ruby-****@sourc*****
ruby-****@sourc*****
2013年 4月 2日 (火) 16:10:46 JST
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REMOTE_ADDR = 70.49.48.128
REMOTE_HOST =
URL = http://ruby-gnome2.sourceforge.jp/hiki.cgi?tut-gtk2-dancr-rbcatut-dwc
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@@ -26,31 +26,61 @@
+
== Drawing with Cairo
(12.3.2){{br}}
+In order to create an image you desire, you have to prepare the ((<context|Cairo::Context>)) for each of the drawing verbs. To use ((<stroke|tut-gtk2-dancr-rbcatut-crdrmd#Stroke>)) or ((<fill|tut-gtk2-dancr-rbcatut-crdrmd#Fill>)) you first need a path. To use ((<show_text()|tut-gtk2-dancr-rbcatut-crdrmd#Show Text - Glyphs>)) you must position your text by its insertion point. To use ((<mask()|tut-gtk2-dancr-rbcatut-crdrmd#Mask>)) you need a second source pattern or surface. And to use any of the operations, including ((<paint|tut-gtk2-dancr-rbcatut-crdrmd#Paint>)), you need a primary source.
-# {{image_right("")}}
-# ((<|URL:http://...>))
-# dialog-warning.png
+{{br}}
+=== Preparing and Selecting a Source
+(12.3.2.1){{br}}
+There are three main kinds of sources in cairo: colors, gradients, and images. Colors are the simplest; they use a uniform hue and opacity for the entire source. You can select these without any preparation with ((<cairo_set_source_rgb()|URL:http://www.cairographics.org/manual/cairo-cairo-t.html#cairo-set-source-rgb>)) and ((<cairo_set_source_rgba()|URL:http://www.cairographics.org/manual/cairo-cairo-t.html#cairo-set-source-rgba>)). Using set_source_rgb(r, g, b) is equivalent to using set_source_rgba(r, g, b, 1.0), and it sets your source color to use full opacity.
-
-{{br}}
-
-=== Preparing and Selecting a Source
-(12.3.2.1){{br}}
{{image_right("1203-p09-setsourcergba-in-C.png")}}
+# FILE: 1203-p09-80-03-00-01-ssrcrgb-noCUT-OFFS-nonGtkCr-dpl01.rb
+
+ #!/usr/bin/env ruby
+ $: << '~/work/HikiLib'
+ require 'hiki2-gtk-w-cairo.rb'
+ include HikiGtk
+
+ # Create cairo context for image surface
+ surface = Cairo::ImageSurface.new(120, 120)
+ cr = Cairo::Context.new(surface)
+ cr.scale(120, 120)
+
+ # -- Your cairo code starts here -------------- -s-
+ cr.set_source_rgb(0, 0, 0)
+ cr.move_to(0, 0)
+ cr.line_to(1, 1)
+ cr.move_to(1, 0)
+ cr.line_to(0, 1)
+ cr.set_line_width(0.2)
+ cr.stroke
+
+ cr.rectangle(0, 0, 0.5, 0.5)
+ cr.set_source_rgba(1, 0, 0, 0.80)
+ cr.fill
+ cr.rectangle(0, 0.5, 0.5, 0.5)
+ cr.set_source_rgba(0, 1, 0, 0.60)
+ cr.fill
+ cr.rectangle(0.5, 0, 0.5, 0.5)
+ cr.set_source_rgba(0, 0, 1, 0.40)
+ cr.fill
+ # -- Your cairo code ends here ---------------- -e-
+
+ cr.target.write_to_png("setsourcergb-nonGtkCr-120:120x120.png")
+ puts "DEBUG: cr.target.class=#{cr.target.class}" #=> Cairo::ImageSurface
-# {{image_right("")}}
-# ((<|URL:http://...>))
-
+{{br}}
{{br}}
=== Creating a Path