U.S. Pat. No. 6,999,085

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A consecutive reading method for a computer game according to a preferred embodiment of the present invention will be described while referring to the accompanying drawings.

In the computer game of the present embodiment, data related to the game and a program for executing the game have been written to a compact disc (CD-ROM) or similar storage medium. The executable program is read into a game console or other computer device and executed while a display of the game graphics is shown on the monitor screen (not shown). In the following description, a car racing game is used as an example.

FIG. 1shows an explanatory diagram for the consecutive reading method of the present invention and an overhead view of a racecourse used in the game. A racecourse11for the car racing game includes a black dot that indicates a graphical region14around the player's position on the course. A course data12includes a segment table13formed of data segments00through08, in this example. The segment table13also includes field data for the graphical region14in the racecourse. A player's position15is indicated in the segment table13. The arrow from the player's position15represents the direction of player movement. In the segment table13, seven data segments00through06have been shaded. These shaded data segments represent the portion of data that has already been read from the CD-ROM or other storage device and currently resides in the memory of the game console. Segments07and08, which have not been shaded, represent course data for the segment table13that is to be read next. The course data12also indicates the player's field of view17and the player's range of action16.

Based on the player's progress during the race, required data in the course data12is read one segment at a time from the storage device into memory while unnecessary data is discarded. In this example, data for the segments00through06have already been read into memory from the CD-ROM or other storage device. If the player's position shifts to segment03, data for segment00is cleared from the memory and data for segment07is read from the storage device. Accordingly, the course can be as long as desired, providing all the course data can fit in the storage device.

In the game of the present embodiment, one segment represents 50 m. Approximately, 2,000 segments are used in the game. However, the total length of the course is approximately 180 km since some parts of the course overlap and contain shared data.

FIG. 2shows a memory map indicating the format in which data is stored in memory for the consecutive reading method according to the present embodiment. Data for the racecourse is read into the memory of the game console from the CD-ROM or other storage device in units of segments. As shown inFIG. 2, a course data121currently resides in the memory of the game console. The course data121comprises a plurality of segments including a segment00131and a segment01132. Each segment further comprises a plurality of sectors133having 2048 bytes of data each.

The most important elements of the segments are a course model data134and a texture data135. The model data134includes data for surrounding scenery that changes according to the player's progress in the race. The texture data135includes data on speed limits for bridges, tunnels, and curves and other road signs, which data is associated with the scenery data, and data accompanying graphical data for controlling the racecars and the like. Some segments contain only the model data134, while others contain both the model data134and the texture data135. In addition to the components, the size of the segments is also not fixed.

Course data written to the storage device is divided into segments of the maximum size that can be read with one random access. This method is used to prevent data reads required during the race from halting movement of the racecars.

Whether or not to display certain course data during a race is determined based on a model number corresponding to the racecourse (graphical region), the start position of the sector in memory, the length of the sector, the center position in the course model (graphical model), and the radius of the course model. This data is saved in a separate table in memory and updated based on the player's movements and progress on the racecourse.

At this time, course data to be displayed in the player's field of view from the player's current position on the racecourse to the point of observation is sorted in order from the point of observation. Display requests for areas exceeding a predetermined number of buffers are discarded at this time. Of course, it is also possible to allow adjustments in the number of buffers in order to support game consoles with higher memory capacity or hardware having a large display capacity.

When a read from memory fails for any reason, the portion of data that was not read is not displayed. Priority is placed on reading data that must be displayed currently or on data that must be read into memory. If a second request is issued for displaying this data, the order of priority is adjusted based on the results of sorting the data in order from the point of observation.

Hence, the decision to display or not to display data in the present invention is performed based on effective use of data and appropriateness of the memory, while conventional methods simply determine what to display from the center position of the course model data to the point of observation.

During this process, data is read into free areas of memory. However, after repeatedly clearing unneeded data and reading in new data, the memory becomes fragmented, making memory use inefficient. At some point, the amount of available memory will become insufficient because a large enough area of consecutive memory cannot be allocated. For this reason, it is necessary to perform garbage collection in which unused gaps between data are eliminated and the recovered memory collected to allocate larger consecutive regions in memory. The determination to perform garbage collection is made based both on tables used when determining whether or not to display data and on display requests. The garbage collection is performed at suitable times to avoid interruptions in the flow of the game.

FIG. 3is a flowchart showing the consecutive reading method for a computer game according to the present embodiment. The process of the flowchart includes setting the number of valid segments displayed for the racecourse to less than 20 and to read course data into memory and delete data therefrom.

When the game program reads course data for the racecourse, the program determines the player's point of observation and direction of movement in S301. In S302, the program determines whether the number of valid segments required for the display is less than 20. If the number is less than 20 (Yes in S302), the course data is sorted in order from the position nearest the player, and the number of segments in memory still keeps a number less than 20 in S303.

If the number of valid segments is 20 or greater (No in S302), then the program determines in S304whether invalid segment data exists. If invalid segment data exists (Yes in S304), then the invalid segment data is deleted in S305.

If invalid segment data does not exist (No in S304), then the program determines in S306whether valid segment data exists in memory. If valid segment data does not exist in memory (No in S306), then a data read request is issued in S307.

If valid segment data exists in memory (Yes in S306), then the program determines in S308whether all valid segment data has been read. If all valid segment data has not been read (No in S308), then the process waits for data to be read in S309.

If all valid segment data has been read (Yes in S308), then the valid segment data is displayed in S310. Subsequently, the program again determines the player's point of observation and direction of movement in S301. This process is repeated to read course data into memory and delete course data from memory.

Since the consecutive reading method of the embodiment described above reads new data segments into memory and deletes unnecessary data segments from memory, a new screen can be displayed for a long continuous racecourse. This method is more attractive to users not only of racing games, but for any game that provides constantly new scenery.

Since the field data contains both graphics and texture data, more complex scenery can be depicted. In the car racing game example, speed limits and road signs for bridges, tunnels, and curves can be associated with the scenery to bring out the feeling of an actual race. Further, by reading field data in units equivalent to the maximum size that can be read in one random access, it is possible to load the maximum amount of graphics data without interrupting the game. By configuring segments of sector units, graphics data can be read at an optimal access rate.

Further, the consecutive reading method of the present invention uses memory effectively by determining what field data to display based on data required for the player's progress, rather than simply examining data up to the player's point of observation.