Class: MiniGL::ImageFont

Inherits:
Object
  • Object
show all
Defined in:
lib/minigl/text.rb

Overview

This class represents a font and exposes most of the methods from Gosu::Font, but allows the font to be created from an image, allowing for better customization and also using the retro option. Moreover, this class can be passed to the TextHelper constructor as if it was a Gosu::Font.

The image used to load the font must meet these criteria:

  • The characters should be laid out in lines of the same height in pixels.

  • The full image must have a height that is a multiple of that line height.

  • The characters should occupy the maximum available space in each line, i.e., if a character fits in the current line it must not be placed in the next one. In the last line there can be any amount of free space at the end.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(img_path, chars, widths, height, space_width, char_spacing = 0, global = true, ext = '.png', retro = nil) ⇒ ImageFont

Creates an ImageFont.

Parameters:

img_path

Identifier of an image fitting the description in the class documentation, as used in Res.img.

chars

A string containing all characters that will be present in the image, in the same order as they appear in the image. Do not include white space.

widths

An integer representing the width of the chars in pixels, if this is a fixed width font, or an array containing the width of each char, in the same order as they appear in the chars string.

height

The height of the lines in the image (see description above).

space_width

The width of the white space character in this font.

char_spacing

The spacing between non-white-space characters when writing text with this font. It can be a decimal number, useful when scaling the text up.

global

Parameter that will be passed to Res.img when loading the image.

ext

Parameter that will be passed to Res.img when loading the image.

retro

Parameter that will be passed to Res.img when loading the image.



43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
 
# File 'lib/minigl/text.rb', line 43

def initialize(img_path, chars, widths, height, space_width, char_spacing = 0, global = true, ext = '.png', retro = nil)
  retro = Res.retro_images if retro.nil?
  img = Res.img(img_path, global, false, ext, retro)
  @chars = chars
  @images = []
  @height = height
  @space_width = space_width
  @char_spacing = char_spacing
  wa = widths.is_a?(Array)
  if wa && widths.length != chars.length
    raise 'Wrong widths array size!'
  end
  x = y = 0
  (0...chars.length).each do |i|
    @images.push(img.subimage(x, y, wa ? widths[i] : widths, height))
    new_x = x + (wa ? widths[i] : widths)
    if i < chars.length - 1 && new_x + (wa ? widths[i+1] : widths) > img.width
      x = 0
      y += height
    else
      x = new_x
    end
  end
end

Instance Attribute Details

#char_spacing ⇒ Object (readonly)

The spacing between characters, in pixels (can be a decimal number).



24
25
26
 
# File 'lib/minigl/text.rb', line 24

def char_spacing
  @char_spacing
end

#chars ⇒ Object (readonly)

A string containing the characters supported by this font.



15
16
17
 
# File 'lib/minigl/text.rb', line 15

def chars
  @chars
end

#height ⇒ Object (readonly)

The height of this font in pixels.



18
19
20
 
# File 'lib/minigl/text.rb', line 18

def height
  @height
end

#space_width ⇒ Object (readonly)

The width of the white space character in this font, in pixels.



21
22
23
 
# File 'lib/minigl/text.rb', line 21

def space_width
  @space_width
end

Instance Method Details

#draw_markup(text, x, y, z, scale_x, scale_y, color) ⇒ Object Also known as: draw_text

See Gosu::Font#draw_markup for details. Note: Markup is not supported, this method is named this way to match Gosu::Font‘s signature.



114
115
116
 
# File 'lib/minigl/text.rb', line 114

def draw_markup(text, x, y, z, scale_x, scale_y, color)
  draw_markup_rel(text, x, y, z, 0, 0, scale_x, scale_y, color)
end

#draw_markup_rel(text, x, y, z, rel_x, rel_y, scale_x, scale_y, color) ⇒ Object Also known as: draw_text_rel

See Gosu::Font#draw_markup_rel for details. Note: Markup is not supported, this method is named this way to match Gosu::Font‘s signature.



91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
 
# File 'lib/minigl/text.rb', line 91

def draw_markup_rel(text, x, y, z, rel_x, rel_y, scale_x, scale_y, color)
  text = text.to_s unless text.is_a?(String)
  if rel_x != 0
    x -= scale_x * markup_width(text) * rel_x
  end
  if rel_y != 0
    y -= scale_y * @height * rel_y
  end
  text.each_char do |c|
    if c == ' '
      x += scale_x * @space_width
      next
    end
    i = @chars.index(c)
    next if i.nil?
    @images[i].draw(x, y, z, scale_x, scale_y, color)
    x += (scale_x * (@images[i].width + @char_spacing)).round
  end
end

#markup_width(text) ⇒ Object Also known as: text_width

Returns the width, in pixels, of a given string written by this font. Note: Markup is not supported, this method is named this way to match Gosu::Font‘s signature.

Parameters:

text

The string to be measured



74
75
76
77
78
79
80
81
82
83
84
85
86
 
# File 'lib/minigl/text.rb', line 74

def markup_width(text)
  w = 0
  text.chars.each_with_index do |c, i|
    if c == ' '
      w += @space_width
    else
      idx = @chars.index(c)
      w += idx ? @images[idx].width : 0
      w += @char_spacing if i < text.chars.size - 1
    end
  end
  w
end