초록 ▼

A map-data distribution method distributes map data from a map-data distribution server to a client and causes the client to draw a map image. The map-data distribution method includes steps of causing the map-data distribution server to store a plurality of map components obtained by dividing the m

A map-data distribution method distributes map data from a map-data distribution server to a client and causes the client to draw a map image. The map-data distribution method includes steps of causing the map-data distribution server to store a plurality of map components obtained by dividing the map data, causing the server to send the map data to the client in an order according to the map component, and causing the client to store the received data in a temporary memory while causing the client to start to draw the map image using one of the received data and the data stored in the temporary memory.

대표청구항 ▼

What is claimed is: 1. A map-data distribution method for distributing map data from a map-data distribution server to a client and causing said client to draw a map image, said map-data distribution method comprising: causing said map-data distribution server to store a plurality of map components

What is claimed is: 1. A map-data distribution method for distributing map data from a map-data distribution server to a client and causing said client to draw a map image, said map-data distribution method comprising: causing said map-data distribution server to store a plurality of map components obtained by dividing said map data, wherein said map data for drawing a map image is separated by type of data into a plurality of different map components which, when drawn and superimposed, constitute the map image; causing the client to specify an order of priority of transmission of said map components and to transmit said order of priority to said server; causing the server to serially send said map data, by map component, to said client in said order of priority received from said client; and causing said client to store the received map data in a temporary memory while causing said client to start to draw the first received map component of the map image using one of the received map data and the map data stored in said temporary memory before all map components of the map data are received by the client; wherein said map components of said map data include at least one of a map component of road images appearing in the map image, a map component of polygon images appearing in the map image, a map component of names appearing in the map image, and a map component of landmark images appearing in the map image. 2. A map-data distribution method according to claim 1, wherein said map data includes, as said map components, road data for drawing a road, polygon data for drawing a construction, and character string data for drawing a character string. 3. A map-data distribution method according to claim 1, wherein when the map data is stored in said temporary memory, said client sends a signal to the server so that the server does not send the map data. 4. A map-data distribution method according to claim 1, wherein: said client includes: a user interface for outputting a map-drawing request based on interpretation of user input; a main thread for accessing the server in accordance with said map-drawing request output from said user interface and for receiving the map components; and a drawing thread for drawing the map image; and said user interface, said main thread, and said drawing thread cooperate so that processing for input from the user, processing for retrieving the map data from the server, and processing for drawing the map image are performed in parallel. 5. A map-data distribution method according to claim 4, wherein said drawing thread includes a drawing queue for storing, according to the map component, a drawing request added by said main thread. 6. A map-data distribution method according to claim 5, wherein said drawing thread processes said drawing request stored in said drawing queue in order and deletes a processed drawing request from said drawing queue. 7. A map-data distribution method according to claim 5, wherein: when said user interface sends said map-drawing request to said main thread, said main thread determines whether a map component related to said map-drawing request is stored in said temporary memory by searching the map components in descending order of priority; when the map component is stored in said temporary memory, the drawing request for said map component is added to the drawing queue of said drawing thread; when the map component is not stored in said temporary memory, the server is accessed via a communication line and is requested to send said map component, and then, when the server sends said map component, said map component is stored in said temporary memory while the drawing request for said map component is added to the drawing queue of said drawing thread; and said drawing thread draws the map image by processing said drawing request stored in said drawing queue in accordance with the added order. 8. A map-data distribution method according to claim 5, wherein said main thread discards unprocessed drawing requests stored in said drawing queue in accordance with a request from said user interface. 9. A map-data distribution method according to claim 5, wherein when new data is to be stored in said temporary memory, and no space is available for storing said new data in said temporary memory, discarding of data stored in said temporary memory is performed starting from data having the least frequency of use. 10. A map-data distribution method according to claim 5, wherein said temporary memory has a capacity sufficient to contain map data for a plurality of screens. 11. A map-data distribution method according to claim 5, wherein said drawing thread expands a plurality of screens of the map image in a video memory and causes one screen from among said plurality of screens of the map image to be displayed. 12. A map-data distribution server comprising: retrieving means for retrieving map components from a map database in accordance with a requested order of priority of transmission, transmitted by a client to the server, according to the map component, wherein map data for drawing a map image is separated by type of data into a plurality of different map components which, when drawn and superimposed, constitute the map image; and sending means for serially sending the retrieved map components in the requested order of priority via a communication line to said client so that said client can start to draw the first received map component of the map image before all map components of the map data are received by the client; wherein said map components of said map data include at least one of a map component of road images appearing in the map image, a map component of polygon images appearing in the map image, a map component of names appearing in the map image, and a map component of landmark images appearing in the map image. 13. A map-data distribution server according to claim 12, wherein road data for drawing a road, polygon data for drawing a construction, and character string data for drawing a character string are included as said map components. 14. A client comprising: a user interface for outputting a map-drawing request; a main thread for accessing a map-data distribution server in accordance with said map-drawing request output from said user interface and for receiving components of map data in an order according to map component, wherein map data for drawing a map image is separated by type of data into a plurality of different map components which, when drawn and superimposed, constitute the map image, and the server provides the map components to the client serially in an order of priority of transmission specified by the client; and a drawing thread for drawing a map image using said received map data, starting with the first received map component and before all map components of the map data are received by the client; wherein said map components of said map data include at least one of a map component of road images appearing in the map image, a map component of polygon images appearing in the map image, a map component of names appearing in the map image, and a map component of landmark images appearing in the map image. 15. A client according to claim 14, wherein said map data includes, as said map components, road data for drawing a road, polygon data for drawing a construction, and character string data for drawing a character string. 16. A client according to claim 14, further comprising storage means, wherein when specified data are stored in said storage means, a signal can be sent to the server so that the server does not send the same data. 17. A client according to claim 14, wherein said user interface, said main thread, and said drawing thread cooperate so that processing for input from a user, processing for retrieving the map data from the server, and processing for drawing the map image are performed in parallel. 18. A client according to claim 14, wherein said drawing thread includes a drawing queue for storing a drawing request added by said main thread according to the map component.