JPH04101191A - Superimposed display processing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Summary] Regarding a superimposed display processing method that combines and displays text information developed in a bitmap video memory and graphic information, it is possible to superimpose text information written in black. The aim is to express the text information to be displayed using code information that is a combination of text pattern information and attribute information, and expand it into a bitmap memory for text, as well as expand the bitmap memory for text. data and the expansion data of the bitmap memory for graphics are input, color information of attribute information is displayed on the display for pixel positions where a text pattern exists, and color information of attribute information is displayed on the display for pixel positions where a text pattern does not exist. By providing a color synthesis processing means that controls the display of color information contained in graphic information located at a pixel position, when text information and graphic information are displayed in a superimposed manner, the black color contained in the text information can be displayed. Configure it to execute.

[Industrial application field]

The present invention relates to an overlapping display processing method for combining and displaying text information developed in a bitmap video memory and graphic information, and in particular, the present invention relates to an overlapping display processing method for combining and displaying text information developed in a bitmap video memory and graphic information. This relates to a combined display processing method.

[Conventional technology]

In a display processing method using a video RAM for text, the character code and attribute information stored in the video RAM for text are read out, the character font pattern corresponding to the character code is read out from the corresponding memory, and the display screen is read out. Add text video RA to the read character font pattern at the desired coordinate position above.
By allocating attribute information (color information, etc.) read from M, desired display processing is executed. In display processing methods that use such text video RAM, character font patterns cannot be read out at high speed, and data to be output to a display device cannot be transferred at a higher speed. However, there is a problem in that it cannot support high-resolution display devices that require high-speed processing.

In a display processing method using such a video RAM for text, the hardware mechanism in charge of display processing reads the character font pattern in rask units, so if the CPU accesses the character font pattern while it is being displayed, the display screen is Since the visual appearance may deteriorate due to noise output, etc., when the CPU accesses the character font pattern, it is necessary to access the character font pattern at the VSYNC timing of the display device. Another problem is that the CPU is forced to wait, resulting in performance deterioration.

Against this background, video RAM for text
A text frame memory method has been adopted in which the contents of the text are expanded and written into a bitmap video RAM using hardware, and the contents expanded to the bitmap video RAM are displayed on the display. .

In a display processing method using this text frame memory method, when text information stored in a bitmap video RAM for text and graphic information stored in a bitmap video RAM for graphics are superimposed ( when superimposing)
When prioritizing the text screen over the graphics screen, conventionally, when all focus data of, for example, 4-bit color information read from the bitmap video RAM for text indicates a zero value, the bits for graphics are given priority. By outputting the color information stored in the map video RAM, processing was performed to give priority to this text screen. FIG. 7 shows the circuit configuration of this conventional color synthesis circuit. Here, “I” in the 4-focus color information
" represents the color intensity expressed in "GBR".

[Problem to be solved by the invention]

However, according to such conventional technology, when the text to be displayed has a color of "0000", that is,
If the text is black, there is a problem in that the text cannot be displayed. In other words, if the display processing method uses a video RAM for text, if a character font pattern exists and the 4-pinto point that specifies color information is 0000'', the character font pattern to be displayed is black. On the other hand, when a character font pattern does not exist and the 4 bits specifying color information are "oooo", it is a blank with no character font pattern. In display processing methods that use the text frame memory method, where information is deleted, the 4 bits that specify color information are “0”.
000", it was not possible to distinguish whether the color was black or blank, and this caused the problem that black character font patterns (text) could not be displayed superimposed on graphics. It is.

This problem can be solved by adding bit information to identify whether "0000" stored in the text bitmap video RAM is black or blank.
This can be solved by adopting a configuration in which the number of screens is provided, but this creates another problem in that the memory capacity increases.

The present invention has been made in view of the above circumstances, and includes processing for superimposing black text information when superimposing text information and graphic information developed in a bitmap video memory and displaying them on a display. The purpose of this invention is to provide a new superimposed display processing method that enables the execution of the following.

[Means to solve the problem]

FIG. 1 is a diagram showing the principle configuration of the present invention.

In the figure, 1 is a data processing device equipped with the present invention, 2 is a display device included in the data processing device 1, 3 is a CPU,
4 is an internal bus, 5 is a video RAM for text,
6 is a bitmap video RAM prepared for graphics and stores display data information of graphic information to be displayed; 7 is for text; 8 is a font pattern memory that stores the font pattern specified by the character code; 9 is the font pattern memory that stores the display data information of the text information to be displayed; A development processing means receives information stored in the text video RAM 5 as input and generates display data information of text information to be displayed and stores it in the bitmap video RAM 7; 10 is a color composition processing means; Display data information of bitmap video RAM 6 and bitmap video RA
The display data information of M7 is input, and the text information and graphic information to be displayed are superimposed and displayed on the display device 2.

[Effect]

In the present invention, the font development processing means 9 generates display data information of text information expressed by code information of a combination of text pattern information and attribute information, and converts the generated code information into a bit map for text. It is stored in the video RAM 7. This bitmap video R
In response to the code information stored in AM7, the color synthesis processing means 10 displays color information having attribute information on the display device 2 for pixel positions where a text pattern exists, and displays color information having attribute information on the display device 2 for pixel positions where a text pattern does not exist. Regarding the position, processing is performed to display color information of the graphic information located at the pixel position.

According to the compositing process of the color compositing processing means 10, even if the color information contained in the attribute information is indistinguishable between black and blank, the indistinguishable color information is written at the pixel position where the text pattern exists. If it is written in a pixel position that does not exist, it will be treated as black, and if it is written in a non-existent pixel position, it will be treated as blank, so black text information can be displayed even when superimposed with graphic information. This is what happens.

〔Example〕

Hereinafter, the present invention will be explained in detail according to examples.

As explained in FIG. 1, in the present invention, the display data information of the text information stored in the bitmap video RAM 7 for text is made different from the data format stored in the original bitmap video memory. , is configured to be expressed using code information that is a combination of text pattern information and attribute information.

In other words, when color information is represented by 4 bits of "IGBR", the conventional bitmap video memory has a memory capacity for 4 planes, as shown in Figure 2, and the characters of each of those branes are By storing the bit data of the display color "IC, BR" at the pixel position of the character pattern within the letter size (8 x 16 bits in the large frame in this figure), the display data information of the text to be displayed is stored. In contrast, in the present invention, a combination of text pattern information and attribute information is expressed using code information.

Specifically, for example, as shown in Figure 3, - character 1
Using 32 bits (8 x 4 bits) for the raster, the first 8 bits (pattern field) of the 32 bits store 110 information that specifies the shape information of the character pattern for one raster. In addition, the remaining 24 bits (attribute field) store attribute designation information such as color information and display format. Since such a data format is adopted, even if the present invention is used, there is no need to prepare a bitmap video RAM 7 for text with a larger memory capacity than the conventional one.

Next, the processing executed by the present invention will be described in detail with reference to the flowchart shown in FIG. Here, among the processing steps divided by broken lines in FIG. It represents the bitmap video RAM 7 for text described in the figure, and the processing portion at the bottom represents the processing executed by the color composition processing means 10 described in FIG.

As shown in this flowchart, when the font development processing means 9 reads the character code and attribute data from the text video RAM 5 described in FIG.
At the same time as reading from the font pattern memory 8 explained in the figure, code information to be the display data information of character data is generated according to the data format described above, and the generated code information is stored in the bitmap video RAM 7 for text.
It is processed so that it is stored in . Here, the font development processing means 9 uses this code information to display and display cursor processing.
Data for hiding purposes will also be included.

As shown in this flowchart, when the color synthesis processing means 10 starts executing display processing, it reads code information expanded as display data information in units of 32 bits from the bitmap video RAM 7 for text, and uses the code information. In accordance with the attribute information specified by , reverse processing, printer processing, color specification, and other allocation processes are executed for each of the eight pixels specified by the read code information. Then, a process of synthesizing the graphic information with display data information read from the computer video RAM 6 for graphics processing is performed on In, and a process of displaying the graphic information on the display is performed.

FIG. 5 shows an embodiment of a color synthesis circuit included in the color synthesis processing means 10 of the present invention for this synthesis process. In the figure, 20 is an 8-bit shift register that stores the 8-bit bit information of the pattern field of the code information read from the bitmap video RAM 7 for text, and sequentially sends out the bit information one pin at a time. 21 is a first AND gate provided with four, which outputs the character color information of one character to be displayed extracted from the attribute field of the read code information and the shift register 20. 22 is an inverter that inverts the bit information output from the shift register 20; 23 is a second AND gate provided with four; 24 calculates the logical product of the color information of one pixel read from the bitmap video RAM 6 and the bit information output from the inverter 22.
The OR gate is provided with "1" from either the first AND gate 21 or the second AND gate 23.
” is output, “1” is output.

The color synthesis processing means 10 of the present invention includes a color synthesis circuit having the circuit configuration shown in FIG. 5, so that when the shift register 20 outputs "1" indicating the presence of a character pattern part, Regarding the pixel position, the color information output from the focus map video RAM 7 for text is selected and displayed, and when "0" is output, the bitman tube video R for graphics is selected and displayed.
A process of selecting and displaying color information output from AM6 is executed. Through this process, the color information output from the bitmap video RAM 7 for text becomes “0000”.
”, it becomes possible to identify whether the “0000” specifies black or blank.

From now on, when text information and graphic information are displayed in a superimposed manner, as shown in FIG. 6(a), in the conventional case, the black text part is not displayed at all. By using this, a black text portion will be displayed as shown in FIG. 6(b).

[Effects of the Invention] As explained above, according to the present invention, when text information developed in a bitmap video memory and graphic information are superimposed and displayed on a display, an increase in the amount of hardware can be avoided. This allows the superimposition process of black text information to be performed without any trouble.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle of the present invention; FIG. 2 is a diagram showing the construction of a bitmap video RAM; FIG. 3 is an embodiment of the data format of display data stored in the bitmap video RAM for text; 5 is an embodiment of the color synthesis circuit provided in the present invention. FIG. 6 is an explanatory diagram of the display processing of the present invention. FIG. 7 is a configuration diagram of a conventional color synthesis circuit. It is. In the figure, 1 is a data processing device, 2 is a display device, and 3 is a data processing device.
is the CPU, 4 is the internal bus, and 5 is the video RAM for text.
, 6 and 7 are focus map video RAMs, 8 is a font pattern memory, 9 is a font development processing means, and 10 is a color composition processing means. Patent applicant Rijin Pfnika Co., Ltd.
Patent Attorney Mori 1) Hiroshi (2 others) Biftoma Noah Video RAM') Tree 1 Construction Figure 2 Unseen Data Ellipsis Moxibustion Data Format Format Example Sentence Yukikodo Attribute Data Present Invention Lf) Chitake Tib Flow Engineer ↑-To Figure 4 Digital text text array (a) Graphic software text text array (b) Explanatory diagram of the Itadori processing of this full day and moon Figure 6 Text 1 pix t Rute 1 Goofic 1 l: o 7 t Rute defeat■ Diagram of the configuration of the conventional color conference abdominal route Figure 7

Claims (1)

[Claims] Text information is developed into a bitmap video memory (7) for text, and the bitmap video memory (7)
In a data processing device that synthesizes text information developed in a graphics bitmap video memory (6) and graphic information developed in a graphics bitmap video memory (6) and displays it on a display, the text information to be displayed is combined with text pattern information and attributes. It is configured to express the code information in combination with information and develop it in the bitmap video memory for text (7), and also to express the data in the bitmap video memory for text (7) and the bitmap video for graphics. memory(
6) is input, the color information of the above attribute information is displayed on the display for pixel positions where a text pattern exists, and the color information of the attribute information is displayed on the display for pixel positions where a text pattern does not exist, and the graphic located at the pixel position is displayed for pixel positions where a text pattern does not exist. By providing the color composition processing means (10) that controls the display of the color information contained in the information, when displaying text information and graphic information in a superimposed manner, it is possible to display the black color contained in the text information. A superimposed display processing method that is characterized by processing in a sequential manner.