JPH06105392B2 - Graphic display method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a graphic display system for displaying a portion within a set window of one screen including various graphics.

[Conventional technology]

For example, a computer technique is used to create a drawing including various figures such as one design drawing. In such a drawing creation technique, a unit element that constitutes one figure such as a straight line or an arc, that is, a single figure or a meaningful figure such as a gear that is a combination of a plurality of single figures, that is, a figure group Representing data (graphic data) is input and stored in the memory, and graphic data is read from the memory and displayed graphically on the display device. A desired drawing is created by correcting the graphic data.

By the way, there is a case where it is desired to display only a part of the drawing during or after the drawing is being created. The memory can store the entire drawing, and when it is desired to display only a part of the drawing in a desired area of the display surface of the display device, the desired area to be displayed (that is, Along with setting the (window), the desired display area (that is, the viewport) on the display surface of the display device is also set, the figure data is read from the memory, and the figure in the window is displayed over the entire viewport. The data is converted and supplied to the display device.

One conventional example of such a graphic display system is disclosed in Japanese Patent Application Laid-Open No. 58-221887.

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

In the above-mentioned conventional example, considering a virtual screen, the graphic data of a single graphic, for example, if it is a straight line, consists of XY coordinate values representing the starting point and the ending point on the virtual screen,
If it is a circular arc, it is converted into a figure command such as adding a value that represents the radius, and the figure data of the figure group is converted into a set of figure commands of the single figure that forms this and stored in memory. I remember. Note that, hereinafter, a set of figure commands for a single figure and a figure command for a figure group will be collectively referred to as a figure command string.

Then, when the window is set, for each single figure or figure group stored in the memory, first, the window and the figure command sequence are compared using coordinate values, and at least one of the single figure or figure group is compared. Part is present in the window, and then the portion included in the window is extracted by extracting the portion included in the window with respect to the figure command sequence for a single figure or a figure group, at least a part of which is present in the window. It is converted into graphic data to be graphic-displayed (hereinafter referred to as image data) by a viewport set on the display surface.

According to this conventional example, a single figure or a group of figures to be displayed can be easily and quickly determined, and, by this determination, only a single figure or a group of figures to be displayed is displayed. Therefore, the processing amount after setting the window can be reduced, and quick graphic display is possible.

[Problems to be solved by the invention]

By the way, in the graphic display method as described above, a part of the currently displayed screen is enlarged and displayed (this is referred to as zoom up display), or a region wider than the region shown on this screen is displayed. In some cases, this is called a zoom-down display, and in other cases, in order to show a desired single figure or group of figures on the display screen, it may be blinked or colored (this is called a pick display). . Also, instead of setting a window and displaying a part of the virtual screen stored in the memory, change a part of the graphic command sequence that composes this screen.
In some cases, the same window may be set again to display the same part of the virtual screen (this is called redisplay).

However, even when such zoom-up display, zoom-down display, pick display, or re-display is performed, when the window is set in the above conventional technique, all graphic command sequences stored in the memory are compared with the window. Then, a single figure or a group of figures at least a part of which is included in the window is searched. This comparison process requires a certain amount of time, and if this is performed for all graphic command sequences stored in the memory, the amount of processing for that will be extremely large.
A long processing time is required for zoom-up display, zoom-down display, pick display, and re-display.

The window that is set for displaying a pick is called a big aperture.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and provide a graphic display method capable of quickly performing zoom-up display, pick display, zoom-down display, and re-display.

[Means for solving problems]

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

[Action]

The flag added to each graphic command string in the memory represents the result of comparison and judgment between the set window and the graphic command string. In the case of zoom-up display or pick-up display, the entire window for this (in the case of pick-up display, especially called the pick aperture) is set to be included in the already set window, and the zoom-down display is set. In some cases, the window for this is set to include the entire window that has already been set. In the case of redisplay, the window for this coincides with the already set window.

In this way, when these are displayed, the new window for this purpose has a specific layout relationship with the already set window, that is, whether the former is included in the latter,
It is set depending on whether the former includes the latter as a whole or both match. From this relationship, there is also a graphic command sequence in which the comparison and determination result with the newly set window becomes clear from the comparison and determination result with the already set window.

For example, when performing zoom-up display, a single figure or group of figures that is wholly outside the already set window will always exist outside the newly set window. The determination result when the graphic command sequence for the graphic group is compared with the already set window and the determination result when it is compared with the newly set window are the same as those outside the window.

From the above, by using the above-mentioned flag indicating the comparison determination result with the already set window, the comparison determination with the newly set window is not performed.
A single figure or group of figures that are or will not be displayed by this newly set window will be clarified, the comparison and judgment processing can be reduced, and the amount of data processing for display will be greatly 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 a graphic display system 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 a graphic data buffer.
Is a graphics processor, 6 is a frame memory, 7 is a CR
T (cathode ray tube display device).

In the figure, the graphic data buffer 4 has a single graphic or a graphic group (hereinafter referred to as “graphical graphic”) in the virtual screen displayed on the display surface of the CRT 7.
The graphics command sequence 10 that defines these (simply called graphics)
Is stored as This virtual screen is, for example, one virtual design drawing.

Here, when the pixel position on the display surface of the CRT 7 is represented by an XY coordinate system in which the horizontal and vertical scans are the X axis and the Y axis, the figure command sequence 10 shows that the figure defined by this is The position of the displayed CRT 7 on the XY coordinates on the display surface (hereinafter referred to as the XY coordinate value of the display surface) is indirectly represented. That is, the figure command sequence 10 is defined in the coordinate system of the screen considering the virtual screen with higher accuracy than the XY coordinate values of the display surface of the CRT7, and the whole or a part of it is CR.
It is displayed on the display surface of T7. As a result, when one design drawing is stored in the graphic data buffer 4, the CR
On the display surface of the T7, it is possible to display the entire blueprint at maximum.

The figure command sequence 10 does not represent the figure defined by this as a group of pixels. For a straight line, for example, it represents the XY coordinate values of its start and end points on the virtual screen. Represents the XY coordinate values of the center and radius.

The graphic command sequence 10 is formed by the control processor 3 based on graphic data input from the input device 1 such as a keyboard or the host computer 2. The graphic data is input from the input device 1 and the host computer 2 for each single graphic or graphic group, and the control processor 3 creates a graphic command sequence 10 for each of these and creates a graphic data buffer 4.
To store. The graphic data buffer 4 also includes a display flag 11 and an inclusion flag 12 for each graphic command sequence 10 stored therein.
Area is provided. These display flag 11 and inclusion flag 12 are 1-bit data used for zoom-up display, zoom-down display, pick display and re-display, as will be described later, and are stored in the graphic data buffer 4 together with the graphic command sequence 10. When stored, all are set to "1".

As described above, when the graphic command string 10 stored in the graphic data buffer 4 is used to display a graphic on the display surface of the CRT 7, the input device 1 or the host computer 2 stores it in the control processor 3 and the graphic data buffer 4 stores it. Window data representing a range (that is, a window) to be displayed of all the drawn figures is input. This window data is represented by XY coordinate values on the virtual screen. The control processor 3 sends the window data 20 and then the display start signal 15 to the graphic processor 5.

Then, the graphic processor 5 is activated with a window set, and the control processor 3 reads the first graphic command sequence 10 from the graphic data buffer 4. This graphic command string 10 is fetched into the graphic processor 5 via the line 19 of the data bus 13.

First, the graphic processor 5 compares and determines the fetched graphic command sequence 10 with the set window. According to this comparison judgment, when the figure defined by this figure command string is partially or entirely contained in the window, "1" bit data is sent to the figure data buffer 4 via the line 17 of the data bus 13, When the display flag 11 for the command string 10 is set to "1" and the whole figure is included in the window, "1" bit data is sent to the figure data buffer 4 via the line 21 of the data bus 13 to make this figure command row. Inclusion flag 12 for 10
To “1”. At the same time, in any case, the portion included in the window is extracted from the graphic command sequence 10, and this portion is converted into image data and sent to the frame memory 6. When the whole figure is outside the window, both the display flag 11 and the inclusion flag 12 for the figure command sequence 10 are set to "0", and no image data is formed.

When the graphic processor 5 finishes the processing, the control processor 3 reads the next graphic command sequence 10 from the graphic data buffer 4, and the graphic processor 5 performs the above-mentioned process on the graphic command sequence 10.
In this way, the graphic processor 5 performs the above processing for each figure command sequence 10 read from the figure data buffer 4, and as a result, for each figure command sequence 10 stored in the figure data buffer 4, If there is no figure defined in the specified window, the display flag 11 and the inclusion flag 12 are "0". If there is a part, only the display flag 11 is "1". , The inclusion flag 12 is further set to “1”.

On the other hand, the graphic processor 5 displays a part of all virtual screens stored in the graphic data buffer 4 which is included in the set window over the entire viewport set on the display surface of the CRT7. Command sequence
Image data is formed for each part included in the window from 10 and sequentially sent to the frame memory 6.

Here, the figure command is an XY coordinate value such as a start point and an end point that represents a figure defined on the virtual screen, and the image data is a CRT7 indicating a portion included in the window set in the virtual screen. It is an XY coordinate value of a pixel that represents the entire figure displayed when the image is displayed over the entire viewport set on the display surface. In this case, the viewport is fixedly set on the display surface of the CRT 7, but the same applies when the viewport is different from this.

A window (particularly called a pick aperture in the case of pick display) is designated by an XY coordinate value of an XY coordinate system fixed on the virtual screen. However, the viewport is also designated by the XY coordinate value of the fixed XY coordinate system set on the display surface of the CRT 7. Once the window and viewport are set, the XY coordinate conversion system is set according to this window and viewport, and the part included in the window is the X-Y coordinate system of the virtual screen from the XY coordinate system on the display surface of the CRT7. The coordinates are converted into the Y coordinate system, and the image data is obtained by this. Such a conversion
This is called window-to-viewport conversion.

Therefore, in FIG. 2, the area A is the entire virtual screen. The all three figures P ₁ on the screen, P _2, P ₃ the size illustrated, assuming that contained in a positional relationship, when the window W is set as shown in, figure P _1, P _{The part of 2} included in window W is window W
Is transformed into the viewport B, and the figure P ₁ ′, P for the viewport B is converted by this similar transformation.
₂ '. Viewport B including such figures P ₁ ′ and P ₂ ′
Is displayed on the display surface C of the CRT 7, the graphic data representing the graphics P ₁ , P ₂ , P ₃ is the graphic command sequence 10, and the graphic data representing the converted graphics P ₁ ′, P ₂ ′ is an image. The data.

Each address of the frame memory 6 is an X on the display surface of the CRT7.
It corresponds to the -Y coordinate value, and the image data from the graphic processor 5 is written in the frame memory 6 at an address corresponding to the display position of the figure represented by the graphic on the display surface of the CRT 7. In this way, the image data output by the graphic processor 5 is sequentially written into the corresponding addresses of the frame memory 6, and at the same time, in the frame memory 6, in synchronization with the horizontal and vertical scanning of the display surface of the CRT 7, The data of the address corresponding to the scanning position is sequentially read. As a result, the screen in the window set on the graphic processor 5 is CR.
Displayed in the viewport set on the display screen of T7.

In order to display all the graphics stored in the graphics data buffer 4, a display all command signal is input from the input device 1 or the host computer 2, and the control processor 3 sends the graphics via the line 20 of the control bus 14. It is sent to processor 5. Along with this, the display activation signal is also on line 15
Is sent to the graphics processor 5 via. The graphic processor 5 sequentially reads the graphic command sequence 10 from the graphic data buffer 4 by the control processor 3, and the graphic processor 5 sequentially takes in these, converts them into image data as they are, and sends them to the frame memory 6. At this time, the display flag 11 and the inclusion flag 12 of the graphic data buffer 4 are not changed.

Next, operations for zoom-up, zoom-down, pick display, and re-display will be described.

The zoom-up display enlarges and displays 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 held in the graphic processor 5, and when the former is included in the latter at all, it is determined to be the zoom-up display.

FIG. 3 is a flow chart showing the operation of the graphic processor 4 of FIG. 1 in the case of zoom-up display. The figure also includes a processing operation for initial display (this is the display for this window first performed after setting the window for the first time) and a processing operation for pick display. These have portions that overlap each other. The processing operation for the initial display is a series of operations consisting of steps 101 to 103 and 106 to 118, and the description of this operation overlaps with the above description, and is therefore omitted.

When the window is set (step 102), it is compared with the windows held so far to determine whether it is the zoom-up display or not (step 103). When the window is the zoom-up display, the graphic data buffer 4 to the graphic command string 10 is displayed. The display flag 11 associated with is read (step 104). When this display flag 11 is "0" (step 105), the graphic defined by the graphic command sequence 10 for this display flag 11 is outside the window (hereinafter referred to as "old window") that has been held up to now, so of course a new It is also outside the window set to (hereinafter, new window). In this case, the process for the graphic command sequence 10 is completed, and the display flag 11 for the next graphic command sequence 10 is read out through steps 118 and 103.

When the display flag 11 is "1" (step 105), the figure command sequence 10 is read out (step 105).
106), after determining whether or not it is a pick display (step 107), it is determined whether or not the figure defined by the figure command sequence 10 is included in at least a part of the new window (step 108). If this figure is outside the new window, the display flag 11 and the inclusion flag 12 are set to "0" (steps 109 and 110), the processing for this figure command sequence 10 is completed, and the next display flag 11 is read out via steps 118 and 103. When at least a part of the figure is in the new window, the display flag 11 is set to "1" (step 111), and when the figure is included in the new window as a whole (step 112), the inclusion flag 12 is set. "1"
If not included (step 113), the inclusion flag 12 is set to "0" (step 114). Next, the portion included in the new window is extracted (step 115), and this is converted into image data (step 116), and the frame memory 6
(Step 117) and the next display flag 11 is read out through steps 118 and 103.

The above processing is performed for all the graphic command sequences 10 stored in the graphic data buffer 4. When this process is completed, the portion of the screen displayed on the entire display surface of the CRT7 with respect to the old window is enlarged and displayed on the display surface of the CRT7.

Therefore, for all the figures stored in the figure data buffer 4, the old window W ₁ is included so as to include a part of the figure P ₁ and the whole figure P ₂ as shown in FIG. 5 (a). When set, the display surface D of the CRT 7, as shown in FIG. 5 (b), is displayed region included in the old window W _1, and figure P ₁ 'for some shapes P ₁ figure graphic P ₂ 'is displayed for the P _2. Next, as shown in FIG. 5 (a), when the new window W ₂ containing only graphics P ₂ old window W ₁ is set, Figure 5 corresponding to this new window W ₂ (b) region d portion of a display plane D of, as shown in FIG. 5 (c), is displayed on the display surface D, figure P ₂ is enlarged than figure P ₂ 'of FIG. 5 (b) Displayed as graphic P ₂ ″.

In the zoom-up display, the graphic outside the old window is always outside the new window. As described above, it is possible to easily determine whether the graphic is outside the old window with the display flag 11. It is sufficient to read only the figure command sequence 10 in which at least a part of the figure is included in the new window from the figure data buffer 4 to form the image data, and the data processing amount for the zoom display up of the graphic processor 5 is determined by the determination by 11. Is greatly reduced, and quick zoom-up display is possible.

Next, the zoom-down display will be described. In contrast to the zoom-up display, the zoom-down display includes the screen currently displayed on the CRT7 display surface, and displays a screen in a wider area than this on the CRT7 display surface. Similarly, a window indicating the enlarged area to be displayed is set in the graphics processor 5, and when this window includes the old window at all, it is determined to be the zoom-down display.

FIG. 4 is a flow chart showing the operation of the graphic processor 4 of FIG. 1 in the case of zoom-down display, including the processing operation 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 description, it will be omitted.

When a new window is set (step 201), this is compared with the old window to determine whether or not zoom-down display is performed (step 202). When the new window is displayed, the graphic data buffer 4 to the graphic command line is determined.
The inclusion flag 12 associated with 10 is read (step 21
Five). When the inclusion flag 12 is "1" (step 21
6) Since the figure defined by the figure command sequence 10 corresponding thereto is included in the new window as a whole, the figure command sequence 10 is read 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).

Even when the inclusion flag 12 read in step 215 is "0", the graphic command sequence 10 corresponding to these is read (step 203), and at least a part of the graphic defined by this graphic command sequence 10 is read. Is determined in this new window (step 204). If this is not included, the display flag 11 and the inclusion flag 12 are both set to "0" to end the processing for this graphic command sequence 10, and the next inclusion flag 12 is read out via steps 214 and 202. If at least a part of the figure is included in the new window, the display flag 11 is set to "1" (step 205). Next, it is judged whether or not the whole figure is included in the new window (step 20).
6) If the whole is included, the inclusion flag 12 is set to "1" (step 207), if only part is included, the inclusion flag 12 is set to "0" (step 208), and the part included in the new window is extracted. Then, the image data is converted (step 212) and sent to the frame memory 212 (step 213).

The above processing is sequentially performed for each figure command sequence 10 stored in the figure data buffer 4, and all figure command sequences 10 are processed.
When the processing is performed for (step 214), the graphic processor 5 finishes the processing for zoom-down display, and complete zoom-down display is performed on the display surface of the CRT 7.

The screen change on the display surface of CRT7 by zoom down display,
This will be described with reference to FIG. 5 used for explaining the zoom-up display.

In this case, in FIG. 5 (a), W ₂ becomes the old window and W ₁ becomes the new window. For the old window W _2, on the display surface D of the CRT 7, the screen shown in FIG. 5 (c) is displayed, the new window W ₁ is set comprising the same for this old window W ₂ as shown in FIG. 5 (b), on the on the display surface D, figure P ₂ (FIG. 5 (a)) in addition to the graphic P ₂ 'of Picture P ₁ (FIG. 5 (a)) of The figure P ₁ ′ for a part is also displayed. The area d in FIG. 5B is the display area of the display surface D shown in FIG. 5C when the old window W ₂ is set.

As described above, in the case of zoom-down display, image data may be immediately formed for a graphic that is entirely contained in the old window without comparing this graphic with the new window. Since the figure can be easily determined by the inclusion flag 12, the amount of data processing for the zoom-down display of the graphic processor 5 is greatly reduced, and a quick zoom-down display can be realized.

Next, the pick display will be described. Pick display is CR
Indicate the desired figure on the screen displayed on the display screen of T7,
This is a display method in which this is indicated by blinking or coloring.

In FIG. 1, in the pick display, the command is given from the input device 1 and the host computer 2, and the pick aperture data is input. This data is supplied from the control processor 3 to the graphics processor 5 via the line 20 of the control bus 14, whereby the graphics processor 5 is set to the pick aperture.

In the case of the graphic display, the graphic processor 5 uses the graphic command sequence 10 stored in the graphic buffer data 4.
If at least a part of the figure defined by is included in the pick aperture, and if at least a part of this figure is included in the pick aperture, the display figure (single figure or figure group) for this is blinked or Data for coloring (hereinafter referred to as pick data) is formed. As with the zoom-up display, the pick-up aperture is set in the window set for the screen currently displayed on the display screen of the CRT7 (hereinafter also referred to as the old window). At least a part of the graphic defined by the graphic command sequence 10 that can be the target of is included in the old window, and other than this, there is no need to perform any processing for displaying the pick. Therefore, it is possible to determine whether or not the graphic command sequence 10 can be a target for pick display by using the display flag 11.

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

That is, in FIG. 3, together with the instruction of the pick display of the input device 1 and the host computer 2, (step 10
1) The pick aperture is set (step 119), and then the display flag 11 is read from the graphic data buffer 4 (step 104). When the display flag 11 is "0" (step 105), the processing is ended by assuming that at least a part of the graphic defined by the graphic command sequence 10 corresponding thereto is not included in the old window. Is "1", the graphic command sequence 10 for this
Is read from the graphic data buffer 4 (step 10
6), it is determined whether or not the display is a pick (step 10
7) After that, it is determined whether or not a part or all of the figure defined by the figure command sequence 10 is included in the pick aperture (pick hit) (step 120). At the time of a pick hit, pick data is formed (step
121) It is transferred to the control processor 3 through the line 9 of the control bus 14, and when it is not a pick-up, the processing is ended there and the next display flag 11 is read.

Therefore, as shown in FIG. 6, when the window W is set so as to include a part of the figure P ₁ and the entire figure P ₂ , and a pic display is performed for this, the object of the pic display Are the figures P ₁ and P ₂ and the window W
The process of FIG. ₃ for the figure P ₃ existing outside is performed in step 10
The judgment of the display flag 11 of 5 also ends.

In such a window in W, the Pitsukuapachiya AP ₁ is set so as to include a part of the graphic P _1, the entire display figure for the portion that is present in the window W of figure P ₁ being displayed on the display surface of CRT7 , Blinking or colored and displayed as a pick. When the pick aperture AP ₂ is set so as to include the figure P ₂ , similarly, the entire display figure for the figure P ₂ is picked up.

As described above, even in the case of the pick display, it is possible to discriminate the target figure by using the display flag 11, so that the data processing amount of the graphic processor 5 is greatly reduced and the pick display can be performed quickly. .

In the case of pick display, the display flag 11 and the inclusion flag 12 are retained as they are in the contents of the old window.

Next, the re-display operation will be described with reference to FIG. Here again, a processing operation for initial display is included, which is represented by a series of operations of steps 301, 302, 307-318.

In the case of re-display, first, when a new window is set (step 301), it is judged to be re-display by matching with the set old window (step 302), and the graphic data buffer 4 is displayed. The inclusion flag 12 is read from (step 303). This inclusion flag 1
When 2 is "1", the graphic command string 10 corresponding thereto is read from the graphic data buffer 4 (step 31).
9) Convert this into image data (step 314)
Send to frame memory 6 (step 315), step 31
The next inclusion flag 12 is read via 8,302.

If the inclusion flag 12 is "0" (step 314), then the display flag 11 attached to the graphic command sequence 10 corresponding thereto is read (step 305). When the display flag 11 is "0" (step 306), the processing is ended thereby and the next inclusion flag 12 is read out.
Is "1", the graphic command sequence 10 is read from the graphic data buffer 4 (step 307), and it is determined whether the graphic defined by the graphic command sequence 10 is partially or wholly included in the window ( Step 308). Since it is determined that the flag is always included in the redisplay, the display flag 11 is set to "1" (step 309) as in the case of the initial display, and when the whole is included (step 310), the inclusion flag 1 is set.
2 is set to "1" (step 311), and the inclusion flag 12 is set to "0" if not all are included (step 312),
Extract the part included in the window (step 31)
3). This part is converted to image data (step 3
14) is sent to the frame memory 6 (step 315).

The above processing operation is performed for all the 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 CRT7. It

As described above, even in the case of redisplay, by using the display flag 11 and the inclusion flag 12, the figure command sequence 10 to be redisplayed can be determined,
No need to compare 10 with the window set by reading from the graphic data buffer, and for the graphic command sequence 10 with the inclusion flag 12 being "1", compare and judge with the set window. Instead, it may be converted into image data immediately. Therefore, the amount of data processing for re-display is greatly reduced, and quick display is possible.

In this embodiment, each time a window is set,
The display flag and the inclusion flag 12 for this are set. Especially, in the redisplay, the new and old windows match, and the display flag 11 and the inclusion flag 12 for these match, so that the display flag 11 is "1". At the time of (step 30
6), processing may be performed so that the processing immediately proceeds from step 307 to step 313.

In addition to the above display, there is a display that sets a new window so that it overlaps with the old window and the other part shifts, and a display that sets the new window so that it does not overlap the old window at all. , The display flag 11 and the inclusion flag 12 are not used, the same processing operation as the initial display is performed for the new window, and the display flag 11 and the inclusion flag 12 are set for this new window.

The above embodiment can be applied to both two-dimensional figures and three-dimensional figures. When targeting three-dimensional figures, the window may be a special volume.

〔The invention's effect〕

As described above, according to the present invention, the comparison determination result of the graphic command sequence and the set window or view volume is added as a flag for each graphic command. When displaying, picking, or re-displaying, the graphic command string to be displayed can be easily identified by the flag, and the number of graphic command strings to be compared with the window set for such display. In addition, the amount of data processing can be significantly reduced, and the display can be speeded up.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the graphic display system according to the present invention, and FIG. 2 is an explanatory view showing the relationship between the graphic command sequence in the window and the image data in the viewport in FIG. 1, and FIG. Is a flow chart showing the processing operation for the zoom-up display and the pick display of the graphic processor in FIG. 1, FIG. 4 is a flow chart showing the processing operation for the zoom-down display, and FIG. 5 is the zoom-up display, the zoom. FIG. 6 is an explanatory view showing a window and a display screen in the down display, FIG. 6 is an explanatory view showing an example of a pick aperture set in the window for the pick display, and FIG. 7 is a redisplay of the graphic processor in FIG. 3 is a flow chart showing a processing operation for. 1 ... Input device, 2 ... Host computer, 3 ... Control processor, 4 ... Graphic data buffer, 5 ... Graphic processor, 6 ... Frame memory, 7 ... CRT, 1
0 …… Graphic command string, 11 …… Display flag, 12 …… Inclusion flag.

Claims (3)

[Claims] 1. A graphic command sequence defining a two-dimensional or three-dimensional single graphic or a graphic group is stored in a memory, and a window or view volume and a window set by reading the graphic command sequence from the memory are stored. Comparing and judging the single figure or group of figures defined by the figure command sequence,
In a method in which only a portion of the single figure or figure group included in the set window or view volume can be displayed as a figure, the result of comparison judgment with the window or view volume for each figure command row in the memory Is added, and a single figure or group of figures to be compared with the next newly set window or volume is determined according to the newly set window or volume. A graphic display method characterized by selecting from a single graphic or a graphic group defined by a column based on the flag. 2. The display flag according to claim 1, wherein the flag is a display flag indicating whether or not at least a part of the single figure or the figure group exists in the set window or the view volume. A graphic display method characterized by being present. 3. The flag according to claim 1, wherein the flag is an inclusion flag indicating whether or not the single figure or the entire figure group is present in the set window or view volume. A graphic display method characterized by.