Method and system for scrolling a map display in a navigation application

Claims

We claim:

1. A map display program for use in a navigation system having a graphics platform and a map database, the map display program adapted to retrieve and render map data from the map database to a display in response to instructions from a navigation application, the map display program comprising:

a map processing layer comprising a scrolling function for providing movement of rendered map data across the display, the map processing layer responsive to the navigation application and in communication with a graphics interface layer, the map processing layer having a multi-tasking abstraction layer defining multi-tasking function requirements;

the graphics interface layer having at least one lookup table, the at least one lookup table comprising drawing attribute information, the graphics interface layer responsive to instructions from the map processing layer; and

a primitive layer in communication with the graphics interface layer and the graphics platform, the primitive layer populating the at least one lookup table in the graphics interface layer with platform specific data types from the graphics platform, wherein the map processing layer is independent of the graphics platform.

2. The map display program of claim 1, wherein the multi-tasking abstraction layer comprises a start thread function requirement, the start thread function requirement containing instructions to retrieve a synchronization object and begin rendering map information to a graphics buffer in a background process.

3. The map display program of claim 2, wherein the multi-tasking abstraction layer comprises an end thread function requirement, the end thread function requirement containing instructions to terminate the background process and retrieve the synchronization object.

4. The map display program of claim 1, wherein the multi-tasking abstraction layer comprises a scroll function requirement, the scroll function requirement containing instructions to retrieve a scroll speed indicator from the navigation application.

5. A map display program for use in a navigation system used with a map database, the map display program adapted to retrieve and display geographical information representative of an area in response to requests from a navigation application in the navigation system, the map display program comprising:

a map object comprising:

a first graphics buffer for holding map data related to a present position; and

a second graphics buffer for holding map data related to a predicted future position, the predicted future position comprising a portion of the map data in the first graphics buffer and map data representative of a geographic area contiguous with, and extending from, a geographic area rendered from the portion of map data in the first graphics buffer and;

a map rectangle defining a portion of the map data in the first graphics buffer presented on a display, wherein each of the first and second graphics buffers comprises a map data storage area configured to hold at least 25% more map data than an amount of map data used to display a geographic area in the map rectangle.

6. The map display program of claim 5, wherein the first graphics buffer has a same size as the second graphics buffer.

7. A map display program for use in a navigation system used with a map database, the map display program adapted to retrieve and display geographical information representative of an area in response to requests from a navigation application in the navigation system, the map display program comprising:

a map object comprising:

a first graphics buffer for holding map data related to a present position;

a second graphics buffer for holding map data related to a predicted future position, the predicted future position comprising a portion of the map data in the first graphics buffer and map data representative of a geographic area contiguous with, and extending from, a geographic area rendered from the portion of map data in the first graphics buffer;

a name table having a plurality of name storage locations for holding a plurality of roadway names retrieved from the map database, each name storage location containing a first list of roadway names; and

at least one name placement position associated with each of the roadway names, wherein the name placement position represents a position on a display.

8. The map display program of claim 7, wherein the map object further comprises:

a name prioritization routine adapted to select roadway name information from the name table according to a predetermined priority list; and

at least one prioritized information list located in the map object, the prioritized information list generated by the name prioritization routine and containing data associated with names selected by the name prioritization routine.

9. The map display program of claim 7, further comprising a point of interest list, the point of interest list containing data from the map database pertaining to at least one point of interest name and location data for the point of interest name.

10. The map display program of claim 7, wherein the plurality of name storage locations contain a plurality of roadway shield icons.

11. The map display program of claim 7, wherein the prioritized information list further comprises located in the map object, the prioritized information list generated by the name prioritization routine and containing data associated with names and icons selected by the name prioritization routine.

12. The map display program of claim 7 further comprising:

a point of interest list containing data from the map database pertaining to at least one point of interest name and location data for the point of interest name; and

a list of roadway shield icons in the plurality of name table locations in the name table, wherein the name prioritization routine is adapted to select roadway name information and roadway shield icon information from the name table according to the priority list, and wherein the name prioritization routine is adapted to select point of interest names according to the priority list.

13. The map display program of claim 7 further comprising a map rectangle defining a portion of the map data in the first graphics buffer presented on a display.

14. The map display program of claim 7 wherein the first graphics buffer has a same size as the second graphics buffer.

15. A map display program for use in a navigation system used with a map database, the map display program adapted to retrieve and display geographical information representative of an area in response to requests from a navigation application in the navigation system, the map display program comprising:

a map object comprising:

a first graphics buffer for holding map data related to a present position; and

a second graphics buffer for holding map data related to a predicted future position, the predicted future position comprising a portion of the map data in the first graphics buffer and map data representative of a geographic area contiguous with, and extending from, a geographic area rendered from the portion of map data in the first graphics buffer;

a point of interest list, the point of interest list containing data from the map database pertaining to at least one point of interest name and location data for the point of interest name; and

a list of roadway shield icons in the plurality of name table locations in the name table, wherein the name prioritization routine is adapted to select roadway name information and roadway shield icon information from the name table according to the priority list, and wherein the name prioritization routine is adapted to select point of interest names according to the priority list.

16. The map display program of claim 15 further comprising a map rectangle defining a portion of the map data in the first graphics buffer presented on a display.

17. The map display program of claim 15 wherein the first graphics buffer has a same size as the second graphics buffer.

18. The map display program of claim 15 wherein the map object further comprises:

a name table having a plurality of name storage locations for holding a plurality of roadway names retrieved from the map database, each name storage location containing a first list of roadway names; and

at least one name placement position associated with each of the roadway names, wherein the name placement position represents a position on a display.

19. The map display program of claim 18 wherein the map object further comprises:

a name prioritization routine adapted to select roadway name information from the name table according to a predetermined priority list; and

at least one prioritized information list located in the map object, the prioritized information list generated by the name prioritization routine and containing data associated with names selected by the name prioritization routine.

20. The map display program of claim 18 further comprising a point of interest list containing data from the map database pertaining to at least one point of interest name and location data for the point of interest name.

21. A method of preparing name information for placement on a map display of a navigation system, the method comprising the steps of:

retrieving map data for a first predetermined geographical area from a map database stored on a computer readable medium, the map data comprising name information;

generating a name table in a map object, the name table comprising all name information for the retrieved map data;

selecting name information from the name table using a predetermined set of name priority rules stored in the map object;

generating at least one list in the map object containing the selected name information in the map object;

rendering the selected name information to a first graphics buffer;

retrieving map data for a second predetermined geographical area from a map database stored on a computer readable medium, the map data comprising name information;

regenerating the name table in the map object, the name table comprising all name information for retrieved map data for the second predetermined location;

selecting name information from the regenerated name table using the predetermined set of name priority rules stored in the map object;

regenerating at least one list in the map object containing the selected name information in the map object; and

rendering the selected name information to a second graphics buffer in the map object.