JP2595012B2 - Display device with two-dimensional and three-dimensional display functions - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device for three-dimensional display, and more particularly to a display device with a function of three-dimensional display and three-dimensional display that can be used for two-dimensional display. .

[Conventional technology]

A conventional example of a three-dimensional display device is "Interactive Computer Graphics II" (translated by Osuga, published by Tuna Hirubuk Co., Ltd., 1984 edition).

[Problems to be solved by the invention]

In the above-mentioned conventional example, various basic matters for three-dimensional display are considered, but no particular description is given of a display combination of two-dimensional and three-dimensional.

For three-dimensional display, it is widely known to use a Z buffer for storing a depth value of a three-dimensional image and a frame memory for storing the three-dimensional image. When a three-dimensional display device is used for two-dimensional display, how to efficiently perform a figure search process (referred to as a pick process) becomes a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a display device with a function of displaying a two-dimensional display graphic and a three-dimensional display while effectively utilizing the Z buffer.

[Means for solving the problem]

In the present invention, the graphic registration information (pic information) in the graphic management information is stored in all or a part of the Z buffer for pick processing of a two-dimensional display graphic.

[Action]

According to the present invention, a picking target graphic can be immediately recognized based on the graphic registration information in the Z buffer.

〔Example〕

FIG. 1 is an embodiment of the overall configuration of the display device of the present invention. This display device is a CP for overall management.
U1, common bus 2, segment buffer 3, graphics processor 4, common bus 5, frame memory 6, Z buffer 7, CRT
8, an I / O controller 9, a keyboard 10, a coordinate input unit 11, and a stylus pen 110.

The segment buffer 3 stores graphic management information, and the graphics processor 4 performs image processing using the graphic management information. When displaying this processing result,
The three-dimensional image is temporarily stored in the frame memory 6 and the depth value of the figure is stored in the Z buffer memory 7. This depth value is given for each display pixel. Therefore, if the number of display pixels is n × m, the Z buffer memory 7 also has a capacity of n × m, and has a depth value corresponding to the pixels in the frame memory 6 on a one-to-one basis.

At the time of display, a pseudo three-dimensional display of the image in the frame memory 6 is performed using the depth value of the Z buffer memory 7. For example, a figure having a deep depth value is displayed dark, and a figure having a shallow depth value is displayed bright. This is a pseudo three-dimensional display. In addition, hidden line erasure may be performed.

In many cases, a figure search process is performed interactively on a display figure. This is called pick processing. The picking process is to designate a figure being displayed, specify the designated figure in the graphics processor, and delete or add the specified figure. In a narrow sense, there is a case where a figure is specified (selected). In this embodiment, the former is broadly defined.

The procedure of the specific picking process in FIG. 1 is as follows.
The operator uses the stylus pen 110 of the coordinate input unit 11 to move the cursor 83 to a graphic position to be added or deleted while watching the cursor 83 on the display 8 that moves in accordance with the movement of the stylus pen 110, and moves the pen down. Perform the above operation. Input coordinate data pen-down from the coordinate input device 11 is taken into the CPU 1 via the I / O controller 9, and the CPU 1 creates a pick area from the taken input coordinate data. This pick area is a minute rectangular area having the input coordinate data as the center coordinates. The size of this minute rectangular area was fixed both vertically and horizontally. Next, start information for starting the picking process is created, and this starting information is sent to the graphic display 4 to start the picking process.
The GDP 4 sequentially reads graphic data from the entire scanning area in the segment buffer 3 included in the startup information, and searches whether or not each graphic data is data existing in the pick area in the startup information.

Here, the scanning area in the segment buffer 3 is a search target area in the segment buffer 3, and more specifically, the scanning area is defined by a start address and an end address of the scanning area on the segment buffer 3. Was defined. GDP4 is
Starting with the start address as the starting point, segment buffer 3
Is stored in The graphic data is read out, and for each graphic data, it is compared whether or not the graphic data exists in the rectangular pick area. If the graphic data exists in the pick area, the GDP 4 is specified as a pick target graphic. If it does not exist in the pick area, the graphic data at the next address is read out and compared with the area. Hereinafter, the graphic data is read out one after another for all the scanning areas up to the end address, and it is compared whether or not the graphic data exists in the picking area.

Pick information is created based on the result of the comparison. If the pick information is a figure existing in the pick area, its figure number becomes the pick information. The graphic number includes a segment number (#A or the like) and a primitive (# 100 or the like) number. It may be expressed only by the primitive number. Thus, as shown in FIG. 2, pick information 41 as end information of the pick process is obtained in the GDP4.

The pick information 41 is a figure specified by the pick process, and is processed as an object to be deleted or the like in the next stage of processing.

In addition, for the entire scanning area, the figure to be picked is 1
Not necessarily individual.

The memory capacity of the segment buffer 3 is usually 2 megabytes to 4 megabytes. The time required to load the graphic data of the segment buffer 4 into the GDP 4 for picking processing is a maximum of 8 seconds if the memory access time is 2 microseconds / 1 byte when the scanning area is the entire area. Cost.

When the displayed graphic is to be picked during the display of the three-dimensional image, the picking process may be performed by the above-described method, but if the picking can be performed in a short processing time during the display of the two-dimensional graphic. preferable.

In this embodiment, the efficiency of the picking process during the display of a two-dimensional figure is improved. For this purpose, the figure registration information for picking is stored in the Z buffer not used during the two-dimensional display. Hereinafter, the picking processing of the three-dimensional display figure and the picking processing of the two-dimensional display figure will be separately described in detail.

(1) Pick processing of three-dimensional display graphics FIG. 2 shows this explanatory diagram. The segment buffer 3 stores graphic management information. The figure management information is composed of information designated by a segment for each display figure. FIG. 2 shows an example having a segment #A of a triangle designation, a segment #B of a circle designation, and a segment #C of a triangulation designation. Indicated. The management information for each of the figures A, B, and C includes the segment information 30 (#A, #B, and #C), each segment rectangular area disclosure data (a rectangular area including the figure for each segment is set in advance. 31), segment constituent elements (referred to as primitives) 32, 34, 36, and state information 33, 35, 37 indicating the state of the graphic (solid line or color display) for each of the primitives. Each primitive element is #
These are indicated by 101 to # 303.

The pick-up information 40 formed by the CPU 1 and sent to the GDP is:
It consists of a start command, drawing / picking designation, scanning area (defined by start address and end address), and pick area (defined by center coordinates and length of vertical and horizontal rectangular sides). An example of the scanning area in this activation information is shown on the segment buffer 3 in FIG. The scan area is compared with the pick area in the start information of the segment rectangular area 31, and it is checked whether or not the scan area is included in the pick area. If not, the next segment #B is skipped.

The check as to whether or not the rectangular area is included in the pick area is defined to be included when all or a part of the rectangular area exists in the pick area.

The same comparison as described above is performed one after another until the end address of the scanning area is reached, and an operation for specifying the figure to be picked is performed.

Note that the rectangular area is determined according to the size of the figure as shown in the display screen 8 in FIG. In the figure, the rectangular area #A is larger both vertically and horizontally than the rectangular area #B.

As a result of the comparison, if it is determined that the segment is included, it is compared whether or not the segment covers the pick area for each of the constituent primitives. To be specified. Here, the pick information 41 includes, for example, a segment number (#A or the like) and a primitive (# 100 or the like). There may be cases where only primitives are used.

FIG. 3 shows a flowchart of the picking process in the three-dimensional display figure. The details are clear from the above description, and thus are omitted.

Note that FIG. 2 shows an example in which the cursor instruction 83 is for the segment #C of triangulation, and the primitive # 300, which is a triangular surface in this structure, is specified as a pick target graphic.

(2) Pick Processing of Two-Dimensional Display Graphic Regarding pick processing of two-dimensional display graphic, the contents of the segment buffer 3 are the same as those of three-dimensional display graphic. That is, the graphic management information on the segment buffer 3 for the two-dimensional display is as shown in FIG.

The difference from the picking process of the three-dimensional display graphics is that the segment number (#A or the like) or the primitive information (# 100 or the like) in the graphic management information is picked up in part or all of the X buffer 7 on the frame memory 6. That is, the Z buffer 7 obtains the pick information only by searching in the picking process. Accordingly, in the picking process of the three-dimensional figure, the procedure of searching the segment buffer 3 to obtain the pick information is adopted, whereas in the picking process of the two-dimensional diagram, the Z process is performed.
Pick information can be obtained only by searching the buffer 7 alone. That is, there is an advantage that the search for the segment buffer 3 becomes unnecessary.

 This will be described in detail with reference to the drawings.

FIG. 4 shows an example of allocation on the segment buffer 3, the Z buffer memory 7, and the display screen 8 when handling both a two-dimensional figure and a three-dimensional figure. In segment buffer 3,
As a command for setting a display area from the CPU 1, a buffer enable / disable command 3A and area data 3B indicating a three-dimensional display area are written. The region data indicating the three-dimensional display region is a three-dimensional display region on the display screen, and the display region other than the display region is a two-dimensional display region. The display area 8 of FIG. 4 shows the display area examples 8A and 8B. Furthermore,
The segment buffer 3 has a data area 3C for storing two-dimensional graphic data and a data area 3D for storing three-dimensional graphic data. The data areas 3C and 3D are the same in form as the contents of the segment buffer 4 shown in FIG. 2. The area 3C stores two-dimensional graphic data to be displayed. The three-dimensional data to be stored is stored.

The Z buffer 7 in FIG. 4 has a Z value storage area 7A corresponding to the three-dimensional display area 8A and a two-dimensional figure pick information storage area 7B corresponding to the secondary dimension display area 8B. This area 7B is
It stores two-dimensional figure pick information, and is the largest feature of this embodiment.

FIG. 5 shows the flow of the process of writing pick information to the Z buffer memory 7 for two-dimensional and three-dimensional use in FIG. First, the CPU 1 starts the GDP4. The GDP reads out the Z buffer valid / invalid command 3A and the three-dimensional display area data 3B in the segment buffer 3. From command 3A, it is determined whether the Z buffer is valid or invalid. Z buffer validity means
It means that the area 7A is effective for three-dimensional display,
The term "invalid" means that the area 7A is invalid, that is, the Z value of the area 7A is not used or becomes unnecessary.

Therefore, when the area is invalid, not only the area 7B but also the area 7A can be used for storing the pick information. Therefore, the entire area of the Z buffer is cleared to "0".

If valid, refer to 3D display area data 3B,
Only the area 7A corresponding to the area data 3B is left as it is, and only the other area 7B is cleared to "0".

After completing the above, area 3C of segment buffer 3
GDP4 captures three-dimensional figure data from Finally, the display is started, the display graphic data is developed and written in the frame memory 6, and the pick information is also written corresponding to the display graphic. Here, the pick information is graphic management information on the segment buffer, and selects one of a segment number (#A or the like) and a primitive number (# 100 or the like). In the following, the primitive number is selected as the pick information.

The write area of this pick information is an area where “0” is cleared on the Z buffer 7. The pick information is stored in the frame memory 6 corresponding to the display graphic data.

FIG. 6 shows the relationship among the frame memory 6, the Z buffer 7, and the display surface 8 in a specific graphic example. A triangular figure was selected as the two-dimensional display figure. This triangle 83 consists of three primitives,. This triangular figure is stored in the frame memory 6 corresponding to the display position as shown in the figure. On the other hand, the Z buffer 7 stores the primitive numbers of the frame memory 6 corresponding to the triangular figures. This primitive number becomes the pick information. As is clear from the figure, in the area where no figure exists,
Pick information does not exist or is "0".

Next, the picking process of a two-dimensional figure will be described with reference to FIG.
First, when the operator positions the cursor 83 on the straight line of the graphic # and performs a picking operation on the graphic, the picked coordinate data is input from the coordinate input unit 11 to the picked coordinate input data (X, Y). Then, a pick area is created, and pick start information is created. This series of processing is the same as the three-dimensional picking processing described in FIG. The processing so far is performed by the CPU 1. Next, CPU1 starts GDP4,
The GDP 4 accesses the Z buffer and reads out the pick information in the pick area. If there is pick information in the pick area,
This is the pick target graphic. FIG. 6 shows an example in which the pick position 83 is designated and the primitive graphic number # 2 is selected. The picked-up information in this area is taken in by the GDP 4 as selected picked-up information, reported to the CPU 1, and the picking process ends.

 The pick area may be other than a rectangle.

〔The invention's effect〕

According to the present invention, when picking up a two-dimensional display under a three-dimensional display device, the picked-up graphic can be searched only by reading out the graphic management information stored in the Z-buffer. Can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram of an embodiment of the present invention, FIG. 2 is a specific example diagram for graphic processing, FIG. 3 is a flowchart for pick processing, FIG. 4 is an explanatory diagram of pick processing of a two-dimensional display graphic, FIG. 5 is a flowchart of a process for storing pick information in a Z buffer, FIG. 6 is a diagram showing a specific example of a process under the display of a triangular figure, and FIG.
The figure is a flowchart for picking a two-dimensional display figure. 1 ... CPU, 3 ... Segment buffer, 4 ... Graphic processor, 6 ... Frame memory, 7 ... Z buffer.

Claims (1)

(57) [Claims] 1. A segment buffer for storing graphic management information, a processor for performing image processing based on the graphic management information of the segment buffer, a frame memory for temporarily storing the image processing result, and the image processing result A display device comprising: a Z-buffer memory for storing a figure depth value for three-dimensional display; and a display unit for performing three-dimensional display based on the frame memory, the Z-buffer memory, and the contents. Means for storing a two-dimensional figure, which is a processing result of the processor, in the frame memory; and in accordance with the storage, a figure in the figure management information is stored in all or a part of the Z buffer in correspondence with an address of an image in the frame memory. Means for storing the registration information as two-dimensional figure pick information; and A display device with a function of two-dimensional display and three-dimensional display, comprising: means for reading out the corresponding pick information and making it a pick processing target.