JPH04308921A - Multiwindow system - Google Patents

Abstract

PURPOSE:To operate the same operation to the image data of the non-display part of a window with that to the display part by providing an image cache and a frame buffer in the same level, in multiwindow. CONSTITUTION:This system is equipped with a frame buffer 105 which holds a displayed subwindow image, and an image cache 106 which holds the subwindow image screened at the back side. A subwindow list storage means 102 which holds subwindow management data and an area management means 101 which updates the subwindow management data are installed. Thus, a coordinate calculation at the time of plotting can be simplified, the image data of the non-display part of the window can be operated as well as the display part, and the processing can be operated independently to a central arithmetic unit.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a subwindow management method in a multi-window system.

0002

2. Description of the Related Art In conventional overlapping multi-window systems, overlapping and hidden sub-windows are held in main memory. Two conventional techniques will be described below with reference to the drawings.

FIG. 4 shows a central processing unit 1 as a first conventional example.
An example of a multi-window system configured only with 07 is shown. In this system, the central processing unit 10 performs both drawing to the frame buffer 105 and drawing to the main memory 108.
7, so when drawing, the two were distinguished and coordinate transformation was performed separately. In addition, each time the window overlapping condition is changed, the saved subwindow image data is transferred from the main memory 108 to the system bus 109.
The central processing unit 107 performs the work of writing back to the frame buffer 105 via the central processing unit 107 .

Next, FIG. 5 shows a second conventional example of a multi-window system including a drawing-only sub-processing unit 501. In this system, the frame buffer 10
The drawing on the main memory 108 was performed by the central processing unit 107, whereas the drawing on the main memory 108 was performed by the sub-processing unit 501 dedicated to drawing. When a change occurs in the degree of window overlap, the central processing unit 10 performs the task of writing the saved subwindow image data back from the main memory 108 to the frame buffer 105 via the system bus 109.
7 and processing by the drawing-only sub-processing unit 501.

[0005]

[Problems to be Solved by the Invention] In any conventional multi-window system, the window currently displayed on the screen is stored in the frame buffer 105.
The sub-windows hidden by superimposition are held in the main memory 108, and it is necessary to distinguish between the two and perform coordinate transformation separately.

Furthermore, at least the coordinate transformation for the main memory 108 must be performed by the central processing unit, which poses a problem in that a very large load is placed on the central processing unit.

The present invention has been made in view of the above problems, and provides an image cache at the same level as the frame buffer that holds subwindow management data and holds image data of subwindows hidden due to overlapping, thereby making it possible to hide windows. The object of the present invention is to provide a multi-window system that allows the same operations as for the display part on the image data of the part.

[0008]

[Means for Solving the Problems] The multi-window system of the present invention includes a frame buffer that holds data currently displayed on the screen, an image cache that holds image data of sub-windows hidden by overlapping, and a window a subwindow list storage means for storing a list of subwindows composed of window units distinguished by identifiers, and determining whether a drawing target is the frame buffer or the image cache based on the subwindow list; coordinate-address converting means for generating an address to be drawn, and, when drawing, a drawing position and image data to be drawn received from the central processing unit, and the subwindow read from the subwindow list storage means. Subwindow management that transmits the list to the coordinate-address conversion means, and when the overlap of windows changes, divides the window into one or more subwindows and stores the subwindow list in the subwindow list storage means. It is characterized by consisting of means.

[0009]

[Operation] When drawing, when the central processing unit specifies the drawing position and the image data to be drawn, the subwindow management means reads out the list of subwindows from the subwindow list storage means and performs coordinate-address conversion. convey to means. The coordinate-address conversion means generates an address to be drawn based on the subwindow list transmitted from the subwindow management means. Coordinates -
Based on the address generated by the address conversion means, it is determined whether the object to be drawn is a frame buffer or an image cache, and the central processing unit writes designated image data to be drawn to that address. This effect makes it possible to obtain a multi-window system in which image data in the non-display portion of the window can be manipulated in exactly the same way as in the display portion.

[0010] Furthermore, when the degree of overlapping of windows changes, the sub-window management means re-divides the original window according to the overlapping portion of the overlapping windows, generates sub-window management information, and stores it in the sub-window list storage means. Remember updated information.

[0011]

Embodiment FIG. 1 is a block diagram of a multi-window system in this embodiment.

In FIG. 1, subwindow management means 1
01 is connected to the system bus 109, and when drawing, it receives the window identifier received from the central processing unit 107, window coordinate values indicating the drawing position, image data to be drawn, and subwindow list storage means. Information about the start address of the subwindow to be drawn and the window position read from 102 is transmitted to coordinate-address conversion means 103. Furthermore, when the overlapping of windows is changed, the window is divided into one or more sub-windows, and a list of the sub-windows is stored in the sub-window list storage means 102.

The coordinate-address conversion means 103 is connected to the subwindow management means 101 and receives information on the start address and window position of the subwindow to be drawn, which are stored in the subwindow list storage means 102, from the subwindow management means 101. Based on this information, an address for drawing is generated and transmitted to the frame buffer 105 or image cache 106.

The frame buffer 105 and the image cache 106 are connected to the coordinate-address conversion means 103, and store image data instructed by the central processing unit 107 at the address generated by the coordinate-address conversion means 103. .

The frame buffer 105 holds image data of a subwindow currently displayed on the screen of the window, and the image cache 106 holds image data of a subwindow hidden behind the window due to overlapping windows.

Image data transfer means 104 is also connected between frame buffer 105 and image cache 106 .

FIG. 2 shows an example of a window display state. In this example, window 1 is displayed on top of window 2 on the screen, as shown in Figure 2(a).
Subwindow B of window 2 is hidden behind window 1. In this state, the image data of subwindow A of window 1 and subwindow C and subwindow D of window 2 are stored in the frame buffer 10.
5 (FIG. 2(b)), and the image data of subwindow B of window 2 is stored in the image cache 106.
is held (Fig. 2(c)).

Table 1 shows the status of the subwindow list stored in the window list storage means 102 at this time. The list of subwindows consists of windows that are distinguished by window identifiers, and stores the number of subwindows indicating the number of divisions, the window position indicating the position on the screen where the window is displayed, and the image data within the subwindow. It consists of a subwindow list that partially includes the start address of the image data in the frame buffer 105 or image cache 106 and indicates the boundary value of each subwindow. Even if the window is not split,
For consistency, it is treated as one sub-window.

[0019]

[Table 1]

In this state, the coordinate values of window 2 (wx
1, wy1) will be used as an example to explain the operation of drawing primitives such as straight lines, curves, characters, and fill.

The window management means 101 receives the coordinate values (wx1, wy1) of the window 2 from the central processing unit 107.
Upon receiving this, the subwindow list related to window 2 stored in the window list storage means 102 is read out, and the boundary values (Table 1) and coordinate values (wx1, wy1) of the three subwindows B, C, and D are compared. Let's do it. As a result of the comparison, it is found that this coordinate value belongs to the subwindow D, and it can be determined that the drawing target is the frame buffer 105. At the same time, a base address ba indicating the start address of the subwindow to be drawn in the frame buffer 105 attached to the list of subwindows D
se, window position of window 2 (sx1, sy1
), and the coordinate values (wx1, wy1) already received from the central processing unit 107, are converted into the coordinate-address conversion means 1.
03.

The coordinate-address conversion means 103 converts the received window position (sx1, sy1) and coordinate value (wx
1, wy1), the drawing position in the frame buffer 105 is calculated and combined with the base address base, a drawing address is generated. The image data to be drawn received from the central processing unit 107 is written to the frame buffer 105 at this address. Central processing unit 10
From 7 onwards, the window identifier of the object to be drawn, the window coordinate values, and the drawing image data are sequentially instructed to complete the drawing.

Next, the coordinate values of window 2 (wx2, w
The operation of drawing on the image cache 106 will be explained by taking as an example the case where drawing is performed at y2).

The method for determining the object to be drawn is exactly the same as in the case of drawing to the frame buffer 105, and after the comparison in the window management means 101, the subwindow B
The address iaddr and the coordinate value (wx2,
wy2) to the coordinate-address conversion means 103. In this case, since the drawing target is the image cache 106, the calculation method is different from the case for the frame buffer 105, and the calculation method is different from that for the frame buffer 105.
, a drawing address in the image cache 106 is generated. The image data to be drawn received from the central processing unit 107 is written to this address.

In FIG. 3, a case where a change in overlapping occurs will be described below, taking as an example a case where window 2 is brought above window 1. 3(a) shows the display state on the screen, FIG. 3(b) shows the storage state in the frame buffer, and FIG. 3(c) shows the storage state in the image cache.

When an instruction to bring window 2 above window 1 is received from central processing unit 107, window management means 101 changes the method of dividing sub-windows. This is shown in FIG. First, scan in the Y direction, divide by Y coordinate unit of the vertices that overlap in the window, and then,
Scan in the X direction and divide by the X coordinate unit of the vertices that overlap within the window. As a result, the division of window 1 is changed from the original subwindow A to subwindows E, F, and G. Also, window 2 is the original subwindow B,
The division changes from C and D to subwindow H. In this way, a new list of subwindows is created in the subwindow list storage means 102 (Table 2) and temporarily coexists with the old one. Even if this division method is changed, nothing changes on the screen.

[0027]

[Table 2]

As described above, when the degree of overlapping of windows changes, the subwindow management means 101 re-divides the original window according to the overlapping portion of the overlapping windows, generates subwindow management information, and creates a subwindow list. The updated information is stored in the storage means 102.

Next, in order to save the subwindow G to the image cache 106, the window management means 10
1 in the image cache 106, a new memory area for holding the image data of subwindow G of window 1 is secured in the image cache 106.

Next, the central processing unit 107 sequentially accesses all coordinates corresponding to subwindow G of window 1 and instructs to save them. The coordinate values received from the central processing unit 107 are converted into addresses by the coordinate-address conversion means 103. After the image data of subwindow G has been transferred to image cache 106, image data of subwindow B of window 2 is transferred from image cache 106 to frame buffer 105. When the transfer is completed, the old subwindow management data stored in the area list storage means 102 is deleted, and the window state change is completed.

Furthermore, in the configuration including the image data transfer means 104, when an area for data transfer is specified,
The image data transfer means 104 performs the data transfer independently of the central processing unit 107 without the central processing unit 107 accessing the coordinates within the subwindow.

As described above, according to this embodiment, the subwindow management means 101, the subwindow list storage means 102, and the image cache 106 are provided, and the subwindows hidden due to overlapping are stored in the image cache 1.
06 and uses the information in the subwindow list storage means 102 to determine whether or not the object to be drawn is displayed, the image data in the non-display part of the window can be manipulated in the same way as in the display part.

[0033]

As described above, according to the present invention, there is a frame buffer that holds the displayed subwindow image, an image cache that holds the subwindow image hidden behind the screen, and a subwindow list that holds the list of subwindows. By providing a storage means and a subwindow management means for updating subwindow management data, coordinate calculation during drawing is simplified, image data of a non-displayed part of the window can be operated in the same way as the displayed part, and , processing can be performed independently of the central processing unit.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a multi-window system in an embodiment of the present invention.

FIG. 2 is a first operational diagram of the multi-window system in the embodiment.

FIG. 3 is a second operational diagram of the multi-window system in the embodiment.

FIG. 4 is a configuration diagram of a multi-window system comprising only a central processing unit, which is a first conventional example.

FIG. 5 is a configuration diagram of a multi-window system configured using a drawing-only sub-processing unit, which is a second conventional example.

[Explanation of symbols]

101 Subwindow management means 102 Subwindow list storage means 103 Coordinate-address conversion means 104 Image transfer means 105 Frame buffer 106 Image cache 107 Central processing unit 108 Main memory 109 System bus

Claims (2)

[Claims] Claim 1: In a multi-window system that displays multiple windows displaying text, graphics, images, videos, etc. on the same screen by allowing them to overlap, data currently displayed on the screen is retained. a frame buffer; an image cache that holds image data of sub-windows hidden by overlapping; a sub-window list storage means that stores a list of sub-windows made up of window units distinguished by window identifiers; a coordinate-address conversion means for determining whether a drawing target is the frame buffer or the image cache and generating respective drawing addresses;
When drawing, the drawing position received from the central processing unit, the image data to be drawn, and the subwindow list read from the subwindow list storage means are transmitted to the coordinate-address conversion means, and the window subwindow management means for dividing a window into one or more subwindows and storing the subwindow list in the subwindow list storage means when the overlap of the windows changes. 2. A multi-window system further comprising an image data transfer means between the frame buffer according to claim 1 and the image cache.