cookbook: Add an empty recipe for shadows under text

Currently, it's just an example and an image, but it should be easy to
flesh it out properly for the "Text" chapter.

doc/cookbook/Makefile.am

@@ -34,6 +34,7 @@ IMAGE_FILES = \
 	images/textures-reflection.png \
 	images/actors-opacity.png \
 	images/actors-opacity-container-affects-opacity.png \
+	images/text-shadow.png \
 	$(NULL)
 VIDEO_FILES = \
 	videos/animations-fading-out.ogv \

doc/cookbook/clutter-cookbook.xml.in

@@ -43,6 +43,7 @@
   <xi:include href="events.xml" />
   <xi:include href="textures.xml" />
   <xi:include href="animations.xml" />
+  <xi:include href="text.xml" />
 
   <appendix id="contributing">
     <title>Contributing to this document</title>

doc/cookbook/examples/.gitignore

@@ -1 +1,2 @@
+/text-shadow
 /textures-reflection

doc/cookbook/examples/Makefile.am

@@ -4,6 +4,7 @@ NULL =
 
 noinst_PROGRAMS = \
 	textures-reflection	\
+	text-shadow		\
 	$(NULL)
 
 INCLUDES = \
@@ -26,3 +27,5 @@ AM_CFLAGS = \
 AM_LDFLAGS = $(CLUTTER_LIBS)
 
 textures_reflection_SOURCES 	= textures-reflection.c
+
+text_shadow_SOURCES 		= text-shadow.c

doc/cookbook/examples/text-shadow.c

@@ -0,0 +1,59 @@
+#include <stdlib.h>
+#include <cogl/cogl.h>
+#include <cogl-pango.h>
+#include <clutter/clutter.h>
+
+#define SHADOW_X_OFFSET         3
+#define SHADOW_Y_OFFSET         3
+
+static void
+_text_paint_cb (ClutterActor *actor)
+{
+  ClutterText *text = CLUTTER_TEXT (actor);
+
+  ClutterActorBox alloc = { 0, };
+  clutter_actor_get_allocation_box (actor, &alloc);
+
+  PangoLayout *layout;
+  layout = clutter_text_get_layout (text);
+
+  ClutterColor text_color = { 0, };
+  clutter_text_get_color (text, &text_color);
+
+  guint8 real_opacity;
+  real_opacity = clutter_actor_get_paint_opacity (actor)
+               * text_color.alpha
+               / 255;
+
+  CoglColor color;
+  cogl_color_set_from_4ub (&color, 0xcc, 0xcc, 0xcc, real_opacity);
+  cogl_pango_render_layout (layout, SHADOW_X_OFFSET, SHADOW_Y_OFFSET, &color, 0);
+}
+
+int
+main (int argc, char *argv[])
+{
+  clutter_init (&argc, &argv);
+
+  ClutterActor *stage;
+
+  stage = clutter_stage_new ();
+  clutter_stage_set_title (CLUTTER_STAGE (stage), "Text shadow");
+  g_signal_connect (stage, "destroy", G_CALLBACK (clutter_main_quit), NULL);
+
+  ClutterActor *text;
+  text = clutter_text_new ();
+  clutter_text_set_text (CLUTTER_TEXT (text), "Hello, World!");
+  clutter_text_set_font_name (CLUTTER_TEXT (text), "Sans 64px");
+  clutter_actor_add_constraint (text, clutter_align_constraint_new (stage, CLUTTER_ALIGN_X_AXIS, 0.5));
+  clutter_actor_add_constraint (text, clutter_align_constraint_new (stage, CLUTTER_ALIGN_Y_AXIS, 0.5));
+  g_signal_connect (text, "paint", G_CALLBACK (_text_paint_cb), NULL);
+
+  clutter_container_add (CLUTTER_CONTAINER (stage), text, NULL);
+
+  clutter_actor_show (stage);
+
+  clutter_main ();
+
+  return EXIT_SUCCESS;
+}

doc/cookbook/text.xml

@@ -0,0 +1,40 @@
+<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+ "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+
+<chapter id="text">
+  <title>Text</title>
+
+  <epigraph>
+    <attribution>Antoine de Saint-Exupery</attribution>
+    <para>A rock pile ceases to be a rock pile the moment a single man
+    contemplates it, bearing within him the image of a cathedral.</para>
+  </epigraph>
+
+  <section id="text-introduction">
+    <title>Introduction</title>
+
+  </section>
+
+  <section id="text-shadow">
+    <title>Drawing a shadow under the text</title>
+
+    <section>
+      <title>Problem</title>
+
+      <para>You want to draw a shadow under the text displayed by a
+      ClutterText actor.</para>
+    </section>
+
+    <section>
+      <title>Solution</title>
+
+    </section>
+
+    <section>
+      <title>Discussion</title>
+
+    </section>
+
+  </section>
+
+</chapter>