Method of displaying labels on maps of wireless communications devices using pre-rendered characters
AssigneeResearch In Motion Limited
InventorsGerhard Dietrich Klassen, Eric Johnson
Life of this patent
Estimating the term…
Abstract
Labels can be rendered on a map displayed on a wireless communications device by using pre-rendered characters. The pre-rendered characters can be pre-rotated to one of a number of angular orientations and stored as a variable transparency bitmap for rapid overlaying on the map. The bitmap can include an array or grid of characters wherein each row has a unique orientation, for example, ranging from zero to ninety degrees. Rotations of 90 to 360 degrees can then be achieved by reflecting the characters about vertical or horizontal axes. Overlaying pre-rotated characters is more computationally efficient than computing rotations for each character when rendering the label.
Claims23
A method of rendering a label on a map displayed on a wireless communications device, the method comprising:
- obtaining label data for rendering the label on the map by downloading the label data to the wireless communications device over a wireless link;
- determining an appropriate orientation on the map for each character of the label;
- determining color attributes of a label position for the label on the map;
- selecting a variable transparency bitmap comprising a set of pre-rotated characters that correspond to the orientation and further having a background color corresponding to the color attributes of the label position, wherein the background color of the variable transparency bitmap is adjusted to concord with the color attributes of the label position;
- and
- rendering each character at the appropriate orientation on the map displayed on the wireless communications device by overlaying pre-rendered characters on the map from the variable transparency bitmap with the background color corresponding to the color attributes of the label position.
A wireless communications device for displaying a map on the wireless communications device, the wireless communications device comprising:
- an input device for enabling the device to download map data to the wireless communications device over a wireless link, the map data including label data, for rendering the map and at least one label on the map;
- a memory for storing pre-rendered characters;
- a processor for determining an appropriate orientation for each character in the label, for determining color attributes of a label position for the label on the map, for selecting a variable transparency bitmap comprising a set of pre-rotated characters that correspond to the orientation and further having a background color corresponding to the color attributes of the label position, wherein the background color of the variable transparency bitmap is adjusted to concord with the color attributes of the label position, and for overlaying the pre-rendered characters on the map from the variable transparency bitmap with the background color that corresponds to the color attributes of the label position;
- and
- a display for displaying the pre-rendered characters of the label on the map.
Dependencies are inferred from the claim text.