JPH01283589A - Character string clip processing system - Google Patents

Abstract

PURPOSE:To perform the clip processing of a character string outside a display area by performing the clip processing of the character string for a character string frame reference point prior to the display processing of the character string. CONSTITUTION:A graphic form and character display device is equipped with a function for enlargement and coordinate transformation for character vector coordinate values outputted by a character pattern generating device and a function for the clip processing of respective coordinate points after the coordinate transformation, and a means which performs the clip processing of the character string outside the display area by making a clip decision on the character string with character string frame segments is provided. Namely, a character string frame vector is generated before character codes are converted into character coordinate vectors to decide whether or not the corresponding character string is in the display area, and when the character string is all outside the display area, the command processing of the character string is finished without converting the respective character codes into the character coordinate vectors. Consequently, the clip processing of the character string outside the display area is speeded up.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a character string clip processing method in a graphic/character display device.

[Prior Art] FIG. 2 is a block diagram showing the configuration of a conventional rask scan type graphic/character display device. In the figure, 1 is an interface circuit, 2 is a control device that converts display data and display commands sent from a computer (not shown) through the interface circuit 1 into an internal format, and 3 is display data converted into an internal format and display commands. 4 is a character pattern generating device that outputs character vector coordinate values of a corresponding character by inputting a character code, which is one of the display data.

The data output from the character pattern generator 4 is sent to a coordinate conversion circuit 5 and a clip circuit 6 based on instructions from the control device 2.
is applied to the straight line generator 7 via.

Further, in the figure, 8 is a frame buffer, 9 is a CRT (cathode ray tube) control device, 10 is a CRT, and 11 is a human-powered device.

FIG. 3 is a flowchart showing character string command processing by the graphic/character display device of FIG.

Next, character string command processing by the conventional graphic/character display device will be described. When the control device 2 receives a character string command, it executes preliminary processing such as setting coordinate transformation parameters for character strings. Next, a character code is read from the storage device 3 that stores the number of character strings N times, and the character code is manually inputted to the character pattern generator 4, and the character vector of the corresponding character is output from the character pattern generator 4. The coordinate values are sent to the coordinate conversion circuit 5. The character vector coordinate values of the corresponding character after the coordinate conversion of enlargement, reduction, rotation, and movement are performed in the coordinate conversion circuit 5 are manually inputted to the clip circuit 6 to determine the display area, and the character vector coordinate values by this clip circuit 6 are As a result of column clipping, only the line segments displayed on the CRT 10 are sent to the line generator 7. In this way, the character code is processed N times and the character string command processing is completed.

[Problems to be Solved by the Invention] Since the conventional graphic/character display device described above is configured as described above, the character string clipping process is performed for each character vector, so that the character string table shown in FIG. As shown in the example, when the number of character strings in the display area is smaller than the character strings outside the display area, the time required to clip the character vector coordinate values of the character strings outside the display area, which should not be necessary, increases. As a result, there is a problem in that it takes a long time to perform the entire display process.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a character string clipping method that easily and quickly clips character strings outside the display area.

[Means for Solving the Problems] A character string clip processing method according to the present invention clips a character string with respect to a character string frame reference point prior to display processing of a character string. It is designed to perform clipping processing on outside character strings.

[Operation] The character string clip processing method of the present invention determines in advance whether or not the relevant character string is within the display area by creating a character string frame vector that converts character codes into character coordinate vectors. However, if all relevant strings are outside the display area, the command processing for the string is terminated without converting each character code to a character coordinate vector, thereby speeding up the clipping process for strings outside the display area. do it like this.

[Example 5] FIGS. 5(a) and 5(b) are diagrams showing definition examples of character string frames. In the figure, PX, PY, and S are values that are calculated in advance as movement terms during coordinate transformation at character string display reference points at intervals of 9 characters. W.

T is the character width of 1 character and the height of 9 characters, expansion during coordinate conversion,
This is a value calculated in advance as a reduction term. N is the number of character strings. There are two character string directions, horizontal and vertical, as shown in Figures 5 (a) and (b), and each character string frame is (PX, PY).

(PX+A, PY), (PX+A, PY+B).

(PX, PY+B) (7) Specified with 4 points.

The first ffl is a flowchart showing character string command processing in a character string clip processing method according to an embodiment of the present invention. In the character string command processing according to the present invention, coordinate transformation and clip processing are performed on the character string display reference points (PX, PY) shown in FIGS. 5(a) and (b), and if this is within the display area, the above-mentioned The same character string display processing as in the conventional example is performed. Character string display reference point (PX,
If PY) is outside the display area, the character string frame lines are clipped according to the flowchart shown in Figure 1. If four character string frame lines fall within the display area, the conventional example described above is performed. Performs the same string display process as . If all the character string frame lines are outside the display area, the corresponding character string is also outside the display area, so at this point, N character codes are discarded and the character string command processing ends.

In Figures 5(a) and (b), the character string display reference point (PX,
PY) is defined as shown in the figure, but no matter where this character string display reference point (PX, PY) is located in the character string frame, it is The character string clip processing method according to the present invention can be realized by simply changing the value calculation formula.

[Effects of the Invention] As described above, according to the character string clip processing method of the present invention, by clipping the character string with respect to the character string frame reference point prior to displaying the character string, Since clipping of strings outside the display area is performed, clipping of strings can be performed at low cost and at high speed, which has the excellent effect of shortening the overall processing speed. be.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing character string command processing in a character string clip processing method that is an embodiment of the present invention, and FIG. 2 is a block diagram showing the configuration of a conventional rask scan type graphic/character display device. Figure 3 is a flowchart showing character string command processing by the graphic/character display device in Figure 2, Figure 4 is a diagram showing an example of character string display, and Figures 5 (a) and (b) are character string frames. It is a figure which shows the example of a definition. In the figure, 1... interface circuit, 2... control device, 3... storage device, 4... character pattern generator, 5... coordinate conversion circuit, 6... clip circuit,
7... Linear generator, 8... Frame buffer, 9...
...CRT control equipment O...CRT, 11...Man-powered equipment. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] When a character code is input, the character vector coordinate value of the corresponding character is output.The character vector coordinate value outputted from the character pattern generator has the function to perform coordinate transformation such as enlargement, reduction, rotation, and movement, and after coordinate transformation. In a graphic/character display device that has a function to perform clipping processing by determining the display area for each coordinate point, character strings outside the display area can be A character string clip processing method characterized by comprising means for performing clip processing.