Added a very simple UserFontFace example

	* examples/text/Makefile.am:
	* examples/text/user-font.cc: Added a very simple example of using a
	UserFontFace to draw text

2 files changed, 69 insertions, 2 deletions

diff --git a/examples/text/Makefile.am b/examples/text/Makefile.am
index adb68b0..19f6e70 100644
--- a/examples/text/Makefile.am
+++ b/examples/text/Makefile.am
@@ -1,9 +1,10 @@
 include $(top_srcdir)/examples/Makefile.am_fragment
 
 # build the executable but don't install it
-noinst_PROGRAMS = text_rotate toy-text
+noinst_PROGRAMS = text_rotate toy-text user-font
 
 text_rotate_SOURCES = text-rotate.cc
 toy_text_SOURCES=toy-text.cc
+user_font_SOURCES=user-font.cc
 
-CLEANFILES = text-rotate.png toy-text.png
+CLEANFILES = text-rotate.png toy-text.png user-font.png
diff --git a/examples/text/user-font.cc b/examples/text/user-font.cc
new file mode 100644
index 0000000..8e5dae9
--- /dev/null
+++ b/examples/text/user-font.cc
@@ -0,0 +1,66 @@
+#include <cairomm/cairomm.h>
+#include <iostream>
+
+const double HEIGHT = 200.0;
+const double WIDTH = 400.0;
+const double FONT_SIZE = 64.0;
+const double TEXT_ORIGIN_Y = (HEIGHT / 2.0) + (FONT_SIZE / 2.0);
+const double TEXT_ORIGIN_X = 50.0;  // arbitrary
+
+// A *very* simple font that just draws a box for every glyph
+class BoxFontFace : public Cairo::UserFontFace
+{
+public:
+  static Cairo::RefPtr<BoxFontFace> create()
+  {
+    return Cairo::RefPtr<BoxFontFace>(new BoxFontFace());
+  }
+
+  virtual Cairo::ErrorStatus
+    render_glyph(const Cairo::RefPtr<Cairo::ScaledFont>& /*scaled_font*/,
+                 unsigned long glyph,
+                 const Cairo::RefPtr<Cairo::Context>& cr,
+                 Cairo::TextExtents& /*metrics*/)
+  {
+    std::cout << "Rendering glyph " << glyph << std::endl;
+    cr->set_line_width(0.05);
+    // FIXME: is the negative Y value correct?
+    cr->rectangle(0.0, 0.0, 1.0, -1.0);
+    cr->stroke();
+    return CAIRO_STATUS_SUCCESS;
+  }
+
+protected:
+  BoxFontFace() : UserFontFace() { }
+};
+
+int main(int, char**)
+{
+  Cairo::RefPtr<Cairo::ImageSurface> surface =
+    Cairo::ImageSurface::create(Cairo::FORMAT_ARGB32, WIDTH, HEIGHT);
+  Cairo::RefPtr<Cairo::Context> cr = Cairo::Context::create(surface);
+  // fill background in white
+  cr->set_source_rgb(1.0, 1.0, 1.0);
+  cr->paint();
+
+  // draw a little dot at the point where text will be drawn
+  cr->arc(TEXT_ORIGIN_X, TEXT_ORIGIN_Y, FONT_SIZE / 4.0, 0, 2*M_PI);
+  cr->set_source_rgba(0.0, 1.0, 0.0, 0.5);
+  cr->fill();
+
+  // draw the text
+  cr->move_to(TEXT_ORIGIN_X, TEXT_ORIGIN_Y);
+  cr->set_source_rgb(0.8, 0.2, 0.2);
+
+  // this scope block is simply to test that the user font can still be
+  // drawn even after the UserFont wrapper object has been de-referenced
+  {
+    Cairo::RefPtr<BoxFontFace> font = BoxFontFace::create();
+    cr->set_font_face(font);
+  }
+
+  cr->set_font_size(FONT_SIZE);
+  cr->show_text("cairomm!");
+  surface->write_to_png("user-font.png");
+  return 0;
+}