Button image via ImageMagick

button-images.rb

#!/usr/bin/env ruby

image_name = "action-background"
width = 29
height = 28
color = '#EF3F39'
stroke_width = 1
stroke = '#EF3F39'
corner_radius = 14
# shadow?

for i in 1..3
    make_image_cmd = "convert -size #{width*i}x#{height*i} xc:none -fill '#{color}' "
    
    stroke_defined = (defined? stroke and !stroke.nil?) and \
    (defined? stroke_width and !stroke_width.nil? and stroke_width > 0)
    
    if stroke_defined
        make_image_cmd += "-stroke '#{stroke}' -strokewidth #{stroke_width*i} "
    end
    
    corner_radius_defined = defined? corner_radius and !corner_radius.nil? and corner_radius > 0
    
    if corner_radius_defined
        corner_radius_offset = (i*stroke_width/2).ceil
        rect = "#{corner_radius_offset},#{corner_radius_offset} #{width*i-corner_radius_offset-1},#{height*i-corner_radius_offset-1} "
        make_image_cmd += "-draw 'roundrectangle #{rect} #{corner_radius*i},#{corner_radius*i}' "
    else
        rect = "0,0 #{width*i-1},#{height*i-1} "
        make_image_cmd += "-draw 'rectangle #{rect}' "
    end
    
    if i == 1
        make_image_cmd += "#{image_name}.png"
    else
        make_image_cmd += "#{image_name}@#{i}x.png"
    end
    
    `#{make_image_cmd}`
end