JPH01159693A - display control device - Google Patents

Abstract

PURPOSE: To increase the drawing speed by providing a table memory and a display control processor and writing characters and figures one over the other. CONSTITUTION: This controller is equipped with the table memory 10 which stores whether or not necessary font data are held in a font data storage memory 8 and a display control processor 2 which indicates a complete return or incomplete return type character display command to a bit map control part 4 according to the contents of the table memory 10. Then when characters and figures are written one over the other, two kinds of character display commands of the complete return type and incomplete return type are issued; when font data on a character code specified for display are already stored in a ROM or a RAM as a cache area, the incomplete return type character display command making asynchronous response is issued and when a display of a character code for which a font fault process needs to be performed is specified, the complete return type character display command is issued. Consequently, the drawing speed can be improved.

Description

[Detailed Description of the Invention] [Summary] An object of the present invention is to improve the drawing speed when drawing characters and graphics in an overlapping manner, regarding a character display control method for a graphics display device that displays graphics and characters on a bit map display or the like. and a table memory that stores whether or not the required font data is held in the font data storage memory, and a character display command of either completion return type or incomplete return type depending on the contents of the table memory. The display control processor includes a display control processor that instructs the control unit, and is configured to overwrite characters and graphics.

[Industrial application field]

The present invention relates to a graphic display device for displaying graphics and characters on a bit map display or the like, and particularly to a character display control method when displaying graphics superimposed on characters.

[Conventional technology]

In a graphics display device that has the function of displaying graphics and characters on a bitmap display, etc., when trying to display graphics superimposed on the characters, write the characters first and then draw the graphics on top of them. If you do not do this, the shape will appear as if it has been erased.

For example, as shown in Figure 3, if you want to draw a figure with black line segments 32 on a red background 31, if you later write the word "mountain" as a character, it will form a ``mountain゛°''. The intersection point (circle part) 34 between the line 33 and the line segment 32 has an indeterminate color change, making it appear as if the line segment has been interrupted.Therefore, the characters and figures cannot be displayed consecutively on the bitmap display. When attempting to display, conventionally, a completion return type command method is used in which a character display command is issued after confirming that a synchronous response is returned, and the figure is drawn after waiting for the character display to completely finish. That's what I was doing.

[Problems to be solved by the invention] However, since the amount of character font data is enormous, character types (JIS level 1 kanji, JIS level 2 kanji, half-width characters, superscript/subscript characters, etc.) and fonts are Seeds (Mincho typeface,
It is not possible to store all the font data (Gothic fonts, etc.) in the memory of the display control unit, so in -i, only a limited amount of font data is stored in ROM (or RAM), and the rest is stored on disk, etc. It can be saved in an external storage device, and when a font fault occurs, the RA for cache can be used as needed.
The font data is stored in M. Therefore, when a font fault occurs, it takes a long time to process the font fault, and since the character display command when displaying characters and figures consecutively must be a return-to-completion type, it takes a long time to process the font fault for characters. The time was always large and the overall drawing speed was slow.

The present invention was devised in view of these problems, and an object of the present invention is to provide a character display control method for a graphic display device that improves the drawing speed when characters and graphics are drawn in an overlapping manner.

[Means for solving problems]

Means for solving the above problems in the present invention are as follows:
A graphic display that includes a bitmap control unit that displays figures and characters, a display control processor that preprocesses the display and controls the bitmap control unit, and a font data storage memory that can be directly accessed by the display control processor. In the character display control method of the device, there is a table memory that stores whether or not the required font data is held in the font data storage memory, and either a completion return type or an incomplete return type depending on the contents of the table memory. and a display control processor that instructs a bitmap control unit to display character display commands, and is based on a character display control method for a graphic display device that overwrites characters and graphics.

[Effect]

In the present invention, when drawing characters and figures in an overlapping manner, two types of character display commands are issued: a completion return type and an incomplete return type, and the font data of the character code specified to be displayed is already If it is stored in the ROM or cache area RAM, issue a character display command with an asynchronous response incomplete return type, and if a character code display that requires font fault processing is specified. In this case, issue a character display command using a completion return type.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a configuration diagram of an embodiment of the present invention.

In the figure, 1 is a system processor, which is composed of a CPU, built-in memory, etc., and has an operating system (O
8) and user programs. 2 is a display control processor which generates a logical screen according to commands from the system processor 1 and develops it in the memory 3 as a logical buffer.

A bitmap control unit 4 clips a part of the logical screen to a window area based on instructions from the display control processor 2 and develops it on the frame memory 5. Reference numeral 6 denotes a display control unit that displays the screen developed in the frame memory 5 on the bitmap display 7 as a physical screen. Also, lN:! itl display control processor 2
9 is a font data storage memory connected to the bus of the system processor 1 as an internal storage device, and 9 is a font data storage disk connected to the bus of the system processor 1 as an external storage device.

The font data storage disk 9 stores font data and its management table, and as an initial operation at startup, the system processor 1 stores a required part of the font data in the font data storage memory 8 according to the management table. At the same time, the management table itself is also written to the table memory 10. This is because if data is read from the disk each time a display operation is performed, the mechanical operation time of the disk unit slows down the processing. Even if the data is not read out in the initial settings, the data read out as required during the display operation is stored as is in the cache area RAM in the font data storage memory 8, and a flag is set in the table memory IO. . Note that the table memory 10 may be a built-in memory of the system processor 1, and the system processor 1 refers to the flag set in the table memory 10 to determine whether it is a completion return type or an incomplete return type.

FIG. 2 is a flowchart 1 showing an example of the operation procedure of the above embodiment. Hereinafter, the operation of the embodiment will be explained while comparing FIGS. 1 and 2.

When the system starts up in stage 0 of the flow shown in FIG. Write to 10.

Now, as shown in step ① of the flow (when trying to display figures and characters overlappingly on bitmap display 7,
The display control processor 2 searches the table memory 10 at the 0th stage of the flow, and determines whether or not the required font data is stored in the font data storage memory 8 at the 0th stage of the flow.

If the required character code is stored in the font data storage memory 8, a font fault will not occur, so an incomplete return type character display command is issued to the bitmap control unit 4 at the 0th stage of the flow. Even if the figure drawing command in the 0th stage of the flow is issued immediately after that, the characters have already been output by jumping to the 0th stage of the flow, so the characters and figures will be correctly overlapped and drawn in the 0th stage of the flow. Ru.

If the character code is not stored in the font data storage memory 8, a font fault occurs and the font data is loaded from the font data storage disk 9 to the cache area RAM in the font data storage memory 8, so that the character is not displayed. takes that much time.

Therefore, even if a figure drawing command is issued after a character display command, the figure may be drawn first, and the already drawn figure may disappear when the text is displayed. At the 0th stage, a completion return type character display command is issued to the bitmap control unit 4, and at the 0th stage of the flow, reading processing from the disk 9 is performed, and after the character display in the 0th stage of the flow is finished, a graphic drawing command is issued. It shall be.

As described above, according to this embodiment, if the character code is not stored in the font data storage memory 8, there is no difference from the conventional method, but if the character code is stored in the memory 8, the processing time is significantly increased. This greatly improves the overall drawing speed.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide a character display control method for a graphic display device that greatly improves the drawing speed when displaying characters and graphics consecutively.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a flowchart of the operating procedure of the embodiment, and FIG. 3 is a sample diagram of overlapping display of characters and figures. 1; System processor; 2; Display control processor; 3; Memory; 4; Bitmap control unit; 5; Frame memory; 6; Display control unit; 7; Bitmap display; 8; Font data storage memory; 9; Font data storage disk, 10; table memory. Figure 1

Claims (1)

[Scope of Claims] A bitmap control unit (4) that displays figures and characters; a display control processor (2) that performs preprocessing of the display and controls the bitmap control unit (4); In a character display control method of a graphics display device having a font data storage memory (8) that can be directly accessed by a processor (2), whether or not required font data is held in the font data storage memory (8). and a display control processor that instructs the bitmap control unit (4) to perform either a completion return type or an incomplete return type character display command depending on the contents of the table memory (10). (
2) A character display control method for a graphic display device, characterized in that characters and graphics are overwritten.