JP2790526B2 - Data management method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data management system for managing and displaying graphic elements displayed on a screen in mesh units.

[Conventional technology]

Conventionally, as a method of displaying a drawing primitive on a screen, as shown in FIG. 3, when drawing a primitive on a screen by a scroll function, a drawing area movement unit in one scroll is divided by a mesh, and It has a figure primitive management table for storing the contents of figure primitives for each mesh, and at the time of drawing the mesh contents of each mesh area divided into meshes based on these management tables, all figure primitives included in the mesh are deleted. I was drawing each time.

That is, in FIG. 3, mesh primitives a, b, and c are shown in mesh 1, mesh 3, and mesh 4, respectively, and a graphics primitive d that spans these is shown in mesh 2, mesh 3, and mesh 4. Forgotten,
For example, the meshes 3 and 4 are provided with management tables T3 and T4 for figure primitives, and the contents are drawn for each mesh area based on these management tables.

[Problems to be solved by the invention]

However, the above method has a drawback that a graphic primitive that spans a plurality of meshes is executed many times each time the mesh content including the graphic primitive is drawn, resulting in a decrease in the display performance of the system. there were.

The present invention has been made in order to solve such a problem of the conventional example, and it is possible to improve the processing performance by performing drawing once only without repeatedly displaying graphic data extending over a plurality of meshes. It is an object of the present invention to provide a data management method capable of improving the data management method.

[Means for solving the problem]

According to the data management method of the present invention, when a graphic primitive is drawn on a screen by a scroll function, a drawing area movement unit in one scroll is divided by a mesh, and a graphic primitive for storing the contents of the graphic primitive for each mesh. In a data management method including a management table and drawing a graphic primitive on a screen based on the management table, the graphic primitive management table for each of the meshes is completely included in the mesh corresponding to the graphic primitive. And a mesh intersection flag indicating whether or not the drawing is performed, and a pointer to the graphic primitive entry stored in the representative mesh management table. A representative mesh management table configured from a representative mesh identification field designating whether or not a figure primitive spans a plurality of meshes is drawn at a time when drawing a figure primitive corresponding to the representative mesh. It is like that.

[Action]

In the present invention, with respect to a graphic primitive spanning a plurality of meshes, a representative mesh management table
It manages which mesh is to be drawn when drawing the figure primitive, and prevents repeated drawing.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 (a) illustrates a drawing example of a figure primitive, and FIG. 1 (b) illustrates a management table thereof. FIG. 1 (a) illustrates a figure primitive A, FIG. 2 illustrates a figure primitive C, and FIG. , A graphic primitive B is drawn, and graphic primitive management tables T1 and T2 corresponding to mesh 1 and mesh 2 are provided, and a representative mesh management table T0 for performing representative mesh management is provided.

These graphic primitive management tables T1 and T2 include a mesh crossing flag (11) indicating whether or not the graphic primitive is completely included in each mesh, and an entry for the graphic primitive entry stored in the representative mesh management table T0. It is composed of two fields of a pointer (12). The representative mesh management table T0 includes a graphic primitive field (13) and representative mesh identification fields (14) and (15) that specify which mesh is to be drawn when the primitive is drawn. Here, the identification field (14) turns ON when the representative mesh is 1, the identification field (15) turns ON when the mesh is 2, and so on.

When the graphic primitive is completely closed in the mesh, the value of the representative mesh identification field has no meaning.

A drawing sequence of three graphic primitives A, B, and C included in the mesh 1 and the mesh 2 in the state managed as described above will be described with reference to FIG.

Draw the contents of mesh 1

Graphic primitive management table corresponding to mesh 1
At T1, the mesh crossing flag (11) of the first entry is checked, and since it is OFF in this case, the pointer (1
The primitive A on the representative mesh management table T0 specified in 2) is drawn (S1 to S3).

Next, the mesh crossing flag of the second entry (11)
Is ON, similarly, an entry on the representative mesh management table T0 indicated by the pointer is obtained, and the representative mesh identification field (14) is checked. In this case, since it is OFF, the primitive B is not drawn at this point (S4, S5 → S2 → S8).

Further, if all the tables have not been searched, the entry is incremented by one (S5), and steps S2 to S4 are repeated. If all the tables have been searched, the mesh number is incremented by one and the mesh 2 is incremented.
Move on to processing.

・ Draw the contents of mesh 2.

Graphic primitive management table corresponding to mesh 2
At T2, since the mesh crossing flag (11) of the first entry is OFF, the primitive C on the representative mesh management table T0 specified by the pointer is drawn (S1 to S1).
3).

Next, the mesh crossing flag of the second entry (11)
Is ON, the representative mesh identification field (15) on the representative mesh management table T0 specified by the pointer is checked, and since it is ON, primitive B is drawn at this point (S4, S5 → S2 → S8) → S3).

Further, when all the tables have been searched, the process proceeds to the next mesh number (S4 → S6, S7).

〔The invention's effect〕

As described above, according to the present invention, when drawing a graphic primitive extending over a plurality of meshes, the representative mesh management table manages which mesh content is to be drawn at the time of drawing the primitive. There is an effect that drawing processing performance can be improved by preventing drawing.

[Brief description of the drawings]

1 (a) and 1 (b) are explanatory diagrams of a graphic primitive and a mesh according to an embodiment of the present invention, and explanatory diagrams of a graphic primitive management table and a representative mesh management table. FIG. 2 is a data management method of the present invention. FIG. 3 is an explanatory view of a conventional mesh data management method. In the figure, A and C are figure primitives completely included in mesh 1 and mesh 2, respectively, and B is mesh 1 and mesh 2
Primitive primitives, T1 and T2 are graphic primitive management tables corresponding to mesh 1 and mesh 2,
T0 is a representative mesh management table, (11) is a mesh crossing flag indicating whether or not a figure primitive is included in the mesh, (12) is a pointer indicated by the figure primitive on the representative mesh management table, and (3) is a figure. The primitive fields (14) and (15) are representative mesh identification fields indicating which mesh is to be displayed when the figure primitive is displayed. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

(57) [Claims] When a graphic primitive is drawn on a screen by a scroll function, a drawing primitive movement table is provided which divides a drawing area movement unit in one scroll by a mesh and stores the contents of the figure primitive for each mesh. In a data management method in which a graphic primitive is drawn on a screen based on these management tables, the graphic primitive management table for each of the meshes is used to determine whether the graphic primitive is completely included in the corresponding mesh. And a pointer to the graphic primitive entry stored in the representative mesh management table. The graphic primitive field and the mesh to be drawn when the primitive is drawn are designated. Representative It has a representative mesh management table consisting of a mesh identification field, and for graphic primitives that span multiple meshes, the graphic primitives belonging to each mesh are drawn at once when drawing the graphic primitive corresponding to the representative mesh. Characteristic data management method.