JPS61180284A - Graphic display unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a graphic display device using a graphic CRT display device, and particularly to a line segment information creation processing method for drawing thick lines.

B0 Summary of the Invention The present invention provides a graphics display device that creates data for drawing a thick line on a CRT monitor from data in a segment structure. By creating the number of line segment data that is parallel-shifted in the direction according to the line width, it is possible to easily draw thick lines by managing the line segment information and line width information that are central.

C1 Conventional technology Graphic CRT display devices have traditionally been manufactured using CAD, CA
Although it is mainly used for off-line operations such as creating and modifying figures in fields such as M and CAE, recently, its use as a terminal device for online systems has been increasing. The graphic CRT display device used as the terminal device of this online system is required to have the following two points in terms of function and performance compared to conventional ones.

(1) High-speed display: Good responsiveness is an essential condition for online systems, and the process from display request to display completion must be performed quickly, and various display updates must also be performed quickly.

(2) Wide area support°°° Since the online system operates on equipment installed in a wide area, it supports a wide display area and can display the necessary area according to display requests.

In order to meet these demands, a system configuration called an intelligent terminal type has been adopted as a graphic display system.

As shown in FIG. 2, in this system, a graphic CRT display device 1 having a computer is used as a terminal side, and a host computer system 2 is connected to this terminal side via a communication line. An online system is constructed by connecting to a terminal device or a host computer. In this configuration, a distributed processing method is used in which the host computer system 2 performs a large amount of arithmetic processing or data processing, and the computer in the terminal-side graphic CRT display device 1 performs display processing, which improves responsiveness on the terminal side. The load on the host computer system 2 is also reduced while improving performance. below,
Graphic display processing in the configuration shown in FIG. 2 will be explained in detail.

The graphic CRT display device 1 has a CRT monitor 3 that performs refreshment drawing using a rask scan display method, has a display processor 4 as a control center, and has graphical information (line segments) to be displayed.

information such as symbols, characters, etc.) is stored in the segment buffer 51. In the segment buffer 51, in K rank,
The individual graphic elements (display figure 'fr: specified data type 1 display position, display color) SD located at the lowest level, and the attributes (visible attributes, visible attributes, It is configured into a tree structure by attribute elements SP that define detection attributes (detected attributes, etc.).

From the graphic information stored in the segment buffer 5I, graphic information in a range (rectangular area determined by coordinate values) requested to be displayed is cut out. This cutting process includes a Mad/Vx calculation processing section 5 which performs parallel translation and rotational transformation of the displayed figure. ．． A clipping processing unit 5 that removes portions that extend beyond the displayable screen frame of the CRT monitor 6; etc. are prepared, and a digital differential analysis (DDA) processing unit 5. further develops a line segment of cut out graphic information from a display position (coordinate position) into on/off information of a corresponding bit on the frame buffer 6. will be prepared.

Frame buffer lj: A memory that physically has a bit plane corresponding to each pixel on the screen of the 1dcRT monitor 3 on a one-to-one basis, and has multiple bit planes for color display.
Determine display color using lookup table Z. This will be explained with reference to FIG. In the figure, the frame buffer 6 has three bit planes #1. #2. #3 is shown, and the on/off bits corresponding to the graphic information in the segment buffer 51 are developed as a combination of bit planes #1 to #3. And CRT monitor 3
The display on the screen is performed by star scanning t-2 on the frame buffer 6, and follows the display color table defined in the lookup table 7 using the bit-on combination value of each bit plane #1 to #3 as an address. R (red), G (green)
, B (evening) are applied to the CRT monitor 3.

The table below shows each bit plane #1 to frame buffer 6.
For the bit combination #3, the strong display color difference for each beam in the lookup table 7 is illustrated as an example, and 8 types of colors are specified for each pixel by the three bit planes #1 to #3. and lookup table 7
By applying 3 bits to each beam of 0R, G, and B, 5
12 (2') colors can be selected.

(Left below) Returning to Fig. 2, the host combinator system 2 uses the host computer 8 as the control center to divide the data processed into graphical information into an appropriate format as one of the processing functions of online processing, and to store the data on the magnetic disk. The graphic information in the range requested by the graphic CRT display device 1 is stored in the auxiliary storage device 9 such as the interface 10.11. The data is transmitted to the graphic CRT display device 1 through the communication line of the transmission line 12, and the received data is sent to the segment buffer 5. Store it in .

D1 Problems to be Solved by the Invention In the configuration of FIG. 2, the host computer system 2
Among the graphical information registered in the graphic CRT display device 1, line segment information includes the starting point P+(Xt, Y,) of the line segment, as shown in FIG.

Pa (Xs, Ym) and the end point P* (Xt, Y
m), PI (X4, Y4) are registered as coordinate data, and from this coordinate data, the DDA processing unit 54 performs bit expansion into a data string necessary for drawing the line segment A+B, and displays the data on the CRT monitor 3 as described above. Displays a line segment above.

Such line segment information and display processing is realized by space bit insertion processing at the time of bit expansion by specifying data types such as solid lines, dashed lines, dashed lines, etc.

However, thick lines in line segment information cannot be realized by the same processing as for broken lines and the like. Therefore, the bold line is
The host computer 8 forms line segment information corresponding to the line width of the thick line, and this group of line segment information is sent to the graphics card CR.
Segment buffer of T display device fii15. It was used to register and draw.

In this conventional method, in order to display thick lines, complicated coordinate position calculations are required to create a large number of line segment information, which increases the burden on the host converter, which does not adversely affect online processing and makes high-speed display difficult. do.

One possible method for creating thick line display information is for the operator to input line segment data from the graphic CRT display device, but this requires accurate input of data for the number of thick line segments, which is difficult for the operator. It will be a huge burden.

Also, to display a thick line, use the line segment information for one line, and
There is a method of waving a beam on the display on the RT monitor 6, but this allows you to obtain visually thick lines for the displayed figure, but in Tocobee, only one line segment information is available. I can't get a copy of the thick line without it.

Means and operation for solving the E0 problem In view of the above problems, the present invention specifies the coordinate data and line width of the starting point and ending point of the central line segment when creating thick line information by the host converter. Sometimes, depending on the slope of the line segment determined from the coordinate data, the reference line width ΔX,
Coordinate data for line segments shifted by Δy will be created for the number of lines that have the above line width, and this line segment information will be registered as thick @ display information on the graphic CRT display device side together with the center line segment information. It is famous because it calculates the coordinate data that will give the necessary line width by adding the reference line width from the coordinate data of the center line segment information and the coordinate data of the center line segment information and specifying the line width.

F. Example FIG. An enlarged view of the display is shown. Among the line segment information, the thick line information specifies the coordinate data and line width data of one line segment that is the center of the thick line. In Fig. 1, the coordinate data is Pu (Xt,
Specify Yt ) and P□(
at (Xs - Ym) and Pat (Xa, Y4
). In addition, the line width data is specified as the width of one line segment, that is, a multiple n of one pixel width, and K1
In order to make the drawing T a thick line with a line width of five lines, n=5 is specified.

The operator gives the coordinate data and line width data to the host computer 8, and the host computer 8 determines that the line segment type is a thick line. Graphic C automatically creates line segment information for displaying thick lines from coordinate data and line width data.
It is registered in the segment buffer 51 of the RT display device 1.

The thick line information creation process ′ in the host computer will be explained below.

First, regarding line segment A, coordinate data PH(Xt - Yt
) and Put (Xt, Yt) to determine whether the line segment has an inclination of more than or less than 45 degrees with respect to the horizontal.

45 degrees or more IY, -Y, l≧IX, -X, less than 145 degrees 1Ku -"+'<l XI XI 1 Perform the following processing according to the result determined by the above formula.

If the inclination is less than 45 degrees, coordinate data is created by translating the coordinate data of the central line segment A in the Y direction by one line segment width Δy. This line segment width Δy is alternately moved positively and negatively by n lines specified with respect to the central line segment A,
Set to standard width. On the other hand, if the inclination is 45 degrees or more, the coordinate data of the center line segment A is changed to one line segment width △ in the X direction.
Create coordinate data that is translated by X. Since the angle of line segment A in Figure 1 is less than 45 degrees, the coordinate data to be created will be: if n = 5, then P □ (Xa - L + Δy) and Pat (X2, Yt
+Δy)Pss (Xa, Ya−Δy) and Pus
(Xt, Yt-△y)P, 4(X,, Y, +2△y
) and Pat (Xs, Yt +2Δy) PII (
XI, Ya 2△y) and Pts (X2.right-2
.DELTA.y), and these coordinate data are registered in the segment folder 51 of the graphic CR7 display device 1 along with the coordinate data of the central line segment A.

Similarly, line segment B has an inclination of 45 degrees or more, so if n=5, the coordinate data of the central line segment is Pat (Xs, Y=), P4, (Xa
, Ya ), the coordinate data Ps@(Xs-Δx, Ys) and Pit(Xa-
Δx, Ya)Pus(Xs+ΔX+Ys)
and Pas (Y4 to X++8X) pH4(X32Δx
, Ya ) and P44 (Xa 2△x, Ya)Ps
s(XB+2Δx, Y3) and Plm(X4+2Δx, Y
a) Automatically create something with the start and end points.

Note that the calculation for creating the coordinate data is not limited to the central line segments A and B, but can be similarly obtained by adding or subtracting ΔX and Δy to the created data. For example, after creating line segment data having coordinate data ptt and Plt, creation of line segment data having coordinate data PI4, P, and 4 is realized by adding +Δyt- to the coordinate data having Plm and Pfl.

G0 Effects of the Invention As described above, according to the present invention, when creating thick line information, the coordinate data of the center line segment and 0 specifying the line width are set by 1°.
1・*/() s 7 e Specify the coordinate data that is widened to the slope of the line segment that is "medium'6" and translated by the reference line segment width △X, Δy in one direction of fcX, Y direction. In order to create a number of line segments with the desired line width and register this line segment information together with the center line segment information in the segment bar/7A for display, the center line segment information is used to create line segment information for thick lines. This can be achieved by simply adding ΔX, Δy to the coordinate data from the slope of This can be easily done by specifying the line width.

[Brief explanation of drawings]

FIG. 1 is an enlarged view of the thick line in the processing method of the present invention;
Figure 2 is a configuration diagram of the graphic display device, Figure 3 is a segment structure diagram of graphic information handled in Figure 2, and Figure 4 is for explaining the bit expansion and color display processing of graphic information in the graphic CR7 display device. , and FIG. 5 are explanatory diagrams of processing for displaying line segments. DESCRIPTION OF SYMBOLS 1... Graphic CRT display device, 2... Host computer system, 6... CRT monitor, 4...
・Display processor, 5. . . . Segment buffer, 52 . . . Matrix calculation processing section, 53 . . . Clipping processing section, 5. ...DDA processing section, 6...
Frame Babufa, 7... Lookup table, 8
...Host converter, 9...Auxiliary storage device, 1
0.11...Interface, 12...Transmission line,
A, B...Central line segments. Figure 1, Guijikuchi shown in bold line

Claims (1)

[Claims] In a graphic display device in which a graphic CRT display device having a display processor is used as a terminal device and graphics are displayed by constructing an online system together with a host computer, the host computer stores the coordinates of the start and end points of the central line segment as thick line information. When the data and line width are specified, the reference line width Δx is calculated in one of the X and Y directions according to the slope of the line segment determined from the coordinate data.
, the coordinate data of line segments translated by Δy is created for the number of line segments corresponding to the line width, and this line segment information is registered as thick line display information on the graphic CRT display device side together with the center line segment information. Characteristic graphic display device.