JPH0553753A - Scrren scroll method - Google Patents

Abstract

PURPOSE:To reduce the quantity of data to be transferred and to attain a smooth and high speed scroll action by reforming a screen during 8 scroll action. CONSTITUTION:A scroll reformation reference axis is set to the picture drawn on the graphic memory of a graphic terminal 2 connected to a host computer 1. Then the terminal 2 gives a partial rewriting request (reforming event) to the computer 1 for the picture of the graphic memory when the edge of a display area reaches the scroll reformation reference axis. At the terminal 2, the rectangular transfer of data (transfer of data) is carried out to transfer the data on the undisplayed part of the graphic memory to the displayed part after the output of the reforming event with an instruction given from the computer 1. At the same time, the terminal 2 carries on a scroll action until the edge of the graphic memory is displayed. Meanwhile the computer 1 instructs the terminal 2 to perform the rectangular transfer of data after reception of the reforming event and then writes the data in an idle part produced by the rectangular transfer to draw the picture.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of scrolling a screen (also called a picture) in a graphic terminal connected to a host computer, and in particular, a smooth scrolling operation of a part of a very large picture exceeding the memory capacity. A scroll method that can be performed.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 4, a graphic system of this type has a host computer 1 (hereinafter, simply referred to as a host), a CRT 3, a keyboard 4, a mouse 5, and a graphic terminal 2 (hereinafter simply referred to as a terminal). Etc. are arranged and configured. By the way, in recent years, many of such graphic terminals have a graphic memory larger than the display screen, and therefore it is usual to realize scrolling by shifting the display start point. On the other hand, in order to scroll a picture larger than the capacity of the graphic memory, the scroll operation is locked once after displaying the end of the picture currently drawn in the graphic memory and the host is informed of this. Generally, the host rewrites the picture in the graphic memory and resumes scrolling when the rewriting operation is completed.

[0003]

However, in such a method, since all the pictures in the graphic memory are rewritten, the amount of data to and from the host increases and the time required for transmission increases. Further, during this time, the operation of the operator cannot be accepted at all, and there is a problem that the responsiveness deteriorates. Therefore, an object of the present invention is to make it possible to scroll a picture larger than the graphic memory at high speed and smoothly.

[0004]

In order to solve such a problem, according to the present invention, when a screen stored in a memory is displayed and scrolled by a graphic terminal connected to a host computer, the memory is stored. The scroll reconfiguration reference axis is set in advance at a predetermined position on the screen, and when the end of the display area reaches this reference axis, the terminal sends a reconfiguration event to the host computer, It is characterized in that after the data in the undisplayed portion of the memory is transferred to the already displayed portion, the data from the host computer is written in the vacant portion to perform scrolling.

[0005]

The scroll reconfiguration reference axis is set for the picture drawn in the graphic memory of the graphic terminal connected to the host, and when the end of the display area approaches this axis, the terminal sends to the host. A request for rewriting a part of the picture in the graphic memory (hereinafter, also referred to as a reconstruction event) is issued. On the terminal side, after issuing the reconfiguration event, the host performs an instruction to transfer the data in the undisplayed part of the memory to the already displayed part in a rectangular transfer (data transfer), while displaying the end of the graphic memory. The scroll operation is continued until it is done. In response to the reconfiguration event, the host side causes the terminal to perform the rectangular transfer, and then writes the data in the empty area by the rectangular transfer and performs drawing. It should be noted that if the edge of the graphic memory is displayed before the reconstruction is completed, the scroll is temporarily locked, but the scroll locked state is released after the reconstruction is completed. In other words, conventionally, since the screen is reconstructed after scrolling to the end of the memory, the amount of data increases and it takes time, but in the present invention, the screen is reconstructed during the scrolling. As a result, the amount of data to be transferred is reduced, the speed is increased, and a smooth scroll operation is enabled.

[0006]

1 is a flow chart showing an embodiment of the present invention. Here, an example of scrolling to the right (scrolling to the right) will be described. That is, when the graphic terminal detects in step S2 that the right scroll operation is executed in step S1 and the right end of the display area reaches a predetermined reconstruction reference axis on the graphic memory, the terminal in step S3. Request to rewrite part of memory to host (reconfiguration event)
To send. Once the reconstruction event is transmitted, the scroll direction is locked in one direction until the reconstruction is completed (step S4). This is to prevent frequent reconfiguration events. Also, even after sending the reconstruction event,
The scrolling continues until the end of the picture in the graphic memory is displayed. When the host receives the reconfiguration event, it sends a command to the terminal to transfer a part of the picture in the graphic memory (rectangular transfer), which causes the terminal to display the data in the undisplayed part of the memory. While the rectangular transfer (data transfer) for transferring to the already-completed portion is executed (step S5), the host draws a subsequent picture in the memory area which is empty by this rectangular transfer (step S6). Next, in step S7, it is determined whether or not the reconstruction is completed. If the end of the picture is displayed even though the reconstruction is not completed, the scroll is locked (steps S8 and S9). On the other hand, if the reconfiguration is completed in step S7, the scroll direction lock is released in step S10, and if it is not determined in step S11 whether or not the scroll operation is locked, the process is finished as it is. After releasing the lock, a series of operations is ended (step S12).

FIG. 2 is an explanatory diagram for explaining the contents of the memory, and FIG. 3 is an explanatory diagram for explaining a concrete example of the scroll operation. Note that reference numerals 10 and 11 in FIG. 2 denote reconstruction reference axes for right and left scrolls, respectively. Assuming that the graphic memory stores the screen data of A to K as shown in FIG. 2 and the scroll is started from the data E, the first display screen is as shown in FIG. Then, when the right end of the display area reaches the reconstruction reference axis, as shown in FIG. 3B, the terminal detects this and sends a reconstruction event to the host and performs rectangular transfer, while the host does Based on Figure 3
The screen data as shown in (c) is reconstructed. In this example, since the display start point (upper left point of the display frame) approaches the reconstruction reference axis in the vicinity of the data F, the data to the data K are moved to the left end by the rectangular transfer, and are free in the rectangular transfer. The data L and M from the host are stored in the open portion. It should be noted that the scroll operation is continued during this period, and when the right end of the memory is displayed as shown in FIG.
The scroll operation is performed again as shown in (e). Although the case of right scrolling has been described above, it goes without saying that the same applies to cases of left scrolling, up scrolling, and down scrolling.

[0008]

According to the present invention, when scrolling a large picture that exceeds the capacity of the graphic memory, a rectangular transfer of a part of the picture on the graphic memory is performed, and drawing is performed on an empty area by the rectangular transfer. As a result, the amount of data between the host and the terminal is reduced, and there is an advantage that a high-speed and smooth scroll operation can be performed.

[Brief description of drawings]

FIG. 1 is a flow chart showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining an example of contents of a graphic memory.

FIG. 3 is an explanatory diagram for specifically explaining a scroll operation according to the present invention.

FIG. 4 is a block diagram showing a general example of a graphic system.

[Explanation of symbols]

 1 Host computer 2 Graphic terminal 3 CRT 4 Keyboard 5 Mouse 10 Scroll reconstruction reference axis 11 Scroll reconstruction reference axis

Claims (1)

[Claims] 1. When a screen stored in a memory is displayed and scrolled by a graphic terminal connected to a host computer, a scroll reconstruction reference axis is set in advance at a predetermined position of the stored screen. When the edge of the display area reaches this reference axis, a reconstruction event is sent from the terminal to the host computer, and the data in the undisplayed part of the memory is transferred to the already displayed part. , A screen scrolling method characterized by writing data from a host computer to an empty space and scrolling.