JPS61834A - Line command processing method of pdi - Google Patents

Abstract

PURPOSE:To attain the line drawing with the coloring for each dot and with optional selection secured for thickness of a line, by using a means which stores the coordinates of both the initiation and the termination of a line and a means which draws with colors a straight line or a texture between the initiation and the termination. CONSTITUTION:When an input line command is processed, the logical picture element size showing tae thickness of a line to be drawn on a display screen, is supplied together with the logical coordinates of the initiation and the termination of a line and the coloring data. The physical coordinates of each display dot is calculated by a subroutine OPRCH, and the X and Y coordinates are stored to an XADBF register and a YADBF register respectively. Based on these physical coordinates and the coloring data, a straight line or a texture is drawn in colors between the initiation and the termination of the line by a line subroutine. This physical drawing is repeated by the frequency of the logical picture element size. Thus a line is drawn in a color between the designated initiation and termination with the thickness corresponding to the designated logical picture element size.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is utilized for graphic processing of a display device in videotex.

[Conventional technology]

Videotex connects the information center and each home using existing telephone lines as a transmission line, uses each home's television receiver as a display device, and transmits various information separately stored at the information center to requests from general households. This is a system that can be provided inexpensively and easily depending on the customer's needs.

The basic configuration of each Videotex terminal device consists of an ordinary home television receiver, an adapter (microprocessor) with built-in image memory, and a simple keyboard for requesting information.

The program that controls the operation of a terminal device may be loaded from an information center or may be provided independently by the terminal device.

In response to requests from a large number of terminal devices connected to the information center, the information center searches a database storing the required information and quickly and accurately transmits it to the requesting terminal. In the terminal, the image is stored in the image memory and then displayed in synchronization with the television screen.

In order to actually build and operate the Videotex system mentioned above, the information center must collect information,
There are many technical problems to be overcome, such as storage and retrieval problems, data transmission problems with terminals, data processing and display problems in terminal devices, etc., and various methods are being developed around the world. .

In these conventional techniques, the display method is block unit coloring in which several display dots are colored as blocks. However, the types of screens to be displayed are becoming more diverse, and as a result, fine-grained, high-quality display screens are required, and as a result, it is necessary to color the display screen in units of dots.

Among the various methods of Videotex, there is the PDI method. This sets the figure to be displayed as a point (POINT>, a straight line (LINE)
), arc (ARC), rectangle (RECTANGLE>, and polygon (POLYGON>). PD I (Picture D
(In5truction)
given by a language called The above basic elements are transmitted in the form of information called terminal device l\command.

Each command is composed of an operation code and data indicating each of the above types. The data includes coordinate position data and coloring data indicating an operation start point for drawing, an operation guide, etc. The data following one command is processed sequentially with the next command being treated as additional information.

Since the PDI videotex is a command transmission method, the ratio of the amount of information to the amount of transmission is large.

[Problem to be solved]

The present invention is a PDI POIN that displays dora 1 through unit coloring, which has not been realized in the past in Videotex.
The purpose of this invention is to provide a method for processing T commands.

[Means for solving problems]

The PCI I-I N E Tl cloak processing method according to the present invention is a videotex display device fit-2 J3 method for drawing black lines, which uses a logic that represents the thickness of the line to be drawn on the display screen. Input the pixel size, logical coordinates of the start and end points of the line, and coloring data, and based on these data, calculate and store the position coordinates of each physical pixel that makes up the start and end points of the line on the display screen. and means for coloring and drawing a straight line or texture between a starting point and an ending point based on these physical coordinates and coloring data.

The above calculation means is configured so that the processing result of the immediately preceding LINE command or POINT command can be used as is as the physical coordinates of the starting point of the line.

[Effect]

With the above configuration, physical drawing is repeated the number of times equal to the logical pixel size, and as a result, a colored line with a thickness corresponding to the specified logical pixel size is drawn between the specified starting point and the ending point.

〔Example〕

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

FIG. 1 is a flowchart showing a PDI LINE command processing method according to the present invention.

In this example, the LINE command is 11NE (A
) and LINE (B).

The LINE (A) command is accompanied by position coordinate data for both the start and end points of the line to draw the ring. On the other hand, L
In the INE (B) command, the starting point coordinates of the line are
Since we use what was calculated and stored in the POINT command (PDI command for drawing a point) that was processed just before, we only have the end point data expressed in relative values as the starting point coordinates reference. There is.

The L, INF command consists of an operation code and data. The command for the operation code is LINE
(A) or LINE (B), a PDI flag indicating whether there is an error in the command, and a REL flag indicating whether the coordinate data is absolute coordinates or relative coordinates.

The data includes the logical pixel size (representing the thickness of the line), end point coordinates, in the case of LINE (A), start point coordinates, and coloring data.

Coloring data represents 16 colors with 4 bits. This is this L
These are 16 colors selected from 4096 colors by other means prior to composing the INE command.

The display surface is 248 horizontal dots x 192 vertical lines.

Figure 1 will be described below. When the LINE command is input, processing starts from step 1, 5TART.

In step 2, this is set to OFF as the initial value of the PDI flag. This flag is LI
It is set to ON if there is no error in the NE command.

In step 3, the type of LINE command ((A) or (B)) is checked, and if it is LINE (B), the RE
After setting the L flag to 1'', the process jumps to step 10 without performing steps 4 to 9.

If it is LINE (A), proceed to step 4 and set the REL flag to "Y°'. If the REL flag is "~", it represents an absolute coordinate, and if it is "Pa1", it represents a relative coordinate.

After step 4, step 5 subroutine 0PRC
Enter H. In this subroutine, the contents of the above REL flag are checked. In this case, it is 110 II, so the first data is regarded as the logical pixel at the starting point of the line, and based on this, the physical coordinates of the physical pixels that make up this logical pixel, that is, each display dot, are calculated, and the X coordinate is calculated. XADBF
In the register (hereinafter, only the symbol is written for the register), enter Y
Store the coordinates in YADBF.

In subroutine 0PRCH, it is checked whether the command is normal. If it is not normal, for example, if there is only an operation code and no data, the process goes from step 6 to step 7, and the subsequent LINE command processing is not performed, but the process moves to other processing.

If the command is normal, proceed to step 8.

In step 8, the contents of XADBF (Xjl mark>
to xAop%, YADBF(7) contents (Y!I[)
Transfer to YADP.

Next, the process advances to step 9, where the PDI flag is set to ON to indicate that the command is normal and processing is continuing.

With the above steps, the physical position coordinates of one dot constituting the starting point have been calculated and stored.

Next, proceed to step 10. In addition to the above-mentioned route, the route to step 10 includes a route via step 4-.

In step 4-, the RE'L flag is set to "1" to indicate relative coordinates. In this case, the coordinate data of the starting point of the line is the one already stored in xAopQ and YADPQ as the processing result of the immediately previous LINE command or POI NT command.

Regardless of which route you take to enter step 10, the calculated physical starting point coordinates are XADP and Y.
It is stored in ADPΦ.

In subroutine 0PRCH of step 10, RE
When the L flag is ゛Φ'°, the physical coordinates of the end points of the lines are calculated using the second coordinate data, and when the REL flag is "1", the physical coordinates of the end points of the lines are calculated using the 111th coordinate data. Also stored in XADBF and YADBF.

Next, in step 11, command errors are checked. This is intended to check against the LINE (B) command. Even in this case, if there is an error, the process goes to step 7 and the following processing is not performed.

If there is no error, proceed to step 12/\\. Step 1
2, the starting point coordinate values XADPΦ and YADPQ are transferred to the drawing registers XADB~ and YADB of the starting point, respectively. The coordinate values of the end point are XADBF and YADBF
to end point drawing register XA[)81 and YADBI
will be moved to

Thereafter, the subroutine LINE of step 13 is entered.

The LINE subroutine creates a straight line or texture connecting the driver 1-coordinates represented by XADB~, YADB and the driver 1-coordinates represented by XADBl, YADBl.
(Dotted lines, chain lines, etc.) are colored and drawn according to the coloring data.

Next, proceed to step 14, where the coordinates of the end point xADB
After moving FSYADBF to XADPΦ and YADPΦ, the process goes to step 15. In step 15 PD
Set the I flag to ON and proceed from step 16 to step 3.
Go back and repeat the above process. If the logical pixel size is 1 dot, 2 in subroutine 0PRCH.
The result of the second processing is an error, which is checked in step 5, and the process proceeds from step 6 to step 7 to proceed to other processing.

If the logical pixel size is 1 or more, the above loop is repeated a number of times equal to the number of physical lines included in the logical pixel size, and finally exits the loop from step 6 and returns to step 7.
It ends with

〔effect〕

The PCI LINE command processing according to the present invention makes it possible to draw lines by coloring dots, which has not been possible in the past. Since the logical pixel size (line thickness) can be selected arbitrarily, it is extremely flexible.

Since it is a command transmission, the ratio of information to transmission amount is large and it is efficient.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing one embodiment of the present invention. 0PRCH: Means for calculating start point and end point coordinates. LINE: Means for coloring and drawing a line. Applicant: NEC Home Electronics Co., Ltd.

Claims (1)

[Claims] 1. A method for drawing a line on a display screen in Videotex, the method comprising inputting a logical pixel size representing the thickness of the line, logical coordinates of the starting point and ending point of the line, and coloring data. means for calculating and storing the positional coordinates of each physical pixel at the starting point and the ending point based on data such as, and calculating a straight line or texture between the starting point and the ending point based on the physical positional coordinates and the coloring data. 1. A PDI LINE command processing method, comprising means for coloring and drawing. 2. The PDI LIN according to claim 1, wherein the physical coordinates of the starting point of the line use the processing result of the immediately preceding LINE command or POINT command.
E command processing method.