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#!/usr/bin/env python
# -*- coding: utf-8 -*-
# -----------------------------------------------------------------------------
#
# pycairo/cairocffi-based glyph-vector example - Copyright 2017 Hin-Tak Leung
# Distributed under the terms of the new BSD license.
#
# rewrite of the numply,matplotlib-based example from Nicolas P. Rougier
# - The code is incomplete and over-simplified, as it ignores the 3rd order
# bezier curve bit when intepolating between off-curve points.
# This is only correct for truetype fonts (which only use 2nd order bezier curves).
# - Also it seems to assume the first point is always on curve; this is
# unusual but legal.
#
# Can cope with well-behaved Postscript/CFF fonts too.
#
# -----------------------------------------------------------------------------
'''
Show how to access glyph outline description.
'''
from freetype import *
# using Matrix class from Cairo, instead of FreeType's
from cairo import Context, ImageSurface, FORMAT_ARGB32, Matrix
# use math.pi for drawing circles
import math
if __name__ == '__main__':
import numpy
from PIL import Image
# Replacement for Path enums:
STOP, MOVETO, LINETO, CURVE3, CURVE4 = 0, 1, 2, 3, 4
face = Face('./Vera.ttf')
face.set_char_size( 48*64 )
face.load_char('S')
slot = face.glyph
outline = slot.outline
points = numpy.array(outline.points, dtype=[('x',float), ('y',float)])
x, y = points['x'], points['y']
cbox = outline.get_cbox()
surface = ImageSurface(FORMAT_ARGB32,
(cbox.xMax - cbox.xMin)//4 + 20,
(cbox.yMax - cbox.yMin)//4 + 20)
ctx = Context(surface)
ctx.scale(0.25,0.25)
ctx.translate(-cbox.xMin + 40,-cbox.yMin + 40)
ctx.transform(Matrix(1,0,0,-1))
ctx.translate(0, -(cbox.yMax + cbox.yMin)) # difference!
Curve_Tag = [FT_Curve_Tag(tag) for tag in outline.tags]
start, end = 0, 0
VERTS, CODES = [], []
# Iterate over each contour
ctx.set_source_rgb(0.5,0.5,0.5)
for i in range(len(outline.contours)):
end = outline.contours[i]
ctx.move_to(outline.points[start][0],outline.points[start][1])
for j in range(start, end+1):
point = outline.points[j]
ctx.line_to(point[0],point[1])
#back to origin
ctx.line_to(outline.points[start][0], outline.points[start][1])
start = end+1
ctx.fill_preserve()
ctx.set_source_rgb(0,1,0)
ctx.stroke()
start, end = 0, 0
for i in range(len(outline.contours)):
end = outline.contours[i]
ctx.new_path()
ctx.set_source_rgb(0,0,1)
for j in range(start, end+1):
if ( Curve_Tag[j] == FT_Curve_Tag_On ):
point = outline.points[j]
ctx.move_to(point[0],point[1])
ctx.arc(point[0], point[1], 40, 0, 2 * math.pi)
ctx.fill()
ctx.new_path()
ctx.set_source_rgb(1,0,0)
for j in range(start, end+1):
if ( Curve_Tag[j] != FT_Curve_Tag_On ):
point = outline.points[j]
ctx.move_to(point[0],point[1])
ctx.arc(point[0], point[1], 10, 0, 2 * math.pi)
ctx.fill()
points = outline.points[start:end+1]
points.append(points[0])
tags = outline.tags[start:end+1]
tags.append(tags[0])
segments = [ [points[0],], ]
for j in range(1, len(points) ):
segments[-1].append(points[j])
if ( FT_Curve_Tag( tags[j] ) == FT_Curve_Tag_On ) and j < (len(points)-1):
segments.append( [points[j],] )
verts = [points[0], ]
codes = [MOVETO,]
tags.pop()
for segment in segments:
if len(segment) == 2:
verts.extend(segment[1:])
codes.extend([LINETO])
elif len(segment) == 3:
verts.extend(segment[1:])
codes.extend([CURVE3, CURVE3])
elif ( len(segment) == 4 ) \
and ( FT_Curve_Tag(tags[1]) == FT_Curve_Tag_Cubic ) \
and ( FT_Curve_Tag(tags[2]) == FT_Curve_Tag_Cubic ):
verts.extend(segment[1:])
codes.extend([CURVE4, CURVE4, CURVE4])
else:
# Intepolation code
verts.append(segment[1])
codes.append(CURVE3)
for i in range(1,len(segment)-2):
A,B = segment[i], segment[i+1]
C = ((A[0]+B[0])/2.0, (A[1]+B[1])/2.0)
verts.extend([ C, B ])
codes.extend([ CURVE3, CURVE3])
verts.append(segment[-1])
codes.append(CURVE3)
[tags.pop() for x in range(len(segment) - 1)]
VERTS.extend(verts)
CODES.extend(codes)
start = end+1
ctx.new_path()
ctx.set_source_rgba(1,1,0, 0.5)
i = 0
while (i < len(CODES)):
if (CODES[i] == MOVETO):
ctx.move_to(VERTS[i][0],VERTS[i][1])
i += 1
elif (CODES[i] == LINETO):
ctx.line_to(VERTS[i][0],VERTS[i][1])
i += 1
elif (CODES[i] == CURVE3):
ctx.curve_to(VERTS[i][0],VERTS[i][1],
VERTS[i+1][0],VERTS[i+1][1], # undocumented
VERTS[i+1][0],VERTS[i+1][1])
i += 2
elif (CODES[i] == CURVE4):
ctx.curve_to(VERTS[i][0],VERTS[i][1],
VERTS[i+1][0],VERTS[i+1][1],
VERTS[i+2][0],VERTS[i+2][1])
i += 3
ctx.fill()
surface.flush()
surface.write_to_png("glyph-vector-cairo.png")
Image.open("glyph-vector-cairo.png").show()
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