www.gnome.org.ru - ��/��Cairo/��1

2008-07-26 11:50:56

�� /�� / �� Cairo / �� 1 �� 2008-07-26 11:50:56 � 2008-07-27 13:19:52

��:

�� Cairo � GTK+ 2.8, �� 1

�� : http://www.gnomejournal.org/article/34/writing-a-widget-using-cairo-and-gtk28
2 �� 2005, �� (Davyd Madeley)
4 �� 2006, �� (sib-mail@mtu-net.ru)

�� 2.8, GTK+ �� Cairo. � �� GTK+, �� Cairo �� .

Cairo �� , �� , �� alpha-blending � ��. �� , �� , �� OpenGL.
�� 2.8, ��a�� GTK+ �� Cairo 1.0, �� API.
�� , �� GTK+, �� Cairo. �� , �� Cairo �� , �� . �� GtkDrawingArea, �� . �� Cairo API.

�� 1. �� GObject

�� , � �� Cairo �� GtkDrawingArea, �� , �� , �� . �� , �� Cairo.
�� GObject. �� GObject �� , �� , �� .
�� GTK+ – ��-�� , �� , �� : �� . �� GtkWidget, � �� .
�� . �� , �� Cairo, �� GtkDrawingArea, �� GtkWidget, GtkObject � � �� GObject. �� , �� GtkDrawingArea �� , �� , �� .
�� , �� , �� . �� -�� , �� , �� .
� �� clock.c � �� :

G_DEFINE_TYPE (EggClockFace, egg_clock_face, GTK_TYPE_DRAWING_AREA);

�� EggClockFace, �� egg_clock_face, �� GtkDrawingArea.
�� . � �� . �� , �� . �� (�� ). �� , � clock.h ��:

typedef struct _EggClockFace            EggClockFace;
 typedef struct _EggClockFaceClass       EggClockFaceClass;

 struct _EggClockFace
 {
        GtkDrawingArea parent;

        /* private */
 };

 struct _EggClockFaceClass
 {
        GtkDrawingAreaClass parent_class;
 };

�� , �� , �� , � �� GTK+. �� , �� clock.h:

#define EGG_TYPE_CLOCK_FACE             (egg_clock_face_get_type ())
 #define EGG_CLOCK_FACE(obj)             (G_TYPE_CHECK_INSTANCE_CAST ((obj), EGG_TYPE_CLOCK_FACE, EggClockFace))
 #define EGG_CLOCK_FACE_CLASS(obj)       (G_TYPE_CHECK_CLASS_CAST ((obj), EGG_CLOCK_FACE,  EggClockFaceClass))
 #define EGG_IS_CLOCK_FACE(obj)          (G_TYPE_CHECK_INSTANCE_TYPE ((obj), EGG_TYPE_CLOCK_FACE))
 #define EGG_IS_CLOCK_FACE_CLASS(obj)    (G_TYPE_CHECK_CLASS_TYPE ((obj), EGG_TYPE_CLOCK_FACE))
 #define EGG_CLOCK_FACE_GET_CLASS        (G_TYPE_INSTANCE_GET_CLASS ((obj), EGG_TYPE_CLOCK_FACE, EggClockFaceClass))

�� , �� egg_clock_face_class_init(), �� . �� , �� . �� clock.c:

static void
 egg_clock_face_class_init (EggClockFaceClass *class)
 {
        GtkWidgetClass *widget_class;

        widget_class = GTK_WIDGET_CLASS (class);

        widget_class->expose_event = egg_clock_face_expose;
 }

��, � �� class_init, � �� g_type_class_add_private() �� .
�� -�� EggClockFace, �� egg_clock_face_init(). �� GtkWidget �� , �� . �� :

static void
 egg_clock_face_init (EggClockFace *clock)
 { 
 }

�� , �� – ��. �� , �� API.
�� -�� , �� egg_clock_face_new().

GtkWidget *
 egg_clock_face_new (void)
 {
        return g_object_new (EGG_TYPE_CLOCK_FACE, NULL); 
 }

�� .
� �� , �� , �� .

static gboolean

 egg_clock_face_expose (GtkWidget *clock, GdkEventExpose *event)
 {
return FALSE; 
 }

�� main(). �� main.c:

int
 main (int argc, char **argv)
 {
        GtkWidget *window;
        GtkWidget *clock;

        gtk_init (&argc, &argv);

        window = gtk_window_new (GTK_WINDOW_TOPLEVEL);

        clock = egg_clock_face_new ();
        gtk_container_add (GTK_CONTAINER (window), clock);

        g_signal_connect (window, "destroy",
                        G_CALLBACK (gtk_main_quit), NULL);

        gtk_widget_show_all (window);

        gtk_main ();
 }

��, �� , � �� clock-ex1.c, clock.h, and main.c.
�� :

gcc -o clock `pkg-config --cflags --libs gtk+-2.0` clock.h clock-ex1.c main.c

�� , �� , �� 1.
file:cairogtk1.png
�� 1 – �� GTK ��
��, ��? �� ... �� . �� -�� .

�� 2. �� Cairo

�� -�� GTK+ �� , �� expose-event. �� 1, ��, �� . �� , GTK+ �� , �� , �� . �� GdkEventExpose.
�� Cairo �� Cairo (�� cairo_t). �� cairo_t �� GdkWindow (�� ). �� , �� GdkWindow � GtkWindow – �� , �� GdkWindow �� . ��, �� , �� .
�� GdkWindow �� (��. GtkDrawingArea), �� window �� , �� widget – > window. �� cairo_t � �� , �� :

static gboolean
 egg_clock_face_expose (GtkWidget *clock, GdkEventExpose *event)
 {
        cairo_t *cr;

        /* �������� cairo_t */
        cr = gdk_cairo_create (clock->window);

        draw (clock, cr);

        cairo_destroy (cr);

        return FALSE;

 }

�� , �� . �� , �� .

static gboolean
 egg_clock_face_expose (GtkWidget *clock, GdkEventExpose *event)
 {
        cairo_t *cr;

        /* �������� cairo_t */
        cr = gdk_cairo_create (clock->window);

        /* ���������� ������� ����������� */
        cairo_rectangle (cr,
                        event->area.x, event->area.y,
                        event->area.width, event->area.height);
        cairo_clip (cr);

        draw (clock, cr);

        cairo_destroy (cr);

        return FALSE; 
 }

�� -�� . � Cairo �� , � �� . �� , �� , � �� . �� , �� . �� , �� , �� .
�� , �� . �� (canvas), �� , �� “allocation”. ��, �� (x,y) �� :

double x, y;
 x = clock->allocation.x + clock->allocation.width / 2;
 y = clock->allocation.y + clock->allocation.height / 2;

�� , �� , �� :

double radius;
 radius = MIN (clock->allocation.width / 2,
              clock->allocation.height / 2) - 5;

�� (x,y) � �� 0 � 2�� :

cairo_arc (cr, x, y, radius, 0, 2 * M_PI);

�� , � �� :

cairo_set_source_rgb (cr, 1, 1, 1);
 cairo_fill_preserve (cr);
 cairo_set_source_rgb (cr, 0, 0, 0);
 cairo_stroke (cr);

�� , �� 2 ��.
file:cairogtk2.png
�� 2 – ��
�� . �� , �� 2�� 12 ��, �� /6 �� .
�� , �� , � �� cairo_move_to() � cairo_line_to().

for (i = 0; i < 12; i++)
 {
        int inset;

        inset = 0.1 * radius;

        cairo_move_to (cr,
                        x + (radius - inset) * cos (i * M_PI / 6),
                        y + (radius - inset) * sin (i * M_PI / 6));
        cairo_line_to (cr,
                        x + radius * cos (i * M_PI / 6),
                        y + radius * sin (i * M_PI / 6));
        cairo_stroke (cr); 
 }

�� , �� 12, 3, 6, 9 �� , �� .

for (i = 0; i < 12; i++)
 {
        int inset;

        cairo_save (cr); /* save pen size to stack */

        if (i % 3 == 0)
        {
                inset = 0.2 * radius;
        }
        else
        {
                inset = 0.1 * radius;
                cairo_set_line_width (cr, 0.5 *
                                cairo_get_line_width (cr));
        }

        cairo_move_to (cr,
                        x + (radius - inset) * cos (i * M_PI / 6),
                        y + (radius - inset) * sin (i * M_PI / 6));
        cairo_line_to (cr,
                        x + radius * cos (i * M_PI / 6),
                        y + radius * sin (i * M_PI / 6));
        cairo_stroke (cr);
        cairo_restore (cr); /* recover pen size from stack */
 }

�� , �� Cairo_save() � cairo_restore(). �� Cairo. �� , �� . �� , �� . �� .
�� clock-ex3.c. �� :

gcc -o clock `pkg-config --cflags --libs gtk+-2.0` clock.h clock-ex3.c main.c

�� , �� 3.
file:cairogtk3.png
�� 3 – ��
��, �� , �� . � �� , �� , �� , �� .
�� Cairo � Cairo API, �� : http://www.cairographics.org/

��:

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2008-07-08 20:56:50

�� /�� / �� Cairo / �� 1 �� 2008-07-08 20:56:50 � 2008-07-26 11:50:56

��:

��:

�� Cairo � GTK+ 2.8, �� 1

�� 1. �� GObject

G_DEFINE_TYPE (EggClockFace, egg_clock_face, GTK_TYPE_DRAWING_AREA);

�� EggClockFace, �� egg_clock_face, �� GtkDrawingArea.
�� . � �� . �� , �� . �� (�� ). �� , � clock.h ��:

typedef struct _EggClockFace            EggClockFace;
 typedef struct _EggClockFaceClass       EggClockFaceClass;

 struct _EggClockFace
 {
        GtkDrawingArea parent;

        /* private */
 };

 struct _EggClockFaceClass
 {
        GtkDrawingAreaClass parent_class;
 };

�� , �� , �� , � �� GTK+. �� , �� clock.h:

#define EGG_TYPE_CLOCK_FACE             (egg_clock_face_get_type ())
 #define EGG_CLOCK_FACE(obj)             (G_TYPE_CHECK_INSTANCE_CAST ((obj), EGG_TYPE_CLOCK_FACE, EggClockFace))
 #define EGG_CLOCK_FACE_CLASS(obj)       (G_TYPE_CHECK_CLASS_CAST ((obj), EGG_CLOCK_FACE,  EggClockFaceClass))
 #define EGG_IS_CLOCK_FACE(obj)          (G_TYPE_CHECK_INSTANCE_TYPE ((obj), EGG_TYPE_CLOCK_FACE))
 #define EGG_IS_CLOCK_FACE_CLASS(obj)    (G_TYPE_CHECK_CLASS_TYPE ((obj), EGG_TYPE_CLOCK_FACE))
 #define EGG_CLOCK_FACE_GET_CLASS        (G_TYPE_INSTANCE_GET_CLASS ((obj), EGG_TYPE_CLOCK_FACE, EggClockFaceClass))

�� , �� egg_clock_face_class_init(), �� . �� , �� . �� clock.c:

static void
 egg_clock_face_class_init (EggClockFaceClass *class)
 {
        GtkWidgetClass *widget_class;

        widget_class = GTK_WIDGET_CLASS (class);

        widget_class->expose_event = egg_clock_face_expose;
 }

��, � �� class_init, � �� g_type_class_add_private() �� .
�� -�� EggClockFace, �� egg_clock_face_init(). �� GtkWidget �� , �� . �� :

static void
 egg_clock_face_init (EggClockFace *clock)
 { 
 }

�� , �� – ��. �� , �� API.
�� -�� , �� egg_clock_face_new().

GtkWidget *
 egg_clock_face_new (void)
 {
        return g_object_new (EGG_TYPE_CLOCK_FACE, NULL); 
 }

�� .
� �� , �� , �� .

static gboolean

 egg_clock_face_expose (GtkWidget *clock, GdkEventExpose *event)
 {
return FALSE; 
 }

�� main(). �� main.c:

int
 main (int argc, char **argv)
 {
        GtkWidget *window;
        GtkWidget *clock;

        gtk_init (&argc, &argv);

        window = gtk_window_new (GTK_WINDOW_TOPLEVEL);

        clock = egg_clock_face_new ();
        gtk_container_add (GTK_CONTAINER (window), clock);

        g_signal_connect (window, "destroy",
                        G_CALLBACK (gtk_main_quit), NULL);

        gtk_widget_show_all (window);

        gtk_main ();
 }

��, �� , � �� clock-ex1.c, clock.h, and main.c.
�� :

gcc -o clock `pkg-config --cflags --libs gtk+-2.0` clock.h clock-ex1.c main.c

�� , �� , �� 1.
file:cairogtk1.png
�� 1 – �� GTK ��
��, ��? �� ... �� . �� -�� .

�� 2. �� Cairo

static gboolean
 egg_clock_face_expose (GtkWidget *clock, GdkEventExpose *event)
 {
        cairo_t *cr;

        /* �������� cairo_t */
        cr = gdk_cairo_create (clock->window);

        draw (clock, cr);

        cairo_destroy (cr);

        return FALSE;

 }

�� , �� . �� , �� .

static gboolean
 egg_clock_face_expose (GtkWidget *clock, GdkEventExpose *event)
 {
        cairo_t *cr;

        /* �������� cairo_t */
        cr = gdk_cairo_create (clock->window);

        /* ���������� ������� ����������� */
        cairo_rectangle (cr,
                        event->area.x, event->area.y,
                        event->area.width, event->area.height);
        cairo_clip (cr);

        draw (clock, cr);

        cairo_destroy (cr);

        return FALSE; 
 }

double x, y;
 x = clock->allocation.x + clock->allocation.width / 2;
 y = clock->allocation.y + clock->allocation.height / 2;

�� , �� , �� :

double radius;
 radius = MIN (clock->allocation.width / 2,
              clock->allocation.height / 2) - 5;

�� (x,y) � �� 0 � 2�� :

cairo_arc (cr, x, y, radius, 0, 2 * M_PI);

�� , � �� :

cairo_set_source_rgb (cr, 1, 1, 1);
 cairo_fill_preserve (cr);
 cairo_set_source_rgb (cr, 0, 0, 0);
 cairo_stroke (cr);

�� , �� 2 ��.
file:cairogtk2.png
�� 2 – ��
�� . �� , �� 2�� 12 ��, �� /6 �� .
�� , �� , � �� cairo_move_to() � cairo_line_to().

for (i = 0; i < 12; i++)
 {
        int inset;

        inset = 0.1 * radius;

        cairo_move_to (cr,
                        x + (radius - inset) * cos (i * M_PI / 6),
                        y + (radius - inset) * sin (i * M_PI / 6));
        cairo_line_to (cr,
                        x + radius * cos (i * M_PI / 6),
                        y + radius * sin (i * M_PI / 6));
        cairo_stroke (cr); 
 }

�� , �� 12, 3, 6, 9 �� , �� .

for (i = 0; i < 12; i++)
 {
        int inset;

        cairo_save (cr); /* save pen size to stack */

        if (i % 3 == 0)
        {
                inset = 0.2 * radius;
        }
        else
        {
                inset = 0.1 * radius;
                cairo_set_line_width (cr, 0.5 *
                                cairo_get_line_width (cr));
        }

        cairo_move_to (cr,
                        x + (radius - inset) * cos (i * M_PI / 6),
                        y + (radius - inset) * sin (i * M_PI / 6));
        cairo_line_to (cr,
                        x + radius * cos (i * M_PI / 6),
                        y + radius * sin (i * M_PI / 6));
        cairo_stroke (cr);
        cairo_restore (cr); /* recover pen size from stack */
 }

�� , �� Cairo_save() � cairo_restore(). �� Cairo. �� , �� . �� , �� . �� .
�� clock-ex3.c. �� :

gcc -o clock `pkg-config --cflags --libs gtk+-2.0` clock.h clock-ex3.c main.c

�� , �� 3.
file:cairogtk3.png
�� 3 – ��
��, �� , �� . � �� , �� , �� , �� .
�� Cairo � Cairo API, �� : http://www.cairographics.org/

2008-07-07 23:17:00

�� /�� / �� Cairo / �� 1 �� 2008-07-07 23:17:00 � 2008-07-08 20:56:50

��:

�� Cairo � GTK+ 2.8, �� 1

�� 1. �� GObject

G_DEFINE_TYPE (EggClockFace, egg_clock_face, GTK_TYPE_DRAWING_AREA);

�� EggClockFace, �� egg_clock_face, �� GtkDrawingArea.
�� . � �� . �� , �� . �� (�� ). �� , � clock.h ��:

typedef struct _EggClockFace            EggClockFace;
 typedef struct _EggClockFaceClass       EggClockFaceClass;

 struct _EggClockFace
 {
        GtkDrawingArea parent;

        /* private */
 };

 struct _EggClockFaceClass
 {
        GtkDrawingAreaClass parent_class;
 };

�� , �� , �� , � �� GTK+. �� , �� clock.h:

#define EGG_TYPE_CLOCK_FACE             (egg_clock_face_get_type ())
 #define EGG_CLOCK_FACE(obj)             (G_TYPE_CHECK_INSTANCE_CAST ((obj), EGG_TYPE_CLOCK_FACE, EggClockFace))
 #define EGG_CLOCK_FACE_CLASS(obj)       (G_TYPE_CHECK_CLASS_CAST ((obj), EGG_CLOCK_FACE,  EggClockFaceClass))
 #define EGG_IS_CLOCK_FACE(obj)          (G_TYPE_CHECK_INSTANCE_TYPE ((obj), EGG_TYPE_CLOCK_FACE))
 #define EGG_IS_CLOCK_FACE_CLASS(obj)    (G_TYPE_CHECK_CLASS_TYPE ((obj), EGG_TYPE_CLOCK_FACE))
 #define EGG_CLOCK_FACE_GET_CLASS        (G_TYPE_INSTANCE_GET_CLASS ((obj), EGG_TYPE_CLOCK_FACE, EggClockFaceClass))

�� , �� egg_clock_face_class_init(), �� . �� , �� . �� clock.c:

static void
 egg_clock_face_class_init (EggClockFaceClass *class)
 {
        GtkWidgetClass *widget_class;

        widget_class = GTK_WIDGET_CLASS (class);

        widget_class->expose_event = egg_clock_face_expose;
 }

��, � �� class_init, � �� g_type_class_add_private() �� .
�� -�� EggClockFace, �� egg_clock_face_init(). �� GtkWidget �� , �� . �� :

static void
 egg_clock_face_init (EggClockFace *clock)
 { 
 }

�� , �� – ��. �� , �� API.
�� -�� , �� egg_clock_face_new().

GtkWidget *
 egg_clock_face_new (void)
 {
        return g_object_new (EGG_TYPE_CLOCK_FACE, NULL); 
 }

�� .
� �� , �� , �� .

static gboolean

 egg_clock_face_expose (GtkWidget *clock, GdkEventExpose *event)
 {
return FALSE; 
 }

�� main(). �� main.c:

int
 main (int argc, char **argv)
 {
        GtkWidget *window;
        GtkWidget *clock;

        gtk_init (&argc, &argv);

        window = gtk_window_new (GTK_WINDOW_TOPLEVEL);

        clock = egg_clock_face_new ();
        gtk_container_add (GTK_CONTAINER (window), clock);

        g_signal_connect (window, "destroy",
                        G_CALLBACK (gtk_main_quit), NULL);

        gtk_widget_show_all (window);

        gtk_main ();
 }

��, �� , � �� clock-ex1.c, clock.h, and main.c.
�� :

gcc -o clock `pkg-config --cflags --libs gtk+-2.0` clock.h clock-ex1.c main.c

�� , �� , �� 1.
file:cairogtk1.png
�� 1 – �� GTK ��
��, ��? �� ... �� . �� -�� .

�� 2. �� Cairo

static gboolean
 egg_clock_face_expose (GtkWidget *clock, GdkEventExpose *event)
 {
        cairo_t *cr;

        /* �������� cairo_t */
        cr = gdk_cairo_create (clock->window);

        draw (clock, cr);

        cairo_destroy (cr);

        return FALSE;

 }

�� , �� . �� , �� .

static gboolean
 egg_clock_face_expose (GtkWidget *clock, GdkEventExpose *event)
 {
        cairo_t *cr;

        /* �������� cairo_t */
        cr = gdk_cairo_create (clock->window);

        /* ���������� ������� ����������� */
        cairo_rectangle (cr,
                        event->area.x, event->area.y,
                        event->area.width, event->area.height);
        cairo_clip (cr);

        draw (clock, cr);

        cairo_destroy (cr);

        return FALSE; 
 }

double x, y;
 x = clock->allocation.x + clock->allocation.width / 2;
 y = clock->allocation.y + clock->allocation.height / 2;

�� , �� , �� :

double radius;
 radius = MIN (clock->allocation.width / 2,
              clock->allocation.height / 2) - 5;

�� (x,y) � �� 0 � 2�� :

cairo_arc (cr, x, y, radius, 0, 2 * M_PI);

�� , � �� :

cairo_set_source_rgb (cr, 1, 1, 1);
 cairo_fill_preserve (cr);
 cairo_set_source_rgb (cr, 0, 0, 0);
 cairo_stroke (cr);

�� , �� 2 ��.
file:cairogtk2.png
�� 2 – ��
�� . �� , �� 2�� 12 ��, �� /6 �� .
�� , �� , � �� cairo_move_to() � cairo_line_to().

for (i = 0; i < 12; i++)
 {
        int inset;

        inset = 0.1 * radius;

        cairo_move_to (cr,
                        x + (radius - inset) * cos (i * M_PI / 6),
                        y + (radius - inset) * sin (i * M_PI / 6));
        cairo_line_to (cr,
                        x + radius * cos (i * M_PI / 6),
                        y + radius * sin (i * M_PI / 6));
        cairo_stroke (cr); 
 }

�� , �� 12, 3, 6, 9 �� , �� .

for (i = 0; i < 12; i++)
 {
        int inset;

        cairo_save (cr); /* save pen size to stack */

        if (i % 3 == 0)
        {
                inset = 0.2 * radius;
        }
        else
        {
                inset = 0.1 * radius;
                cairo_set_line_width (cr, 0.5 *
                                cairo_get_line_width (cr));
        }

        cairo_move_to (cr,
                        x + (radius - inset) * cos (i * M_PI / 6),
                        y + (radius - inset) * sin (i * M_PI / 6));
        cairo_line_to (cr,
                        x + radius * cos (i * M_PI / 6),
                        y + radius * sin (i * M_PI / 6));
        cairo_stroke (cr);
        cairo_restore (cr); /* recover pen size from stack */
 }

�� , �� Cairo_save() � cairo_restore(). �� Cairo. �� , �� . �� , �� . �� .
�� clock-ex3.c. �� :

gcc -o clock `pkg-config --cflags --libs gtk+-2.0` clock.h clock-ex3.c main.c

�� , �� 3.
file:cairogtk3.png
�� 3 – ��
��, �� , �� . � �� , �� , �� , �� .
�� Cairo � Cairo API, �� : http://www.cairographics.org/

��:

well, In some ways it must have been an emotional thing to tell the story, for anyone to read, as the person may or may not know you com Brilliant but simple idea. http://kasonoli.white.prohosting.com/com3236.html com I, http://kasonolia.calimerou.fr/com7879.html com, Thanks

2006-04-09 12:38:17

�� /�� / �� Cairo / �� 1 �� 2006-04-09 12:38:17 � 2008-07-07 23:17:00

��:

��:

�� Cairo � GTK+ 2.8, �� 1

�� 1. �� GObject

G_DEFINE_TYPE (EggClockFace, egg_clock_face, GTK_TYPE_DRAWING_AREA);

�� EggClockFace, �� egg_clock_face, �� GtkDrawingArea.
�� . � �� . �� , �� . �� (�� ). �� , � clock.h ��:

typedef struct _EggClockFace            EggClockFace;
 typedef struct _EggClockFaceClass       EggClockFaceClass;

 struct _EggClockFace
 {
        GtkDrawingArea parent;

        /* private */
 };

 struct _EggClockFaceClass
 {
        GtkDrawingAreaClass parent_class;
 };

�� , �� , �� , � �� GTK+. �� , �� clock.h:

#define EGG_TYPE_CLOCK_FACE             (egg_clock_face_get_type ())
 #define EGG_CLOCK_FACE(obj)             (G_TYPE_CHECK_INSTANCE_CAST ((obj), EGG_TYPE_CLOCK_FACE, EggClockFace))
 #define EGG_CLOCK_FACE_CLASS(obj)       (G_TYPE_CHECK_CLASS_CAST ((obj), EGG_CLOCK_FACE,  EggClockFaceClass))
 #define EGG_IS_CLOCK_FACE(obj)          (G_TYPE_CHECK_INSTANCE_TYPE ((obj), EGG_TYPE_CLOCK_FACE))
 #define EGG_IS_CLOCK_FACE_CLASS(obj)    (G_TYPE_CHECK_CLASS_TYPE ((obj), EGG_TYPE_CLOCK_FACE))
 #define EGG_CLOCK_FACE_GET_CLASS        (G_TYPE_INSTANCE_GET_CLASS ((obj), EGG_TYPE_CLOCK_FACE, EggClockFaceClass))

�� , �� egg_clock_face_class_init(), �� . �� , �� . �� clock.c:

static void
 egg_clock_face_class_init (EggClockFaceClass *class)
 {
        GtkWidgetClass *widget_class;

        widget_class = GTK_WIDGET_CLASS (class);

        widget_class->expose_event = egg_clock_face_expose;
 }

��, � �� class_init, � �� g_type_class_add_private() �� .
�� -�� EggClockFace, �� egg_clock_face_init(). �� GtkWidget �� , �� . �� :

static void
 egg_clock_face_init (EggClockFace *clock)
 { 
 }

�� , �� – ��. �� , �� API.
�� -�� , �� egg_clock_face_new().

GtkWidget *
 egg_clock_face_new (void)
 {
        return g_object_new (EGG_TYPE_CLOCK_FACE, NULL); 
 }

�� .
� �� , �� , �� .

static gboolean

 egg_clock_face_expose (GtkWidget *clock, GdkEventExpose *event)
 {
return FALSE; 
 }

�� main(). �� main.c:

int
 main (int argc, char **argv)
 {
        GtkWidget *window;
        GtkWidget *clock;

        gtk_init (&argc, &argv);

        window = gtk_window_new (GTK_WINDOW_TOPLEVEL);

        clock = egg_clock_face_new ();
        gtk_container_add (GTK_CONTAINER (window), clock);

        g_signal_connect (window, "destroy",
                        G_CALLBACK (gtk_main_quit), NULL);

        gtk_widget_show_all (window);

        gtk_main ();
 }

��, �� , � �� clock-ex1.c, clock.h, and main.c.
�� :

gcc -o clock `pkg-config --cflags --libs gtk+-2.0` clock.h clock-ex1.c main.c

�� , �� , �� 1.
file:cairogtk1.png
�� 1 – �� GTK ��
��, ��? �� ... �� . �� -�� .

�� 2. �� Cairo

static gboolean
 egg_clock_face_expose (GtkWidget *clock, GdkEventExpose *event)
 {
        cairo_t *cr;

        /* �������� cairo_t */
        cr = gdk_cairo_create (clock->window);

        draw (clock, cr);

        cairo_destroy (cr);

        return FALSE;

 }

�� , �� . �� , �� .

static gboolean
 egg_clock_face_expose (GtkWidget *clock, GdkEventExpose *event)
 {
        cairo_t *cr;

        /* �������� cairo_t */
        cr = gdk_cairo_create (clock->window);

        /* ���������� ������� ����������� */
        cairo_rectangle (cr,
                        event->area.x, event->area.y,
                        event->area.width, event->area.height);
        cairo_clip (cr);

        draw (clock, cr);

        cairo_destroy (cr);

        return FALSE; 
 }

double x, y;
 x = clock->allocation.x + clock->allocation.width / 2;
 y = clock->allocation.y + clock->allocation.height / 2;

�� , �� , �� :

double radius;
 radius = MIN (clock->allocation.width / 2,
              clock->allocation.height / 2) - 5;

�� (x,y) � �� 0 � 2�� :

cairo_arc (cr, x, y, radius, 0, 2 * M_PI);

�� , � �� :

cairo_set_source_rgb (cr, 1, 1, 1);
 cairo_fill_preserve (cr);
 cairo_set_source_rgb (cr, 0, 0, 0);
 cairo_stroke (cr);

�� , �� 2 ��.
file:cairogtk2.png
�� 2 – ��
�� . �� , �� 2�� 12 ��, �� /6 �� .
�� , �� , � �� cairo_move_to() � cairo_line_to().

for (i = 0; i < 12; i++)
 {
        int inset;

        inset = 0.1 * radius;

        cairo_move_to (cr,
                        x + (radius - inset) * cos (i * M_PI / 6),
                        y + (radius - inset) * sin (i * M_PI / 6));
        cairo_line_to (cr,
                        x + radius * cos (i * M_PI / 6),
                        y + radius * sin (i * M_PI / 6));
        cairo_stroke (cr); 
 }

�� , �� 12, 3, 6, 9 �� , �� .

for (i = 0; i < 12; i++)
 {
        int inset;

        cairo_save (cr); /* save pen size to stack */

        if (i % 3 == 0)
        {
                inset = 0.2 * radius;
        }
        else
        {
                inset = 0.1 * radius;
                cairo_set_line_width (cr, 0.5 *
                                cairo_get_line_width (cr));
        }

        cairo_move_to (cr,
                        x + (radius - inset) * cos (i * M_PI / 6),
                        y + (radius - inset) * sin (i * M_PI / 6));
        cairo_line_to (cr,
                        x + radius * cos (i * M_PI / 6),
                        y + radius * sin (i * M_PI / 6));
        cairo_stroke (cr);
        cairo_restore (cr); /* recover pen size from stack */
 }

�� , �� Cairo_save() � cairo_restore(). �� Cairo. �� , �� . �� , �� . �� .
�� clock-ex3.c. �� :

gcc -o clock `pkg-config --cflags --libs gtk+-2.0` clock.h clock-ex3.c main.c

�� , �� 3.
file:cairogtk3.png
�� 3 – ��
��, �� , �� . � �� , �� , �� , �� .
�� Cairo � Cairo API, �� : http://www.cairographics.org/

2006-04-09 12:34:26

�� /�� / �� Cairo / �� 1 �� 2006-04-09 12:34:26 � 2006-04-09 12:38:17

��:

�� 2.8, ��a�� GTK+ �� Cairo 1.0, �� API.
��, �� , � �� clock-ex1.c, clock.h, and main.c.
�� clock-ex3.c. �� :

��:

�� 2.8, ��a�� GTK+ �� Cairo 1.0, �� API.
��, �� , � �� clock-ex1.c, clock.h, and main.c.
�� like clock-ex3.c. �� :

2006-04-09 12:31:11

�� /�� / �� Cairo / �� 1 �� 2006-04-09 12:31:11 � 2006-04-09 12:34:26

��:

�� . �� , �� Cairo, �� GtkDrawingArea, �� GtkWidget, GtkObject � � �� GObject. �� , �� GtkDrawingArea �� , �� , �� .

��:

�� . �� , �� Cairo, �� Gtk Drawing Area?, �� GtkWidget, Gtk Object? � � �� GObject. �� , �� Gtk Drawing Area? �� , �� , �� .

2006-04-09 12:30:01

�� /�� / �� Cairo / �� 1 �� 2006-04-09 12:30:01 � 2006-04-09 12:31:11

��:

�� Cairo �� Cairo (�� cairo_t). �� cairo_t �� GdkWindow (�� ). �� , �� GdkWindow � GtkWindow – �� , �� GdkWindow �� . ��, �� , �� .

��:

�� Cairo �� Cairo (�� cairo_t). �� cairo_t �� "'GdkWindow (�� ). �� , �� Gdk Window? � Gtk Window? - �� , �� Gdk Window?"" �� . ��, �� , �� .

2006-04-09 12:18:37

�� /�� / �� Cairo / �� 1 �� 2006-04-09 12:18:37 � 2006-04-09 12:30:01

��:

Cairo �� , �� , �� alpha-blending � ��. �� , �� , �� OpenGL.
�� , �� GTK+, �� Cairo. �� , �� Cairo �� , �� . �� GtkDrawingArea, �� . �� Cairo API.
�� , � �� Cairo �� GtkDrawingArea, �� , �� , �� . �� , �� Cairo.
�� GTK+ – ��-�� , �� , �� : �� . �� GtkWidget, � �� .
�� . �� , �� Cairo, �� Gtk Drawing Area?, �� GtkWidget, Gtk Object? � � �� GObject. �� , �� Gtk Drawing Area? �� , �� , �� .
�� EggClockFace, �� egg_clock_face, �� GtkDrawingArea.
�� -�� EggClockFace, �� egg_clock_face_init(). �� GtkWidget �� , �� . �� :
file:cairogtk1.png
�� -�� GTK+ �� , �� expose-event. �� 1, ��, �� . �� , GTK+ �� , �� , �� . �� GdkEventExpose.
�� Cairo �� Cairo (�� cairo_t). �� cairo_t �� "'GdkWindow (�� ). �� , �� Gdk Window? � Gtk Window? - �� , �� Gdk Window? �� . ��, �� , �� .
�� Gdk Window? �� (��. Gtk Drawing Area?), �� window �� , �� widget - > window. �� cairo_t � �� , �� :
file:cairogtk2.png
�� . �� , �� 2�� 12 ��, �� / 6?"" �� .
file:cairogtk3.png

��:

Cairo �� , �� , �� alpha-blending � ��. �� , �� , �� Open GL?.
�� , �� GTK+, �� Cairo. �� , �� Cairo �� , �� . �� Gtk Drawing Area?, �� . �� Cairo API.
�� , � �� Cairo �� Gtk Drawing Area?, �� , �� , �� . �� , �� Cairo.
�� GTK+ – ��-�� , �� , �� : �� . �� Gtk Widget?, � �� .
�� . �� , �� Cairo, �� Gtk Drawing Area?, �� Gtk Widget?, Gtk Object? � � �� GObject. �� , �� Gtk Drawing Area? �� , �� , �� .
�� Egg Clock Face?, �� egg_clock_face, �� Gtk Drawing Area?.
�� -�� Egg Clock Face?, �� egg_clock_face_init(). �� Gtk Widget? �� , �� . �� :
�� GTK ��
�� -�� GTK+ �� , �� expose-event. �� 1, ��, �� . �� , GTK+ �� , �� , �� . �� Gdk Event Expose?.
�� Cairo �� Cairo (�� cairo_t). �� cairo_t �� Gdk Window? (�� ). �� , �� Gdk Window? � Gtk Window? – �� , �� Gdk Window? �� . ��, �� , �� .
�� Gdk Window? �� (��. Gtk Drawing Area?), �� window �� , �� widget – > window. �� cairo_t � �� , �� :
��
�� . �� , �� 2�� 12 ��, �� / 6? �� .
��

2006-04-09 12:17:11

�� /�� / �� Cairo / �� 1 �� 2006-04-09 12:17:11 � 2006-04-09 12:18:37

No differences.

www.gnome.org.ru - ����������/�������Cairo/�����1

2008-07-26 11:50:56

�������� �������� � �������������� Cairo � GTK+ 2.8, ����� 1

��� 1. ����� GObject

��� 2. ������ � Cairo

2008-07-08 20:56:50

�������� �������� � �������������� Cairo � GTK+ 2.8, ����� 1

��� 1. ����� GObject

��� 2. ������ � Cairo

2008-07-07 23:17:00

�������� �������� � �������������� Cairo � GTK+ 2.8, ����� 1

��� 1. ����� GObject

��� 2. ������ � Cairo

2006-04-09 12:38:17

�������� �������� � �������������� Cairo � GTK+ 2.8, ����� 1

��� 1. ����� GObject

��� 2. ������ � Cairo

2006-04-09 12:34:26

2006-04-09 12:31:11

2006-04-09 12:30:01

2006-04-09 12:18:37

2006-04-09 12:17:11

www.gnome.org.ru - ��/��Cairo/��1

�� Cairo � GTK+ 2.8, �� 1

�� 1. �� GObject

�� 2. �� Cairo

�� Cairo � GTK+ 2.8, �� 1

�� 1. �� GObject

�� 2. �� Cairo

�� Cairo � GTK+ 2.8, �� 1

�� 1. �� GObject

�� 2. �� Cairo

�� Cairo � GTK+ 2.8, �� 1

�� 1. �� GObject

�� 2. �� Cairo