[pango/pango2] Add PANGO_RENDERING_CAIRO

[Matthias Clasen <matthiasc src gnome org>]

commit e5b725236f6f7b65a1887d5805ce02f52fce759c
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Jun 16 07:16:01 2022 -0400

    Add PANGO_RENDERING_CAIRO
    
    To check something before including pangocairo.h

 pango/meson.build            | 3 +++
 pango/pango-features.h.meson | 2 ++
 pango/pango-utils.h          | 8 +++++++-
 3 files changed, 12 insertions(+), 1 deletion(-)
---
diff --git a/pango/meson.build b/pango/meson.build
index cfefc641..78514ec9 100644
--- a/pango/meson.build
+++ b/pango/meson.build
@@ -170,6 +170,9 @@ pango_features_conf.set('PANGO_VERSION_MINOR', pango_minor_version)
 pango_features_conf.set('PANGO_VERSION_MICRO', pango_micro_version)
 pango_features_conf.set('PANGO_API_VERSION', pango_api_version)
 pango_features_conf.set('PANGO_CURRENT_MINUS_AGE', '0')
+if cairo_dep.found()
+  pango_features_conf.set('PANGO_RENDERING_CAIRO', 1)
+endif
 
 pango_features_h = configure_file(
   input: 'pango-features.h.meson',
diff --git a/pango/pango-features.h.meson b/pango/pango-features.h.meson
index d39343c8..d0043ff3 100644
--- a/pango/pango-features.h.meson
+++ b/pango/pango-features.h.meson
@@ -5,3 +5,5 @@
 #mesondefine PANGO_VERSION_MICRO
 
 #define PANGO_VERSION_STRING "@PANGO_VERSION_MAJOR@.@PANGO_VERSION_MINOR@.@PANGO_VERSION_MICRO@"
+#
+#mesondefine PANGO_RENDERING_CAIRO
diff --git a/pango/pango-utils.h b/pango/pango-utils.h
index 75c082d3..0fd5507f 100644
--- a/pango/pango-utils.h
+++ b/pango/pango-utils.h
@@ -37,9 +37,15 @@ void     pango_find_paragraph_boundary (const char *text,
                                         int        *paragraph_delimiter_index,
                                         int        *next_paragraph_start);
 
-/* Pango version checking */
+/**
+ * PANGO_RENDERING_CAIRO:
+ *
+ * Defined to 1 at compile time if Pango was built with cairo support.
+ */
 
 /* Encode a Pango version as an integer */
+/* Pango version checking */
+
 /**
  * PANGO_VERSION_ENCODE:
  * @major: the major component of the version number