestPoint(a,b,c): + "nearest point to point c on line a_b" + magnitude = np.linalg.norm(b-a) + if magnitude == 0: + raise Exception, "Line segment cannot be 0 length" + return (b-a) * np.dot((c-a) / magnitude, (b-a) / magnitude) + a + +# pts = np.array([[1,1],[2,2],[3,3],[4,4]]) +# pts2 = np.array([[1,0],[2,0],[3,0],[4,0]]) +# print alignPoints(pts2, start = pts[0], end = pts[0]+pts[0]) +# # print findCorner(pts,pts2)
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