# -*- coding: utf-8 -*-

import os
import freetype
import numpy as np
from PIL import Image

FONT_FILE = r'C:\Windows\Fonts\STLITI.TTF'
BG_FILE = r'D:\temp\bg.png'

def text2image(word, font_file, size=128, color=(0,0,0)):
"""使用指定字库将单个汉字转为图像

word - 单个汉字字符串
font_file - 矢量字库文件名
size - 字号，默认128
color - 颜色，默认黑色
"""

face = freetype.Face(font_file)
face.set_char_size(size*size)

face.load_char(word)
btm_obj = face.glyph.bitmap
w, h = btm_obj.width, btm_obj.rows
pixels = np.array(btm_obj.buffer, dtype=np.uint8).reshape(h, w)

dx = int(face.glyph.metrics.horiBearingX/64)
if dx > 0:
patch = np.zeros((pixels.shape[0], dx), dtype=np.uint8)
pixels = np.hstack((patch, pixels))

r = np.ones(pixels.shape) * color[0] * 255
g = np.ones(pixels.shape) * color[1] * 255
b = np.ones(pixels.shape) * color[2] * 255
im = np.dstack((r, g, b, pixels)).astype(np.uint8)

return Image.fromarray(im)

def write_couplets(text, horv='V', quality='L', out_file=None, bg=BG_FILE):
"""写春联

text - 春联字符串
bg - 背景图片路径
horv - H-横排，V-竖排
quality - 单字分辨率，H-640像素，L-320像素
out_file - 输出文件名
"""

size, tsize = (320, 128) if quality == 'L' else (640, 180)
ow, oh = (size, size*len(text)) if horv == 'V' else (size*len(text), size)
im_out = Image.new('RGBA', (ow, oh), '#f0f0f0')
im_bg = Image.open(BG_FILE)
if size < 640:
im_bg = im_bg.resize((size, size))

for i, w in enumerate(text):
im_w = text2image(w, FONT_FILE, size=tsize, color=(0,0,0))
w, h = im_w.size
dw, dh = (size - w)//2, (size - h)//2

if horv == 'V':
im_out.paste(im_bg, (0, i*size))
im_out.paste(im_w, (dw, i*size+dh), mask=im_w)
else:
im_out.paste(im_bg, (i*size, 0))
im_out.paste(im_w, (i*size+dw, dh), mask=im_w)

im_out.save('%s.png'%text)
os.startfile('%s.png'%text)
if __name__ == '__main__':
write_couplets('普天同庆', horv='V', quality='H')
write_couplets('欢度春节', horv='V', quality='H')
write_couplets('国泰民安', horv='H', quality='H')