JPS6318233B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to computer graphics devices. In more detail, this device is equipped with
This invention relates to the improvement of a device that can perform various designs such as pattern design for printed circuit boards while displaying a cursor on a CRT (Cathode Ray Tube).

Conventionally, with the help of a computer, an arbitrary point on a CRT is used as a base point, and this base point and a cursor are connected with a straight line that looks like a rubber band. There are devices designed to do this. In some types of graphic design (for example, pattern design for printed circuit boards), the slope of the line segments that make up the pattern is vertical, centered on the base point,
There are cases where drawing is limited to eight directions, diagonal and horizontal. In such cases, even if the operator does not have to accurately set the angle θ of the rubber band to vertical (90°), diagonal (45°), or horizontal (0°), the cursor position can be set to approximately the same angle. Conventionally, a function has been used in which a pattern of vertical lines, diagonal lines, or horizontal lines that is close to that angle is automatically selected and input into the computer. This function is called a cursor lock function, and the present invention is a computer graphics device having a cursor lock function.

First, the conventional cursor lock function will be explained using FIGS. 1 to 3. FIG. 1 is a diagram showing the configuration of a general display terminal. In Figure 1, 10 is a CRT, 20 is a tablet, 4
0 is a touch pen, and 40 is a keyboard. The operator uses the touch pen 30 to touch the tablet 2.
When the user points to a certain point on the tablet 20, a cursor is displayed at a position on the CRT 10 that is similar to the point on the tablet 20, and this cursor shifts on the CRT 10 as the stylus pen 30 moves. That is, the operator can set the cursor at any point on the CRT 10.

Here, if the device shown in Figure 1 displays a rubber band display (when the rubber band function is selected and operated by the operator), then the CRT
10, a display as shown in FIG. 2 is obtained. In other words, with point P ₁ as the base point, move the cursor from point C ₁ to
When the cursor is shifted to _C4 and an arbitrary position, a straight line l connecting the base point _P1 and the cursor points _C1 to _C4 is displayed as the cursor moves. This straight line l is called a rubber band because it expands and contracts between the base point _P1 and the cursor point as the cursor moves. In Figure 2, four cursor points are drawn, but these are drawn to explain the rubber band display; in reality, one cursor mark is positioned one after another on the CRT. As the rubber band l moves, it is displayed as if it were expanding or contracting between the base point _P1 and the cursor mark.

FIG. 3 is a diagram for explaining the conventional cursor lock function. Conventionally, even if the operator selected the cursor lock function, the CRT1
The line diagram displayed on 0 is the second one as in the normal case.
The diagram is as shown by the dotted line in Figure 3 and Figure 3. That is, it is displayed as a rubber band connecting the base point _P1 and the cursor position. In this state, for example, the read (Read) line provided in the device is used to input the line P ₁ - C ₂ shown in Figure 2 (also the dotted line in Figure 3 A) to the computer.
When you press the button (hereinafter simply referred to as the RD button),
At this time, the cursor lock function is activated, and the dotted line P ₁ -C ₂ is input to the computer as the solid line P ₁ -C ₂ ' in FIG. 3A, and displayed on the CRT 10. That is, the conventional cursor lock function operates in such a way that the cursor lock function is activated only when the data is read into the computer.

Thereafter, the cursor lock function is operated at each angle as shown in FIG. After that, one end of this newly input solid line (for example, point C ₂ ′ in Figure 3 A) is used as the new base point, and the next line is set from this point C ₂ ′, and the shapes are successively set. I'm doing the design.

The conventional cursor lock function as described above has the following drawbacks.

(i) When operating the cursor, only a temporary display is displayed using a rubber band, and the line corresponding to the true drawing (solid line in Figure 3) is displayed only after pressing the RD button, so the density is high. When drawing, it is necessary to concentrate very carefully on cursor operation.

(ii) Also, when you press the RD button, the coordinate values are entered into the database, so if you make a mistake, you will have to start over from erasing it.

The present invention has been made in view of the above points, and in the state of cursor lock mode, the line corresponding to the true drawing is always drawn on the CRT10.
The screen is displayed upwards to improve operability.

4 and 5 are diagrams for explaining the cursor lock function of the computer graphics device according to the present invention. Further, FIG. 6 is a diagram showing an example of an operation flow for realizing the cursor lock function of the present invention.

First, the operation of the cursor lock function of the computer graphics device according to the present invention will be briefly described. When the operator selects the cursor lock mode, the line segment that the operator is about to set with the cursor will be displayed on the CRT as a straight line in eight directions with the base point as the center, as shown in Figure 4. The slope of this straight line does not change.
That is, in the cursor lock mode of the device according to the present invention, a display as shown by the solid line in FIG. 5 is made so that the operator can operate the graphics device while viewing the data itself being input to the computer. It is something.

The present invention will be explained in detail below using the drawings.

4 and 5 are diagrams for explaining the cursor lock function of the device according to the present invention. Fourth
In the figure and FIG. 5, _P2 is the base point, and a line segment is to be set from this point using the cursor. The base point _P2 is determined by pointing at a certain point on the tablet 20 with the stylus pen 30 and pressing a predetermined key on the keyboard 40 in this state to input into the computer that the point on the tablet 20 is the base point _P2 . be able to. In the present invention, as in the prior art, various figures are expressed only by line segments having angles in eight directions (shown in FIG. 4) with the base point _P2 as the center. However, in the present invention, as shown in _FIG .
A square plane having two angular areas and having a size such that the cursor is positioned on one side thereof is set, and the line segment of the angular area including the cursor position is always displayed on the CRT 10. For example, in the case of angle θ ₁ as shown in FIG. 5A, it is displayed on the CRT as a line segment of FIG. The angle of the line segment displayed on the CRT 10 does not change as the cursor shifts within the range of each angle region shown in FIG. Of course, if the cursor moves freely within one of the eight angular regions shown in Figure 4, the angle of the line segment from base point _P2 remains unchanged, but the length of the line segment is It changes depending on the positional relationship with the cursor as shown by the arrow in Figure 4.

Next, if the cursor makes an angle θ ₂ as shown in Figure 5 B and enters an adjacent area beyond the angle area in case A, the line segment in Figure 4 will be replaced.
It will be displayed on CRT10.

The cursor is further shifted to the angle θ ₃ shown in Figure 5.
When this happens, the line segment shown in Figure 4 will be displayed.

To explain the above operation using Figure 6, when the cursor lock mode is off, the cursor coordinates
Xc, Yc and base point coordinates Xp, Yp are output, and a rubber band display as shown in FIG. 2 is performed.

Next, if cursor lock mode is on,
From the cursor coordinates Xc, Yc and base point coordinates Xp, Yp,
Calculate the angle θ shown in Figure 5 using a computer,
It is determined to which of the eight angle regions shown in FIG. 4 the angle θ belongs. As a result, one of the eight line segments shown in Figure 4 is selected and the CRT10
displayed above.

Although the rubber band is drawn as a dotted line in FIGS. 2 to 5, the display of the rubber band on the CRT is not limited to the dotted line.

Furthermore, a rubber band may be displayed between the tip of the line and the cursor as shown in FIG. 5B.

As described above, according to the present invention, in the cursor lock mode, any of the line segments in eight directions is displayed, and the operator can perform the graphic design process while checking the line segment to be input into the computer. Since the line can be moved forward, the desired line segment can be reliably input into the computer without using unnecessary nerves as in the conventional method.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the configuration of a general display terminal, Figure 2 is a diagram to explain the rubber band display, Figure 3 is a diagram to explain the conventional cursor lock function, Figures 4 and 2 are diagrams to explain the conventional cursor lock function. FIG. 5 is a diagram for explaining the cursor lock function of the device according to the present invention, and FIG. 6 is a diagram showing the operation flow of the device according to the present invention. 10...CRT, 20...tablet, 30...touch pen, 40...keyboard.

Claims (1)

[Claims] 1. A cursor for drawing using a line segment whose one end is the base coordinate, whose length changes as the cursor moves, and whose slope is limited to eight directions: vertical, diagonal, and horizontal. In a computer graphics device with a lock function, means 20, 30 for inputting an arbitrary point on a CRT as cursor coordinates to a computer described later, means 20, 30, 40 for inputting base point coordinates to a computer described later, and a base point. A means for calculating the angle θ of a straight line connecting the coordinates and the cursor coordinates, and a means for calculating the angle θ of a straight line connecting the coordinates and the cursor coordinates, and an 8-axis method for calculating the angle θ of a straight line that connects the coordinates of the cursor and the angle θ in the eight directions (vertical, diagonal, and horizontal) centered on the base point coordinates.
means for setting a square plane having two angular regions and having a size such that the cursor coordinates are located on a side; selecting one of the angular regions to which the calculated angle θ belongs; means for constantly displaying on a CRT a line segment having an inclination in any of eight diagonal or horizontal directions and having a length extending to the base point coordinates and a side of the square plane; and a computer comprising: computer graphics equipment.