JPH0434175B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a graphic display device such as a graphic CRT display device.

(Conventional technology) Graphic CRT display devices have traditionally been
They are mainly used for offline work such as creating and modifying figures in fields such as CAD, CAM, and CAE, but recently their use as terminal devices for online systems has been increasing. Also, in engineering workstations that have recently begun to be used in various fields, they are used as graphics processors in a form tightly coupled to a host processor within the workstation.

(Problems to be Solved by the Invention) This graphic CRT display device, which can be used as a terminal device for an online system or as a graphics processor for a workstation, has the following two points in function and performance compared to conventional ones. is strongly required.

(1) High-speed display: Good responsiveness is an essential condition for online systems, and the process from display request to display completion must be performed quickly, and various display updates must be performed quickly.

(2) Advanced interactive function: Select, change, and process contents using a pointing device such as a mouse.
Interactive functions such as specifying processing targets also require responsiveness.

In order to meet these demands, a system configuration called an intelligent terminal type has been adopted as a graphic display system.
As shown in Fig. 1, this system is connected to a host computer system 2, which is an external control device, through a communication circuit (transmission line 12) and a graphic CRT display device 1 having an intelligent function. An online system is constructed by connecting to other graphic display devices or a host computer via the computer.
In this configuration, the host computer system 2 performs a large amount of arithmetic processing or data processing to realize the application, and the graphics CRT
By using a distributed processing method in which the processor in the display device 1 performs display processing, the load on the host computer system 2 is reduced while improving responsiveness on the graphic CRT display device side. The graphic display process in the configuration shown in FIG. 1 will be explained in detail below.

The graphic CRT display device 1 performs refresh drawing using a raster scan display method.
It has a CRT monitor 3, a control processor 4 as a control center, and graphic information (information such as line segments, symbols, characters, etc.) to be displayed is stored in a picture memory 5. As shown in FIG. 2, the picture memory 5 generally includes a work area 51 in which management data, temporary save data, etc. necessary for the control processor 4 and display processor 6 to work are stored, and figures such as characters, vectors, and polygons. A common data area 52 in which character fonts, symbol definition data, line texture patterns, fill patterns, etc. commonly used in a plurality of segments forming a graphic unit by a set of primitives are stored, and a segment button in which segment data is stored. It has a fur 53. The display processor 6 cuts out the graphic information stored in the segment buffer 53 within the range requested for display. This cutting process by the display processor 6 includes enlarging and
Coordinate conversion processing to reduce, rotate, and move; clipping processing to remove portions that protrude from the designated display screen frame on the CRT monitor 3; There is a digital differential analysis (DDA) process that develops the on/off information of the bits.

On the other hand, the host computer system 2, which is an external control device, uses the host processor 8 as a control center and divides the data processed into graphical information into an appropriate format as one of the processing functions of online processing.
Graphic information in the range required by the graphic CRT display device 1 is stored in an auxiliary storage device 9 such as a magnetic disk, and is transmitted to the interfaces 10, 11,
Graphics through the communication line of transmission path 12
The graphics CRT display device 1 transmits the received data to the control processor 4.
The image is stored in the picture memory 5 by the following.

Some of the online systems include disaster prevention systems,
There are systems, such as emergency systems, that require urgent information search and prompt display of that information on a graphic CRT display. At this time, graphic information in the display requested range is transferred from the host computer system 2 to the graphic CRT display device 1 via the transmission line 12. The problem here is the processing time required to convert graphical information on the host computer system into external commands that can control the graphics CRT display device 1.
Considering a CRT display device, since a serial line communication line for character transfer is used, the external command transmission time and the processing time for the control processor 4 to convert external commands into internal commands are long, which is unsatisfactory in terms of high-speed drawing.

(Means for Solving the Problem) In order to solve this problem, the present invention provides a work area 51 for management data etc. and a plurality of segments of data already stored in the picture memory 5 of the graphic CRT display device 1 as graphic information. A means is provided for rapidly transferring only the segment data stored in the segment buffer 53 to and from the auxiliary storage device 9 of the host computer system 2 without re-registering the data stored in the common data area 52 common to the host computer system 2. By this, graphic
When using segment data in the CRT device 1, the segment data once registered is transferred from the host computer system 2, and command conversion processing is minimized, and the conversion processing time and control to external commands by the host processor 8 are reduced. By minimizing the processing time required for conversion into internal commands by the processor 4, and by using direct transfer as the segment data transfer means, high-speed drawing can be achieved.

(Example) Examples of the present invention will be described below. For high-speed drawing, which is the purpose of this invention, the host computer system 2 and the graphic CRT display device 1 are connected by a parallel data transfer interface, or the graphic CRT display device 1 is tightly coupled to the bus of the host computer system 2. It is necessary to do so. Two embodiments are shown in FIGS. 3a and 3b.

Figure 3a shows the interface 1 shown in Figure 1.
0 and 11 are respectively parallel data interfaces. When reading the segment data (in the segment buffer 53) of a segment specified by the host computer system 2 from the graphic CRT display device 1 to the disk 9 of the host computer system 2 (this is called a save function), the host computer system 2 The save command is transferred to the graphics CRT display device 1, and the control processor 4 points to the DMA (direct memory access) transfer mechanism in the parallel interface 11 at which address of the segment buffer 53 the specified segment is located. hand,
Control is given to parallel interface 11 and DMA
Start.

The interface 10 of the host computer system 2 also performs DMA transfer to the memory 13 of the host computer system 2 while coordinating with the parallel interface 11 and reads the segment data. After that, the segment data is saved from the memory 13 to the disk 9. Conversely, from host computer system 2 to graphics CRT
When transferring segment data saved in advance to the display device 1 (this is called a load function), the segment data of the display area is stored from the disk 9 to the memory 13 for high-speed drawing, and then loaded to the graphics CRT display device 1. After issuing the command, the parallel interface 10
The DMA mechanism transfers the data from the memory 13 to the graphic CRT display device 1 through the parallel data transmission line 12. Graphic CRT display device 1
Then, the control processor 4 uses the segment buffer 53.
It searches for an empty area, indicates the address of the empty area to the parallel interface 11, and loads it into the segment buffer 53 using the DMA method as well. Thereafter, in order to display the loaded segment, a display command for that segment is issued, and the display processor 6 starts displaying the segment.

In the configuration shown in FIG. 3B, the host computer system 2 and the graphic CRT display device 1 are tightly coupled by directly connecting the control processor 4' to the system bus 14 of the host computer system 2. The control processor 4' is
Except for having a mechanism for coupling the system bus 14 and the image bus 15 by DMA, the processing procedure for the save/load function can be performed in the same manner as in the embodiment shown in FIG. 3a. In the form (b), the data transmission time is generally shorter than in the form a. Also,
Serial transmission is also possible between the host computer and the graphic CRT display device, if the transmission time is allowed to increase slightly.

(Effects of the Invention) As explained above, when using segment data on a graphic display device, once registered segment data is transferred from an external control device, command conversion processing is minimized, and the host processor By minimizing the processing time for converting to commands and the processing time for converting internal commands by the control processor, and by using direct transfer as the segment data transfer means, it is possible to make it possible to make a display request for a certain display object and then actually display it. The time required for data transmission and the actual drawing operation are the same, and high-speed drawing can be achieved. That is,
High-speed drawing can be achieved by re-registering only the segment data in the segment buffer using the DMA method and parallel transmission or tightly coupled method.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the general configuration of a graphic display system, FIG. 2 is an internal structure diagram of a picture memory,
FIG. 3 shows a form for realizing the save/load function in an embodiment of the present invention. 1... Graphic display device (Graphic CRT display device), 2... External control device (host computer system), 4, 4'... Control processor, 5...
...Picture memory, 9...Disk, 10, 11
... Parallel interface, 12 ... Parallel data transmission line, 13 ... Memory, 14 ... System bus, 15 ... Image bus, 53 ... Segment buffer.

Claims (1)

[Scope of Claims] 1. It has a picture memory and a frame buffer for displaying figures expressed by a plurality of segments, and converts segment data given as external commands from an external control device into internal commands by a control processor. In a graphics display device that registers the internal commands in a picture memory and develops bits in a frame buffer by a display processor based on the registered internal commands and displays them, the registered internal commands stored in the segment buffer in the picture memory are processed segment by segment. means for directly transferring the transferred internal commands to an external control device; and means for directly transferring the transferred internal commands from the external control device again in segment units to a segment buffer in a picture memory in the graphic display device without performing command conversion processing; A graphic display device comprising: