CN101114443A - Indentation method of dot-matrix characters in two-dimensional graphics engine and Chinese processing method - Google Patents

Abstract

The invention discloses an indentation method of a dot matrix character in a two-dimensional graphics engine and a Chinese processing method completed by using the algorithm, including: reading character data; opening a dot matrix font library file for backup; and encrypting characters in the character data Processing; use the indentation method of dot matrix characters to calculate the actual length of each character, and then accumulate the total length of all read characters; process the height of characters and line spacing; compare the total length of characters with the width of the screen, Characters on the screen are omitted or line-wrapped, and the total length of characters that can be displayed is recorded; various channel attributes and registers of the two-dimensional graphics engine are set; centering, left alignment and right alignment in Chinese display The aligned position is processed and calculated; the characters are trimmed using the indentation method of the dot matrix characters; the trimmed characters are sent to the two-dimensional graphics channel to wait for display output.

Description

Indentation method of dot-matrix characters in two-dimensional graphics engine and Chinese processing method

technical field

The invention relates to the technology of using a 2-dimensional graphics engine to support dot matrix fonts. In particular, the indentation algorithm for dot matrix characters is involved.

Background technique

At present, more and more embedded products use two-dimensional graphics engine to support the TV OSD layer display of graphics and text. This makes display technology that supports Chinese necessary. However, due to the limitations of the 2D graphics engine, it cannot support vector fonts, so it can only choose to use dot matrix fonts as the fonts required to support Chinese.

The dot matrix character library contains ASCII codes, Chinese characters and other symbols, and each character is represented by a 0, 1 bitmap. Among them, if a certain bit is 1, it means that this character needs to be filled in this bit, so the color of this bit should be set as the character color. If this bit is 0, it means that this bit does not need to be filled, and the color corresponding to this bit should be set as the background color. In practical applications, vector ASCII codes and Chinese characters used in Windows can be converted into dot matrix fonts, so there can be multiple fonts (such as Song, Kai, Hei, Kindergarten, etc.), and each font has multiple sizes. Model, so that the required font and character model can be selected according to actual needs.

The method of displaying Chinese characters in the Western language environment is to call the Chinese character library to display Chinese characters. The internal code of the Chinese characters in the national standard code is from AO-FF, the first byte is called the area, and the second byte is called the bit. There are only 96 areas*96 bits of available Chinese characters. The ASCII code in the character set is 1 Byte, and the largest hexadecimal is FFH, that is, 255 Western characters, which are common characters, such as "+", "^", etc., and also include graphic characters. Chinese characters are composed of two bytes. The definition of early countries is that 1 Word (2 Byte) represents a Chinese character. The national standard stipulates: the Chinese character library is divided into 94 districts, and each district has 94 Chinese characters (distinguished by bits), and each Chinese character has a definite district and bit number in the Chinese character library, which is the location code of the Chinese character. Each Chinese character is stored in the form of dot matrix fonts in the library, generally using 16×16 dot matrix (32 bytes), 24×24 dot matrix (72 bytes), each point uses a binary bit (0 or 1 ) represents that corresponding Chinese characters are displayed on the screen.

Because in the Chinese environment, the input is the internal code of the Chinese character, so it must be converted into the area code, the offset is calculated, the corresponding Chinese character is found from the font library, and the font is displayed.

However, using dot-matrix characters has its drawbacks. Its main shortcoming is exactly that for a character that cannot fill the 24-dot matrix (here, take the 24-dot matrix font library as an example), there will be a large part of it empty in the display space of 24*24. This results in an extremely loose effect after certain characters are displayed. If you encounter continuous ASCII characters, the effect displayed by the dot matrix font is unacceptable. For example, for an English word "lily", since the 24-dot matrix font is used, the displayed effect becomes "lily". Therefore, the dot matrix font display technology still needs to be improved.

Contents of the invention

The purpose of the present invention is to overcome the problem of loose characters when multiple ASCII characters are continuously displayed due to the limitation of fixed dot matrix in the dot matrix font library, thereby providing a method capable of effectively indenting dot matrix characters.

In order to achieve the above object, the invention provides a method for indenting dot matrix characters in a two-dimensional graphics engine, comprising the following steps:

a), Take out a character from a segment of characters read in, judge whether the current character exceeds the total byte length of the character in this segment, if not, execute the next step, otherwise, interrupt the execution and jump out of the loop; in bytes The number is cyclically calculated;

b), distinguish whether the current character is a Chinese character or an English character or a symbol, if it is a Chinese character, perform the next step, if it is an English character or a symbol, perform step d);

c), the Chinese character is converted into the location code by the hexadecimal internal code, and then executes step e);

d), English characters or symbols are converted into area codes from hexadecimal internal codes, and then step e) is performed;

E), carry out positioning retrieval to the opened dot matrix font file in described step 2) by location code, read the font of the dot matrix character of character, and deposit in a two-dimensional array;

f), perform "AND" operation on each value of the two-dimensional array, obtain and record the positions of the leftmost point and the rightmost point in the dot matrix character, and combine the position of the rightmost point with the position of the leftmost point Positions are subtracted to get the actual length of a character, and the blank parts on the left and right sides are trimmed;

g), return to step a).

A Chinese processing method using the indentation method of dot matrix characters in the described two-dimensional graphics engine, comprising:

1), read the character data from the receiving data cache of the two-dimensional graphics engine, and set a flag to identify whether to continue reading;

2), open the dot matrix font file for backup;

3), process the encrypted characters in the character data;

4), use the indentation method of dot matrix characters to calculate the actual length of each character read in, and then add up the actual length of each character to obtain the total length of all characters read in;

5), process the height of the character and the line spacing, add the height of the character and the line spacing to obtain the longitudinal position of the character;

6), compare the total length of the characters obtained in step 4) with the screen width, if the total width of the characters exceeds the width of the screen, then omit or wrap the characters beyond the screen, and record what can be displayed total length of characters;

7), setting various channel attributes and registers of the two-dimensional graphics engine;

8), use the total width of the read-in characters after the indentation processing obtained in step 4) to process and calculate the centered, left-aligned and right-aligned positions in the Chinese display;

9), utilize the indentation method of dot-matrix characters to cut the displayable characters obtained in step 6);

10). Send the trimmed characters into the two-dimensional graphics channel and wait for display output.

In the above technical solution, in step 1), when the character data is read from the received data cache of the two-dimensional graphics engine, the character data read at one time is within 256 bytes.

In the above technical solution, the dot matrix characters in the dot matrix font file include a 16×16 dot matrix font, a 20×20 dot matrix font, a 24×24 dot matrix font, and a 32×32 dot matrix font.

In the above-mentioned technical scheme, in described step 7), when setting various channel properties and registers of the two-dimensional graphics engine, three input channels and one output channel of the two-dimensional graphics engine are respectively set, and input, The buffer used by the output channel.

The advantages of the present invention are:

Indent the dot matrix characters through the indentation algorithm of dot matrix characters in the two-dimensional graphics engine, so that the characters in the dot matrix font library can be well combined, reducing the distance between characters and making them look more beautiful . In addition, the indentation algorithm of dot matrix characters is used to effectively modify the Chinese processing in the two-dimensional graphics engine, so that it can be well combined with the indentation algorithm of dot matrix characters to deal with various requirements.

Description of drawings

Fig. 1 is the flowchart of dot matrix character indentation method;

Fig. 2 is the flowchart of the Chinese processing method in a kind of two-dimensional graphics engine of the present invention;

Fig. 3 is the arrangement sequence of 24 dot matrix character points;

Fig. 4 is a comparison diagram of the character display effect after being processed by the indentation method and the character before processing.

Detailed ways

The method for indenting embedded system dot matrix characters of the present invention will be described below in conjunction with the accompanying drawings and specific embodiments.

In this embodiment, it is assumed that a 24×24 dot matrix is used in the font library, as shown in FIG. 1 and FIG. 2 , the processing, indentation method and display flow of dot matrix characters in the embedded system are as follows.

Step 1. Read the character data from the received data buffer, the character data must be within 256 bytes, and set a flag to identify whether to continue reading;

Step 2. Open the dot matrix font file and prepare to call it;

Step 3. Process the encrypted characters according to the attributes of the characters, and the encrypted characters include characters requiring special processing such as passwords and user names.

Step 4. After accurately calculating the actual length of each character read in by using the indentation algorithm, the total length of all characters read in is obtained through accumulation. In this step, calculating the total length of the characters refers to calculating the total width of the indentation of the entire line of characters, the purpose of which is to facilitate the comparison between the width of the screen and the total width of characters when processing super-long characters. Before the characters are displayed on the screen, they need to be indented to avoid the defect that the character spacing is too loose in the prior art. Therefore, the width of the indented characters is no longer all 24 bits, and the width of each character will vary depending on the width of each character. determined by the difference. When calculating, it can no longer be generally considered that the total width of a line of characters, as shown in formula (1), is equal to the number of characters in the line multiplied by 24, but as shown in formula (2), it should be each character The cumulative sum of the widths.

Total character width = 24*number of characters(1)

The total width of characters = the accumulated width of a single character after indentation (2)

The dot rule of 24-dot matrix characters is shown in Figure 3: From the figure, it can be seen that the characters of 24-dot matrix are composed of 24 lines, and each line is composed of 24 bits. Each point is the point that makes up the text. If the text is "1" at this point, it means that the point should be displayed, otherwise the point will not be displayed.

Use bit operations to record the start position bejin_pos and end position end_pos of the 24 points in each line that are "1", compare the start value bejin_pos and end value end_pos recorded in each line, and select the smallest start value The initial value bejin_pos and the maximum end value end_pos are used to locate the position of the character in the 24*24 dot matrix. Once the text is positioned, the text can be trimmed to the left and right margins, and the actual width of each trimmed text is shown in Formula 3:

The actual width of each trimmed text = end value end_pos - start value bejin_pos(3)

After obtaining the indented width of each character, the total length of the characters can be obtained according to formula (2).

Step 5, process the height of the characters and the line spacing, and accumulate the height of the characters and the line spacing to obtain the vertical position of the characters to be displayed on the screen.

Step 6. Comparing the total width of the characters calculated by the indentation algorithm in step 4 with the screen width, if the total width of the characters exceeds the width of the screen, the characters beyond the screen are omitted or line-wrapped. If the characters need to be omitted, the width of the characters should be determined one by one, and the characters beyond the screen should be discarded at any time.

Step 7, setting various channel attributes and buffers (BUFFER) of the two-dimensional graphics engine; wherein, three input channels and one output channel of the 2D graphics engine, and buffers used by the input and output channels are set respectively .

Step 8. Use the total width of the characters read in after the indentation processing obtained in step 4 to process and accurately calculate the positions of centering, left alignment and right alignment in Chinese display.

Step 9, take a character, judge whether the current character exceeds the length of the character read in step 1, if not, execute the next step, otherwise, interrupt the execution and jump out of the loop.

Characters are read in in the form of hexadecimal internal codes, and Length is the number of bytes occupied by the read characters. A Chinese character takes up two bytes, and an English or symbol takes up one byte. If it is Chinese, m will be incremented by two each time the while loop is cycled. If it is English or symbols, m will be incremented by one each time the while loop is cycled. m is an accumulator, which controls which byte is processed by the current while loop, that is, if it is Chinese, it currently processes the mth and m+1 bytes of all bytes read this time, and if it is English or symbols, it processes this Read the mth byte of all bytes

Step 10, distinguish whether the current character is a Chinese character or an English character or a symbol, if it is a Chinese character, perform the next step, if it is an English or a symbol, perform step 12; in the ASCII code, the Chinese character occupies two bytes, while the English or The symbol only occupies one byte. If the internal code data is directly sent to the function of reading the font file without processing, an error will occur, resulting in garbled characters or incorrect characters retrieved from the font. Therefore It is necessary to distinguish between Chinese and English and symbols, and deal with them separately.

Step 11, convert the Chinese characters from the hexadecimal internal code into the area code, and then perform step 13; wherein the Chinese area code is equal to the mth byte data (text[m]) minus 0xa0, and the bit code is the first m+1 bytes of data (text[m+1]) minus 0xa0. That is, Chinese area code=text[m]-0xa0, Chinese bit code=text[m+1]-0xa1.

Step 12, convert the English characters or symbols from the hexadecimal internal code to the area code, and then perform step 13; English or symbols have a fixed area code, their area code is 0xa3, and the bit code is the mth byte After the content is converted into hexadecimal data (text[m]), add 0x80 and then subtract 0xa0.

Step 13, perform location search on the font file through the location code; calculate the offset of the character in the font library after the location code of the character is obtained through the above steps. Offset=((area code-1)×94+(bit code-1))×72, wherein 94 means that there are 94 areas, and 72 means that a character is marked with 72 bytes, and the marks here are 0, 1 dotted mark. It is equivalent to 24 points in one line (24 points occupy three bytes, each byte is 8 bits, that is, 8 points), and there are 24 lines in total. Therefore, 24×3 bytes are required to represent a 24-dot matrix character. After calculating the offset, read the 72 bytes of the character in the font according to the offset.

Step 14, use the idea in the indentation algorithm to calculate the indentation of the current character, and determine the starting position of the next character.

Step 15. Send the current character into the two-dimensional graphics channel and wait for display output, then take the next character and go to step 9.

The indentation algorithm adopted in the above step 4 performs precise indentation calculation on the total length of the read characters to provide accurate length calculation data for centered, left-aligned, and right-aligned displays.

The above steps 9 to 14 adopt the processing idea of the indentation algorithm, and each time a character is processed, the distribution of 0 and 1 of the character must be read from the font library, that is, the distribution of 0 and 1 of 72 bytes. Then indent the character according to the processing method of the indentation algorithm, and obtain the starting address of the next character.

In the above step 15, the indented characters are finally sent to the output buffer channel of the 2D graphics engine for display. For the display of characters, the character 0 is generally used for background color or transparent display, and the 1 bit is displayed with a color different from the background color.

As shown in Figure 1, the specific implementation steps of the indentation calculation of the characters described in the above steps are as follows:

Step 300: cyclically calculate the number of bytes for a segment of characters read in. Because the characters read in are all read into BUFFER in the form of bytes. Therefore, it loops according to the number of bytes until all bytes are completely completed and exits the loop.

Step 301: According to the difference between Chinese characters and English symbols, process them respectively. Since each character is read in in the form of an internal code when reading in, the Chinese internal code occupies two bytes, while the English or symbol occupies one byte. If the internal code is sent directly without processing, an error will occur, resulting in garbled codes or incorrect characters.

Chinese character area code = internal code of the mth byte -0xa0

Chinese character bit code=inner code-0xa0 of the m+1th character

The area code of English or symbols = 0xa3

Bit code of English or symbol=inner code of the mth byte+0x80-0xa0

Step 302: Perform a location search on the font file through the location code. The location retrieval of the font file depends on the offset of the character in the font calculated by the character location code.

Offset = ((area code-1)×94+(bit code-1))×72

Step 303: read the dot matrix characters from the font library according to the offset and put them into a 72-byte Buffer (a 24-dot matrix Chinese is composed of 24×24 dots, and every 8 dots are one Byte, such a line has 3 bytes, a total of 24 lines, once for the font file of 0 and 1, it uses 24×3 bytes to represent a character), if this bit is 1, it means this character bit It needs to be filled, so the color of this bit should be set to the character color. If this bit is 0, it means that this bit does not need to be filled, and the color corresponding to this bit should be set as the background color.

Step 304: Perform an "AND" operation on each value of the two-dimensional array to obtain and record the positions of the leftmost point and the rightmost point in the 24-dot matrix character. For those blank parts on the left and right sides, you can perform tailoring.

Step 305: After cutting each character of the character segment one by one and accumulating its width, the actual width of the character character segment can be obtained.

The method of the present invention is described by taking the character "i" as an example. Figure 4 shows the display before the indentation algorithm is used and the display after the indentation algorithm is used. It can be seen that the display distribution of the first three "i" characters is not scattered, but the distribution of the three "i" after processing has been significantly improved, and the left and right sides of the character "i" have been significantly cut .

The processing of the three characters "i" first reads the corresponding font from the font library according to the dot matrix character indentation algorithm, and obtains the initial value bejin_pos (initial value bejin_pos= 8), and end value end_pos (end value end_pos=14). The actual width of i is the end value end_pos minus the start value bejin_pos (end value end_pos−start value bejin_pos=6). The total width of the three characters i is 6×3=18. Processing requirements such as centering and off-screen characters are ignored here. Assuming that the three characters only require left alignment, the starting position of the first i on the screen = screen edge width X1+0, according to the starting position and the arrangement order of 0 and 1, use the background color for 0 Display is displayed in a color different from the background color for 1 digit. The starting position of the second i on the screen = screen edge width + 6 (the actual width of the first i) + character spacing (set by yourself, generally 0), the display method is the same as the first character i, Only the starting position is different. The starting position of the third i on the screen = screen edge width + 12 (the actual width of the two i) + character spacing (set by yourself, generally 0), the display method is the same as the first character i, only The starting position is different.

Through the above processing, the three characters i processed by the dot matrix character indentation algorithm of the two-bit graphics engine can be simply displayed.

Claims (5)

1. an indentation method of a dot matrix character in a two-dimensional graphics engine, comprising the following steps: a), read a section of characters, take out a character from the read section of characters, judge whether the current character exceeds the total byte length of this section of characters, if not, then execute the next step, otherwise, interrupt the execution and jump out of the loop ;Calculate with the number of bytes; b), distinguish whether the current character is a Chinese character or an English character or a symbol, if it is a Chinese character, perform the next step, if it is an English character or a symbol, perform step d); c), the Chinese character is converted into the location code by the hexadecimal internal code, and then executes step e); d), English characters or symbols are converted into area codes from hexadecimal internal codes, and then step e) is performed; E), carry out positioning retrieval to the opened dot matrix font file in described step 2) by location code, read the font of the dot matrix character of character, and deposit in a two-dimensional array; f), perform "AND" operation on each value of the two-dimensional array, obtain and record the positions of the leftmost point and the rightmost point in the dot matrix character, and combine the position of the rightmost point with the position of the leftmost point Positions are subtracted to get the actual length of a character, and the blank parts on the left and right sides are trimmed; g), return to step a). 2. a Chinese processing method of the indentation method of the dot matrix character in the two-dimensional graphics engine of application claim 1, comprising: 1), read the character data from the receiving data cache of the two-dimensional graphics engine, and set a flag to identify whether to continue reading; 2), open the dot matrix font file for backup; 3), process the encrypted characters in the character data; 4), use the indentation method of dot matrix characters to calculate the actual length of each character read in, and then add up the actual length of each character to obtain the total length of all characters read in; 5), process the height of the character and the line spacing, add the height of the character and the line spacing to obtain the longitudinal position of the character; 6), compare the total length of the characters obtained in step 4) with the screen width, if the total width of the characters exceeds the width of the screen, then omit or wrap the characters beyond the screen, and record what can be displayed total length of characters; 7), setting various channel attributes and registers of the two-dimensional graphics engine; 8), use the total width of the read-in characters after the indentation processing obtained in step 4) to process and calculate the centered, left-aligned and right-aligned positions in the Chinese display; 9), utilize the indentation method of dot-matrix characters to cut the displayable characters obtained in step 6); 10). Send the trimmed characters into the two-dimensional graphics channel and wait for display output. 3. the Chinese processing method in the two-dimensional graphics engine according to claim 2, is characterized in that, in described step 1), when described from the received data cache of two-dimensional graphics engine, read character data , the character data read at one time is within 256 bytes. 4. The Chinese processing method in the two-dimensional graphics engine according to claim 2, wherein the dot matrix characters in the dot matrix font file include 16*16 dot matrix font, 20*20 dot matrix font, 24 ×24 dot matrix font, 32×32 dot matrix font. 5. the Chinese processing method in the two-dimensional graphics engine according to claim 2, is characterized in that, in described step 7), when various channel attributes and buffers of the two-dimensional graphics engine are set, respectively Set the three input channels and one output channel of the 2D graphics engine, as well as the registers used by the input and output channels.

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