Home | History | Annotate | Download | only in tables 
      1 from __future__ import print_function, division, absolute_import
      2 from fontTools.misc.py23 import *
      3 from fontTools.misc import sstruct
      4 from fontTools.misc.textTools import safeEval
      5 from . import DefaultTable
      6 
      7 
      8 hheaFormat = """
      9 		>  # big endian
     10 		tableVersion:           16.16F
     11 		ascent:                 h
     12 		descent:                h
     13 		lineGap:                h
     14 		advanceWidthMax:        H
     15 		minLeftSideBearing:     h
     16 		minRightSideBearing:    h
     17 		xMaxExtent:             h
     18 		caretSlopeRise:         h
     19 		caretSlopeRun:          h
     20 		caretOffset:            h
     21 		reserved0:              h
     22 		reserved1:              h
     23 		reserved2:              h
     24 		reserved3:              h
     25 		metricDataFormat:       h
     26 		numberOfHMetrics:       H
     27 """
     28 
     29 
     30 class table__h_h_e_a(DefaultTable.DefaultTable):
     31 	
     32 	dependencies = ['hmtx', 'glyf']
     33 	
     34 	def decompile(self, data, ttFont):
     35 		sstruct.unpack(hheaFormat, data, self)
     36 	
     37 	def compile(self, ttFont):
     38 		if ttFont.isLoaded('glyf') and ttFont.recalcBBoxes:
     39 			self.recalc(ttFont)
     40 		return sstruct.pack(hheaFormat, self)
     41 	
     42 	def recalc(self, ttFont):
     43 		hmtxTable = ttFont['hmtx']
     44 		if 'glyf' in ttFont:
     45 			glyfTable = ttFont['glyf']
     46 			INFINITY = 100000
     47 			advanceWidthMax = 0
     48 			minLeftSideBearing = +INFINITY  # arbitrary big number
     49 			minRightSideBearing = +INFINITY # arbitrary big number
     50 			xMaxExtent = -INFINITY          # arbitrary big negative number
     51 			
     52 			for name in ttFont.getGlyphOrder():
     53 				width, lsb = hmtxTable[name]
     54 				advanceWidthMax = max(advanceWidthMax, width)
     55 				g = glyfTable[name]
     56 				if g.numberOfContours == 0:
     57 					continue
     58 				if g.numberOfContours < 0 and not hasattr(g, "xMax"):
     59 					# Composite glyph without extents set.
     60 					# Calculate those.
     61 					g.recalcBounds(glyfTable)
     62 				minLeftSideBearing = min(minLeftSideBearing, lsb)
     63 				rsb = width - lsb - (g.xMax - g.xMin)
     64 				minRightSideBearing = min(minRightSideBearing, rsb)
     65 				extent = lsb + (g.xMax - g.xMin)
     66 				xMaxExtent = max(xMaxExtent, extent)
     67 
     68 			if xMaxExtent == -INFINITY:
     69 				# No glyph has outlines.
     70 				minLeftSideBearing = 0
     71 				minRightSideBearing = 0
     72 				xMaxExtent = 0
     73 
     74 			self.advanceWidthMax = advanceWidthMax
     75 			self.minLeftSideBearing = minLeftSideBearing
     76 			self.minRightSideBearing = minRightSideBearing
     77 			self.xMaxExtent = xMaxExtent
     78 		else:
     79 			# XXX CFF recalc...
     80 			pass
     81 	
     82 	def toXML(self, writer, ttFont):
     83 		formatstring, names, fixes = sstruct.getformat(hheaFormat)
     84 		for name in names:
     85 			value = getattr(self, name)
     86 			writer.simpletag(name, value=value)
     87 			writer.newline()
     88 	
     89 	def fromXML(self, name, attrs, content, ttFont):
     90 		setattr(self, name, safeEval(attrs["value"]))
     91 
     92