JPH04188280A - Picture display method for cad drawing data - Google Patents

Abstract

PURPOSE:To shorten time for processing picture display by excluding character data from the picture display when it is judged in advance that the character data can not be identified. CONSTITUTION:When a source drawing includes graphic data such as graphics 21-1-21-3 or the like and character data such as characters 22-1-22-3 or the like and is reduced to be 1/2, the clear picture display is obtained since the characters not to be identified as the result of reduction are not displayed on a screen and the characters not to be identified like dust are not displayed on the screen although all the graphics 21-1-21-3 or the like and the character 22-1 to be identified are displayed on the screen. Thus, time for processing picture display is considerably shortened.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention aims to shorten the processing time required for screen display by omitting the screen display of unidentifiable character data.
D This relates to a method of displaying drawing data on a screen.

(Prior Art) Conventionally, when displaying a CAD drawing created by a CAD system on a screen, the method (vector scan method) shown in FIG. 4, for example, is a boat fishing method.

First, the operator commands enlargement or reduction (this command includes data regarding the range to which the command is applied in the CAD drawing, the enlargement/reduction magnification, etc.)
When input from the input device 30, the central processing unit (hereinafter referred to as CPU) 31 determines the screen display range according to the input and stores it in the storage device 32.The zero-order CPU 31 corresponds to this screen display range. The selected data was selected from the CAD drawing data (including figure data and character data) stored in the storage device 33 and subjected to output processing (processing of enlarging/reducing according to the enlargement/reduction ratio). Later, it is stored in the image memory (predetermined storage area in the storage device for screen display) 34. An arbitrary range of the original drawing obtained by such a series of operations and processes is displayed on the display device 35.

(Problem to be solved by the invention) However, in the conventional screen display method described above,
Since minute character data that becomes unidentifiable as a result of reduction is displayed on the screen along with character data of a recognizable size, character data composed of multiple vectors requires processing to display on the west side regardless of size. Since the time is almost the same in proportion to the number of vectors that make up a character, the time it takes to draw such meaningless and unintelligible characters causes a problem in which the processing time required to display the screen becomes longer than necessary. Furthermore, the screen display may become unsightly due to unintelligible characters such as drawn garbage.

The present invention, before actually displaying the west side, checks in advance whether or not each piece of character data can be identified when displayed on the screen, and excludes character data determined to be unidentifiable from the screen display. The purpose is to solve the above-mentioned problems.

(Means for Solving the Problems) For this purpose, the method for displaying CAD drawing data on a screen of the present invention provides a method for displaying CAD drawing data on a display device by commanding to enlarge or reduce an arbitrary range of CAD drawing data stored in a storage device. When displaying on the screen at a predetermined position of
The screen display range to be actually displayed on the screen is determined in the AD drawing data, the figure data and character data within this screen display range are extracted from the CAD drawing data, and the character data is displayed on the actual display screen based on the instructions. The character size is calculated, the character size is compared with a judgment standard value indicating the discrimination limit of the west side display, and when the character size is less than the judgment standard value, the character data is excluded from the screen display. That is.

(Function) According to the method of the present invention, in order to display a part (arbitrary range) of CAD drawing data stored in a storage device on a screen on a display device, when an operator issues an instruction to enlarge or reduce the Based on the above-mentioned CAD drawing data, figure data and character data within the screen display range that is actually displayed on the screen are extracted, and the dimensional data included in this character data is multiplied by the enlargement/reduction ratio determined by the above-mentioned command. By comparing the character size on the actual display screen with the criterion value that indicates the discrimination limit of the screen display,
If the character size falls below the determination reference value, that is, if the character data is determined in advance to be unidentifiable, the character data is excluded from the screen display. By reducing unnecessary parts of the processing time for character data, which accounts for a large proportion of the processing time, it is possible to significantly shorten the processing time required for screen display, and the screen display becomes clearer by not drawing unrecognizable characters such as garbage. This effect can also be obtained.

(Example) Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is a diagram showing the configuration of a CAD system used to implement the screen display method of CAD drawing data of the present invention, in which 10 is an input device, 11 to 13 are storage devices, and 14 is a central processing unit (hereinafter referred to as CPU). ), 15 is an image memory, 16
indicates a display device.

Note that the CAD system used in this example is a personal computer level CAD system.

The input device 10 inputs signals to the CPU 14 in response to various input operations by an operator (command input for drawing, command input for enlargement or reduction for screen display, which is the subject of the present invention, etc.). Generally, a keyboard, mouse, tablet, etc. are used.

The storage device 11 stores the screen display range (the range actually used for screen display in the CAD drawing data) determined by the CPU 14 based on the enlargement or reduction command input, and stores the stored screen display range. The data of CP
It is read by a command from U14.

The storage device 12 is a C storage device containing graphic data, character data, etc.
It stores AD drawing data, and the figure data includes data representing figure components such as straight lines, curves, circles, etc. and the origin of the figure, as well as the drawing size and scale at which the figure is drawn. The character data includes data representing character dimensions, character positions, and the like.

The storage device 13 stores, for each display device, a criterion value for screen display, which is a threshold value that indicates whether or not the character data can be identified on the display screen when the character data is displayed. . The reason for selectively using a plurality of determination reference values in this manner is that the resolution of each differs depending on the type of display device, the size of its display west side, etc., and the discrimination limit of each character also differs.

The CPU 14 performs normal CAD drawing by inputting commands for drawing from the input device 10.
Based on the command input for screen display from , the control program shown in FIG. When displaying a screen on the device 16, the screen display is performed in such a way that the processing time required for screen display is shortened, as is the aim of the present invention.

That is, in the screen display control program shown in FIG.
First, in step 101, the operator reads an enlargement/reduction command (including data regarding range specification of CAD drawing data to which the command is applied, enlargement/reduction magnification, etc.). As a method for inputting enlargement/reduction commands by the operator, for example, when reducing the entire target CAD drawing data, there is a method of inputting the reduction command and reduction magnification manually from the keyboard; range), enter the reduction command and the coordinates of two points on the diagonal of the rectangle that specify the area to be reduced in the CAD drawing data using the keyboard (or mouse, tablet), and then enter the reduction magnification using the keyboard. There are various methods for inputting information (there are also various methods for enlarging).

In the next step 102, based on this command input, a screen display range indicating the range actually displayed on the screen in the CAD drawing data is determined, and in step 103, the CAD drawing data (graphic data, character data) is read. , this reading is repeatedly executed until the determination in step 104 becomes Yes, that is, until all data has been read.In the next step 105, the read CAD drawing data enters the screen display range determined in step 102. If the CAD drawing data is within the screen display range, it is determined in step 106 whether it is character data or not (if it is outside the screen display range, control is transferred from No in step 105 to step 103). Proceed to read the next CAD drawing data).

In the case of character data for which the determination in step 106 is Yes, the character size on the display screen is calculated in step 107.
If the character size in drawing D is l and the enlargement/reduction magnification is K, it can be determined by L=ffi -K).

In the next step 108, the character size on this display screen is compared with the judgment reference value Lo, and if L > Lo, screen display processing is performed in step 109, and if L≦L0, in other words, If the character data is unidentifiable small character data, step 109 is skipped and it is excluded from the screen display. Note that the predetermined reference value L0 is a constant that is determined depending on the type of display device 16, the size of the display screen, etc.
It is assumed that the determination reference value L0 has been read from the storage device 13.

In the case of graphic data for which the determination in step 106 is No, steps 107 and 108 are skipped and the control immediately advances to step 109, so all graphic data within the screen display range undergoes the screen display process in step 109. It will be administered. Here, this screen display processing refers to the target data (that is, figure data and character data within the screen display range specified in step 102 in the CAD drawing data, and in the case of character data, the conditions in step 108 are The CPU 14 enlarges or reduces the character data (character data of a discernible size to be cleared) according to the enlargement/m small magnification ratio determined by the command input in step 101, and temporarily stores it in the image memory 15, and then displays it on the display device 16.
It is displayed facing west.

Next, the above screen display will be explained in detail using a specific example.

For example, the west side size of the effective display screen of the display device 16 is width 2
80 cm x height 200 cm, A3 size (420 cm x
When displaying the original drawing of 300 cabinets on the entire screen, the 3■ characters drawn on the original drawing (in this case, the width and height of the characters are not always 3-, but 3■ x 3■ (meaning that the character occupies the area of ) is indistinguishable, then the criterion value is Jυ0. Under these conditions, the Al size (840×60
When displaying the original drawing of 0m) on the entire screen, the characters 4■ drawn on the original drawing will be 4 × small characters on the screen, so they will not be displayed on the screen by executing No in steps 107-108. become. Moreover, since the character 10-kaku drawn in the original drawing becomes a large character 10 on the west side, it will be displayed on the screen by executing Yes-109 in steps 107-108. Note that some of the original drawings of the above Al size (for example, if the lower left corner of the original drawing is set as the origin (0,0), the points (500°300), (500,400),
(640,300), (range surrounded by (640,400)) is enlarged and displayed on the entire west side of the display, 4■ drawn in that range is displayed on the screen under the same judgment conditions. (In the case where li is small, the display propriety determination is made in the same way.) Note that the character data that is no longer displayed as described above is simply deleted from the display screen, and the character data in the CAD drawing data stored in the storage device 12 is not deleted.

Next, an example in which the screen display of this example is applied to an actual CAD drawing will be explained with reference to FIGS. 3(a) to 3(c).

For example, the original diagram as shown in FIG. 3(a) is displayed on the display screen 20 (
For example, 280 cabinets x 200 cabinets), and this original diagram is figure 21-1 (rectangle), figure 21-2.2
Figure data such as l-3 (switch) and character 22-1 (
F/MAINLINB), character 22-2 (MODE
), character 22-3 (SPBOOI), etc., if it is reduced to 1/2, the result will be as shown in Figure 3(b).
As shown, all figures such as figures 21-1, 21-2, 21-3, etc. and distinguishable characters 22-1 (F/MAI
N LINf is displayed on the screen, but characters that become unidentifiable as a result of reduction (characters 22-2, 22-3, etc.) are not displayed on the screen, which greatly reduces the processing time required for screen display. A clear screen display can be obtained because unrecognizable characters such as dust are not displayed on the screen display. Also the third
If you extract the part of figure 21-3 (switch) from the original figure of figure (a) and enlarge it twice, as shown in figure 3 (c), when the whole figure of figure (a) is displayed, is step 108
Character 22-4 that was not displayed because it did not meet the criteria for
(BUTTON C0LORBLACK) will be restored and displayed.

When drawing with a CAD system, the drawing size of the drawing to be created is often larger than the display screen size, and it is common for the drawing to be enlarged/reduced many times until it is completed. In that case, the processing time required for screen display is shortened by the screen display method of this example, and the overall drawing time is also significantly shortened.

(Effects of the Invention) Thus, as described above, the method for displaying CAD drawing data on a screen according to the present invention checks in advance whether or not each piece of character data can be identified when displayed on the screen, before actually displaying it on the screen. Since character data determined to be unidentifiable is excluded from the screen display, the processing time required for screen display can be significantly reduced by reducing unnecessary parts of the processing time for character data, which accounts for a large proportion of the processing time required for screen display. This makes it possible to shorten the size of the screen, and it also has the effect of making the screen display clearer by not drawing unrecognizable characters such as garbage.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating the configuration of a CAD system used to implement the method for displaying CAD drawing data on a screen according to the present invention, FIG. 2 is a flowchart showing a control program for screen display in the same example, and FIGS. (c) is a diagram illustrating a screen display in the same example, and FIG. 4 is a diagram illustrating the configuration of a CAD system used to implement a conventional method for displaying CAD drawing data on a screen. 10... Input device 11-13... Storage device 14... Central processing unit (CPU) 15...
Image memory 16...Display device (Display) Figure 1 Figure 2 Figure 3 (C)

Claims (1)

[Claims] 1. When displaying an arbitrary range of CAD drawing data stored in a storage device on a screen at a predetermined position on a display device by an enlargement or reduction command, the CAD drawing data is Determine the screen display range to be actually displayed on the screen, extract graphic data and character data within this screen display range from the CAD drawing data, and calculate the character dimensions of the character data on the actual display screen based on the command. and comparing the character size with a criterion value indicating a discrimination limit of the screen display, and excluding the character data from the screen display when the character size is less than the criterion value. How data is displayed on screen.