164 lines
5.5 KiB
Python
164 lines
5.5 KiB
Python
# -*- coding: utf-8 -*-
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"""font abstraction"""
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# imports ####################################################################
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from itertools import chain
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from ctypes import byref, string_at
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from .utils import get_font
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from . import freetype2 as _ft2
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_FT = _ft2.FT
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_library = _ft2._library
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# globals ####################################################################
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def _on(tag):
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return bool(tag & 1)
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def _cubic(tag):
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return bool(tag & 2)
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# face #######################################################################
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class Face(object):
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def __init__(self, font_families, font_weight, font_style, px=10):
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font_name, index = get_font(font_families, font_weight, font_style)
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self.face = _ft2.Face()
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self.pen = _ft2.Vector()
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print('_library = %s' % str(_library))
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print('font_name = %s' % str(font_name))
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print('font_name.encode() = %s' % str(font_name.encode()))
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if _FT.New_Face(_library, font_name.encode(), index, byref(self.face)) != 0:
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raise ValueError("unable to create '%s' face" % font_name)
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_FT.Select_Charmap(self.face, _ft2.ENCODING_UNICODE)
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if px is not None:
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self.set_size(px)
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self._FT = _FT # keep a ref for finalizer
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def __del__(self):
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try:
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self._FT.Done_Face(self.face)
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except AttributeError:
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pass
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def set_size(self, px):
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_FT.Set_Pixel_Sizes(self.face, 0, px)
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def set_transform(self, a=1., b=0., c=0., d=1., e=0., f=0.):
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matrix = _ft2.Matrix()
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matrix.xx, matrix.xy = int(a * 0x10000), int(b * 0x10000)
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matrix.yx, matrix.yy = int(c * 0x10000), int(d * 0x10000)
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self.pen.x = int(e * 64)
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self.pen.y = int(-f * 64)
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_FT.Set_Transform(self.face, byref(matrix), byref(self.pen))
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def _glyph(self, uc):
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glyph_index = _FT.Get_Char_Index(self.face, ord(uc))
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_FT.Load_Glyph(self.face, glyph_index, _ft2.LOAD_DEFAULT)
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return self.face.contents.glyph.contents
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def get_hkerning(self, ucl, ucr):
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if ucl is None:
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return 0.
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left_glyph = _FT.Get_Char_Index(self.face, ord(ucl))
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right_glyph = _FT.Get_Char_Index(self.face, ord(ucr))
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kerning = _ft2.Vector()
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_FT.Get_Kerning(self.face, left_glyph, right_glyph,
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_ft2.KERNING_DEFAULT, byref(kerning))
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return kerning.x / 64.
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def get_bbox(self, text):
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width = 0
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top, bottom = 0, 0
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up = None
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glyph = None
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for uc in text:
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width += self.get_hkerning(up, uc)
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up = uc
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glyph = self._glyph(uc)
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width += glyph.metrics.horiAdvance / 64.
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top = max(top, glyph.metrics.horiBearingY / 64.)
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bottom = min(bottom, (glyph.metrics.horiBearingY -
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glyph.metrics.height) / 64.)
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if glyph:
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width += (glyph.metrics.horiBearingX + glyph.metrics.width -
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glyph.metrics.horiAdvance) / 64.
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return (0., -top), (width, top - bottom)
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def bitmap(self, uc):
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glyph = self._glyph(uc)
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_FT.Render_Glyph(byref(glyph), _ft2.RENDER_MODE_NORMAL)
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origin = glyph.bitmap_left, -glyph.bitmap_top
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bitmap = glyph.bitmap
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assert bitmap.pixel_mode == _ft2.PIXEL_MODE_GRAY, bitmap.pixel_mode
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rows, columns = bitmap.rows, bitmap.pitch
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size = columns, rows
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offset = glyph.advance.x / 64., -glyph.advance.y / 64.
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data = string_at(bitmap.buffer, rows * columns)
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data = bytes(chain(*([255, 255, 255, c] for c in data)))
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return origin, size, offset, data
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def outline(self, uc):
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glyph = self._glyph(uc)
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outline = glyph.outline
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data = []
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b = 0
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for c in range(outline.n_contours):
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e = outline.contours[c]
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# ensure we start with an 'on' point
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for s in range(b, e + 1):
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if _on(outline.tags[s]):
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break
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# generate path data
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contour = []
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command, offs = 'M', []
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for i in chain(range(s, e + 1), range(b, s + 1)):
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point, tag = outline.points[i], outline.tags[i]
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point = (point.x / 64., -point.y / 64.)
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if _on(tag): # 'on' point
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contour.append(command)
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if command is 'Q' and len(offs) >= 2:
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(x0, y0) = offs[0]
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for (x1, y1) in offs[1:]:
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contour += [(x0, y0), ((x0 + x1) / 2, (y0 + y1) / 2), 'Q']
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x0, y0 = x1, y1
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contour.append((x0, y0))
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else: # 'off' point
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contour += offs
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contour.append(point)
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command, offs = 'L', []
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else:
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offs.append(point)
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command = 'C' if _cubic(tag) else 'Q'
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if contour:
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contour.append('Z')
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data += contour
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b = e + 1
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# bbox
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bbox = _ft2.BBox()
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_FT.Outline_Get_BBox(byref(outline), byref(bbox))
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xmin, xmax = bbox.xMin / 64., bbox.xMax / 64.
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ymin, ymax = bbox.yMin / 64., bbox.yMax / 64.
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origin = xmin, -ymax
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size = xmax - xmin, ymax - ymin
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offset = glyph.advance.x / 64., -glyph.advance.y / 64.
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return origin, size, offset, data
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