doc/cookbook/examples/textures-split-go.c

   1 #include <clutter/clutter.h>
   2
   3 /* Context will be used to carry interesting variables between functions */
   4 typedef struct
   5 {
   6   ClutterActor *sub_nw, *sub_ne, *sub_sw, *sub_se;
   7   gfloat image_width, image_height;
   8 } Context;
   9
  10 /* Here, we animate the texture to go way by giving the new coordinates
  11  * outside of the stage. We rotate the sub-textures around their anchor
  12  * point (set in setup_sub() as well, it looks cool. */
  13 static gboolean
  14 go_away (gpointer data)
  15 {
  16   Context *context = data;
  17
  18   clutter_actor_animate (context->sub_nw, CLUTTER_EASE_OUT_CUBIC, 1500,
  19                          "x", -context->image_width,
  20                          "y", -context->image_height,
  21                          "rotation-angle-z", 2000.,
  22                          NULL);
  23   clutter_actor_animate (context->sub_ne, CLUTTER_EASE_OUT_CUBIC, 1500,
  24                          "x", +context->image_width,
  25                          "y", -context->image_height,
  26                          "rotation-angle-z", 2000.,
  27                          NULL);
  28   clutter_actor_animate (context->sub_sw, CLUTTER_EASE_OUT_CUBIC, 1500,
  29                          "x", -context->image_width,
  30                          "y", +context->image_height,
  31                          "rotation-angle-z", 2000.,
  32                          NULL);
  33   clutter_actor_animate (context->sub_se, CLUTTER_EASE_OUT_CUBIC, 1500,
  34                          "x", -context->image_width,
  35                          "y", +context->image_height,
  36                          "rotation-angle-z", 2000.,
  37                          NULL);
  38   return G_SOURCE_REMOVE; /* remove the timeout source */
  39 }
  40
  41 /* We split the four sub-textures faking to be the big texture, moving them
  42  * away by 10 pixels in each direction */
  43 static gboolean
  44 split (gpointer data)
  45 {
  46   Context *context = data;
  47   gfloat x, y;
  48
  49   clutter_actor_get_position (context->sub_nw, &x, &y);
  50   clutter_actor_animate (context->sub_nw, CLUTTER_EASE_OUT_CUBIC, 300,
  51                          "x", x - 10,
  52                          "y", y - 10,
  53                          NULL);
  54   clutter_actor_get_position (context->sub_ne, &x, &y);
  55   clutter_actor_animate (context->sub_ne, CLUTTER_EASE_OUT_CUBIC, 300,
  56                          "x", x + 10,
  57                          "y", y - 10,
  58                          NULL);
  59   clutter_actor_get_position (context->sub_sw, &x, &y);
  60   clutter_actor_animate (context->sub_sw, CLUTTER_EASE_OUT_CUBIC, 300,
  61                          "x", x - 10,
  62                          "y", y + 10,
  63                          NULL);
  64   clutter_actor_get_position (context->sub_se, &x, &y);
  65   clutter_actor_animate (context->sub_se, CLUTTER_EASE_OUT_CUBIC, 300,
  66                          "x", x + 10,
  67                          "y", y + 10,
  68                          NULL);
  69
  70   /* In 500ms the textures will flee! */
  71   clutter_threads_add_timeout (500, go_away, context);
  72
  73   return G_SOURCE_REMOVE; /* remove the timeout source */
  74 }
  75
  76 static ClutterActor *
  77 setup_sub (CoglHandle texture,
  78            gint       image_width,
  79            gint       image_height,
  80            gint       t_x,
  81            gint       t_y,
  82            gint       t_width,
  83            gint       t_height)
  84 {
  85   CoglHandle sub_texture;
  86   ClutterActor *sub_image;
  87
  88   /* Create a new sub-texture from textures */
  89   sub_texture = cogl_texture_new_from_sub_texture (texture,
  90                                                    t_x, t_y,
  91                                                    t_width, t_height);
  92
  93   /* Create the corresponding ClutterTexture */
  94   sub_image = g_object_new (CLUTTER_TYPE_TEXTURE,
  95                             "cogl-texture", sub_texture,
  96                             NULL);
  97
  98   /* Set the anchor point in the middle of each sub_image so the position and
  99    * rotation of the textures are relative to that point */
 100   clutter_actor_set_anchor_point (sub_image, image_width / 4, image_height / 4);
 101
 102   return sub_image;
 103 }
 104
 105 #define IMAGE "smiley.png"
 106
 107 int
 108 main (int    argc,
 109       char **argv)
 110 {
 111   gfloat image_width, image_height, stage_width, stage_height;
 112   ClutterActor *stage, *image;
 113   GError *error = NULL;
 114   CoglHandle texture;
 115   Context context;
 116
 117   if (clutter_init (NULL, NULL) != CLUTTER_INIT_SUCCESS)
 118     return 1;
 119
 120   stage = clutter_stage_new ();
 121   clutter_actor_get_size (stage, &stage_width, &stage_height);
 122   clutter_stage_set_title (CLUTTER_STAGE (stage), "Animate sub-textures");
 123   g_signal_connect (stage, "destroy", G_CALLBACK (clutter_main_quit), NULL);
 124
 125   /* Load smiley.png, creating a new ClutterTexture, get its size and the
 126    * Cogl texture handle */
 127   image = clutter_texture_new_from_file (IMAGE, &error);
 128   if (error != NULL)
 129     {
 130       g_warning ("Could not load " IMAGE ": %s", error->message);
 131       g_clear_error (&error);
 132       return 1;
 133     }
 134   clutter_actor_get_size (image, &image_width, &image_height);
 135   texture = clutter_texture_get_cogl_texture (CLUTTER_TEXTURE (image));
 136
 137   /* Create four sub-textures from image, actually splitting the image in
 138    * four */
 139   context.sub_nw = setup_sub (texture, image_width, image_height,
 140                               0, 0, image_width / 2 , image_height / 2);
 141   context.sub_ne = setup_sub (texture, image_width, image_height,
 142                               image_width / 2 , 0,
 143                               image_width / 2, image_height / 2);
 144   context.sub_sw = setup_sub (texture, image_width, image_height,
 145                               0.f, image_height / 2,
 146                               image_width / 2, image_height / 2);
 147   context.sub_se = setup_sub (texture, image_width, image_height,
 148                               image_width / 2, image_height / 2,
 149                               image_width / 2, image_height / 2);
 150
 151   /* We don't need the image anymore as we won't display it and as
 152    * cogl_texture_new_from_sub_texture() keeps a reference to the underlying
 153    * texture ressource */
 154   g_object_unref (image);
 155
 156   /* Position the sub-texures in the middle of the screen, recreating the
 157    * original texture */
 158   clutter_actor_set_position (context.sub_nw,
 159                               stage_width / 2 - image_width / 4,
 160                               stage_height / 2 - image_height / 4);
 161   clutter_actor_set_position (context.sub_ne,
 162                               stage_width / 2 + image_width / 4,
 163                               stage_height / 2 - image_height / 4);
 164   clutter_actor_set_position (context.sub_sw,
 165                               stage_width / 2 - image_width / 4,
 166                               stage_height / 2 + image_height / 4);
 167   clutter_actor_set_position (context.sub_se,
 168                               stage_width / 2 + image_width / 4,
 169                               stage_height / 2 + image_height / 4);
 170
 171   /* Add the four sub-textures to the stage */
 172   clutter_container_add (CLUTTER_CONTAINER (stage), context.sub_nw,
 173                          context.sub_ne, context.sub_sw, context.sub_se, NULL);
 174
 175   clutter_actor_show_all (stage);
 176
 177   context.image_width = image_width;
 178   context.image_height = image_height;
 179
 180   /* In two seconds, we'll split the texture! */
 181   clutter_threads_add_timeout (2000, split, &context);
 182
 183   clutter_main ();
 184
 185   return 0;
 186 }