JPH03155593A - Graphic display device - Google Patents

Abstract

PURPOSE:To shorten plotting time as a whole by preserving the command block and the leading address of a character when the character is converted to a command block, and attaching a mark on a bit table corresponding to a character code. CONSTITUTION:A command block preservation area 14 to preserve plural command blocks, and the bit table 12 corresponding to the character code to set the mark representing the preservation of the command block are provided. At such a case, when the mark is attached on the bit table 12 corresponding to a supplied character, it shows the fact that the command block for the plotting of the character is already converted and preserved, therefore, it is enough to take out the leading address of the command block from a command index table 13 in which the character code is set as an index, and to supply it to a graphic processor. Thereby, it is possible to omit the coordinate transformation of the coordinate data of the character and conversion to the command block when an image is processed in such a way that the same character with the same size is plotted repeatedly, which shortens the plotting time as a whole.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a graphic display device used for monitoring and controlling general industrial equipment.

(Conventional technology) Generally, a graphic display device has the configuration shown in FIG.

Transmission control device from host computer 1! When a graphic drawing command is received via the CPU 2, the CPU 3 decodes the command, the floating processor 4 performs coordinate transformation, and the graphic processor 5 draws the graphic on the frame memory 6A.

The graphics drawn in the frame memory 6A are displayed on the display monitor 8 by the video interface circuit 7.

Such graphic display devices use so-called stroke fonts in which characters are represented by X and y coordinate points in order to enlarge or reduce the characters (FIG. 5).

The straw font memory 6B includes a data table 51 storing coordinate points of all characters, and a data table 51 storing the coordinate points of all characters, in order of character code.
It consists of an index table 50 indicating the start address of coordinate data in the data table corresponding to the character code (FIG. 6).

The data table 51 is kanji JIS 1st and 2nd level.
It has approximately 6,600 characters and is generally stored in compressed form to reduce memory capacity.

In addition, the data table 51 includes coordinate data.

Control codes are also stored. The control codes include a pen up code, a pen down code, and a data end code for - characters.

Moreover, the coordinate data needs to have coordinate data of many points in order to make the font beautiful even when enlarged.

The procedure for drawing a straw font will be explained using FIG. 7.

First, the start address of the data table is extracted from the index table using the given character code as an index (Sl).

Next, data is retrieved in order from the top of the retrieved table (S2.S3.S4), and if it is a pen-up code, the drawing flag is set to FALSE and S5. S6)
, if it is a pen down code, set the drawing flag to TRUE (
S7. S8).

If it is coordinate data, check the drawing flag after coordinate conversion in S9. SIO, 5ll), if FALSE, stores a MOVE command to move the drawing position to the specified coordinates, and stores the coordinate data at the next address (S13
). If TRUE, a LINE command is stored to draw a line from the current drawing position to the specified coordinates, and coordinate data is stored at the next address (S12). This process is repeated until one character of the end code is extracted. −
If it is a character end code, store the END command (515)
By setting the start address of the command block in the graphics processor (S16), the graphics processor draws while decoding the command.

The general form of coordinate conversion processing is: coordinates extracted from the data table (x+y) - coordinates after coordinate conversion (x'+y')
Then, it is expressed as follows.

x' = ax + by + c y' = dx 1 ey + f These calculations use floating point arithmetic.

In this manner, in the conventional method, every time a character is drawn, coordinate conversion of all coordinate points, conversion to graphic commands, and drawing processing are performed.

(Problems to be Solved by the Invention) Incidentally, in such monitoring displays, the types and sizes of characters used are often limited to some extent for each display screen.

Further, the coordinate conversion process requires four multiplications and six additions in floating point calculations per point, which is a large overhead relative to the drawing processing time.

However, in the above method, the characters to be drawn are the same,
Furthermore, even if the size is the same as the previous drawing, all coordinate transformations and conversion processing to graphic commands are always performed, resulting in a large overhead in the overall drawing time.

Such monitoring displays must be displayed as quickly as possible to improve man-machine interactivity, and such overhead must be minimized.

Therefore, when a character is converted into a command block, the present invention saves the command block of that character and its start address, and also adds a mark to the bit table corresponding to the character code. , if a mark has been added to the bit table corresponding to that character code, by giving the saved command block to the graphics processor, the coordinate conversion process of the character coordinate point and the conversion process to a command block can be omitted. It is an object of the present invention to provide a graphic display device that can draw one character at high speed and improves man-machine performance.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a graphic display device capable of enlarging and reducing figures and characters, which is equipped with a stroke font and saves a command block of a character once drawn, so that the same image can be displayed again. The present invention is characterized in that when attempting to draw a character, the coordinate conversion process and the conversion process of the character into a command block are omitted.

(Function) This makes it possible to omit the processing for characters corresponding to the saved command block.

(Example) An example of the present invention will be described below. FIG. 1 shows a data table of the graphic display device of the present invention.
In the present invention, a command block storage area 14 for storing a plurality of command blocks and a bit table 12 corresponding to a character code for setting a mark indicating that a command block is stored are provided. These are included in the memory (2) in FIG.

The size of the command block storage area 14 is 200 to 30, although only the types of characters to be drawn are prepared at the same size.
In many cases, it is sufficient to have 0 types of characters.

First, the bit table corresponding to the given character code is checked (S1, S2), and if there is no mark, the start address of the data table is extracted from the index table using the given character code as an index (S3). Next, data is retrieved in order from the specified start address in the data table.
5,86).

Then, the results of conversion into graphic commands are stored in order from the beginning of the free area of the command block storage area.

If the retrieved data is a pen-up code, set the drawing flag to FALSE (S6, 513).
).

If it is a pen down code, the drawing flag is set to TRUE (S7, 514).

If the retrieved data is coordinate data, perform coordinate conversion in S8.
．． S9), First, check the drawing flag (S10)
, if it is not set, stores the MOVE command in the graphic command area, then stores the coordinate data (
S12). If the drawing flag is set, a LINE command is stored in the graphic command area, and then coordinate data is stored (Sll). These processes are repeated until the - character end code is extracted (S15.S
3°S4. S5). - When the end code of a character is retrieved, an END command is stored in the graphic command area (S19), and the start address of the one-character graphic command string converted here is saved in the command index table that uses the character code as an index, and the character Add a mark to the bit table corresponding to the code (31
6.517). Then, the graphic command sequence is given to the graphic processor (S20) (Figure 2)
. The graphics processor performs drawing while sequentially decoding command blocks.

Next, when a mark is added to the bit table corresponding to a given character code, the command block for drawing that character has already been converted and saved, so the command that uses the character code as an index It is only necessary to extract the start address of the command block from the index table (S2, 518) and provide it to the graphics processor (820).

In this way, in the present invention, data is drawn according to the flowchart in FIG.

In addition to the above-mentioned character drawing commands from the host computer, commands for changing the size of characters are also available. This command is processed according to the flowchart in FIG. When this command is received from the host computer, change the coordinate conversion coefficients a"f so that the specified character size is reached (Sl), and clear the bit table since the saved command block will become invalid. (S2).

In this way, according to this embodiment, by saving command blocks of characters that have already been drawn, if the same character is drawn many times in the same size, the coordinate data of the character can be saved. Since coordinate conversion and conversion to command blocks can be omitted, the overall drawing time can be shortened.

〔Effect of the invention〕

As described above, according to the present invention, the overall drawing time can be shortened, and man-machine performance can be improved.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a table of the graphic display device of the present invention, Fig. 2 is an explanatory diagram of a single character graphic command block, Fig. 3 is a flowchart for drawing using the table of the present invention, and Fig. 4 is an explanatory diagram of a graphic command block of a single character. A flowchart for clearing the bit table by changing the font size. Figure 5 is an explanatory diagram of the stroke font font. Figure 6 is an explanatory diagram of the index table and data table of the stroke font. Figure 7 is an illustration of the conventional stroke font. A flowchart for drawing, FIG. 8 is a block diagram of a graphic display device. 10... Index table, 11... Data table, 12... Bit table, 13... Command index table, 14...
Command block storage area, 40... Index table, 41... Data table, 42... Coordinate data in the data table, 43...
X coordinate. 44...X coordinate, 45...Control code in data table, 50...
Index table. 51...Data table.

Claims (1)

[Claims] A graphic display device capable of enlarging and reducing figures and characters, which is equipped with a bit table corresponding to stroke fonts and character codes and a graphic command block storage area, extracts coordinate data of stroke fonts during drawing, and after coordinate conversion, displays graphic commands. When converting to a string and drawing, you can set the corresponding bit in the bit table corresponding to the character code, save the graphic command string in the graphic command block storage area, and memorize its start address. When drawing the same character in the same size as the previous time,
A graphic display device characterized in that the coordinate conversion process and the conversion into a graphic command string are omitted by using an already saved graphic command string without converting coordinate data into a graphic command string.