JPH0130177B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a simple graphics processing device that creates line graphics in a conversational manner between the graphics processing device and an operator, and particularly relates to a simple graphics processing device that creates line graphics in a conversational manner between the graphics processing device and an operator. This relates to a device that performs certain graphic editing.

[Prior art]

Generally, this type of simple graphic processing device displays a predetermined line segment on the screen based on position information (coordinate values) and commands (shape, line type, line width, etc.) input by the operator. It is composed of
For example, in the case of straight line information, the coordinates of the start and end points of the straight line are input using a position information input device such as a joystick, tablet, or light pen, and then a straight line drawing command is input. If it is circle information, input the center point and its radius, and then input the circle drawing command.

As mentioned above, the simple graphics processing device uses a cathode ray tube (CRT)
The information is displayed as visual information on a display unit such as a computer, etc., and is sequentially stored in a storage unit built into a processing device to construct a final figure (for example, a block diagram or a flowchart diagram) intended by the operator. FIG. 1 embodies the storage state of the storage unit of this simplified graphic processing device.

As mentioned above, if the operator can input all the line segments correctly, the graphics processing device only stores the input information in the storage section and displays the vector information generated from that information on the display section. However, there is always an operator error or deletion of line segments due to changes. First, in order to delete a previously input line segment, the graphics processing device must detect the line segment to be deleted, delete that line segment from the memory, and also delete the display information for that line segment. Must be. The means for detecting this one line segment differs depending on the display method of the display section, but here, it will be explained as a graphic processing device having a display section using a raster scan method.

The basic form of line graphic display using this raster scan method will be explained next, and then the line segment detection method using the conventional device and its drawbacks will be explained.

FIG. 2 is a diagram illustrating the basic method of displaying line figures in the raster scan method. Reference numeral 1 in the figure is a storage unit that stores the line information shown in FIG.
2 is a vector/raster conversion unit (hereinafter simply referred to as a conversion unit) for converting the information stored in the storage unit into raster information (also referred to as dot information); 3
is a frame memory (hereinafter simply referred to as
(abbreviated as FM), 4 is a video generating section for periodically reading out dot information stored in the FM and converting it into visual information, and 5 is a display section using a raster scan method.

In the above configuration, the storage capacity of the FM 3 is usually associated with the number of effective display pixels of the display section 5, and the effective display pixels of the display section 5 are 512 vertically (raster),
If there are 512 pixels (dots) horizontally, FM3 also has a capacity to store 512×512 pixels. Further, the display operation on the display unit 5 is performed independently of the conversion process of the conversion unit 2,
The dot information of FM3 is generated at a rate of about 30 to 40 times per second according to the display control signal from the video generator 4 (a signal generated based on the horizontal synchronization signal, vertical synchronization signal, etc. of the display section 5). The information is sequentially read out and finally sent to the display section 5 as visual information. on the other hand,
The converting unit 2 reads the line information stored in the storage unit 1 and performs conversion processing to sequentially convert pixels on the FM 3 corresponding to the line information into bright spots. This conversion process is basically performed only once for one line segment.

FIG. 3 is a diagram for explaining in detail the operation of the converter 2, and the line segment in the diagram is the "straight line 1" shown in FIG. 1. First, when a new request for generation of "straight line 1" arises, it is stored in the storage section 1 and input to the conversion section 2. This conversion unit 2 converts a predetermined line segment from the shape, line type, line width, and position (xs ₁ , ys ₁ ), (xe ₁ , ye ₁ ) associated with “straight line 1”.
Draw on FM3. The generation procedure is the position (xs ₁ ,
ys ₁ ) as the starting point (black circle at the bottom of the figure), and (ye ₁ −
Find out that it is a line segment with a slope of ys ₁ )/(xe ₁ − xs ₁ ) whose end point is the position (xe ₁ , ye ₁ ), and the distance from the start point to the end point is Raster conversion (dot conversion) of "Line 1" is performed by performing interpolation (white circle in the figure) derived from the intersection of the slope of the line segment and the grid network in which the pixels are arranged.
end.

As described above, this type of device does not hold the position information of all pixels of a generated line segment, but stores it in the form of vector information. Conventionally, in a graphic processing device having such a storage format, an operator can specify an arbitrary position on a line segment displayed on the display unit 5 using a positional information input device such as a joystick to select a line to be deleted. It was beginning to detect the minute. For example, when deleting "straight line 1" shown in FIG. do. Assume that this input position is the pixel position of the point (xn, yn) shown in FIG. In order to detect the line segment corresponding to the point (xn, yn) corresponding to this deletion request, the graphic processing device raster-converts all the vector information stored in the storage unit 1 again using the conversion unit 3, Extracts line segments that have pixels that match the input position information (xn, yn). In this example, the expansion of the seventh pixel of "straight line 1" matches the input position information, and the line segment to be deleted is determined to be "straight line 1." However, the above method is a theoretical determination method, and in reality, the operator's input position does not necessarily indicate a position on the developed line segment, but rather detects a certain range. The range can be taken as square, circular, etc.
Although there are various methods, a square method is generally used because it is easy to configure the circuit. This square method is a square (x±m, y±m) centered on the position information (x, y) input by the operator.
All vector information is expanded using the detection area as a detection area, and line segments expanded in that area are candidates for deletion.
This reduces the accuracy of position input for the operator. On the other hand, expanding this area creates new problems. There is a possibility that multiple line segments may be developed within the area, and in order to extract one line segment from among the multiple line segments, confirmation with the operator is required again (high-intensity display for each line segment). I need to go and decide.

The conventional method for extracting line segments to be deleted using this type of device has been explained above.According to this method, this is done by inputting an arbitrary position on the expanded line segment. There were drawbacks like (b).

(a) By inputting the position of the deletion target, all the vector information stored in the storage unit 1 must be converted into dot information again to extract the target line segment.
This takes 500ms to develop one point of pixel information,
If there are 200 line segments with 200 dots per line, it will actually take 20 ms to develop all the vector information.

(b) Since there is a possibility that multiple line segments may enter the line segment detection area, a reconfirmation method is required.

[Summary of the invention]

This invention was made in order to eliminate these drawbacks, and is configured to display a mark near the displayed line segment, and by inputting the position of the mark, the line to be deleted can be selected. The present invention provides a graphic editing device that extracts the parts.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. In FIG. 4, reference numerals 1 to 5 are the same as those explained in connection with FIG. 2, and detailed explanation will be omitted. Reference numeral 6 denotes a line identification unit that reads a line segment stored in the storage unit 1 and determines a mark display position for the line segment; 7 a mark pattern according to the mark display position given by the line identification unit; This is a mark generation unit that generates a mark and embeds it in a predetermined position of FM3.

In the above configuration, when a deletion request is made by the operator, the line identification section is activated by the control section, reads out all vector information stored in the storage section 1, and displays a mark near the line segment. Calculate the position to perform. As an example of this calculation,
If it is a straight line, the starting point (xs, ys) and the ending point (xe, ye)
or the midpoint of the line segment [｜xe−xs｜/2+min
(xs, xe), |ye−ys|/2+min(ys, ye)],
If it is a circle, the position of the center point (xo, yo) or a certain point on the circumference (xc, yc) can be assumed. This calculated position is sent to the mark generation section 7. This mark generation section 7 develops the mark pattern to the position of the FM 3 corresponding to the given position. At this time, it is expanded by exclusive OR (EXOR) with other information expanded in FM3.

FIG. 5 shows the display unit 5 when marks are displayed in addition to vector information. The operator inputs the mark position associated with the target line segment using a position information input device such as a joystick while checking the display section 5 on which the vector information and mark are displayed. The control section of the graphic processing device activates the line identification section 6 again using this input position information.
Upon this activation, the line identification section 6 sequentially performs association with the vector information stored in the storage section 1. Now, the marks are displayed from the starting point (xs, ys) of the line segment to the point (xs+d _X , ys+d _Y ) as shown in Figure 6.
If the input position is (x, y) and the starting point of vector information is (xs, ys), then the correspondence is a line that satisfies the following conditions Extract the minute as a symmetric line segment.

xs _{< x} <xs+d The target line segment can be deleted by expanding this extracted line segment into FM3 using exclusive OR (EXOR) through the raster conversion unit 2.

In addition, the displayed mark is determined by the above-mentioned condition judgment in the line identification section 6, and the same mark is placed in the same position through the mark display section 7 using the above exclusive OR.
By expanding to 3, only the mark can be erased without destroying the displayed vector information.

In the above-described embodiment, a mark is attached to all vector information in response to a deletion request, but the present invention is not limited to this. The line identification section 6 may be provided with a determination section that allows the user to set the line segment accordingly and displays a mark only on the corresponding line segment. Also,
By making it possible to switch the display position of the mark between the start point, middle point, and end point according to instructions from the operator, the display position switching section is designed to make it easier for the operator to recognize the line segment that corresponds to the mark. may be provided in the line identification section 6.

〔Effect of the invention〕

As described above, the figure editing device according to the present invention is configured to input in a predetermined mark area, so there is no need to redeploy all vector information, and mark display line segments and mark display positions By changing , the target line segment can be easily extracted. Furthermore, since the mark display section can be created by defining one symbol of the character generation section that is basically provided in the simple graphic processing device, there is no need to prepare it specially and it does not depend on the hardware. However, all of the above can be handled using software, and can be applied to simple graphic processing using a personal computer or the like.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing various storage formats of graphical information, Fig. 2 is a block diagram showing a conventional example, Fig. 3 is an explanatory diagram showing the operation of the main part of the one shown in Fig. 2, and Fig. 4 is the invention. FIG. 5 is an explanatory diagram showing an example of the display screen according to the one shown in FIG. 4, and FIG. 6 is an explanatory diagram showing mark display positions. 1: Storage unit, 2: Vector/raster conversion unit, 3:
Frame memory, 4: video generation section, 5: display section, 6: line identification section, 7: mark display section.

Claims (1)

[Claims] 1. A display unit that displays arbitrary figures including characters, symbols, etc. on a display screen, a frame memory unit that stores image information corresponding to display pixels, and a display unit that displays image information in the frame memory unit. A video generation section that performs readout control according to time, a storage section that stores graphic information input by the operator, and a vector generator that generates dot information from the input graphic information and expands it to the frame memory section. In a graphic processing device having a raster conversion unit and a means for inputting a position, a graphic line segment to be deleted is read from the storage unit in response to a line segment deletion request from an operator, and coordinate values of the graphic line segment are stored. Based on
A line identification section for prompting mark display and a mark display section for displaying the mark are provided in the vicinity of the line segment, and the mark specified by the position input means for pointing at the mark display position is detected. , a figure editing device characterized by extracting target line segments.