JPH04257977A - Drawing device - Google Patents

Abstract

PURPOSE:To offer a drawing device, which can indirectly designate a coordinate position to be hardly directly designated and can display a central point, even when it is difficult for the drawing device such as a CAD or the like to designate the central point of an already drawn graphic later. CONSTITUTION:A graphic type designating means 8 is provided to designate the type of the graphic to be drawn, a pointing device 4, I/F circuit 5 and coordinate detecting means 6 are provided to designate a position on a display screen 2a, a storing means 7 is provided to store the designated position, a reference point calculating means 9 is provided to calculate the central point of the designated graphic based on plural stored coordinate data, and a display control means 3 is provided to display the calculated central point on the display screen 2a.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a device for drawing while specifying a position on a display screen. The present invention relates to a drawing device that can indirectly specify the center of the object. [0002] Means for specifying the type of figure, means for specifying the size of the figure, means for specifying the reference point of the figure, and displaying the specified figure on the generated display screen. Plotting devices with means are known. [0003] In this drawing device, the type of figure, such as a circle, arc, polygon, or star, is specified, and data regarding the size of the figure is input using a keyboard or the like. Then, use a pointing device such as a light pen or mouse, or use the cursor movement keys on the keyboard to move the position specifying cursor on the display screen and specify the desired reference point (center of the figure). , a drawing operation is performed on that figure, and it is displayed on the screen. On the other hand, as a drawing method that does not directly specify the reference point of a figure, Japanese Patent Application Laid-Open No. 193276/1983 discloses the following technique. This drawing method uses a handwriting input device such as a touch pen to draw, for example, a circle by hand on a coordinate input device such as a digitizer provided integrally with the display screen, and then selects the type of shape using a menu. Specifies that it is a circle. [0005] The calculation/display device detects the maximum and minimum values on the X and Y coordinates from the handwritten coordinate data, and calculates the center point and diameter of the circle based on these coordinate values. , An accurate circle is drawn and displayed based on the calculated center point and diameter. [0006] However, with a device that directly inputs the reference point of a figure, it is difficult to draw a figure (for example, concentric circles) with the same reference point for a figure that has already been drawn (for example, a circle). In this case, since the reference point is not displayed on the previous figure, it is difficult to specify the point, resulting in a trial-and-error input process. [0007] In addition, in the case of the technique disclosed in Japanese Patent Application Laid-Open No. 193276/1983, it is difficult to accurately trace even if a previously specified circle is traced, and the calculated reference point is the same as the previous reference point. does not match completely. Furthermore, with conventional drawing devices, if, for example, a circle overlaps another shape and only part of the original shape is displayed due to hidden line processing, etc., it is not possible to trace the entire original shape. . Further, in such a case, even if a scale is displayed on the display screen, it is not possible to determine the reference point based on the scale. Furthermore, it is extremely difficult to draw a circle that is tangent to a plurality of line segments that have already been drawn. The present invention was made to solve these problems, and its purpose is to provide a device that can efficiently draw a diagram by indirectly specifying coordinate positions that are difficult to specify directly. . Means for Solving the Problems In order to solve the above problems, a drawing device according to the present invention includes means for specifying the type of figure to be drawn, means for specifying the position on the display screen, and a means for specifying the position on the display screen. a reference point calculation means for calculating a drawing reference point of a specified figure based on a plurality of stored coordinate data; and a display control means for displaying the calculated reference point on a display screen. It is characterized by having [0010] The designated figure may be displayed by providing means for generating drawing data of a specified figure based on a plurality of coordinate data. [Operation] By specifying a figure to be drawn (for example, a circle) with the figure type specifying means and specifying a plurality of points on the display screen (for example, at least three points on the circumference) with the position specifying means, the reference The point calculating means calculates a drawing reference point (for example, the center of a circle) of the specified figure based on coordinate data of a plurality of points stored in the storage means, and the display means displays the reference point on the screen. Therefore, a figure concentric with the previous figure (for example, a concentric circle) can be easily drawn based on this drawing reference point. Furthermore, even if only a portion of the previous figure is displayed, its reference point can be specified. Further, since the drawing data generating means generates data for displaying the specified figure based on the specified figure and the plurality of stored coordinate data, the figure can be displayed on the screen. Therefore, when drawing a figure that is inscribed in another line segment, it is only necessary to confirm the displayed figure, and efficient drawing can be achieved. [Embodiments] Hereinafter, embodiments of the present invention will be explained based on the accompanying drawings. FIG. 1 is a block diagram of a drawing device according to the present invention. The drawing device 1 includes a display device 2 such as a CRT, a display control means 3 for driving the display device, a pointing device 4 for specifying a position on the display screen 2a, and an interface (I/F) circuit 5 for the display device 2. and coordinate data 6a of the position specified by the pointing device 4.
At the same time, the coordinate data 6a on the display screen 2a is correlated with the position on the drawing to obtain the coordinate data 6b of the drawing, and the coordinate data 6b is The coordinate detection means 6 controls writing into the storage means 7, and the stored coordinate data 7a and figure type designation information 8a output from the figure type designation means 8.
a reference point calculation means 9 that calculates data 9a related to the reference point of a specified figure (hereinafter referred to as reference point data) based on the reference point, and data for drawing the specified figure (hereinafter referred to as drawing data). 10a. As a position specifying means for specifying a position on the display screen 2a, a light pen or a cursor movement key on a keyboard may be used, but here, the pointing device 4 includes a bowl that rotates as the main body moves, and an shaft·
The following description will be made assuming that a mouse is used that includes two rotary encoders that detect the amount of rotation in the Y-axis direction and at least one input button (input switch). For convenience of explanation, it is assumed that the coordinate data of the current position of the mouse cursor 2b displayed on the display screen 2a has already been given to a counter or register in the coordinate detection means 6. In addition, it has a drawing enlargement display function, etc., and is configured so that even when a part of the drawing is displayed on the screen 2a, the positional relationship between the coordinates of the drawing and the coordinates on the display screen 2a can correspond. shall be taken as a thing. The coordinate detection means 6 detects the movement designation input of the cursor 2b by monitoring pulse signals for each predetermined unit of movement amount output from each rotary encoder in the pointing device (hereinafter referred to as mouse) 4. , supplies the cursor display position data 6a to the display control means 3, controls the movement of the cursor 2b on the display screen 2a in accordance with the operation of the mouse 4, and also controls the cursor specified position in the coordinates of the drawing currently being drawn. It is configured to manage. The figure type specifying means 8 is for selecting and specifying the type of figure to be drawn and conditions related to its drawing in the form of a menu, and is provided with respective menu control means 8b and 8c. FIG. 2 is an explanatory diagram showing a display example of the main menu. The main menu control means 8b constantly monitors the cursor position data 6a, and when it detects that the mouse cursor 2c has been moved to area A in the upper left of the screen, it displays a figure prepared in advance below this area A. Show type. [0018] When the mouse cursor 2b is moved to, for example, an area displayed as a circle, that area is displayed in reverse video or the display color is changed to indicate that a circle can be specified, When the mouse button 4 is clicked in this state, data indicating that the figure to be drawn is a circle is stored in an internal register or the like. The submenu control means 8c displays a corresponding instruction message or a menu for setting conditions for drawing the figure based on the figure specified in the main menu. If a circle is specified in the main menu, 3 on the circumference
A message such as "Please specify a point" is displayed on the screen. If a square or rectangle is specified on the main menu, a submenu for setting drawing conditions will be displayed. FIG. 3 is an explanatory diagram showing a display example of a submenu for setting drawing conditions for a square. In the same figure, (a) shows the diagonal point designation, (b) shows the designation of three vertices, and (c) shows the designation of both end positions of one side and the side where the square is located. The submenu control means 8c displays the submenu control means 7 when a drawing condition is selected using the mouse in the same way as the main menu.
c displays a message corresponding to the selected drawing condition (for example, please specify two diagonal points) to prompt the input of points for drawing, and also displays the coordinate detection means 6.
A coordinate data recording command 8d is output to the coordinate data recording command 8d, and the drawing coordinates of points clicked with the mouse 4 thereafter are controlled to be written into the storage means 7. [0021] Then, when the figure type specifying means 8 confirms that the points necessary for drawing have been input by counting the number of clicks, etc., the figure type specifying means 8 sets the information 8a related to the figure type and its drawing conditions as a reference point. It is output to the calculation means 9 and the drawing data generation means 10. The reference point calculation means 9 receives information from a storage means such as a ROM that stores calculation algorithms for determining the center point of various figures displayed in the main menu and submenu and their drawing conditions, and from the figure type specification means 8. a calculation means that reads out a necessary calculation algorithm based on information 8a regarding the type of figure given and its drawing conditions, and reads coordinate data 7a of a previously specified point from storage means 7 to calculate the center point; , means for converting the calculated center point data on the drawing coordinates into corresponding display position data on the display screen, and display position data 9 of the center point.
a to the display control circuit 3. The drawing data generating means 10 includes a storage means such as a ROM that stores various figures displayed in the main menu and submenus and algorithms for drawing the figures for the drawing conditions, and data provided from the figure type specifying means 8. calculation means for reading out a necessary algorithm based on the information 8a relating to the type of figure to be drawn and its drawing conditions, and reading the coordinate data 7a of the previously specified point from the storage means 7 to calculate drawing data; and means for converting the plotting data into corresponding display position data on the display screen, and outputs the converted plotting data 10a to the display control circuit 3. The display control circuit 3 is configured to display, for example, a plus sign at the center point based on the display position data 9a, and to display a figure based on the drawing data 10a. With the above configuration, as shown in FIG. 4, three different points P1 on the circumference of the circle R1 that has already been drawn
, P2, and P3, it is possible to display the center point O1 of the circle as well as the circle. Therefore, concentric circles can be easily drawn based on the center point O1 indirectly specified from the three points. In addition, as shown in FIG. 5, when drawing a circle inscribed in two lines L1 and L2 that have already been drawn, the inscribed points P4 and P5 are based on the data of the specified lines L1 and L2. , by providing an algorithm for calculating the center O2, radius r2, etc. of the circle with reference point calculation means or drawing data generation means,
The inscribed circle R2 can be drawn by indirect designation. [0026] As explained above, the drawing device according to the present invention allows you to specify the type of figure and input a plurality of coordinates necessary to confirm the specified figure. Since the drawing reference point (center point) is calculated, it is possible to indirectly specify the drawing reference point (center point) of a previously drawn figure. In addition, by providing means for generating drawing data for a shape based on the type of the shape and multiple pieces of coordinate data required to determine the shape, the shape can be displayed on the display screen. .

[Brief explanation of the drawing]

[Fig. 1] Block configuration diagram of a drawing device according to the present invention

[Figure 2] Explanatory diagram showing a display example of the main menu

[Figure 3] Explanatory diagram showing a display example of a submenu for setting square drawing conditions

[Figure 4] Explanatory diagram showing indirect specification of the center of a circle

[Figure 5] Explanatory diagram showing the designation for drawing a circle inscribed in two straight lines

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1...Drawing device, 2...Display device, 3...Display control means, 4...
Pointing device (position designation means such as a mouse),
6...Coordinate detection means, 7...Storage means, 8...Picture type specification means,
9...Reference point calculation means, 10...Drawing data generation means.

Claims (2)

[Claims] 1. A figure type specifying means for specifying the type of figure to be drawn; a position specifying means for specifying a position on a display screen; and a storage means for storing coordinate data of the specified position.
a reference point calculation means for calculating a drawing reference point of a specified figure based on coordinate data of a plurality of positions stored in the storage means; and a display control means for displaying the calculated reference point on a display screen. A plotting device characterized by comprising: 2. Drawing data generation means for generating drawing data of a designated figure based on a plurality of position coordinate data stored in the storage means, wherein the figure type is designated via the display control means. 2. A drawing apparatus according to claim 1, wherein a figure specified by said means is displayed on said display screen.