JPH0411908B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a figure editing method in which figures are drawn one after another on a display device through man-machine interaction.

In conventional computer graphics technology, the main focus is on converting design data and technical calculation results expressed inside a computer into a form that is easy for humans to understand. Little consideration has been given to so-called figure editing functions, such as configuring various figures by editing or inserting new figures.

Recently, for example, ACM (Association for
As shown in "Computing Machinery", SIGGRAPH 80, Conference, Proceedings, pp. 314-320, studies have begun to consider rewriting figures on the screen. However, the method described in the above-mentioned document has the problem that even unnecessary portions on the screen are rewritten, making the rewriting operation difficult.

SUMMARY OF THE INVENTION An object of the present invention is to provide a graphic editing method that allows an operator to arbitrarily draw various diagrams on a display device.

In order to achieve the above object, in the present invention, a diagram is considered as a set of figures stacked in layers, and each figure constituting the diagram is inputted with coordinate values x and y on the diagram, and the truth or falsehood is determined by logic. It is defined as having a calculation system that outputs values 1 and 0. This basic idea makes it possible to define more complex composite figures by logical combinations of relatively simple basic figures, and also allows you to define a single point x on the screen of a display device.
By simply giving y, it has become extremely easy to discover the figure drawn there.
Therefore, it has become possible to efficiently perform so-called figure editing processing, in which figures are deleted, inserted, or transformed.

Hereinafter, the present invention will be explained in detail with reference to Examples.

FIG. 1 shows an example of the configuration of a graphic editing device that implements the graphic editing method according to the present invention. In the figure, a processing device 1 stores graphic information in a memory 3 as a graphic command in response to an operator's command from a keyboard 2, and also stores graphic information in an image memory in an image control circuit 4 based on the graphic information. Draw a shape. The image memory is continuously raster scanned in both the horizontal and vertical directions, and the obtained video signal is displayed on the display device 5. A joy stick 6 is used to control the position of a cursor (crosshair) displayed on the screen of the display device 5. Reference numeral 7 denotes a graphic output device for transferring the finished drawing, and if a normal film output device is used, a slide film can be produced. Also, depending on the application, a hard copy of the diagram can be obtained using an ordinary printer. On the other hand, 8 is an arbitrary file device, in which the completed diagram can be saved for later reuse. In the present invention, since the diagrams are expressed as a group of graphical commands as will be described later, they can be stored in an extremely small storage capacity, and therefore a mini-floppy device can be used as the file device 8.
Since a normal microcomputer can be used as the above-mentioned treatment device 1, the method of the present invention can be realized even in a small-sized figure editing device, such as a tabletop stand-alone type.

Now, in the above configuration, the operator presses the keyboard 2 while looking at the screen of the display device 5.
Graphic information is input to the processing device 1 by the joystick 6. The figure information is the type of figure to be drawn and parameters as attributes of the figure. For example, the types of shapes include circles, squares,
A predetermined menu of triangles, ellipses, letters, symbols, etc. is displayed using a part of the screen of the display device 5 in letters, for example, along with numbers, and selection is made by pressing the number key corresponding to the number. Can be input. For example, if a circle is selected,
Subsequently, characters such as ``Please enter the diameter'' are displayed on the screen of the display device 5, and numerical input from the numeric keys of the keyboard 2 can be accepted. Furthermore, when inquiring about the position (x ₀ , y ₀ ) at which the circle should be drawn, input can be made using the numeric keys or as a cursor position. In this way, all the geometric parameters x ₀ , y ₀ , and R of the circle in the following equation (1) are determined.

(x−x ₀ ) ² +(y−y ₀ ) ² ≦R ² (1) Note that R is the diameter of the circle.

In this method, characters are also considered to be a type of figure, and if ``character'' is selected as the type of figure, it will be followed by smaller categories such as plain, katakana, kanji, and alphanumeric characters. A menu is displayed, and when a kanji is selected here, the reading is further queried, and the reading is input from the keyboard 2, for example, in Roman letters. Thereby, candidate kanji corresponding to the reading are displayed, and a desired kanji can be selected from among them. For character selection, the method used in ordinary word processors can be used instead.

In this way, using an interactive method based on menu selection, the type of figure and its attributes are input as parameters from the keyboard 2 and joystick 6, and these are stored in the memory 3 as a set of information. Store as one graphic command.

In this way, when all parameter input is completed and it is determined as a graphic command, this graphic command is subsequently executed, the graphic is written to the image memory in the image control circuit 4, and the graphic is written to the display device 5.
displayed above.

When such processes are executed one after another, a diagram as shown in FIG. 2, for example, is created on the display device 5. This figure schematically shows a circle drawn in red at a certain position, a square drawn in blue at a slightly shifted position, and a triangle drawn in green. In other words, if you create shapes one after another,
On the display device 5, these figures are expressed as a diagram as if they were superimposed in multiple layers, and in the memory 3, figure commands are sequentially written in accordance with the order in which they are written. It's done. That is, in the memory 3, the diagram is expressed as an ordered graphic command string as shown in FIG.

In FIG. 3, a diagram is expressed as a graphic command string consisting of n figures, and each command has m parameters. Among these, parameter 1 is the type of figure described above, and parameter 2 and subsequent parameters correspond to the geometric parameters, colors, etc. described above. By predetermining a unique graphic code for each graphic, this graphic code may be stored in parameter 1. Especially if the figure is a kanji,
Kanji codes defined by Japanese Industrial Standards can be used as is. At this time, based on this kanji code, the dot pattern of the corresponding kanji stored in another location can be indexed. Each of the above commands is
They do not necessarily have to be of equal length, and additional information can be provided as a separate table. In this case, the storage location and length of this additional information may be retained as parameters of each command. The above-mentioned kanji dot pattern is a type of attached information that can be accessed directly from the parameter representing the type of figure. In addition to this, the attached information includes information indicating how to color a figure in a manner that gradually changes, information on a hatching pattern when hatching is applied, and the like.

FIG. 4 shows a specific embodiment of the image control circuit 4 shown in FIG. 1, which has an image memory 10 and a color designation memory 11 as its main components. In this example, the image memory 10 is a memory having 512×512 picture elements and a depth of 3 bits, and each picture element is associated with each position on the screen of the display device 5. Normally, in response to the raster scanning of the display device 5, the scanning address is supplied by the scanning address bus 17 via the multiplexer 12, and the information of each pixel is read out one after another, and the color is specified via the multiplexer 13. It is input as an address of memory 11. Color specification memory 1
1 normally stores information as shown in FIG. 5, and in this example, 6-bit information is successively output in response to 3-bit input from the image memory.
This 6-bit information consists of 2 bits as shown in Figure 5.
Each bit corresponds to red (R), green (G), and blue (B), and represents a total of four levels of mixing amounts from 0 to 3 of each of the three primary colors. Therefore, if each of these two bits is converted into analog by the DA converter 14 and sent to the color terminal of the display device 5, a color figure is displayed on the screen. In this example, 64 colors represented by a mixture of 3 colors of 2 bits each can be displayed, and if any combination of 8 of them is written in advance from the data bus 16 to the color specification memory 11, this can be displayed. 3-bit information written in image memory 10 000~
111 and outputs the corresponding color. Therefore, drawing a figure in the image memory 10 means writing specified color codes at all x and y positions on the image memory corresponding to the figure. This writing is performed by sending x and y coordinate data from the processing device 1 to the address bus 15, accessing the image memory 10 via the multiplexer 12, and simultaneously outputting the color code to the data bus 16, thereby eliminating the need for display breaks. It can be executed.

Further, in FIG. 4, 18 is a cursor control circuit which receives a signal 19 from the joystick and updates a counter therein, and also controls the video in order to display a crosshair at a position corresponding to the value represented by the counter. Signal 2 superimposed on the signal
Outputs 0. The contents of this counter are read into the processing device via the data bus 16, so that the processing device always knows the current cursor position.

In the configuration described above, to draw a diagram like the one shown in FIG. 2, first use command 1 to draw a circle with the color code set to 001 (red). In this case, the circle is painted efficiently by using, as one of the parameters of the circle, the range of the circle that is automatically calculated and stored when the command is created. In other words, if you consider a rectangle circumscribed to a circle and memorize it as part of the parameters for the maximum value (x _nax , y _nax ) and minimum value (x _nio , y _nio ) of the coordinates, you can use the circle shape command. When executing, the coordinates x and y are changed one after another within this domain, and if the condition shown in equation (1) is satisfied, the specified color code is assigned to the point (x, y) in the image memory. I'll write it down. After drawing a circle in this way, if you specify a square as command 2, the domain will be the square circumscribed to that square (which coincides with the original square if there is no rotation), |X|≦A, |Y|≦ B (2) is calculated, and if both are true, it is regarded as the interior point of the square and painted with the specified color code 011 (blue). Here, A and B are the values input when creating the figure command as parameters corresponding to half the length of the two sides of the square, and X and Y are the rotation angle θ of the figure from the coordinates x and y in the domain. It shows the coordinate values that have been rotationally transformed based on the parameters representing . Similarly, when a triangle is specified using command 3, the color code 010 (green) is written to its interior points in the same way. In this way,
As each figure is written one after another into the image memory 10, the overlapping parts of each figure are naturally recolored with the color code of the newly written figure.
Therefore, a diagram as shown in FIG. 2 will be displayed on the screen.

Now, the following problem arises. In other words, what kind of processing should be performed when a user wants to delete a rectangle in FIG. 2?
If you simply apply and erase only the color code, you will end up with something like a in Figure 6, and if you erase all the rectangular parts, you will end up with something like b in Figure 6. In the present invention, consideration has been given to allowing such deletion and insertion of figures to be carried out in a very natural manner, as shown in FIG. That is, in the present invention, when deleting a certain figure, a part of the figure hidden by the figure is restored, and
When inserting a shape, it does not affect any shapes drawn after it.

In order to easily carry out such processing, the present invention defines a figure as shown in FIG. 8. In other words, a figure is a calculation system that takes parameters and coordinate values x, y as input, and outputs true (logical value "1") if certain calculation conditions are met, and false (logical value "0") if not. It is something that has. The simplest example is a circle with a calculation system shown in equation (1), and a square with a calculation system shown in equation (2). In a processing device such as a computer, this calculated body diameter can be configured as a subroutine that takes the storage position of the parameter and the coordinates x and y as arguments and outputs a logical value of "1" or "0". Furthermore, in a slightly specialized processing device, it can be implemented as a microprogram activated by a graphic code representing the type of graphic in the parameter.

Under the above definition of figure, any geometric figure that can be expressed mathematically can be a figure, and letters can also be figures. In other words, for example, if one kanji is stored as a dot pattern consisting of 16 x 18 dots, then this kanji has two sides of 16 and 18 (i.e. A=8,
B=9), and can be thought of as a rectangle with lots of gaps. Similar to a rectangle, a domain is defined, and parameters such as magnification and rotation angle are also given as attributes. That is, the coordinates x, y in the domain
First, it is determined whether it is an interior point of this rectangle, and if it is an interior point, the coordinates are further mapped onto the original kanji pattern, and finally it is determined whether it is an interior point depending on the presence or absence of dots in the original kanji pattern. Only the processing of determining whether or not this is the case is added.

In addition, a straight line with an arbitrary width can also be expressed as a figure with an area in which a rectangle is degenerated in one direction, within the scope of the definition shown in Figure 8. Closed figures connected by straight lines can also be realized based on the same definition, greatly diversifying the figures that can be handled by the figure editing method of the present invention.

As mentioned above, each figure has its own unique calculation system, but by combining these into one calculation system, parameter 1 (type of figure)
By branching within it, a calculation system specific to that figure can be activated. That is, one comprehensive calculation system is used in which different subroutines are activated depending on parameter 1 among input parameters. In this way,
The concept shown in FIG. 8 can be commonly applied to all figures used in the method of the present invention.

At this time, if you want to write a certain figure, you can fix the parameters of that figure and change the coordinates x, y, but conversely, if you fix the coordinates x, y,
If the parameters are changed one after another, it can be determined to which figure the coordinate points x and y belong, depending on which figure the logical output 1 is output for. That is, for example, suppose that the command string shown in FIG. 3 is scanned upward one after another from the bottom based on the cursor positions x and y on the screen. That is, with x and y fixed, the parameters of command n are first given as parameters, and if the logical output is 0, then the parameters of command n-1 are given. Such parameter changes can usually be performed by simply calling the above-mentioned comprehensive calculation system using the parameter's starting address as an argument. In this way, the command i that first outputs a logic output of 1 becomes the figure designated by the cursor. In this way, by simply positioning the cursor on the joystick, which is an "arbitrary point" on a figure, and scanning the figure command string in the reverse direction, the figure command corresponding to that figure can be found.
To erase a graphical command i found in this way, simply erase it in memory, e.g. i
The command string after i may be incremented such that +1 is i, i+2 is i+1, . . . n is n-1.
In this way, deletion on a graphic command can be executed extremely easily, but on a displayed graphic, it can be done as follows. That is, in order to erase figure i, the domain of figure i written in command i is first drawn out, and one coordinate x, y is determined therein. This x,
If the logic output of the figure i under y is 1, then the parameter is changed to command i+ one after another starting from the last command n of the command sequence in FIG.
Change it to 1 and check the output at that time. If logical output 1 is output midway, it means that another figure is written at that point after that figure, so proceed to the next coordinate without performing any operations on that coordinate point. At this time, if all logical outputs are 0 between the command string n to i+1, then the points x and y are to be erased because the later drawn figure is not superimposed on this point. At this time, further scan backwards from command i-1 to command 1, find the command that outputs logic output 1 for the first time, and use the color code written in the parameter of that command to Replace the x and y color codes. That is, the color of the points x and y of the figure to be erased is replaced with the color of the figure that was already written before it was written. If a backward scan is performed up to command 1 and there is no logic output of 1, it means that there was originally no figure there, so it can be replaced with a predetermined background color code (for example, black). While scanning the command string in the reverse direction, the coordinates x,
By the process of scanning y, other figures hidden behind that figure are restored in a natural form, and the natural deletion process as shown in FIG. 7 can be executed.

On the other hand, in the insertion process, the commands after command i are simply moved down on the command string, and a new graphic command is inserted into command i. To execute this on the displayed graphic, do as follows. First, determine the coordinates x and y within the domain of the figure to be inserted, and if that point is an interior point of the figure, further scan the figure command sequence in the reverse direction from figure command n to i, and if even one If there is a logic output of 1, that point is a point that should be hidden in the subsequent figure, so no operation is performed and the process proceeds to the next coordinate point. If there is no logical output between commands n to i, the color code of the newly inserted figure is written at that point. If such processing is executed over the entire domain of the figure to be inserted, natural insertion processing as shown in FIG. 7 can be realized.

Furthermore, if you want to enlarge, move, or rotate a previously drawn figure, you can find the corresponding figure command i by placing the cursor on any point on the figure as described above. Modify the corresponding parameter in this command.
Processing on such a command sequence can be easily realized using appropriate man-machine interaction techniques. On the other hand, changes to the displayed figure can be made by using the above-mentioned deletion process and insertion process together. That is, the figure with the old parameters is deleted and the figure with the new parameters is inserted.

As mentioned above, if a figure is expressed as a figure command string and a figure is expressed as a calculation system using coordinates x, y and parameters as input, a new figure can be created by fixing the parameters and changing the coordinates x, y. can be written, and by the process of changing the coordinates x and y while changing the parameters by scanning the figure command sequence in the reverse direction, it is possible to delete, insert, and erase the already written figures.
Changes can be easily made, which enables a variety of graphic editing.

Another great advantage of the method of the present invention is that since a figure is defined as a set of coordinate points x and y that produce a logical output of 1, logical operations between figures can be easily performed. The point is that a variety of complex figures can be defined by logical connections of figures. For example, the logical sum of figure A and figure B becomes the union AUB of both figures, but this can be done if a logical output of 1 is output from either the calculation system of figure A or the calculation system of figure B. In other words, the logical operations between the outputs from the calculation system directly mean the logical connections of the figures. In this case, it is sufficient to write a color code at a point where the logical sum of both calculation systems is 1 while changing x and y one after another.

On the other hand, a negation figure of a certain figure A simply inverts the truth of the output in Figure 8, so for example, a ring can be defined by the logical product A of the large circle A and the negation of the small circle. To write, output A, B of calculation system A and calculation system B while changing x and y.
All you have to do is write the color code at the points x and y where A.=1. Such a logical connection can be expressed as a single figure command in the figure command string shown in Figure 3, and the style of the logical connection is stored as one of the parameters, and information about the connected figures is attached. Just keep it as information. In this way, a compound figure created by a logical connection between figures can also be expressed as a single figure, and whether a given point It can be determined by performing logical operations.
Further, in this case, the domain of the composite figure can also be automatically calculated and determined from the domains of the unit figures that constitute it, taking into consideration the mode of logical connection. Therefore, in the method of the present invention described above, it can be handled without any contradiction with other figures.

As described in detail above, in the graphic editing method according to the present invention, the editing process can be easily executed by expressing a diagram as a graphic command string and scanning the graphic command string in the reverse direction. As a result of actually configuring a figure editing device using this method, it was demonstrated that a variety of figures can be created by simple scanning.
In particular, since the graphics command string is stored as-is in the completed graphics file, not only is it easy to re-edit it later, but the storage capacity is usually 1 smaller compared to the case where graphics are saved in units of pixels. It has become clear that it can be done with about /20.

In the method of the present invention, a figure is defined as having an area from the beginning, and ordinary computer graphics is constructed based on lines connecting points, and a set of such lines or a Unlike the case where a surface is defined as a region, it is extremely distinctive in that the editing process can be executed in an orderly manner. In particular, the calculation system that corresponds to each of the figures mentioned above can be realized as a figure generator by using dedicated hardware, which is a big difference when compared to the straight line generator and curve generator in normal graphics. There is.

In addition, the method of the present invention not only allows for easy implementation of a device that edits figures to create original images for slides, but also enables applications such as application as a document processor by combining with word processing technology, and original images for still image broadcasting. It can be used for various purposes such as image creation, and has extremely high industrial value.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a specific example of the configuration of a device that implements the graphic editing method of the present invention, and FIG. 2 is a schematic diagram showing the display result of a diagram drawn by the method of the present invention. FIG. 3 is a diagram for explaining that the diagram created by the method of the present invention is expressed as a graphic command string, and FIG. 4 is a block line diagram showing a specific example of the image control circuit of FIG. 1. Figure 5 is an explanatory diagram showing an example of the contents of the color specification memory shown in Figure 4, and Figure 6 is an example of defect results obtained using the conventional method when deleting a certain figure from the diagram shown in Figure 2. FIG. 7 is an explanatory diagram showing the state of the figure when a figure is deleted or inserted by the method of the present invention, and FIG. 8 is an explanatory diagram showing the concept of figures which is the basis of the present invention. This is a diagram for 1... Processing device, 2... Keyboard, 3... Memory, 4... Image control circuit, 5... Display device.

Claims (1)

[Claims] 1. A first storage means for storing, in a predetermined order, parameters indicating the type of the figure and attributes of the figure, including at least geometric parameters, as figure commands for figures constituting a figure to be displayed, and the stored figure commands. and a second storage means for storing the pattern, and when changing a figure, the processing means reads the figure and expands it into a pattern of a diagram to be displayed, and when changing a figure, the processing means reads the At least a part of the parameters of the graphic command stored in the first storage means are read out in an order opposite to the above-described predetermined order, and it is determined whether each point belonging to the figure to be changed is an inner point of the displayed figure. A graphic editing method characterized in that the pattern stored in the second storage means is changed based on the determination.