JPS63100493A - Graphic display system - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a graphic display method that displays a portion within a set window of one screen containing various graphics.

[Conventional technology]

For example, computer technology is used to create drawings that include various figures, such as a single blueprint. In such drawing creation techniques, unit elements constituting one figure such as a straight line or circular arc, that is, a single figure, or a meaningful figure such as a gear, which is a combination of multiple single figures, that is, a group of figures. Data representing (graphical data) is input and stored in memory, and graphical data is read out from memory and displayed graphically on a display device. A desired drawing is created by modifying the graphic data.

By the way, during the process of creating such a drawing, or after creating the drawing, there are cases where it is desired to display only a part of the drawing. The memory can store the entire drawing, and when you want to display only a part of the drawing in a desired area on the display surface of the display device, you can store this desired area (i.e., window), and also sets the desired display area (i.e., viewport) on the display surface of the display device, reads the graphic data from memory, and displays the graphic so that the part inside the window is displayed throughout the viewport. Converts the data and supplies it to the display device.

One conventional example of such a graphical display system is Japanese Patent Application Laid-Open No. 58-2218.
It is disclosed in Publication No. 87.

In order to display the part of the window in the drawing stored in memory in the viewport, it is necessary to extract (clipping) the part contained in the window of a single figure or a group of figures stored in memory. It is.

In the above conventional example, considering a virtual screen, the graphic data of a single figure is composed of X-Y coordinate values representing the starting point and ending point on the virtual screen if it is a straight line, for example,
If it is a circular arc, a value representing the radius is added to convert it into a shape command such as ``become'', and the shape data of a group of shapes is converted into a set of shape commands for the single shape that forms it and stored in memory. I remember. Note that hereinafter, a set of graphic commands for a single graphic and graphic commands for a group of graphics will be collectively referred to as a graphic command string.

When a window is set, for each single figure or group of figures stored in memory, first, the window and the figure command string are compared using coordinate values, and at least one of the single figure or group of figures is It is determined whether the part exists within the window, and then the part included in the window is extracted for a shape command string for a single figure or a group of figures whose at least part of it exists within the window, and the part contained in the window is extracted and displayed on the display device. The data is converted into graphic data (hereinafter referred to as image data) to be graphically displayed in a viewport set for the display surface.

According to this conventional example, the determination of a single figure or a group of figures to be displayed is performed easily and quickly, and moreover, only the single figure or group of figures to be displayed is determined to be displayed. Since this process is performed, the amount of processing after setting the window can be reduced.
Quick graphic display becomes possible.

[Problem that the invention seeks to solve]

By the way, in the above-mentioned graphical display method, it is possible to enlarge and display a part of the currently displayed screen (this is called zoom-up display), or to display a wider area than what is represented on this screen. (This is called a zoom-down display), or you may want to display a desired single figure or group of figures on the display screen by blinking or in color (this is called a pick display). There is also. Also, if you set a window to display a part of the virtual screen stored in memory, change part of the graphical command string that makes up this screen, and then set the same window and display it again. There are cases where it is desired to display the same part of the virtual screen (this is called redisplay).

However, even when performing such zoom-up display, zoom-down display, pick display, or redisplay, in the above conventional technology, once a window is set, all graphic command strings stored in memory are compared with the window. Then, a search is performed for a single figure or a group of figures that are at least partially contained within the window. This comparison process takes a certain amount of time, and if this was done for all the graphic command strings stored in memory, the amount of processing would be extremely large.
Zoom-up display, zoom-down display, pick display, and redisplay require a long processing time.

Note that the window set for pick display is particularly called a pick aperture.

SUMMARY OF THE INVENTION An object of the present invention is to provide a graphic display method that solves these problems and allows quick zoom-up display, zoom-down display, pick display, and redisplay.

[Means for solving problems]

In order to achieve the above object, the present invention adds a flag to each graphical command string stored in a memory, so that the flag represents the result of comparison between the window and the graphical command string.

[Effect]

The flag attached to each graphic command string in the memory represents the result of comparison between the set window and the graphic command string. In the case of zoom-up display or pick display, a window for this purpose (in the case of pick display, especially called a big aperture) is set to be entirely contained within the already configured window, and when zooming down In the case of display, the window for this is set to include the entire previously set window. Also, in the case of redisplay, the window for this corresponds to the already set window.

In this way, when performing these displays, the new window for this purpose must have a specific arrangement relationship with the already set window, that is, whether the former is entirely included in the latter, or
The relationship is set depending on whether the former includes the entire latter or whether the two match. Based on this relationship, there are some graphics command sequences in which the comparison and judgment results with a newly set window become clear from the comparison and judgment results with an already set window.

For example, when performing a zoom-up display, a single figure or a group of figures whose entirety exists outside the previously set window will always exist entirely outside the newly set window, so such a single figure or group of figures will always exist entirely outside the newly set window. The determination result when the graphic command string for the graphic group is compared with an already set window and the determination result when compared with a newly set window are both the same as outside the window.

From the above, by using the above flag that represents the comparison judgment result with the already set window, it is possible to avoid the comparison judgment with the newly set window (,
The single figure or group of figures that will or will not be displayed in this newly set window will become clear, the comparison and judgment process will be reduced, and the amount of data processing for display will be significantly reduced. .

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the graphic display method according to the present invention, in which 1 is an input device, 2 is a host computer, 3 is a control processor, 4 is a graphic data buffer, and 5
is the graphics processor, 6 is the frame memory, and 7 is the C
RT (cathode ray tube display).

In the figure, a figure data buffer 4 stores a single figure or a group of figures (hereinafter simply referred to as figures) in a virtual screen displayed on the display surface of a CRT 7 as a figure command string 10 that defines these figures. . This virtual screen is
It is a virtual blueprint, etc.

Here, the pixel position on the display screen of the CRT 7 is determined by its horizontal
Expressed in an X-Y coordinate system with vertical scanning as the X and Y axes,
The graphic command string 10 defines the position (
Hereinafter, the X-Y coordinate values of the display surface are indirectly represented. That is, the graphic command string 10 is defined in the coordinate system of a virtual screen that is more accurate than the X-Y coordinate values of the display surface of the CRT 7, and the entire or part of it is defined by the coordinate system of the screen. displayed on the screen.

As a result, when one design drawing is stored in the graphic data buffer 4, the entire design drawing can be displayed at most on the display surface of the CRT 7.

Note that the graphic command string 10 does not represent the graphic defined by it as a collection of pixels; for example, for a straight line, the X-Y coordinates of its starting point and ending point on the virtual screen are
Represents the coordinate value, and for a circle, the X-Y of its center and radius
It represents the coordinate value.

Such a graphical command string 1O is formed by the control processor 3 based on graphical data input from the input device 1 such as a keyboard or the host computer 2. Graphic data is input from the input device 1 and the host computer 2 for each single graphic or group of graphics, and the control processor 3 creates a graphic command string 10 for each of these and stores it in the graphic data buffer 4. Further, the graphic data buffer 4 is provided with areas for display flags 11 and inclusion flags 12 for each stored graphic command string 10. As described later, these display flags 11 and gold flags 12 are 1-bit data used during zoom-up display, zoom-down display, big display, and redisplay, and are stored in the graphic data buffer 4 along with the graphic command string 10. When stored, both are set to IF I It.

When displaying a graphic on the display surface of the CRT 7 using the graphic command string 10 stored in the graphic data buffer 4 as described above, the graphic data buffer 4 is sent from the input device 1 or host computer 2 to the control processor 3. Window data representing a range (ie, a window) to be displayed among all the figures stored in is input. This window data is represented by X-Y coordinate values on the virtual screen. The control processor 3 sends this window data 2° and then a display activation signal 15 to the graphics processor 5.

Then, the graphics processor 5 is activated with a window set, and the control processor 3 reads out the first graphic command string 1o from the graphic data buffer 4. It is taken into the processor 5.

The graphic processor 5 first compares and determines the imported graphic command sequence 10 and the set window. As a result of this comparison, if the figure defined by this figure command string is partially or completely included in the window, 1"1" is sent via line 17 of the data bus 13.
Send the bit data to the graphic data buffer 4 and set the display flag 11 for this graphic command string 10.
t, and when the entire figure is contained within the window, ``11-bit data is sent to the figure data buffer 4 via line 21 of the data bus 13, and the gold flag 12 for this figure command string 10 is set to Ft 1 tF. At the same time, in either case, a portion included in the window is extracted from this graphic command string 10, and this portion is converted to image data and stored in the frame memory 6.
When the entire 0 figure sent to is outside the window, the display flag 11 and inclusion flag 12 for the figure command string 1° are both set to 0'', and no image data is formed.

When the graphics processor 5 finishes the drawing process, the control processor 3 reads the next graphics command string 1o from the graphics data buffer 4, and reads out the next graphics command string 1o.
0, the graphics processor 5 performs the above processing. In this way, the graphic processor 5 performs the above processing for each graphic command string 10 read out from the graphic data buffer 4, and as a result, the graphic data buffer 4
For each figure command string 10 stored in , if the figure defined by this does not exist in the set window, display flag 11 and inclusion flag 12 are set.
is "0", and if a portion exists, only the display flag 11 becomes tt 1 tt, and if all exists, the inclusion flag 12 becomes It I If.

On the other hand, the graphic processor 5 sends graphic commands to display a portion of the virtual screen stored in the graphic data buffer 4 that is included in the set window over the entire viewport set on the display surface of the CRT 7. Image data is formed for each portion included in the window starting from column 10 and is sequentially sent to frame memory 6.

Here, the figure command is the X-Y coordinate values of the starting point, end point, etc. representing the figure defined on the virtual screen, and the image data is the part included in the window set in this virtual screen. This is the X-Y coordinate value of a pixel that represents the entire displayed figure when displayed over the entire view board set on the display screen of. In this case, it is assumed that the view port is fixedly set on the display surface of the CRT 7, but the same applies even if the view port is different from this.

A window (particularly called a pick aperture in the case of pick display) is specified by X-Y coordinate values in an X-Y coordinate system fixed on the virtual screen. However, the viewport is designated by X-Y coordinate values of a fixed X-Y coordinate system set on the display surface of the CRT 7. Once the window and viewport are set, an X-Y coordinate transformation system is set according to this window and viewport, and the part included in the window is transformed from the virtual screen's X-Y coordinate system to the CR
The coordinates are transformed into the x-y coordinate system on the display surface of T7, thereby obtaining image data. Such a transformation is called a window-viewport transformation.

Therefore, in FIG. 2, area A is the entire virtual screen. There are three shapes P t and P z in this full screen.

Assuming that P is included in the size and positional relationship shown in the figure, when the window W is set as shown in the figure, the figures PI, P! Assuming that the window W is topologically transformed to the viewport B, the portion included in the window W becomes a figure P+", Pt" for the viewport B by this similar transformation. A viewport B including such figures Pt'' and Pg' is displayed on the display surface C of the CRT 7, but the figures P+ and Pg' are displayed on the display surface C of the CRT 7.
The graphic data representing z and Ps is the graphic command string 10, and the graphic data representing the converted shapes Pt'' and Pg'' is image data.

Each address of the frame memory 6 corresponds to the X-Y coordinate value of the display surface of the CRT 7, and this frame memory 6
, image data from the graphics processor 5 is written to an address corresponding to the display position on the display surface of the CRT 7 of the figure represented by the image data. In this way, the image data output by the graphic processor 5 is sequentially written to the corresponding address of the frame memory 6, and at the same time, in the frame memory 6, the CRT
In synchronization with the horizontal and vertical scanning of the display surface 7, data at addresses corresponding to the scanning positions are sequentially read out. As a result, the screen within the window set by the graphic processor 5 is displayed within the view board set on the display surface of the CRT 7.

Note that when displaying all the graphics stored in the graphics data buffer 4, an all-display command signal is input from the input device 1 or the host computer 2, and the graphics are sent from the control processor 3 via the line 20 of the control bus 14. It is sent to processor 5. At the same time, a display activation signal is also sent to the graphics processor 5 via line 15. The control processor 3 sequentially reads out the graphic command string 10 from the graphic data buffer 4 , and the graphic processor 5 sequentially takes in these commands, converts them into image data as is, and sends it to the frame memory 6 . At this time, the display flag 11 and inclusion flag 12 of the graphic data buffer 4 are not changed.

Next, operations for zooming up, zooming down, pick display, and redisplay will be explained.

The zoom-up display is to enlarge and display a part of the screen currently displayed on the display surface of the CRT 7, and a window representing this part is set in the graphic processor 5. This window is compared with the window previously set and maintained in the graphics processor 5, and if the former is included in the latter at all, it is determined that zoomed-up display is to be performed.

FIG. 3 is a flowchart showing the operation of the graphic processor 4 of FIG. 1 in the case of zoomed-up display. The figure also includes a processing operation for initial display (this is the first display for this window after setting the window for the first time) and a processing operation for pick display. These have mutually overlapping parts. The processing operation for the initial display is a series of operations consisting of steps 101 to 103 and 106 to 118, and the explanation of this operation is omitted because it overlaps with the above explanation.

When the window is set (step 102), it is compared with the previously held window to determine whether it is a zoomed-up display (step 103), and if it is a zoomed-up display, a graphics command string is read from the graphics data buffer 4. The display flag 11 associated with 10 is read out (step 104). This display flag 11 is “0”
When (step 105), the figure defined by the figure command string 10 for this display flag 11 is displayed in the window that was previously held (hereinafter referred to as the old window).
Since it is outside, it is naturally also outside the newly set window (hereinafter referred to as new window).

In this case, the processing for this graphic command string 10 is completed, and the display flag 11 for the next graphic command string 10 is read out through steps 118 and 103.

When the display flag 11 is 11” (step 105)
, reads the graphic command string lO for this (
Step 106), after determining whether or not it is a pick display (step 107), it is determined whether the figure defined by this figure command string 10 is included at least in part in the new window (step 108); If the figure is outside the new window, set the display flag 11 and inclusion flag 12 to "0" (steps 109 and 110), end the processing for this figure command string 10, and
The next display flag 11 is read out through steps 18 and 103, but if at least a part of the above figure is within the new window, the display flag 11 is set to tt 1 tt (step 111), and the above figure is within the new window. When included as a whole (step 112), inclusion flag 1
2 If 1 tt (step 113), and if not included, set the inclusion flag 12 to "0" (step 114)
Next, extract the part included in the new window (step 115), convert it to image data (step 116), and send it to the frame memory 6 (step 1).
17), the next display flag 11 is read out through steps 118 and 103.

The above processing is performed for all graphic command strings 10 stored in the graphic data buffer 4. When this process is completed, a portion of the screen displayed on the entire display surface of the CRT 7 with respect to the old window, which is defined by the new window, is enlarged and displayed on the display surface of the CRT 7.

Now, for all the figures stored in the figure data buffer 4, as shown in FIG. 5(a), a part of the figure P and a part of the figure P! Old window Wl to include the whole of
is set, on the CRT7 display surface,
As shown in FIG. 5(b), the area included in the old window W is displayed, and the figure P+ for a part of the figure P is displayed.
' and figure P for figure Pz! Next, as shown in FIG. 5(a), a new window W! containing only the figure P2 in the old window W1 is displayed. When is set,
The area d within the display surface of FIG. 5(b) corresponding to this new window W8 is displayed on the display surface as shown in FIG. 5(c), and the figure P! is the figure P3 in Fig. 5(b)
The figure is displayed as a figure P2'' that is larger than the figure P2''.

In zoom-up display, a figure that is outside the old window will always be outside the new window, and as described above, whether or not a figure is outside the old window can be easily determined using display flag 11. 11, it is only necessary to read out from the graphic data buffer 4 only the graphic command string 10 in which at least a part of the graphic is included in the new window and form image data, which reduces the data processing amount for the zoomed display up of the graphic processor 5. is significantly reduced, allowing quick zoom-up display.

Next, zoom down display will be explained. Contrary to zoom-up display, zoom-down display includes the screen currently displayed on the display surface of CRT 7 and displays a wider area of the screen on the display surface of CRT 7,
As in the case of zoom-up display, a window representing an enlarged area to be displayed is set in the graphics processor 5, and when this window completely includes the old window, zoom-down display is determined.

FIG. 4 is a flowchart showing the operation of the graphic processor 4 of FIG. 1 in the case of zoomed-down display, and also includes processing operations for initial display. The processing operation for this initial display is a series of operations consisting of steps 201 to 214, and since this also overlaps with the above explanation, it will be omitted.

When a new window is set (step 201), it is compared with the old window to determine whether it is a zoomed-down display (step 202), and if it is a zoomed-down display, a graphic command is sent from the graphic data buffer 4. The inclusion flag 12 associated with column 10 is read (step 215).

When the inclusion flag 12 is 1” (step 216
), the figure defined by the figure command string 10 for this is entirely included in the new window, so this figure command string 10 is read out from the figure data buffer 4 (step 217) and further converted into image data. (Step 212) and sends it to the frame memory 6 (Step 213).

If the inclusion flag 12 read in step 215 is
Also at the time of OIt, the graphic command string 10 for these
is read out (step 203), and it is determined whether at least a part of the figure defined by this figure command string 10 is within this new window (step 204). If this is not included, display flag 11
, the inclusion flags 12 are both set to 0'', and the processing for this graphic command string 10 is ended, and steps 214 and 2
02, the next inclusion flag 12 is read. If at least a part of the figure is included in the new window, the display flag 11 is set to °11'' (step 205).Next, it is determined whether the whole figure is included in the new window. A determination is made (step 206), and if the whole is included, the inclusion flag 12 is set to 1 It (step 207), and if only a part is included, the inclusion flag 12 is set to 11 OIf (step 20B).
, extract the part included in the new window (step 209), and convert it to image data (step 212).
) to the frame memory 212 (step 213).

The above processing is performed sequentially for each graphic command string 10 stored in the graphic data buffer 4, and when all the graphic command strings 10 have been processed (step 214),
The graphic processor 5 completes the process for zoom-down display, and a complete zoom-down display is performed on the display surface of the CRT 7.

The screen change on the display surface of the CRT 7 due to the zoom-down display will be explained with reference to FIG. 5, which is used to explain the zoom-up display.

In this case, in FIG. 5(a), W□ becomes the old window and Wl becomes the new window.

For the old window W2, the screen shown in FIG. 5(c) is displayed on the display surface of the CRT 7, and when a new window W including this is set for the old window W2, As shown in Figure 5(b), in addition to the figure Pg'' for the figure Pz (Figure 5(a)), the figure P+ for a part of the figure P+ (Figure 5(a)) is displayed on the display surface. , ' are also displayed.The area d in FIG. 5(b) is the fifth window when the old window Wt was set.
This is the display area on the display surface shown in Figure (C).

As described above, in the case of zoom-down display, image data may be created immediately for a figure that is entirely contained within the old window without comparing this figure with the new window. Since a figure can be easily determined by the inclusion flag 12, the graphics processor 5
The amount of data processing required for zoom-down display is also significantly reduced, making it possible to quickly zoom-down display.

Next, pick display will be explained. Pick display is C
This is a display method in which a desired figure on the screen displayed on the RT7 screen is designated and the figure is made clear by blinking or coloring.

In FIG. 1, for pick display, an instruction is issued from the input device 1 or the host computer 2, and pick aperture data is input. This data is transferred from control processor 3 to line 20 of control bus 14.
This signal is supplied to the graphics processor 5 via the graphics processor 5, and thereby the pick aperture is set in the graphics processor 5.

In the case of pick display, the graphic processor 5 uses the graphic command string 1 stored in the graphic buffer data 4.
It is determined whether at least part of the figure defined by 0 is included in the big aperture, and when at least part of this figure is included in the pick aperture, the display figure (single figure or group of figures) for this figure is determined. Data for blinking or coloring (hereinafter referred to as pick data) is formed. The pick aperture is set within a window (hereinafter also referred to as the old window) set for the screen currently displayed on the display surface of the CRT 7, as in the case of zoom-up display.
A small number of the figures defined in the figure command string 10 that can be displayed by pick display are included in the old window, and there is no need to perform any processing for displaying them by pick display. It can be determined whether or not the command string 10 can be displayed as a pick display by using the display flag 11.

The processing operation for displaying picks in the graphic processor 5 is as follows.

That is, in FIG. 3, along with an instruction to display a pick on the input device 1 or host computer 2 (step 101),
), the big aperture is set (step 119).
Then, the display flag 11 is read out from the graphic data buffer 4 (step 104).
When is tt Ott (step 105), it is assumed that at least a part of the figure defined by the figure command string lO for this is not included in the old window, and the process ends here, but this display flag 11 is set to we1 At the time of tt, the graphic command string 10 for this is read out from the graphic data buffer 4 (step 106), and it is determined whether or not it is to be displayed as a pick (step 107). It is determined whether part or all of the data is included in the big aperture (pick hit) (step 120). If it is a pick hit, big data is formed (step 121).
) It is transferred to the control processor 3 via line 9 of the control bus 14, and if it is not a pick hit, the process is ended there and the next display flag 11 is read.

Therefore, as shown in FIG. 6, the figure P.

If we consider the case where window W is set to include a part of figure P2 and the whole of figure P2, and pick display is performed on this, the objects of pick display are figures P, , P, and the area outside window W is The process shown in FIG. 3 for the figure P existing in , ends with the determination of the display flag 11 in step 105 .

In such a window W, when the big aperture A P + is set to include a part of the figure P, C
The entire displayed figure corresponding to the portion of the figure P displayed on the display surface of the RT7 existing in the window W is flashed or colored and displayed as a pick. Furthermore, when the pick aperture APt is set to include the figure Pt, the entire display figure for this figure P8 is similarly picked and displayed.

As mentioned above, even in the pick display, the display flag 11
It is possible to determine a figure that can be a target using the above, and the amount of data processing by the graphic processor 5 can be significantly reduced, so that pick display can be performed quickly.

Note that in the case of pick display, the display flag 11 and inclusion flag 12 are maintained as they were for the old window.

Next, the redisplay operation will be explained with reference to FIG.

Again, processing operations for initial display are included, which are represented by a series of operations in steps 301, 302, and 307-318.

In the case of redisplay, first, a new window is set (step 301), and it is determined that it is a redisplay by making it part of the old window that has been set (step 302), and the graphic data buffer 4 is From inclusion flag 12
is read out (step 303). When the inclusion flag 12 is It 1 tT, the corresponding graphic command string 10 is read from the graphic data buffer 4 (step 319), converted to image data (step 314), and sent to the frame memory 6 (step 319). 315), reads the next inclusion flag 12 via steps 318 and 302.

When the inclusion flag 12 is tp Ott (step 3
14) Next, the display flag 11 associated with the graphic command string 10 for this is read out (step 305).

When this display flag 11 is 0°1 (step 30
6), the process is now finished and the next inclusion flag 12 is read out, but when the display flag 11 is tt 1 tt, the graphic command string 10 is read out from the graphic data buffer 4 (Step 307), this graphic command string lO
A determination is made as to whether the figure defined in (308) is partially or completely framed within the window. In the redisplay, it is determined that it is definitely included, so similarly to the initial display, set the display flag 11 to 11'' (step 309), and when all are included (step 310), set the inclusion flag 12 to "1" (step 309). 311), if the entire window is not included, set the inclusion flag 12 to "0" (step 312), and extract the part included in the window (step 313). This part is converted to image data (step 314). , is sent to the frame memory 6 (step 315).

The above processing operations are performed for all graphic command strings 10 stored in the graphic data buffer 4, and when this is completed (step 318), the same screen as the old window is displayed as a whole on the display surface of the CRT 7. be done.

As described above, even in the case of redisplay, the graphic command string 10 to be redisplayed can be determined by using the display flag 11 and the inclusion flag 12. There is no need to read and compare it with the set window,
In addition, the graphic command string 1 whose inclusion flag 12 is "1"
For 0, it is sufficient to immediately convert it to image data without performing a comparison with a set window. Therefore, the amount of data to be processed for redisplaying is significantly reduced, and prompt display is possible.

Note that in this embodiment, each time a window is set,
The display flag and inclusion flag 12 are set for this, but in particular, the new and old windows match when redisplayed, and the display flag 11 and inclusion flag 12 for these match, so the display flag 11 is set to "11". When (
Step 306) and step 307 may be followed by the process immediately proceeding to step 313.

In addition to the above displays, there are displays that set the new window so that some parts overlap with the old window and other parts are offset, and displays that set the new window so that it does not overlap with the old window at all. In this case, the display flag 11 and the inclusion flag 12 are not used, and the same processing operation as the initial display is performed on the new window, and each display flag 11 and the inclusion flag 12 are set for this new window.

Note that the above embodiment can be applied to both two-dimensional figures and three-dimensional figures, and when three-dimensional figures are used, the window may be used as a view volume.

〔Effect of the invention〕

As explained above, according to the present invention, the comparison judgment result between the graphic command string and the set window or view volume is added as a flag to each graphic command. When displaying, big displaying, or redisplaying, the graphical command string to be displayed can be easily determined by the flag, and the number of graphical command strings to be compared with the window set for such display can be greatly reduced. This greatly reduces the amount of data to be processed, making it possible to speed up such display.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the graphic display method according to the present invention, FIG. 2 is an explanatory diagram showing the relationship between the graphic command string in the window and the image data in the viewport in FIG. The figure is a flowchart showing the processing operations for the zoom-up display and pick display of the graphic processor in Fig. 1, Fig. 4 is a flowchart showing the processing operations for the zoom-down display, and Fig. 5 is the zoom-up display and zoom-down display. FIG. 6 is an explanatory diagram showing an example of the pick aperture set in the window for pick display, and FIG. 7 is an explanatory diagram showing an example of the pick aperture set in the window for pick display. 3 is a flowchart showing processing operations. 1... Input device, 2... Host computer, 3... Control processor, 4...
Graphic data buffer, 5...Graphic processor, 6...Frame memory, 7...
CRT, 10... Graphic command string, 11...
...Display flag, 12...Inclusion flag. Figure 2 嘱J 1 Figure 3 4th prisoner Figure 5 tσ 6th prisoner

Claims (1)

[Claims] A graphical command string that defines a one-, two-dimensional, or three-dimensional single figure or a group of figures is stored in a memory, and a window or view that is set by reading the graphical command string from the memory is stored in a memory. In a method in which only a portion of the single figure or a group of figures included in the set window or view volume can be displayed graphically by comparison with a volume, the window or view is displayed in the memory for each graphic command string. A graphical display method characterized by adding a flag indicating the result of comparison with a volume. 2. Claim 1 provides that the flag is a display flag indicating whether at least a part of the single figure or group of figures exists within the set window or view volume. Characteristic graphic display method. 3. Claim 1 is characterized in that the flag is an inclusion flag indicating whether or not the single figure or the entire figure group exists within the set window or viewing volume. Image display method.