src/texsourc/lib/libhpdf/if/ruby/demo/ext_gstater_demo.rb

   1 #
   2 # << Haru Free PDF Library 2.0.6 >> -- ext_gstate_demo.rb
   3 #
   4 # http://libharu.org/
   5 #
   6 # Copyright (c) 1999-2006 Takeshi Kanno
   7 #
   8 # Permission to use, copy, modify, distribute and sell this software
   9 # and its documentation for any purpose is hereby granted without fee,
  10 # provided that the above copyright notice appear in all copies and
  11 # that both that copyright notice and this permission notice appear
  12 # in supporting documentation.
  13 # It is provided "as is" without express or implied warranty.
  14 #
  15
  16 require "hpdf"
  17
  18 def draw_circles(page, description, x, y)
  19   page.set_line_width(1)
  20   page.set_rgb_stroke(0, 0, 0)
  21
  22   page.set_rgb_fill(1, 0, 0)
  23   page.circle(x + 40, y + 40, 40)
  24   page.close_path_fill_stroke()
  25
  26   page.set_rgb_fill(0, 1, 0)
  27   page.circle(x + 100, y + 40, 40)
  28   page.close_path_fill_stroke()
  29
  30   page.set_rgb_fill(0, 0, 1)
  31   page.circle(x + 70, y + 74.64, 40)
  32   page.close_path_fill_stroke()
  33
  34   page.set_rgb_fill(0, 0, 0)
  35   page.begin_text()
  36   page.text_out(x + 0.0, y + 130.0, description)
  37   page.end_text()
  38 end
  39
  40 pdf = HPDFDoc.new
  41
  42 PAGE_WIDTH = 600
  43 PAGE_HEIGHT = 900
  44
  45 # add a new page object. #
  46 page = pdf.add_page
  47 page.set_height(PAGE_HEIGHT)
  48 page.set_width(PAGE_WIDTH)
  49
  50 font = pdf.get_font("Helvetica-Bold", nil)
  51
  52 page.set_font_and_size(font, 10)
  53
  54 # normal
  55 page.gsave()
  56 draw_circles(page, "normal", 40, PAGE_HEIGHT - 170)
  57 page.grestore()
  58
  59 # transparency (0.8)
  60 page.gsave()
  61 gstate = pdf.create_ext_gstate()
  62 gstate.set_alpha_fill(0.8)
  63 gstate.set_alpha_stroke(0.8)
  64 page.set_ext_gstate(gstate)
  65 draw_circles(page, "alpha fill = 0.8", 230, PAGE_HEIGHT - 170)
  66 page.grestore()
  67
  68 # transparency (0.4)
  69 page.gsave()
  70 gstate = pdf.create_ext_gstate()
  71 gstate.set_alpha_fill(0.4)
  72 gstate.set_alpha_stroke(0.4)
  73 page.set_ext_gstate(gstate)
  74 draw_circles(page, "alpha fill = 0.4", 420, PAGE_HEIGHT - 170)
  75 page.grestore()
  76
  77 # blend-mode=HPDF_BM_MULTIPLY
  78 page.gsave()
  79 gstate = pdf.create_ext_gstate()
  80 gstate.set_blend_mode(HPDFDoc::HPDF_BM_MULTIPLY)
  81 page.set_ext_gstate(gstate)
  82 draw_circles(page, "HPDF_BM_MULTIPLY", 40, PAGE_HEIGHT - 340)
  83 page.grestore()
  84
  85 # blend-mode=HPDF_BM_SCREEN
  86 page.gsave()
  87 gstate = pdf.create_ext_gstate()
  88 gstate.set_blend_mode(HPDFDoc::HPDF_BM_SCREEN)
  89 page.set_ext_gstate(gstate)
  90 draw_circles(page, "HPDF_BM_SCREEN", 230, PAGE_HEIGHT - 340)
  91 page.grestore()
  92
  93 # blend-mode=HPDF_BM_OVERLAY
  94 page.gsave()
  95 gstate = pdf.create_ext_gstate()
  96 gstate.set_blend_mode(HPDFDoc::HPDF_BM_OVERLAY)
  97 page.set_ext_gstate(gstate)
  98 draw_circles(page, "HPDF_BM_OVERLAY", 420, PAGE_HEIGHT - 340)
  99 page.grestore()
 100
 101 # blend-mode=HPDF_BM_DARKEN
 102 page.gsave()
 103 gstate = pdf.create_ext_gstate()
 104 gstate.set_blend_mode(HPDFDoc::HPDF_BM_DARKEN)
 105 page.set_ext_gstate(gstate)
 106 draw_circles(page, "HPDF_BM_DARKEN", 40, PAGE_HEIGHT - 510)
 107 page.grestore()
 108
 109 # blend-mode=HPDF_BM_LIGHTEN
 110 page.gsave()
 111 gstate = pdf.create_ext_gstate()
 112 gstate.set_blend_mode(HPDFDoc::HPDF_BM_LIGHTEN)
 113 page.set_ext_gstate(gstate)
 114 draw_circles(page, "HPDF_BM_LIGHTEN", 230, PAGE_HEIGHT - 510)
 115 page.grestore()
 116
 117 # blend-mode=HPDF_BM_COLOR_DODGE
 118 page.gsave()
 119 gstate = pdf.create_ext_gstate()
 120 gstate.set_blend_mode(HPDFDoc::HPDF_BM_COLOR_DODGE)
 121 page.set_ext_gstate(gstate)
 122 draw_circles(page, "HPDF_BM_COLOR_DODGE", 420, PAGE_HEIGHT - 510)
 123 page.grestore()
 124
 125 # blend-mode=HPDF_BM_COLOR_BUM
 126 page.gsave()
 127 gstate = pdf.create_ext_gstate()
 128 gstate.set_blend_mode(HPDFDoc::HPDF_BM_COLOR_BUM)
 129 page.set_ext_gstate(gstate)
 130 draw_circles(page, "HPDF_BM_COLOR_BUM", 40, PAGE_HEIGHT - 680)
 131 page.grestore()
 132
 133 # blend-mode=HPDF_BM_HARD_LIGHT
 134 page.gsave()
 135 gstate = pdf.create_ext_gstate()
 136 gstate.set_blend_mode(HPDFDoc::HPDF_BM_HARD_LIGHT)
 137 page.set_ext_gstate(gstate)
 138 draw_circles(page, "HPDF_BM_HARD_LIGHT", 230, PAGE_HEIGHT - 680)
 139 page.grestore()
 140
 141 # blend-mode=HPDF_BM_SOFT_LIGHT
 142 page.gsave()
 143 gstate = pdf.create_ext_gstate()
 144 gstate.set_blend_mode(HPDFDoc::HPDF_BM_SOFT_LIGHT)
 145 page.set_ext_gstate(gstate)
 146 draw_circles(page, "HPDF_BM_SOFT_LIGHT", 420, PAGE_HEIGHT - 680)
 147 page.grestore()
 148
 149 # blend-mode=HPDF_BM_DIFFERENCE
 150 page.gsave()
 151 gstate = pdf.create_ext_gstate()
 152 gstate.set_blend_mode(HPDFDoc::HPDF_BM_DIFFERENCE)
 153 page.set_ext_gstate(gstate)
 154 draw_circles(page, "HPDF_BM_DIFFERENCE", 40, PAGE_HEIGHT - 850)
 155 page.grestore()
 156
 157 # blend-mode=HPDF_BM_EXCLUSHON
 158 page.gsave()
 159 gstate = pdf.create_ext_gstate()
 160 gstate.set_blend_mode(HPDFDoc::HPDF_BM_EXCLUSHON)
 161 page.set_ext_gstate(gstate)
 162 draw_circles(page, "HPDF_BM_EXCLUSHON", 230, PAGE_HEIGHT - 850)
 163 page.grestore()
 164
 165 pdf.save_to_file($0 + ".pdf")
 166