JP3551963B2 - Scroll control device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a scroll control device that scrolls characters and the like on a display screen at high speed.
[0002]
[Prior art]
Conventionally, in a scroll control device that expands document data in which characters, graphics, and the like are mixed into display data in a bitmap format, and scrolls the display data as needed, a newly appearing document data is displayed every time scrolling is performed. It was very slow scrolling because it was necessary to re-expand the entire screen, including the bitmap.
[0003]
On the other hand, in the method disclosed in JP-A-2-310592, display data for several screens before and after the currently displayed screen is stored in a buffer in advance, and the display data is stored in a VRAM in response to a scroll request. , A relatively high-speed scroll is realized.
[0004]
[Problems to be solved by the invention]
However, when the color display becomes general, the capacity of the VRAM increases greatly in order to express multi-colors, and the buffer for storing the display data of the several screens requires a very large capacity. There is a problem that the time required to transfer the contents of the buffer to the VRAM cannot be ignored because of its large capacity.
[0005]
The scroll control device of the present invention solves such a problem, and does not require a large amount of buffers and realizes extremely high-speed scrolling even on a multicolor color display screen. Aim.
[0006]
[Means for Solving the Problems]
The scroll control device of the present invention transfers code data and document data having attribute information attached to the code information to storage means used for image display as bitmap data, and transfers the transferred bitmap data to a display unit. A scroll control device that controls display and rewrites bitmap data in storage means used for displaying the image in accordance with scrolling of the document data,
A scroll buffer that stores monochrome data corresponding to the document data for several screens including a screen corresponding to the bitmap data of the storage unit used for the image display;
When scrolling occurs, the monochrome data of the scroll buffer corresponding to the document data newly displayed by the scrolling is transferred to storage means used for displaying the image, and the monochrome data of the document data not stored in the scroll buffer is transferred. When scrolling reaches an area and the scroll buffer is completely used, a part of the data stored in the scroll buffer is discarded, and monochrome data corresponding to document data newly displayed by scrolling is transferred to the scroll buffer. Control means for controlling to be stored in
Means for converting the document data newly displayed by the scroll to bitmap data capable of color display when a predetermined time has elapsed after the scroll, and transferring the bitmap data to storage means used for the image display; ,
It is characterized by having.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in order to further clarify the configuration of the present invention described above. FIG. 1 is a block diagram showing a schematic configuration as one embodiment of the present invention. A CPU 2 for controlling the entire apparatus, a ROM 6 for storing a basic control program, an OS, an application program, etc., are expanded, a RAM 4 for storing buffers, parameters, and the like used by each of them, and a bit map format displayed on the display unit 12. The VRAM 10 to which the display data is written and the timer 8 are mutually connected by a system bus 14.
[0009]
FIG. 2 is a diagram showing the flow of display data according to the present embodiment. A document area 30 in the RAM 4 is an area for storing document data created by an application program and the like, including character codes, ruled line codes, attributes, image data, and the like. The upper part of the figure is the sentence head, and the lower part is the data at the end of the sentence. Further, the inside thereof is divided into a document area 32 corresponding to the current screen, a document area 34 corresponding to the previous screen, and a document area 36 corresponding to the screen before the previous screen.
[0010]
In the present embodiment, the VRAM 10 is divided into four planes of an R plane 54, a G plane 55, a B plane 56, and an I (Intensity: light / dark data) plane 57, and 4 bits are distributed per 1 DOT of the display screen to display 16 colors. Becomes possible. It is also possible to increase the number of planes to achieve more colors, or to use a so-called packed pixel type VRAM in which several bits representing 1 DOT are arranged side by side.
[0011]
Normally, the document data of the document area 32 corresponding to the current screen is converted into the bit data corresponding to the actual display character according to the attribute according to the attribute, and is selected in the VRAM 10 while selecting the plane according to the designated color. Written. For example, in the case of a DOT in which white is specified, all the corresponding bits of the R plane 54, the G plane 55, the B plane 56, and the I plane 57 are 1, and in the case of black, all the bits are 0. Each plane has a palette register (not shown) corresponding thereto. By manipulating the data of the palette register, the role of each plane can be freely changed to R, G, B, light red, dark green, black, or the like. it can. Further, it is also possible to invalidate each plane (data is not displayed even if data is drawn).
[0012]
The scroll buffer 40 is a main part of the present invention, and is an area for storing monochrome data corresponding to the document area 30 for several screens. The current screen buffer 42 stores monochrome data corresponding to the document area 32 corresponding to the current screen. The previous screen buffer 44 corresponds to the document area 34 corresponding to the previous screen. Monochrome data for a total of three screens is buffered so as to correspond to the document area 36 corresponding to the screen before the previous screen.
[0013]
The monochrome data is data before the character code data or the like in the document area 30 is developed into bitmap data and colored (distributed to each plane data of the VRAM), and data corresponding to one plane It is possible to select ON-OFF (white, black) of the display DOT only by the amount. Therefore, the memory area of the RAM 4 can be largely saved.
[0014]
The new area 48 is a scroll buffer added when scrolling reaches an area not covered by the current screen buffer 42, the previous screen buffer 44, and the screen buffer 46 before the previous screen. The old area 50 is a buffer area that is deleted when the new area 48 is added. In the figure, the data is scrolled downward, the data of the lower one line is read from the document area 30, expanded, and added as a new area 48.
[0015]
When scrolling occurs, the data of the R plane 54 of the VRAM 10 is erased, and then the monochrome data of the scroll buffer 40 at the scroll destination is written to the R plane 54. The R plane 54 is set to emit black color according to the value of the palette register, and the remaining planes are invalidated, so that the display unit 12 performs monochrome display corresponding to the R plane 54. In this case, since the drawing is performed only on one plane, very high-speed drawing is possible.
[0016]
FIG. 3 is a flowchart showing the procedure of the high-speed scroll according to the present embodiment, which will be described with reference to FIG. If there is a screen scroll request in S1, it is determined in S2 whether the data at the scroll destination has already been created in the scroll buffer 40. If "No" (if scrolling downward in FIG. 2), then in S4 It is checked whether all the scroll buffers 40 have been used. If “Yes”, the old area 50 having the data farthest from the scroll position is discarded in S5. If "No", a new area 48 is secured in S6, and the scroll destination image data is newly created in monochrome.
[0017]
In the case of "Yes" in S2 (in the case of scrolling upward in FIG. 2), it is checked whether the data of the document area 34 corresponding to the previous screen has been changed, and in the case of "Yes", the determination of S4 is started. However, in this case, the determination is “No”, and the new data is overwritten on the previous screen buffer 44 in S6. If "No" in S3, the process directly proceeds to S7 without creating new monochrome image data.
[0018]
In S7, the image data of the scroll destination in the scroll buffer 40 is transferred to the R plane 54. At this time, the R plane 54 is set to a monochrome plane, and the other planes are invalidated. In step S8, a predetermined time is waited by the timer 8. If there is no scroll request, the palette register of each plane of the VRAM 10 is restored, and in step S9, the data at the scroll destination of the document area 30 is developed to extract color information, and the R plane is extracted. 54, the G plane 55, the B plane 56, and the I plane 57 are redrawn.
[0019]
If a VRAM buffer for backing up all the planes of the VRAM 10 is provided, when scrolling several lines, the image data in the VRAM buffer is transferred from the VRAM buffer to each plane of the VRAM 10, and only the newly appearing image is converted to monochrome data. Thus, the data can be transferred from the scroll buffer 40 to the VRAM 10. In this case, since the entire screen is not monochrome, it is effective when scrolling the end of the screen by several lines.
[0020]
If there is room in the RAM 4, the scroll buffer 40 can be used for more screens or added for horizontal scrolling. If two scroll buffers 40 are provided, high-speed scrolling by four-color display is possible. It is. For example, by setting the normal scrolling with the “arrow” key, the high-speed scrolling with the “shift” + “arrow” key on the monochrome screen, the semi-high-speed scrolling with the “Ctrl” + “arrow” key on the four-color screen, etc. I do.
[0021]
As described above, according to the present embodiment, high-speed scrolling can be performed by temporarily or partially displaying the entire display screen in monochrome, and after a predetermined time has elapsed after scrolling, the display screen can be rewritten to color display. it can.
[0022]
In addition, since most documents for normal printing are composed of monochrome, there is no practical problem if monochrome display is temporarily returned to color display at the time of scrolling.
[0023]
【The invention's effect】
According to the present invention, high-speed scrolling can be performed because a display portion newly displayed by scrolling is displayed by transferring monochrome data while effectively using a limited scroll buffer area.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration as one embodiment of the present invention.
FIG. 2 is a diagram showing a flow of display data according to the embodiment.
FIG. 3 is a flowchart showing a high-speed scroll procedure according to the embodiment.
[Explanation of symbols]
2: CPU
4: RAM
6: ROM
8: Timer 10: VRAM
12: display unit 14: system bus 30: document area 32: document area 34 corresponding to the current screen: document area 36 corresponding to the previous screen: document area 40 corresponding to the screen before the previous screen 40: scroll buffer 42: current screen buffer 44 : Previous screen buffer 46: Last screen buffer 48: New area 50: Old area 54: R plane 55: G plane 56: B plane 57: I plane

Claims (1)

Document information having code information and attribute information attached to the code information is transferred as bitmap data to storage means used for image display, and the transferred bitmap data is controlled to be displayed on a display unit, and A scroll control device that rewrites bitmap data in storage means used for displaying the image according to scrolling of document data,
A scroll buffer that stores monochrome data corresponding to the document data for several screens including a screen corresponding to the bitmap data of the storage unit used for the image display;
When scrolling occurs, the monochrome data of the scroll buffer corresponding to the document data newly displayed by the scrolling is transferred to storage means used for displaying the image, and the monochrome data of the document data not stored in the scroll buffer is transferred. When scrolling reaches an area and the scroll buffer is completely used, a part of data stored in the scroll buffer is discarded, and monochrome data corresponding to document data newly displayed by scrolling is transferred to the scroll buffer. Control means for controlling to be stored in
Means for converting the document data newly displayed by the scroll to bitmap data capable of color display when a predetermined time has elapsed after the scroll, and transferring the bitmap data to storage means used for the image display; ,
A scroll control device comprising:

Images