Using Graphene with GObject

In order to discover at compile time if Graphene exposes type information for the GType type system, you need to check if the graphene-gobject-1.0 pkg-config file exists.

If you're using Meson to build your project, you can use a typical dependency() object, for instance:

  graphene_dep = dependency('graphene-gobject-1.0')

If you're using Autotools to build your project, you can use the PKG_CHECK_EXISTS m4 macro, for instance:

  PKG_CHECK_EXISTS([graphene-gobject-1.0],
                   [action-if-found],
                   [action-if-not-found]

All the types provided by Graphene are boxed types, which means you will have to use the GBoxed API when dealing with GValue, GParamSpec, and signal marshallers. For instance, to install a property in a GObject class that uses graphene_rect_t, you can use:

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g_object_class_install_property (object_class, PROP_BOUNDS,
  g_param_spec_boxed ("bounds", "Bounds", "Bounds of an object",
                      GRAPHENE_TYPE_RECT,
                      G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);

You'll then need to use g_value_set_boxed() and g_value_get_boxed() in order to access the graphene_rect_t pointer from the GValue data structure.

Whereas for creating a new signal that has a graphene_point_t parameter you can use:

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signals[HIT_TEST] =
  g_signal_new ("hit-test",
                G_TYPE_FROM_CLASS (object_class),
                G_SIGNAL_RUN_LAST,
                0,
                g_signal_accumulator_true_handled, NULL,
                marshal_BOOLEAN__BOXED,
                G_TYPE_BOOLEAN, 1,
                GRAPHENE_TYPE_POINT);

Using Graphene via GObject introspection

When using Graphene with another language than C, the GObject Introspection bindings change the type names to the CamelCase version of the C name, minus the _t suffix; for instance:

There is no direct access for the low level graphene_simd4f_t and graphene_simd4x4f_t SIMD types.