demo/cpml-test.c

   1 #include <adg/adg.h>
   2 #include <gtk/gtk.h>
   3
   4
   5 static void     path_constructor        (AdgEntity      *entity,
   6                                          cairo_t        *cr,
   7                                          gpointer        user_data);
   8 static void     path_expose             (GtkWidget      *widget,
   9                                          GdkEventExpose *event,
  10                                          AdgCanvas      *canvas);
  11
  12
  13 typedef struct {
  14     AdgPair p1;
  15     AdgPair p2;
  16     AdgPair p3;
  17     AdgPair p4;
  18 } Bezier;
  19
  20 static Bezier bezier_samples[] = {
  21     { { 0, 0 }, { 0, 40 }, { 120, 40 }, { 120, 0 } },   /* Simmetric low */
  22     { { 40, 0 }, { 40, 160 }, { 80, 160 }, { 80, 0 } }, /* Simmetric high */
  23     { { 0, 0 }, { 33.1371, 33.1371 }, { 86.8629, 33.1371 }, { 120, 0 } },
  24                                                         /* Arc approximation */
  25     { { 0, 0 }, { 70, 120 }, { 50, 120 }, { 120, 0 } }, /* Twisted controls */
  26
  27     { { 0, 0 }, { 0, 120 }, { 60, 120 }, { 120, 0 } },  /* Vertical p1-p2 */
  28     { { 0, 0 }, { 60, 120 }, { 120, 120 }, { 120, 0 } },/* Vertical p3-p4 */
  29     { { 0, 120 }, { 120, 120 }, { 120, 60 }, { 0, 0 } },/* Horizontal p1-p2 */
  30     { { 0, 120 }, { 120, 60 }, { 120, 0 }, { 0, 0 } },  /* Horizontal p3-p4 */
  31
  32     { { 0, 0 }, { 0, 120 }, { 120, 120 }, { 120, 0 } }, /* Down */
  33     { { 0, 120 }, { 120, 120 }, { 120, 0 }, { 0, 0 } }, /* Right */
  34     { { 0, 120 }, { 0, 0 }, { 120, 0 }, { 120, 120 } }, /* Up */
  35     { { 120, 120 }, { 0, 120 }, { 0, 0 }, { 120, 0 } }, /* Left */
  36
  37     { { 0, 60 }, { 60, 120 }, { 120, 60 }, { 60, 0 } }, /* Down-right */
  38     { { 60, 120 }, { 120, 60 }, { 60, 0 }, { 0, 60 } }, /* Up-right */
  39     { { 120, 60 }, { 60, 0 }, { 0, 60 }, { 60, 120 } }, /* Up-left */
  40     { { 60, 0 }, { 0, 60 }, { 60, 120 }, { 120, 60 } }, /* Down-left*/
  41
  42     { { 0, 0 }, { 60, 0 }, { 60, 120 }, { 120, 120 } }, /* Step left */
  43     { { 120, 0 }, { 60, 0 }, { 60, 120 }, { 0, 120 } }, /* Step right */
  44     { { 0, 0 }, { 60, 90 }, { 90, 120 }, { 120, 90 } }, /* Unbalanced opened */
  45     { { 0, 0 }, { 40, 120 }, { 120, 120 }, { 60, 80 } } /* Unbalanced closed */
  46 };
  47
  48
  49 int
  50 main(gint argc, gchar **argv)
  51 {
  52     GtkWidget *window;
  53     GtkWidget *vbox;
  54     GtkWidget *button_box;
  55     GtkWidget *widget;
  56     AdgCanvas *canvas;
  57     AdgEntity *entity;
  58     gint n;
  59
  60     gtk_init(&argc, &argv);
  61
  62     /* Create the canvas and populate it */
  63     canvas = adg_canvas_new();
  64
  65     /* Add the Bézier curve samples */
  66     for (n = 0; n < G_N_ELEMENTS(bezier_samples); ++n) {
  67         entity = adg_path_new(path_constructor, GINT_TO_POINTER(n));
  68         adg_container_add(ADG_CONTAINER(canvas), entity);
  69     }
  70
  71     /* User interface stuff */
  72     window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
  73     g_signal_connect(window, "delete-event", G_CALLBACK(gtk_main_quit), NULL);
  74
  75     vbox = gtk_vbox_new(FALSE, 0);
  76
  77     widget = gtk_drawing_area_new();
  78     gtk_widget_set_size_request(widget, 800, 800);
  79     g_signal_connect(widget, "expose-event", G_CALLBACK(path_expose), canvas);
  80     gtk_container_add(GTK_CONTAINER(vbox), widget);
  81
  82     button_box = gtk_hbutton_box_new();
  83     gtk_container_set_border_width(GTK_CONTAINER(button_box), 5);
  84     gtk_box_set_spacing(GTK_BOX(button_box), 5);
  85     gtk_button_box_set_layout(GTK_BUTTON_BOX(button_box), GTK_BUTTONBOX_END);
  86     gtk_box_pack_end(GTK_BOX(vbox), button_box, FALSE, TRUE, 0);
  87
  88     widget = gtk_button_new_from_stock(GTK_STOCK_QUIT);
  89     g_signal_connect(widget, "clicked", G_CALLBACK(gtk_main_quit), NULL);
  90     gtk_container_add(GTK_CONTAINER(button_box), widget);
  91
  92     gtk_container_add(GTK_CONTAINER(window), vbox);
  93     gtk_widget_show_all(window);
  94
  95     gtk_main();
  96
  97     return 0;
  98 }
  99
 100
 101 static void
 102 path_constructor(AdgEntity *entity, cairo_t *cr, gpointer user_data)
 103 {
 104     gint n;
 105     Bezier *bezier;
 106     cairo_path_t *path;
 107     CpmlSegment segment;
 108     CpmlPair pair;
 109     CpmlVector vector;
 110     double t;
 111
 112     n = GPOINTER_TO_INT(user_data);
 113     bezier = bezier_samples + n;
 114
 115     /* The samples are arranged in a 4x? matrix of 200x150 cells */
 116     if (n == 0)
 117         cairo_translate(cr, 25., 25.);
 118     else if (n % 4 == 0)
 119         cairo_translate(cr, -600., 150.);
 120     else
 121         cairo_translate(cr, 200., 0.);
 122
 123     /* Draw the Bézier curve */
 124     cairo_move_to(cr, bezier->p1.x, bezier->p1.y);
 125     cairo_curve_to(cr, bezier->p2.x, bezier->p2.y,
 126                    bezier->p3.x, bezier->p3.y, bezier->p4.x, bezier->p4.y);
 127
 128     /* Checking cpml_segment_offset */
 129     path = cairo_copy_path(cr);
 130     cpml_segment_init(&segment, path);
 131     cpml_segment_offset(&segment, 20);
 132     cairo_append_path(cr, path);
 133     cairo_path_destroy(path);
 134
 135     /* Checking cpml_pair_at_curve and cpml_vector_at_curve */
 136     for (t = 0; t < 1; t += 0.1) {
 137         cpml_pair_at_curve(&pair, &bezier->p1, &bezier->p2,
 138                            &bezier->p3, &bezier->p4, t);
 139         cpml_vector_at_curve(&vector, &bezier->p1, &bezier->p2,
 140                              &bezier->p3, &bezier->p4, t, 20);
 141         cpml_vector_normal(&vector);
 142
 143         cairo_new_sub_path(cr);
 144         cairo_arc(cr, pair.x, pair.y, 2.5, 0, M_PI*2);
 145         cairo_move_to(cr, pair.x, pair.y);
 146         cairo_line_to(cr, pair.x + vector.x, pair.y + vector.y);
 147     }
 148 }
 149
 150 static void
 151 path_expose(GtkWidget *widget, GdkEventExpose *event, AdgCanvas *canvas)
 152 {
 153     cairo_t *cr = gdk_cairo_create(widget->window);
 154
 155     adg_entity_render(ADG_ENTITY(canvas), cr);
 156
 157     cairo_destroy(cr);
 158 }