1

#!/usr/bin/python2.5

     2

import cgi, cgitb

     3

     4

cgitb.enable()

     5

     6

from PIL import Image, ImageDraw, ImageFont

     7

from cStringIO import StringIO

     8

import random

     9

    10

    11

# settings

    12

text = [

    13

    "aalto",

    14

    "unive",

    15

    "rsity"

    16

]

    17

    18

random_chars = [ '"', '!', '?' ]

    19

    20

line_colors = [

    21

    "#0469af",

    22

    "#fbc614",

    23

    "#e1313b",

    24

]

    25

    26

fonts = {

    27

    'dejavu-sans-bold':     "/usr/share/fonts/truetype/ttf-dejavu/DejaVuSans-Bold.ttf",

    28

    'helvetica':            "HELR65W.TTF",

    29

}

    30

    31

font_name = 'helvetica'

    32

font_size = 30

    33

    34

def randomize (seq) :

    35

    """

    36

        Returns the given sequence in random order as a list

    37

    """

    38

    39

    # copy

    40

    l = list(seq)

    41

    42

    # rearrange

    43

    random.shuffle(l)

    44

    45

    return l

    46

    47

def build_data (text, chars, line_colors) :

    48

    """

    49

        Returns a matrix of (text, color) tuples representing the data to render

    50

    51

        [ [ (str, str) ] ]

    52

    53

            text        - list of lines

    54

            chars       - list of random chars to interpse

    55

            line_colors - list of colors to draw the chars in

    56

    """

    57

    58

    data = []

    59

    60

    for line, char, color in zip(text, chars, line_colors) :

    61

        # pick position to place char

    62

        pos = random.randint(1, len(line) - 1)

    63

    64

        # split into three parts

    65

        data.append([

    66

                (line[:pos], "#000000"),

    67

                (char, color),

    68

                (line[pos:], "#000000"),

    69

            ])

    70

    71

    return data

    72

    73

def load_font (font_name, font_size) :

    74

    """

    75

        Load a font by name

    76

    """

    77

    78

    # load font

    79

    font_path = fonts[font_name]

    80

    font = ImageFont.truetype(font_path, font_size)

    81

    82

    return font

    83

    84

def render_img (data, font, background_color="#ffffff", line_spacing=0) :

    85

    """

    86

        Render the data (as from build_data) as an image, using the given PIL.ImageFont, and return the PIL Image object

    87

    """

    88

    89

    img_width = img_height = 0

    90

    91

    img_data = []

    92

    93

    # compute image width/height

    94

    for segments in data :

    95

        line_width = line_height = 0

    96

    97

        # build a new list of segments with additional info

    98

        line_segments = []

    99

   100

        for seg_text, seg_color in segments :

   101

            # compute rendered text size

   102

            seg_width, seg_height = font.getsize(seg_text)

   103

   104

            # update line_*

   105

            line_width += seg_width

   106

            line_height = max(line_height, seg_height)

   107

   108

            # build the new segments list

   109

            line_segments.append((seg_text, seg_color, seg_width))

   110

   111

        # update img_*

   112

        img_width = max(img_width, line_width)

   113

        img_height += line_height

   114

        img_data.append((line_segments, line_height))

   115

   116

    # calculate height needed for line spacing

   117

    img_height += (len(img_data) - 1) * line_spacing

   118

   119

    # create image

   120

    img = Image.new("RGB", (img_width, img_height), background_color)

   121

    draw = ImageDraw.Draw(img)

   122

   123

    # draw text

   124

    img_y = 0

   125

    for segments, line_height in img_data :

   126

        img_x = 0

   127

   128

        # draw each segment build above, incremeing along img_x

   129

        for seg_text, seg_color, seg_width in segments :

   130

            draw.text((img_x, img_y), seg_text, font=font, fill=seg_color)

   131

   132

            img_x += seg_width

   133

   134

        img_y += line_height + line_spacing

   135

   136

    return img

   137

   138

def build_png (img) :

   139

    """

   140

        Write the given PIL.Image as a string, returning the raw binary data

   141

    """

   142

   143

    # render PNG output

   144

    buf = StringIO()

   145

    img.save(buf, "png")

   146

    data = buf.getvalue()

   147

   148

    return data

   149

   150

def response (type, data) :

   151

    """

   152

        Write out the HTTP Response

   153

    """

   154

   155

    from sys import stdout

   156

   157

    stdout.write("Content-Type: %s\r\n" % type)

   158

    stdout.write("Content-Length: %d\r\n" % len(data))

   159

    stdout.write("\r\n")

   160

    stdout.write(data)

   161

   162

def main () :

   163

    data = build_data(text, randomize(random_chars), line_colors)

   164

    font = load_font(font_name, font_size)

   165

   166

    img = render_img(data, font)

   167

    png_data = build_png(img)

   168

   169

    response("image/png", png_data)

   170

   171

if __name__ == '__main__' :

   172

    main()

   173