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Tracks your current position within a hierarchy and lets you build up a graph of transformations as you traverse through a hierarchy such as a scenegraph.

A #CoglMatrixStack always maintains a reference to a single transformation at any point in time, representing the transformation at the current position in the hierarchy. You can get a reference to the current transformation by calling cogl_matrix_stack_get_entry().

When a #CoglMatrixStack is first created with cogl_matrix_stack_new() then it is conceptually positioned at the root of your hierarchy and the current transformation simply represents an identity transformation.

As you traverse your object hierarchy (your scenegraph) then you should call cogl_matrix_stack_push() whenever you move down one level and call cogl_matrix_stack_pop() whenever you move back up one level towards the root.

At any time you can apply a set of operations, such as "rotate", "scale", "translate" on top of the current transformation of a #CoglMatrixStack using functions such as cogl_matrix_stack_rotate(), cogl_matrix_stack_scale() and cogl_matrix_stack_translate(). These operations will derive a new current transformation and will never affect a transformation that you have referenced using cogl_matrix_stack_get_entry().

Internally applying operations to a #CoglMatrixStack builds up a graph of #CoglMatrixEntry structures which each represent a single immutable transform.

Hierarchy

Index

Constructors

  • Parameters

    Returns MatrixStack

  • Allocates a new #CoglMatrixStack that can be used to build up transformations relating to objects in a scenegraph like hierarchy. (See the description of #CoglMatrixStack and #CoglMatrixEntry for more details of what a matrix stack is best suited for)

    When a #CoglMatrixStack is first allocated it is conceptually positioned at the root of your scenegraph hierarchy. As you traverse your scenegraph then you should call cogl_matrix_stack_push() whenever you move down a level and cogl_matrix_stack_pop() whenever you move back up a level towards the root.

    Once you have allocated a #CoglMatrixStack you can get a reference to the current transformation for the current position in the hierarchy by calling cogl_matrix_stack_get_entry().

    Once you have allocated a #CoglMatrixStack you can apply operations such as rotate, scale and translate to modify the current transform for the current position in the hierarchy by calling cogl_matrix_stack_rotate(), cogl_matrix_stack_scale() and cogl_matrix_stack_translate().

    Parameters

    Returns MatrixStack

Properties

g_type_instance: TypeInstance
name: string

Methods

  • Creates a binding between source_property on source and target_property on target.

    Whenever the source_property is changed the target_property is updated using the same value. For instance:

      g_object_bind_property (action, "active", widget, "sensitive", 0);
    

    Will result in the "sensitive" property of the widget #GObject instance to be updated with the same value of the "active" property of the action #GObject instance.

    If flags contains %G_BINDING_BIDIRECTIONAL then the binding will be mutual: if target_property on target changes then the source_property on source will be updated as well.

    The binding will automatically be removed when either the source or the target instances are finalized. To remove the binding without affecting the source and the target you can just call g_object_unref() on the returned #GBinding instance.

    Removing the binding by calling g_object_unref() on it must only be done if the binding, source and target are only used from a single thread and it is clear that both source and target outlive the binding. Especially it is not safe to rely on this if the binding, source or target can be finalized from different threads. Keep another reference to the binding and use g_binding_unbind() instead to be on the safe side.

    A #GObject can have multiple bindings.

    Parameters

    • source_property: string

      the property on source to bind

    • target: GObject.Object

      the target #GObject

    • target_property: string

      the property on target to bind

    • flags: BindingFlags

      flags to pass to #GBinding

    Returns Binding

  • Creates a binding between source_property on source and target_property on target, allowing you to set the transformation functions to be used by the binding.

    This function is the language bindings friendly version of g_object_bind_property_full(), using #GClosures instead of function pointers.

    Parameters

    • source_property: string

      the property on source to bind

    • target: GObject.Object

      the target #GObject

    • target_property: string

      the property on target to bind

    • flags: BindingFlags

      flags to pass to #GBinding

    • transform_to: TClosure<any, any>

      a #GClosure wrapping the transformation function from the source to the target, or %NULL to use the default

    • transform_from: TClosure<any, any>

      a #GClosure wrapping the transformation function from the target to the source, or %NULL to use the default

    Returns Binding

  • connect(sigName: string, callback: ((...args: any[]) => void)): number
  • connect_after(sigName: string, callback: ((...args: any[]) => void)): number
  • disconnect(id: number): void
  • emit(sigName: string, ...args: any[]): void
  • force_floating(): void
  • This function is intended for #GObject implementations to re-enforce a [floating][floating-ref] object reference. Doing this is seldom required: all #GInitiallyUnowneds are created with a floating reference which usually just needs to be sunken by calling g_object_ref_sink().

    Returns void

  • freeze_notify(): void
  • Increases the freeze count on object. If the freeze count is non-zero, the emission of "notify" signals on object is stopped. The signals are queued until the freeze count is decreased to zero. Duplicate notifications are squashed so that at most one #GObject::notify signal is emitted for each property modified while the object is frozen.

    This is necessary for accessors that modify multiple properties to prevent premature notification while the object is still being modified.

    Returns void

  • frustum(left: number, right: number, bottom: number, top: number, z_near: number, z_far: number): void
  • Replaces the current matrix with a perspective matrix for a given viewing frustum defined by 4 side clip planes that all cross through the origin and 2 near and far clip planes.

    Parameters

    • left: number

      X position of the left clipping plane where it intersects the near clipping plane

    • right: number

      X position of the right clipping plane where it intersects the near clipping plane

    • bottom: number

      Y position of the bottom clipping plane where it intersects the near clipping plane

    • top: number

      Y position of the top clipping plane where it intersects the near clipping plane

    • z_near: number

      The distance to the near clipping plane (Must be positive)

    • z_far: number

      The distance to the far clipping plane (Must be positive)

    Returns void

  • Resolves the current stack transform into a #CoglMatrix by combining the operations that have been applied to build up the current transform.

    There are two possible ways that this function may return its result depending on whether the stack is able to directly point to an internal #CoglMatrix or whether the result needs to be composed of multiple operations.

    If an internal matrix contains the required result then this function will directly return a pointer to that matrix, otherwise if the function returns %NULL then matrix will be initialized to match the current transform of stack.

    matrix will be left untouched if a direct pointer is returned.

    Returns [Cogl.Matrix, Cogl.Matrix]

  • get_data(key?: string): object
  • Gets a named field from the objects table of associations (see g_object_set_data()).

    Parameters

    • Optional key: string

      name of the key for that association

    Returns object

  • Gets a reference to the current transform represented by a #CoglMatrixEntry pointer.

    The transform represented by a #CoglMatrixEntry is immutable.

    #CoglMatrixEntrys are reference counted using cogl_matrix_entry_ref() and cogl_matrix_entry_unref() and you should call cogl_matrix_entry_unref() when you are finished with and entry you get via cogl_matrix_stack_get_entry().

    Returns MatrixEntry

  • get_property(property_name?: string, value?: any): void
  • Gets a property of an object.

    The value can be:

    • an empty #GValue initialized by %G_VALUE_INIT, which will be automatically initialized with the expected type of the property (since GLib 2.60)
    • a #GValue initialized with the expected type of the property
    • a #GValue initialized with a type to which the expected type of the property can be transformed

    In general, a copy is made of the property contents and the caller is responsible for freeing the memory by calling g_value_unset().

    Note that g_object_get_property() is really intended for language bindings, g_object_get() is much more convenient for C programming.

    Parameters

    • Optional property_name: string

      the name of the property to get

    • Optional value: any

      return location for the property value

    Returns void

  • get_qdata(quark: number): object
  • getv(names: string[], values: any[]): void
  • Gets n_properties properties for an object. Obtained properties will be set to values. All properties must be valid. Warnings will be emitted and undefined behaviour may result if invalid properties are passed in.

    Parameters

    • names: string[]

      the names of each property to get

    • values: any[]

      the values of each property to get

    Returns void

  • is_floating(): boolean
  • load_identity(): void
  • notify(property_name: string): void
  • Emits a "notify" signal for the property property_name on object.

    When possible, eg. when signaling a property change from within the class that registered the property, you should use g_object_notify_by_pspec() instead.

    Note that emission of the notify signal may be blocked with g_object_freeze_notify(). In this case, the signal emissions are queued and will be emitted (in reverse order) when g_object_thaw_notify() is called.

    Parameters

    • property_name: string

      the name of a property installed on the class of object.

    Returns void

  • Emits a "notify" signal for the property specified by pspec on object.

    This function omits the property name lookup, hence it is faster than g_object_notify().

    One way to avoid using g_object_notify() from within the class that registered the properties, and using g_object_notify_by_pspec() instead, is to store the GParamSpec used with g_object_class_install_property() inside a static array, e.g.:

      enum
    {
    PROP_0,
    PROP_FOO,
    PROP_LAST
    };

    static GParamSpec *properties[PROP_LAST];

    static void
    my_object_class_init (MyObjectClass *klass)
    {
    properties[PROP_FOO] = g_param_spec_int ("foo", "Foo", "The foo",
    0, 100,
    50,
    G_PARAM_READWRITE);
    g_object_class_install_property (gobject_class,
    PROP_FOO,
    properties[PROP_FOO]);
    }

    and then notify a change on the "foo" property with:

      g_object_notify_by_pspec (self, properties[PROP_FOO]);
    

    Parameters

    • pspec: ParamSpec

      the #GParamSpec of a property installed on the class of object.

    Returns void

  • orthographic(x_1: number, y_1: number, x_2: number, y_2: number, near: number, far: number): void
  • Replaces the current matrix with an orthographic projection matrix.

    Parameters

    • x_1: number

      The x coordinate for the first vertical clipping plane

    • y_1: number

      The y coordinate for the first horizontal clipping plane

    • x_2: number

      The x coordinate for the second vertical clipping plane

    • y_2: number

      The y coordinate for the second horizontal clipping plane

    • near: number

      The distance to the near clipping plane (will be negative if the plane is behind the viewer)

    • far: number

      The distance to the far clipping plane (will be negative if the plane is behind the viewer)

    Returns void

  • perspective(fov_y: number, aspect: number, z_near: number, z_far: number): void
  • Replaces the current matrix with a perspective matrix based on the provided values.

    You should be careful not to have too great a z_far / z_near ratio since that will reduce the effectiveness of depth testing since there wont be enough precision to identify the depth of objects near to each other.

    Parameters

    • fov_y: number

      Vertical field of view angle in degrees.

    • aspect: number

      The (width over height) aspect ratio for display

    • z_near: number

      The distance to the near clipping plane (Must be positive, and must not be 0)

    • z_far: number

      The distance to the far clipping plane (Must be positive)

    Returns void

  • pop(): void
  • Restores the previous transform that was last saved by calling cogl_matrix_stack_push().

    This is usually called while traversing a scenegraph whenever you return up one level in the graph towards the root node.

    Returns void

  • push(): void
  • Saves the current transform and starts a new transform that derives from the current transform.

    This is usually called while traversing a scenegraph whenever you traverse one level deeper. cogl_matrix_stack_pop() can then be called when going back up one layer to restore the previous transform of an ancestor.

    Returns void

  • Increases the reference count of object.

    Since GLib 2.56, if GLIB_VERSION_MAX_ALLOWED is 2.56 or greater, the type of object will be propagated to the return type (using the GCC typeof() extension), so any casting the caller needs to do on the return type must be explicit.

    Returns GObject.Object

  • Increase the reference count of object, and possibly remove the [floating][floating-ref] reference, if object has a floating reference.

    In other words, if the object is floating, then this call "assumes ownership" of the floating reference, converting it to a normal reference by clearing the floating flag while leaving the reference count unchanged. If the object is not floating, then this call adds a new normal reference increasing the reference count by one.

    Since GLib 2.56, the type of object will be propagated to the return type under the same conditions as for g_object_ref().

    Returns GObject.Object

  • rotate(angle: number, x: number, y: number, z: number): void
  • Multiplies the current matrix by one that rotates the around the axis-vector specified by x, y and z. The rotation follows the right-hand thumb rule so for example rotating by 10 degrees about the axis-vector (0, 0, 1) causes a small counter-clockwise rotation.

    Parameters

    • angle: number

      Angle in degrees to rotate.

    • x: number

      X-component of vertex to rotate around.

    • y: number

      Y-component of vertex to rotate around.

    • z: number

      Z-component of vertex to rotate around.

    Returns void

  • Multiplies the current matrix by one that rotates according to the rotation described by euler.

    Parameters

    Returns void

  • run_dispose(): void
  • Releases all references to other objects. This can be used to break reference cycles.

    This function should only be called from object system implementations.

    Returns void

  • scale(x: number, y: number, z: number): void
  • Multiplies the current matrix by one that scales the x, y and z axes by the given values.

    Parameters

    • x: number

      Amount to scale along the x-axis

    • y: number

      Amount to scale along the y-axis

    • z: number

      Amount to scale along the z-axis

    Returns void

  • Replaces the current stack matrix value with the value of matrix. This effectively discards any other operations that were applied since the last time cogl_matrix_stack_push() was called or since the stack was initialized.

    Parameters

    • matrix: Cogl.Matrix

      A #CoglMatrix replace the current matrix value with

    Returns void

  • set_data(key: string, data?: object): void
  • Each object carries around a table of associations from strings to pointers. This function lets you set an association.

    If the object already had an association with that name, the old association will be destroyed.

    Internally, the key is converted to a #GQuark using g_quark_from_string(). This means a copy of key is kept permanently (even after object has been finalized) — so it is recommended to only use a small, bounded set of values for key in your program, to avoid the #GQuark storage growing unbounded.

    Parameters

    • key: string

      name of the key

    • Optional data: object

      data to associate with that key

    Returns void

  • set_property(property_name: string, value?: any): void
  • steal_data(key?: string): object
  • Remove a specified datum from the object's data associations, without invoking the association's destroy handler.

    Parameters

    • Optional key: string

      name of the key

    Returns object

  • steal_qdata(quark: number): object
  • This function gets back user data pointers stored via g_object_set_qdata() and removes the data from object without invoking its destroy() function (if any was set). Usually, calling this function is only required to update user data pointers with a destroy notifier, for example:

    void
    object_add_to_user_list (GObject *object,
    const gchar *new_string)
    {
    // the quark, naming the object data
    GQuark quark_string_list = g_quark_from_static_string ("my-string-list");
    // retrieve the old string list
    GList *list = g_object_steal_qdata (object, quark_string_list);

    // prepend new string
    list = g_list_prepend (list, g_strdup (new_string));
    // this changed 'list', so we need to set it again
    g_object_set_qdata_full (object, quark_string_list, list, free_string_list);
    }
    static void
    free_string_list (gpointer data)
    {
    GList *node, *list = data;

    for (node = list; node; node = node->next)
    g_free (node->data);
    g_list_free (list);
    }

    Using g_object_get_qdata() in the above example, instead of g_object_steal_qdata() would have left the destroy function set, and thus the partial string list would have been freed upon g_object_set_qdata_full().

    Parameters

    • quark: number

      A #GQuark, naming the user data pointer

    Returns object

  • thaw_notify(): void
  • Reverts the effect of a previous call to g_object_freeze_notify(). The freeze count is decreased on object and when it reaches zero, queued "notify" signals are emitted.

    Duplicate notifications for each property are squashed so that at most one #GObject::notify signal is emitted for each property, in the reverse order in which they have been queued.

    It is an error to call this function when the freeze count is zero.

    Returns void

  • translate(x: number, y: number, z: number): void
  • Multiplies the current matrix by one that translates along all three axes according to the given values.

    Parameters

    • x: number

      Distance to translate along the x-axis

    • y: number

      Distance to translate along the y-axis

    • z: number

      Distance to translate along the z-axis

    Returns void

  • unref(): void
  • Decreases the reference count of object. When its reference count drops to 0, the object is finalized (i.e. its memory is freed).

    If the pointer to the #GObject may be reused in future (for example, if it is an instance variable of another object), it is recommended to clear the pointer to %NULL rather than retain a dangling pointer to a potentially invalid #GObject instance. Use g_clear_object() for this.

    Returns void

  • vfunc_constructed(): void
  • vfunc_dispatch_properties_changed(n_pspecs: number, pspecs: ParamSpec): void
  • vfunc_dispose(): void
  • vfunc_finalize(): void
  • vfunc_get_property(property_id: number, value?: any, pspec?: ParamSpec): void
  • Emits a "notify" signal for the property property_name on object.

    When possible, eg. when signaling a property change from within the class that registered the property, you should use g_object_notify_by_pspec() instead.

    Note that emission of the notify signal may be blocked with g_object_freeze_notify(). In this case, the signal emissions are queued and will be emitted (in reverse order) when g_object_thaw_notify() is called.

    virtual

    Parameters

    Returns void

  • vfunc_set_property(property_id: number, value?: any, pspec?: ParamSpec): void
  • watch_closure(closure: TClosure<any, any>): void
  • This function essentially limits the life time of the closure to the life time of the object. That is, when the object is finalized, the closure is invalidated by calling g_closure_invalidate() on it, in order to prevent invocations of the closure with a finalized (nonexisting) object. Also, g_object_ref() and g_object_unref() are added as marshal guards to the closure, to ensure that an extra reference count is held on object during invocation of the closure. Usually, this function will be called on closures that use this object as closure data.

    Parameters

    • closure: TClosure<any, any>

      #GClosure to watch

    Returns void

  • compat_control(what: number, data: object): number
  • Find the #GParamSpec with the given name for an interface. Generally, the interface vtable passed in as g_iface will be the default vtable from g_type_default_interface_ref(), or, if you know the interface has already been loaded, g_type_default_interface_peek().

    Parameters

    • g_iface: TypeInterface

      any interface vtable for the interface, or the default vtable for the interface

    • property_name: string

      name of a property to look up.

    Returns ParamSpec

  • Add a property to an interface; this is only useful for interfaces that are added to GObject-derived types. Adding a property to an interface forces all objects classes with that interface to have a compatible property. The compatible property could be a newly created #GParamSpec, but normally g_object_class_override_property() will be used so that the object class only needs to provide an implementation and inherits the property description, default value, bounds, and so forth from the interface property.

    This function is meant to be called from the interface's default vtable initialization function (the class_init member of #GTypeInfo.) It must not be called after after class_init has been called for any object types implementing this interface.

    If pspec is a floating reference, it will be consumed.

    Parameters

    • g_iface: TypeInterface

      any interface vtable for the interface, or the default vtable for the interface.

    • pspec: ParamSpec

      the #GParamSpec for the new property

    Returns void

  • Lists the properties of an interface.Generally, the interface vtable passed in as g_iface will be the default vtable from g_type_default_interface_ref(), or, if you know the interface has already been loaded, g_type_default_interface_peek().

    Parameters

    • g_iface: TypeInterface

      any interface vtable for the interface, or the default vtable for the interface

    Returns ParamSpec[]

  • Allocates a new #CoglMatrixStack that can be used to build up transformations relating to objects in a scenegraph like hierarchy. (See the description of #CoglMatrixStack and #CoglMatrixEntry for more details of what a matrix stack is best suited for)

    When a #CoglMatrixStack is first allocated it is conceptually positioned at the root of your scenegraph hierarchy. As you traverse your scenegraph then you should call cogl_matrix_stack_push() whenever you move down a level and cogl_matrix_stack_pop() whenever you move back up a level towards the root.

    Once you have allocated a #CoglMatrixStack you can get a reference to the current transformation for the current position in the hierarchy by calling cogl_matrix_stack_get_entry().

    Once you have allocated a #CoglMatrixStack you can apply operations such as rotate, scale and translate to modify the current transform for the current position in the hierarchy by calling cogl_matrix_stack_rotate(), cogl_matrix_stack_scale() and cogl_matrix_stack_translate().

    Parameters

    Returns MatrixStack

  • Creates a new instance of a #GObject subtype and sets its properties.

    Construction parameters (see %G_PARAM_CONSTRUCT, %G_PARAM_CONSTRUCT_ONLY) which are not explicitly specified are set to their default values.

    Parameters

    • object_type: GType<unknown>

      the type id of the #GObject subtype to instantiate

    • parameters: GObject.Parameter[]

      an array of #GParameter

    Returns GObject.Object

  • value_get_object(value: any): object
  • value_set_object(value: any, object: object): void

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