* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+/**
+ * SECTION:gis-tile
+ * @short_description: Latitude/longitude overlays
+ *
+ * Each #GisTile corresponds to a latitude/longitude box on the surface of the
+ * earth. When drawn, the #GisTile renders an images associated with it to the
+ * surface of the earth. This is primarily used to draw ground overlays.
+ *
+ * Each GisTile can be split into subtiles in order to draw higher resolution
+ * overlays. Pointers to subtitles are stored in the parent tile and a parent
+ * pointer is stored in each child.
+ *
+ * Each #GisTile has a data filed which must be set by the user in order for
+ * the tile to be drawn. When used with GisOpenGL the data must be an integer
+ * representing the OpenGL texture to use when drawing the tile.
+ */
+
#include <config.h>
#include "gis-util.h"
#include "gis-tile.h"
{"10.", "11."},
};
+/**
+ * gis_tile_new:
+ * @parent: the parent for the tile, or NULL
+ * @n: the northern border of the tile
+ * @s: the southern border of the tile
+ * @e: the eastern border of the tile
+ * @w: the western border of the tile
+ *
+ * Create a tile associated with a particular latitude/longitude box.
+ *
+ * Returns: the new #GisTile
+ */
GisTile *gis_tile_new(GisTile *parent,
gdouble n, gdouble s, gdouble e, gdouble w)
{
return tile;
}
+/**
+ * gis_tile_get_path:
+ * @child: the tile to generate a path for
+ *
+ * Generate a string representation of a tiles location in a group of nested
+ * tiles. The string returned consists of groups of two digits separated by a
+ * delimiter. Each group of digits the tiles location with respect to it's
+ * parent tile.
+ *
+ * Returns: the path representing the tiles's location
+ */
gchar *gis_tile_get_path(GisTile *child)
{
/* This could be easily cached if necessary */
return view_res < tile_res;
}
+/**
+ * gis_tile_update:
+ * @root: the root tile to split
+ * @res: a maximum resolution in meters per pixel to split tiles to
+ * @width: width in pixels of the image associated with the tile
+ * @height: height in pixels of the image associated with the tile
+ * @lat: latitude of the eye point
+ * @lon: longitude of the eye point
+ * @elev: elevation of the eye point
+ * @load_func: function used to load the image when a new tile is created
+ * @user_data: user data to past to the load function
+ *
+ * Recursively split a tile into children of appropriate detail. The resolution
+ * of the tile in pixels per meter is compared to the resolution which the tile
+ * is being drawn at on the screen. If the screen resolution is insufficient
+ * the tile is recursively subdivided until a sufficient resolution is
+ * achieved.
+ */
void gis_tile_update(GisTile *root,
gdouble res, gint width, gint height,
gdouble lat, gdouble lon, gdouble elev,
}
}
+/**
+ * gis_tile_find:
+ * @root: the root tile to search from
+ * @lat: target latitude
+ * @lon: target longitude
+ *
+ * Locate the subtile with the highest resolution which contains the given
+ * lat/lon point.
+ *
+ * Returns: the child tile
+ */
GisTile *gis_tile_find(GisTile *root, gdouble lat, gdouble lon)
{
gint rows = G_N_ELEMENTS(root->children);
return root;
}
+/**
+ * gis_tile_gc:
+ * @root: the root tile to start garbage collection at
+ * @atime: most recent time at which tiles will be kept
+ * @free_func: function used to free the image when a new tile is collected
+ * @user_data: user data to past to the free function
+ *
+ * Garbage collect old tiles. This removes and deallocate tiles that have not
+ * been used since before @atime.
+ *
+ * Returns: a pointer to the original tile, or NULL if it was garbage collected
+ */
GisTile *gis_tile_gc(GisTile *root, time_t atime,
GisTileFreeFunc free_func, gpointer user_data)
{
}
/* Use GObject for this */
+/**
+ * gis_tile_free:
+ * @root: the root tile to free
+ * @free_func: function used to free the image when a new tile is collected
+ * @user_data: user data to past to the free function
+ *
+ * Recursively free a tile and all it's children.
+ */
void gis_tile_free(GisTile *root, GisTileFreeFunc free_func, gpointer user_data)
{
if (!root)
GisObjectClass parent_class;
};
+/**
+ * GisTileLoadFunc:
+ * @tile: the tile to load
+ * @user_data: data paseed to the function
+ *
+ * Used to load the image data associated with a tile. For GisOpenGL, this
+ * function should store the OpenGL texture number in the tiles data field.
+ */
typedef void (*GisTileLoadFunc)(GisTile *tile, gpointer user_data);
+
+/**
+ * GisTileFreeFunc:
+ * @tile: the tile to free
+ * @user_data: data paseed to the function
+ *
+ * Used to free the image data associated with a tile
+ */
typedef void (*GisTileFreeFunc)(GisTile *tile, gpointer user_data);
/* Forech functions */
+/**
+ * gis_tile_foreach:
+ * @parent: the #GisTile to iterate over
+ * @child: a pointer to a #GisTile to store the current subtile
+ *
+ * Iterate over each imediate subtile of @parent.
+ */
#define gis_tile_foreach(parent, child) \
for (int _x = 0; _x < G_N_ELEMENTS(parent->children); _x++) \
for (int _y = 0; child = parent->children[_x][_y], \
_y < G_N_ELEMENTS(parent->children[_x]); _y++)
+/**
+ * gis_tile_foreach_index:
+ * @parent: the #GisTile to iterate over
+ * @x: integer to store the x index of the current subtile
+ * @y: integer to store the y index of the current subtile
+ *
+ * Iterate over each imediate subtile of @parent.
+ */
#define gis_tile_foreach_index(parent, x, y) \
for (x = 0; x < G_N_ELEMENTS(parent->children); x++) \
for (y = 0; y < G_N_ELEMENTS(parent->children[x]); y++)
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