JP2006039780A - Display apparatus, program and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display apparatus capable of rapidly displaying a character having a curve. <P>SOLUTION: The display apparatus is provided with a display device for displaying a line and a control section for controlling the display device. The control section, regarding a given first point, second point and third point, decides first positional relation between at least one of the first point and second point and the third point, selects a pattern, that is the pattern of at least one previously prepared line, of one line corresponding to the decided first positional relation from among patterns of at least one line passing through the first point and second point. The control section displays the line passing through the first point and second point on the display device, according to the pattern of the selected line. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a display device, a program, and a recording medium that include a display device that displays a line and a control unit that controls the display device. According to the present invention, for example, a character having a curve can be displayed at high speed on a low-medium resolution display device.

The outline font represents a character with a contour of a closed curve. This outline font is widely used in a technique for displaying characters based on vector data. The outline font is, for example, a TrueType font or a PostScript font. For the curve of the TrueType font, a quadratic B-spline curve is used (see Equation 1). For the script of the PostScript font, a Bezier curve is used (see Equation 2).
[Formula 1]
x = (1-t) ² x ₁ + 2t (1-t) x ₂ + t ² x _{3
^{y = (1-t) 2}} y 1 + 2t (1-t) y 2 + t 2 y 3
0 ≦ t ≦ 1
[Formula 2]
_{^{x = (1-t) 3}} x 1 +3 (1-t) 2 tx 2 +3 (1-t) t 2 x 3 + t 3 x 4
y = (1-t) ² y ₁ + 3t (1-t) ² ty ₂ +3 (1-t) t ² y ₃ + t ³ y ₄
0 ≦ t ≦ 1
These fonts are suitable for displaying characters on a high-resolution display device. These fonts are particularly suitable when printing characters on paper. In addition, although the curve represented by Formula 1 and Formula 2 passes through the both ends (start point and end point) of a curve, the point (control point) between a start point and an end point does not pass.

  A stroke font represents characters with a stroke having no thickness. Like the outline font, this stroke font is widely used in a technique for displaying characters based on vector data.

  This font is suitable for displaying characters on a low-medium-resolution display device. When displaying this stroke font on a display device, in general, regardless of whether the line to be expressed is a curve or a straight line, the curve or straight line is formed by connecting each of a plurality of points with a straight line. Because it is expressed, it can be drawn faster than the outline font.

  Patent Document 1 discloses a technique for drawing a straight line connecting two points at high speed.

  This technique obtains a quotient sequence based on the slope of a straight line. Next, a control number sequence is obtained from the quotient number sequence, and a straight line is drawn at high speed based on the control number sequence.

  For example, the quotient sequence {2, 1, 1, 3} is obtained based on the straight line slope 7/18. Next, from the quotient sequence {2, 1, 1, 3} to the control sequence {1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1,0}. When the value of the control matrix is “1” when increasing the drawing position of the straight line in the x direction, the value of y is increased to draw a straight line, and the value of the control matrix is “0” In this case, a straight line is drawn without increasing the value of y.

  Patent Document 1 also discloses that a quotient number sequence and a control number sequence are calculated in advance.

  Patent Document 2 discloses a technique for drawing a curve at high speed. In this technique, values relating to parametric variables are calculated and stored in advance, and these values are used when a curve is expressed by a Bezier curve or the like.

For example, when the parameter t is divided into 1024 in Equation 2, the possible values of t are (0, 1/1024, 2/1024, 3/1024, ..., 1023/1024, 1024/1024). Here, the relationship between the value of t and the value of t ³ and the relationship between the value of t and the value of 3 (1-t) t ² are calculated in advance, and these relationships are tabulated. The ^{(1-t) 3} and 3t ^{(1-t) 2} calculations, the value of ^{t 3,} utilizing the value of ^{3 (1-t) t 2} . Thus, according to the technique disclosed in Patent Document 2, the calculation represented by Expression 2 can be processed at high speed.
Japanese Patent Laid-Open No. 9-161082 JP-A-1-255076

  However, the conventional techniques have the following problems.

  When an outline font is displayed on a medium / low resolution display device, variations in line width and line collapse are likely to occur, and the quality of characters is not good.

  In the technique of Patent Document 2, calculation with a floating point operation occurs each time a plurality of points are drawn, and there is a limit to speeding up display. In general, CPU floating point operations are slower than CPU integer operations.

  When a stroke font is displayed on the display device, rattling is conspicuous in the curved portion of the character. This is because the stroke font represents the curved portion of the character as a straight line. In particular, rattling becomes more noticeable as characters are enlarged.

It is difficult to design a stroke font with no thickness by expressing a curved portion of a character by a secondary B-spline curve or a Bezier curve. This is because the line does not pass through the control points between the ends of the curve. As a curve interpolation that passes through all control points, there is a curve interpolation using a cubic spline. However, this interpolation has a problem that it is difficult to perform conditioning because it is necessary to provide a constraint on the end points. The present invention also has a problem that it is difficult to increase the speed. The present invention has been made in view of the above problems, and is capable of drawing a line at a high speed and reducing a recording capacity of data indicating the line, a program and a program An object is to provide a recording medium.

  The display device of the present invention is a display device including a display device that displays a line, and a control unit that controls the display device, wherein the control unit is provided with the first point, the second point, and the second point. Determining a first positional relationship between at least one of the first point and the second point and the third point with respect to three points, and a pattern of at least one line prepared in advance; A line pattern corresponding to the determined first positional relationship is selected from at least one line pattern passing through the first point and the second point, and the selected line pattern is selected. In response, a line passing through the first point and the second point is displayed on the display device, whereby the above object is achieved.

  The image processing apparatus further includes a holding unit that holds pattern information indicating a correspondence relationship between the first positional relationship and the line pattern, and the line pattern is selected by referring to the pattern information held in the holding unit. It may be done.

  The first positional relationship may be determined according to an angle between a first straight line connecting the first point and the second point and a second straight line connecting the second point and the third point. .

  The control unit determines a second positional relationship between at least one of the first point and the second point and the fourth point with respect to the first point, the second point, and the fourth point. The control unit selects one line pattern corresponding to the determined second positional relationship from the at least one line pattern, and a plurality of patterns around the second point An area is assigned, and the third point and the fourth point are given to the same area of the plurality of areas, and the pattern of one line corresponding to the selected first positional relationship and the selection The pattern of one line corresponding to the second positional relationship may be the same.

  The first point may be given to the origin and the second point may be given to the first quadrant.

  A plurality of regions are assigned around the second point, and the third point is given to one of the plurality of regions, and one region of the plurality of regions and the one point The area different from the area may have a different size.

  A plurality of regions may be assigned to only a part of the periphery of the second point, and the third point may be given to one of the plurality of regions.

  The program according to the present invention is a program for causing an information display device provided with a display device for displaying a line to execute a display process, wherein the display process is performed for a given first point, second point, and third point. Determining a first positional relationship between at least one of the first point and the second point and the third point, and a pattern of at least one line prepared in advance, Selecting one line pattern corresponding to the determined first positional relationship from at least one line pattern passing through one point and the second point; and the selected line pattern And displaying the line passing through the first point and the second point on the display device, thereby achieving the above object.

  The recording medium of the present invention is a recording medium readable by an information display device provided with a display device for displaying lines, and the recording medium records a program for causing the information display device to perform display processing, The display processing determines a first positional relationship between at least one of the first point and the second point and the third point with respect to the given first point, second point, and third point. And at least one line pattern prepared in advance, wherein the determined first positional relationship is selected from among at least one line pattern passing through the first point and the second point. Selecting a corresponding one line pattern, and displaying a line passing through the first point and the second point on the display device in accordance with the selected line pattern; This Serial object is achieved.

  According to the display device, the program, and the recording medium of the present invention, the pattern of at least one line passing through the first point and the second point without obtaining the trajectory of the line passing through the first point and the second point by calculation. A line passing through the first point and the second point can be displayed by selecting one line pattern corresponding to the determined positional relationship. Therefore, it is not necessary to calculate the trajectory of the line passing through the first point and the second point, which requires complicated calculations, and the line passing through the first point and the second point can be displayed at high speed.

  In the present invention, a curve connecting the three points is drawn using a table indicating the correspondence between the pattern of lines passing through the first point and the second point and the positional relationship between the three points. Therefore, a curve can be drawn only by reading the table, and no complicated calculation occurs. As a result, a line passing through the first point and the second point can be drawn at high speed.

  Further, the angles of the straight line passing through the first point and the second point and the straight line passing through the second point and the third point are classified and tabulated. As a result, the capacity can be reduced.

  Furthermore, only when the second point is in the first quadrant, the straight line passing through the first point and the second point and the angle of the straight line passing through the second point and the third point are classified and tabulated. Therefore, the number of combinations of the three points can be reduced. As a result, the capacity can be further reduced.

1. The principle of the present invention will be described below with reference to the drawings.

  The present invention pays attention to a curve connecting three points when drawing a curve, and selects one of the patterns of at least one line passing through the first point and the second point corresponding to the determined positional relationship. By selecting a line pattern, a line passing through the first point and the second point can be displayed. By calculating the pattern of the line passing through the first point and the second point without calculating the trajectory of the line passing through the first point and the second point, the line passing through the first point and the second point is determined. It can be displayed at high speed.

  In addition, a holding unit that holds pattern information indicating a correspondence relationship between the positional relationship and the line pattern is further provided, and the selection of the line pattern is performed with reference to the pattern information held in the holding unit. The pattern information is represented by a table, and a curve is drawn based on this table.

  The reason why pattern information is represented by tables and a curve is drawn based on these tables is shown below.

  The first point is the origin (0, 0). The second point is assumed that the increase / decrease in the distance in the x direction and the increase / decrease in the distance in the y direction from the first point are within ± d. The third point is assumed that the increase / decrease in the distance in the x direction and the increase / decrease in the distance in the y direction from the second point are within ± d.

In these cases, there are (2d + 1) × (2d + 1) combinations of the first point and the second point. There are (2d + 1) × (2d + 1) combinations of the second point and the third point. Accordingly, there are (2d + 1) ⁴ combinations of the three points. Thus, the combination of the positions of the three points increases dramatically according to d. For example, when d = 5, there are 14,641 ways, but when d = 10, there are 194481 ways, and when d = 20, there are 2825761 ways. Since there is a limit to the amount of data that can be stored in the character display device, when there are many combinations of the positions of the three points, these combinations are represented by a table, and storing these tables in the character display device Have difficulty.

  As described above, the present invention displays the first point and the second point of the first curve and the first point and the second point of the second curve even when displaying two different curves (first curve and second curve). The two points are the same, the angle between the straight line passing through the first point and the second point of the first curve, the straight line passing through the second point and the third point of the first curve, and the first of the second curve. If the angle between the straight line passing through the point and the second point and the straight line passing through the second point and the third point of the second curve are closer than a predetermined value, the line passing through the first point and the second point It is noted that even if the patterns are the same, there is no sense of incongruity for those who watch the first curve and the second curve.

  FIG. 1 shows an example of a curve passing through three points.

  This curve passes through the first point (0, 0), the second point (7, 4), and the third point (10, 10). In FIG. 1, black points are these three points, points with many hatches are points included in a line passing through the first point and the second point, and points with few hatches are the second points. And a point included in a line passing through the third point. Also, a straight line passing through the first point and the second point and a straight line passing through the second point and the third point are shown.

  FIG. 2 shows another example of a curve passing through three points.

  This curve passes through the first point (0, 0), the second point (7, 4), and the third point (13, 16). The first point (0, 0) and the second point (7, 4) are the same as the first point and the second point in FIG. 1, and the third point (13, 16) is the second point in FIG. And a point on an extension of a straight line passing through the third point.

  When the line pattern of FIG. 1 is compared with the line pattern of FIG. 2, the line pattern passing through the second point and the third point is different, but the line pattern passing through the first point and the second point is The same.

  FIG. 3 shows still another example of a curve passing through three points.

  This curve passes through the first point (0, 0), the second point (7, 4), and the third point (12, 17). The first point (0, 0) and the second point (7, 4) are the same as the first point and the second point in FIG. 2, and the third point (12, 17) is the third point in FIG. This is the upper left point. The angle between the straight line passing through the first point and the second point in FIG. 2 and the straight line passing through the second point and the third point, and the straight line passing through the first point and the second point in FIG. The angle with the straight line passing through the third point is close.

  When the line pattern of FIG. 2 is compared with the line pattern of FIG. 3, the line pattern passing through the second point and the third point is different, but the line pattern passing through the first point and the second point is The same.

  FIG. 4 shows yet another example of a curve passing through three points.

  This curve passes through the first point (0, 0), the second point (7, 4), and the third point (14, 16). The first point (0, 0) and the second point (7, 4) are the same as the first point and the second point in FIG. 2, and the third point (14, 16) is the third point in FIG. This is the lower right point.

  When the line pattern of FIG. 2 is compared with the line pattern of FIG. 4, the line pattern passing through the second point and the third point is different, but the line pattern passing through the first point and the second point is The same.

  As described with reference to FIGS. 1 to 4, even when different curves are drawn, even if the pattern of the lines passing through the first point and the second point is the same, the viewer who feels the curve feels uncomfortable. Absent.

  FIG. 5 shows still another example of a curve passing through three points. This curve passes through the first point (0, 0), the second point (7, 4), and the third point (5, 12).

  FIG. 6 shows still another example of a curve passing through three points. This curve passes through the first point (0, 0), the second point (7, 4), and the third point (14, 6).

  The first point (0, 0) and the second point (7, 4) shown in FIGS. 5 and 6 are the same as the first point and the second point shown in FIGS. The angles of the straight line passing through the first point and the second point and the straight line passing through the second point and the third point are greatly different from the angles shown in FIGS. 1 to 4. The first point and the second point The trajectory of the line passing through and is different from that in FIGS.

  FIG. 7 shows the areas 1 to 28 allocated around the second point.

  Areas 1 to 28 are allocated by dividing the area around the second point into 28 equal parts. When there is a third point in the same region, the number of combinations of the three points is reduced by making the pattern of lines passing through the first point and the second point the same. For example, in the first curve, when the third point is at position A in the region 1 and in the second curve, the third point is in region 1 and at a position B different from the position A, the first point The pattern of the line passing through the first point and the second point of one curve is made the same as the pattern of the line passing through the first point and the second point of the second curve.

Areas 1 to 28 are assigned around the second point, the first point is the origin (0, 0), the second point is (X, Y) (X ≦ ± d, Y ≦ ± d: from the first point In the case where the increase / decrease in the distance in the x direction and the distance in the y direction is within ± d), the position of the third point is any one of the regions 1 to 28. Therefore, there are (2d + 1) ² × 28 combinations of the three points.

  Further, only when the second point is in the first quadrant, a table indicating the correspondence between the positional relationship and the line pattern is generated, and when the second point is in a quadrant other than the first quadrant, this table is used. Thus, the number of tables can be reduced by obtaining the correspondence between the positional relationship and the line pattern.

Only when the second point is in the first quadrant, an angle between a straight line passing through the first point and the second point, a straight line passing through the second point and the third point, and a curve passing through the first point and the second point The correspondence with the pattern is expressed in a table. When the second point is in the second quadrant, consider symmetry with respect to the y-axis, when the second point is in the third quadrant, consider symmetry with respect to the origin, and when the second point is in the fourth quadrant Considers symmetry with respect to the x-axis. In this case, there are (d + 1) ² × 28 combinations of the three points. For example, when d = 5, there are 1008 combinations, when d = 10, there are 3388 combinations, and when d = 20, there are 12348 combinations. The capacity required to store the represented table can be reduced.

  Note that the area allocated around the second point is not limited to 28 divisions. The number of divisions is arbitrary. Increasing the number of divisions increases the capacity of the table, but can improve the quality of the curve. Moreover, it is not limited to equal division. It may be finely divided at a shallow angle and roughly divided at a deep angle.

  FIG. 28 shows an example of an area allocated around the second point.

  FIG. 28A shows a plurality of regions (division form 1) having different sizes.

  A plurality of regions 1 to 8 are assigned around the second point. The third point is given to region 2. For example, the region 1 and the region 4 have different sizes.

  FIG. 28B shows a region (partition form 2) assigned to only a part around the second point.

  A plurality of regions 1 to 5 are assigned around the second point. However, no area is allocated to other portions (shaded portions).

  The division form around the second point can be selected according to the display target. For example, when displaying Chinese characters, the division form 1 is selected. When displaying katakana, the division form 2 is selected. Note that the “display target” means a target displayed on the display device. For example, characters (kanji, hiragana, katakana, alphabet, etc.), figures, and symbols.

  Embodiments of the present invention will be described below with reference to the drawings.

2. Character Display Device FIG. 8 shows a configuration of a character display device 100 according to the embodiment of the present invention.

  The character display device 100 may be a personal computer, for example. As the personal computer, any type of computer such as a desktop type or a laptop type may be used. Alternatively, the character display device may be a word processor.

  Furthermore, the character display device can be any information display terminal such as an electronic device or an information device provided with a display device. For example, the character display device may be an electronic device provided with a liquid crystal display device, a portable information terminal as a form information tool, a mobile phone including a PHS, or a communication device such as a general telephone / FAX.

  The character display device 100 includes an input device 10, a display device 30 that displays lines, a control unit 20 that controls the display device 30, and an auxiliary storage device 40.

  The input device 10 is used to input information representing characters to be displayed on the display device 30 to the control unit 20. The information representing the character includes, for example, a code for recognizing the character and size information indicating the size of the character.

As the input device 10, any type of input device capable of inputting a code and a size can be used. An input device such as a keyboard, mouse or pen input device may be used. When the character display device 100 is a mobile phone, a numeric key for designating a communication destination telephone number may be used for inputting a code and a size. When the character display device 100 includes means for connecting to a communication line including the Internet, a message included in an e-mail received from the communication line may be displayed on the display device 30. In this case, the means for connecting to the communication line functions as the input device 10.
The auxiliary storage device 40 stores a character display program 41, character data 42 necessary for executing the program, a straight line table 43, and a curved table 44.

  The character display program 41 includes a scaling program 41a for scaling the character data 42 according to the size to be output to the display device, a quantization program 41b for quantizing the scaled result, and the quantized result displayed on the display device. A drawing data conversion program 41c for converting the result quantized so as to become drawing data.

  As the auxiliary storage device 40, any type of auxiliary storage device capable of storing the character display program 41, the character data 42, the straight line table 43, and the curve table 44 can be used. In the auxiliary storage device 40, any recording medium can be used as a storage medium for storing the character display program 41, the character data 42, the straight line table 43, and the curve table 44. For example, a hard disk, CD-ROM, CD-R, MO, DVD, and IC card can be suitably used.

  Note that the character display program 41, the character data 42, the straight line table 43, and the curve table 44 are not limited to being stored in a recording medium provided in the auxiliary storage device 40. For example, the character display program 41, the character data 42, the straight line table 43, and the curve table 44 may be stored in the main memory 22 or stored in a ROM (not shown). The ROM can be, for example, a mask ROM, EPROM, EEPROM, or flash ROM. When these data are stored in the ROM, various processing variations can be easily realized simply by exchanging the ROM. For example, the ROM can be suitably applied when the character display device is a portable information terminal or a mobile phone.

  Furthermore, the character display program 41, the character data 42, the straight line table 43, and the curve table 44 can be held in a storage medium that holds the program and data in a fixed manner, such as a storage device such as the disk or card or a semiconductor memory. . When the character display device is provided with means for connecting to a communication line including the Internet, the character display program 41, the character data 42, the straight line table 43, and the curve table 44 are downloaded from the communication line. I can do it. In this case, a loader program necessary for downloading may be stored in advance in a ROM (not shown), or may be installed in the control unit 20 from the auxiliary storage device 40.

  The control unit 20 includes a CPU 21 and a main memory 22.

  The CPU 21 controls and monitors the entire character display device and executes a character display program 41 stored in the auxiliary storage device 40.

  The main memory 22 temporarily stores data input from the input device 10, data to be displayed on the output device 30, and data necessary to execute the character display program 41. The main memory 22 is controlled by the CPU 21.

  The CPU 21 generates drawing data by executing the character display program 41 based on various data stored in the main memory 22. The generated drawing data is temporarily stored in the main memory 22 and then output to the display device 30. The timing at which the drawing data is output to the display device 30 is controlled by the CPU 21.

  FIG. 9 shows an example of the character data 42. Specifically, the character data shown in FIG. 9 is vector data of the character “large” and has a resolution of 256 mesh. The character data shown in FIG. 9 includes a plurality of coordinate data.

  The line number is a number assigned to a line that forms the character “Large”. X represents the X coordinate value of a point on the line constituting the character “Large”. Y indicates the Y coordinate value of a point on the line constituting the character “Large”.

  The letter “Large” consists of three lines. Each of the three lines has a plurality of coordinate data representing positions. Line No1 connects two points (8,184) and (247,184), and Line No2 includes (127,246), (127,181), (103,106), (61,49) and The five points (11, 14) are connected, and the line No. 3 connects (127, 181), (144, 127), (176, 73), (208, 40), and (246, 14).

  FIG. 10 is an example of display of the character data 42. Specifically, it is a display of the character data shown in FIG.

  FIG. 11 shows an example of the straight line table 43. The straight line table 43 is stored in the auxiliary storage device 40 (see FIG. 8).

  “Index” indicates a record number of the table, and “(dx, dy)” indicates an increase in the x direction and an increase in the y direction from the first point.

  In this embodiment, the increase in the x direction and the increase in the y direction are within 20 but the increase in the x direction and the increase in the y direction are not limited to 20 or less. The increase in the x direction and the increase in the y direction are arbitrary.

  The “control string” is represented by “0” and “1”. In the case of dx ≧ dy, the increment of y when incremented by 1 in the x direction is indicated by “0” and “1”. “0” indicates that the increase in the y direction is 0 when 1 is increased in the x direction, and “1” indicates that the increase in the y direction is 1 when 1 is increased in the x direction. Show.

  For example, when (dx, dy) = (1, 2), the control string is {0, 1}. This control sequence {0, 1} has an increase in the y direction of 0 when it increases by 1 in the x direction from the first point, and an increase in the y direction when it increases by 1 in the x direction. 1 is shown. The pattern of lines represented by this control sequence indicates a pattern of lines passing through the first point and the second point.

  FIG. 12 shows an example of the curve table 44. The curve table 44 is stored in the auxiliary storage device 40 (see FIG. 8).

  FIG. 13 shows values that the control column has.

  “Index” indicates a record number of the table, and “(dx, dy)” indicates an increase in the x direction and an increase in the y direction from the first point.

  In this embodiment, the increase in the x direction and the increase in the y direction are within 15; however, the increase in the x direction and the increase in the y direction are not limited to 15 or less. The increase in the x direction and the increase in the y direction are arbitrary. In general, the range of the increase in the x direction and the increase in the y direction of the curve table is smaller than the range of the increase in the x direction and the increase in the y direction of the straight line table. This is because the distance is smaller than the distance between two points on the straight line.

  “Angle” indicates which of the regions 1 to 28 is the third point (see FIG. 7).

  The “control string” is represented by “0” to “7” (see FIG. 13). “0” indicates a movement to the right with respect to the second point, “1” indicates a movement to the upper right, “2” indicates an upward movement, “3” indicates an upper left movement, “4” indicates movement to the left, “5” indicates movement to the lower left, “6” indicates movement to the lower side, and “7” indicates movement to the lower right. For example, when (dx, dy) = (7, 4) and the third point is in the region 2, the control sequence is {0, 0, 1, 0, 1, 1, 1} (see FIG. 12). ). This control column indicates that the movement from the first point is right, right, upper right, right, upper right, upper right, upper right. The pattern of the line represented by this movement is the first point and the second point when the three points are the first point (0, 0), the second point (7, 4), and the third point (10, 10). A pattern of lines passing through the points is shown (see FIG. 1).

  As described with reference to FIG. 12, the information included in the curve table 44 indicates the correspondence between the positional relationship between the second point and the third point and the line pattern. The curve table 44 is prepared in advance in the auxiliary storage device 40.

  The line pattern represented by the “control column” included in the curve table 44 is not limited to a curve. The pattern of lines represented by “control columns” may be a straight line. Such a control string is {1, 1, 1, 1}, for example.

  The character display device 100 according to the embodiment of the present invention has been described above with reference to FIGS. 1 to 13 and FIG.

  For example, in the examples of FIGS. 1 to 13 and FIG. 28, the display device 30 corresponds to “a display device that displays a line”, and the control unit 20 includes “a control unit that controls the display device” and “given first A control unit for determining a first positional relationship between at least one of the first point and the second point and the third point with respect to the point, the second point, and the third point, and “at least one prepared in advance; A control unit that selects one line pattern corresponding to the determined first positional relationship from among at least one line pattern that passes through the first point and the second point. And “a control unit that displays on the display device a line passing through the first point and the second point according to the selected line pattern”. Further, the auxiliary storage device 40 that stores the straight line table 42 and the curve table 44 corresponds to “a holding unit that holds pattern information indicating a correspondence relationship between the first positional relationship and the line pattern”.

  However, the embodiment shown in FIGS. 1 to 13 and FIG. 28 is merely an example of the function of the character display device of the present invention. As long as the functions of the respective means described above are achieved, a character display device having an arbitrary configuration can be included in the scope of the present invention.

  For example, the straight line table 42 and the curve table 44 may be input to the display device from the outside of the display device. For example, when the straight line table 42 and the curve table 44 are held in the holding unit connected to the display device via the network, the straight line table 42 and the curve table 44 are input to the display device from the outside of the display device. .

  For example, each unit described above may be realized by hardware, may be realized by software, or may be realized by hardware and software.

  For example, the character display device stores a program for executing a character display processing procedure (hereinafter referred to as a character display processing program). The character display processing program may be stored in advance in a program storage unit included in the character display device when the computer is shipped.

  Alternatively, the character display processing program may be stored in the program storage means after the computer is shipped. For example, the user may download a character display processing program from a specific website on the Internet for a fee or free of charge, and install the downloaded program in a computer. When the character display processing program is recorded on a computer-readable recording medium such as a flexible disk, CD-ROM, or DVD-ROM, the character display processing program is stored in the computer using an input device (for example, a disk drive device). You may make it install in. The installed program is stored in the program storage means.

  Details of the character display processing procedure will be described later.

  As described with reference to FIG. 1 to FIG. 13 and FIG. 28, according to the display device of the present invention, the first point is obtained without calculating the trajectory of the line passing through the first point and the second point. A line passing through the first point and the second point can be displayed by selecting one line pattern corresponding to the determined positional relationship from the pattern of at least one line passing through the second point. Therefore, it is not necessary to calculate the trajectory of the line passing through the first point and the second point, which requires complicated calculations, and the line passing through the first point and the second point can be displayed at high speed.

  In the present invention, a curve connecting the three points is drawn using a table indicating the correspondence between the pattern of lines passing through the first point and the second point and the positional relationship between the three points. Therefore, a curve can be drawn only by reading the table, and no complicated calculation occurs. As a result, a line passing through the first point and the second point can be drawn at high speed.

  Further, the angles of the straight line passing through the first point and the second point and the straight line passing through the second point and the third point are classified and tabulated. As a result, the capacity can be reduced.

  Furthermore, only when the second point is in the first quadrant, the straight line passing through the first point and the second point and the angle of the straight line passing through the second point and the third point are classified and tabulated. Therefore, the number of combinations of the three points can be reduced. As a result, the capacity can be further reduced.

3. Display Method FIG. 14 shows a character display processing procedure. Character display processing is performed by the CPU 121 executing the character display program 141.

  Hereinafter, the character display processing procedure will be described step by step with reference to FIGS.

  Step S101: Character data representing a designated character is read from the character data 42 in accordance with an instruction input from the input device 10. For example, the read character data includes a plurality of coordinate data (see FIG. 9).

  Step S102: The coordinate data included in the read character data is scaled to fit the output size. When the output size is n dots, the coordinate data (x, y) is scaled by a predetermined calculation and changed to scaled data (X, Y). The predetermined calculations are X = (n−1) × x / 255, Y = (n−1) × y / 255.

  For example, when the output size is 36 dots, the coordinate data (x, y) (see FIG. 9) is scaled by a predetermined calculation and changed to scaled data (see FIG. 22).

  Step S103: The scaled data is quantized and changed to quantized data. For example, there is a rounding method as a quantization method. For example, the coordinate data (x, y) (see FIG. 9) is scaled by a predetermined calculation and further quantized to be changed to quantized data (see FIG. 22).

  Note that the quantization method is not limited to rounding. Another method of quantization is disclosed in the present application and the application filed by the same applicant (Japanese Patent Application No. 2003-137918). The disclosed method includes a method for suppressing a quantization error.

  Step S104: Referring to the straight line table 43 and the curve table 44, drawing data is obtained from the quantized data.

  Step S105: An image is displayed on the display device 30 based on the drawing data.

  After the image is displayed on the display device 30, the process ends.

  FIG. 15 shows the drawing data conversion processing procedure executed in step S104.

  Hereinafter, the drawing data conversion processing procedure will be described step by step with reference to FIG.

  Step S201: Quantized data is extracted. For example, in the case of the character “Large”, the quantized data corresponding to the called line No. is extracted (see FIG. 22). First, the line No. 1 is called, and the corresponding quantized data ((1, 25), (34, 25)) is extracted. Next, line No. 2 is called and the corresponding quantized data ((17, 34), (17, 25), (14, 15), (8, 7), (2, 2)) is extracted. Finally, line no. 3 is called, and the corresponding quantized data ((17, 25), (20, 17), (24, 10), (29, 5), (34, 2)) is extracted.

  Step S202: It is determined whether or not three or more coordinate points are included in the quantized data corresponding to the called line No.

  If it is determined that three or more coordinate points are included (Yes), the process proceeds to step S204. If it is determined that three or more coordinate points are not included (No), the process proceeds to step S203.

  Step S203: Drawing data is obtained so that the line indicated by the called line No is drawn as a straight line. With reference to the straight line table 43, drawing data is obtained from the quantized data.

  Step S204: Drawing data is determined so that the line indicated by the called line No is drawn with a curve. With reference to the curve table 44, drawing data is obtained from the quantized data.

  Step S205: It is determined whether there is a line to be called.

  If it is determined that there is a line to be called (Yes), the process proceeds to step S201. If it is determined that there is no line to call (No), the process ends.

  FIG. 16 shows a straight line drawing process procedure executed in step S203.

  Hereinafter, the straight line drawing processing procedure will be described step by step with reference to FIG.

Step S301: The next value of the given two coordinate points (x ₁ , y ₁ ) and (x ₂ , y ₂ ) is obtained. The distance dx between x ₁ and x ₂ is obtained by dx ← abs (x ₂ −x ₁ ), and the distance dy between y ₁ and y ₂ is obtained by dy ← abs (y ₂ −y ₁ ).

  The function abs (t) indicates the absolute value of t.

Furthermore, when representing a variable indicating the drawing position (x, y) at, x ← x ₁ and y ← y ₁ shows a process of setting a drawing start position of the first point.

  Step S302: The first point (x, y) is converted into drawing data.

  Step S303: A control row is acquired from the straight line table 43. Access to the linear table is performed by the following calculation.

  If the range of the table is n, the ((n + 1) × dy + dx + 1) th control column in the straight line table 43 is acquired. In this embodiment, since the table range is 20, the ((20 + 1) × dy + dx + 1) th control column is acquired.

Step S304: determining which one is greater of _{x 1} and _{x 2.}

In the case where x ₂ is determined to be _{x 1} or more (Yes), then the process proceeds to step S305. In the case where x ₂ is determined to be _{x 1} is smaller than (No), then the process proceeds to step S306.

  Step S305: A value “1” is set in the variable incx. Increase / decrease in the x direction is controlled by the variable incx.

  Step S306: A value “−1” is set in the variable incx. Increase / decrease in the x direction is controlled by the variable incx.

Step S307: determining either the greater of _{y 1} and _{y 2.}

In the case where y ₂ is determined to be _{y 1} or more (Yes), then the process proceeds to step S308. In the case where y ₂ is determined to be _{y 1} is less than (No), then the process proceeds to step S309.

  Step S308: A value “1” is set in the variable incy. Increase / decrease in the y direction is controlled by the variable incy.

Step S309: A value “−1” is set in the variable incy. Increase / decrease in the y direction is controlled by the variable incy Step S310: It is determined which of dx and dy is greater.

  If it is determined that dx is greater than or equal to dy (Yes), the process proceeds to step S311. If it is determined that dx is smaller than dy (No), the process proceeds to step S314.

  Step S311: It is determined whether or not the control sequence is over. If it is determined that the control sequence is finished (Yes), the process ends. If it is determined that the control string is not over (No), the process proceeds to step S312.

  Step S312: The next point of (x, y) is calculated. Specifically, the value of incx for controlling the increase / decrease in x is added to x (the next value of x = x + incx), and the value of incy for controlling the increase / decrease in y is multiplied by the value (Δy) in the control column ( Next value of y = y + incy × Δy).

  Step S313: (x + incx) and (y + incy × Δy) are converted into drawing data. Specifically, a point (x + incx, y + incy × Δy) is plotted. Thereafter, the process proceeds to step S311.

  Step S314: It is determined whether or not the control sequence is over. If it is determined that the control sequence is finished (Yes), the process ends. If it is determined that the control sequence is not over (No), the process proceeds to step S315.

  Step S315: The next point of (x, y) is calculated. Specifically, a value obtained by multiplying x by incx for controlling the increase / decrease of x and the value (Δx) of the control column (the next value of x = x + incx × Δx), and the value of incy for controlling the increase / decrease of y by y Add (next value of y = y + incy).

  Step S316: (x + incx × Δx) and (y + incy) are converted into drawing data. Specifically, a point (x + incx × Δx, y + incy) is plotted. Thereafter, the process proceeds to step S314.

  FIG. 17 shows a curve drawing process procedure executed in step S204.

  Hereinafter, the curve drawing processing procedure will be described step by step with reference to FIG.

Step S401: Three points are extracted from the given coordinate points. For example, given coordinate points are 5 points ((a ₁ , b ₁ ), (a ₂ , b ₂ ), (a ₃ , b ₃ ), (a ₄ , b ₄ ), (a ₅ , b ₅ ). ), In the first call, three points (a ₁ , b ₁ ), (a ₂ , b ₂ ), (a ₃ , b ₃ ) are taken out, and in the next call, (a ₂ , b ₂ ), (a ₃ , b ₃ ), (a ₄ , b ₄ ) are taken out. The three consecutive points are taken out one by one while being shifted.

Step S402: The next values of the three extracted coordinate points (x ₁ , y ₁ ), (x ₂ , y ₂ ), (x ₃ , y ₃ ) are obtained. The distance dx between x ₁ and x ₂ is obtained by dx ← abs (x ₂ −x ₁ ), and the distance dy between y ₁ and y ₂ is obtained by dy ← abs (y ₂ −y ₁ ).

Furthermore, when representing a variable indicating the drawing position (x, y) at, x ← x ₁ and y ← y ₁ shows a process for setting the first point of the third point to the drawing start position.

  Step S403: Of the three extracted points, the first point (x, y) is converted into drawing data.

  Step S404: An angle pattern is obtained from an angle between a straight line passing through the first point and the second point and a straight line passing through the second point and the third point.

It can be calculated as an angle pattern a = round (((Θ ₂ −Θ ₁ ) × 28) / (2 × Π)).

Here, the angle Θ ₁ is an angle between the straight line passing through the first point and the second point and the x axis (Θ ₁ = tan ⁻¹ ((y ₂ −y ₁ ) / (x ₂ −x ₁ ))) The angle Θ ₂ is the angle between the straight line passing through the second point and the third point and the x axis (Θ ₂ = tan ⁻¹ ((y ₃ −y ₂ ) / (x ₃ −x ₂ ))) It is.

The function round (t) indicates the rounding off of t. The calculation of tan ⁻¹ is complicated, but in the case of the present invention, it can be applied to any angle pattern finally divided into 28, and the accuracy requirement is not high. Therefore, it is possible to speed up the calculation of tan ⁻¹ using a table in which the tan ⁻¹ argument is classified into several patterns.

Details of techniques to speed up the calculation of ^{tan -1} using a table showing the correspondence between the value of the argument and ^{tan -1} of ^{tan -1} will be described later.

  As described above with reference to steps S401 to S404, the first point and the second point are given to the first point, the second point, and the third point by executing steps S401 to S404. A positional relationship between at least one of the two points and the third point is determined.

  Step S405: A control string is acquired (selected) from the curve table 44. Access to the curve table is performed by the following calculation.

  When the table range is n, the number of divisions is t, and the angle pattern is a, the ((n + 1) × t × dy + t × dx + a) -th control column in the curve table 44 is acquired. In this embodiment, the range of the table is 15, and the number of divisions is 28, so the ((15 + 1) × 28 × dy + 28 × dx + a) -th control column is acquired.

  As described with reference to step S405, by executing step S405, from the curve table 44 including information indicating the correspondence between the positional relationship between the second point and the third point and the line pattern, A control column showing the desired line pattern is selected.

Step S406: determining which one is greater of _{x 1} and _{x 2.}

In the case where x ₂ is determined to be _{x 1} or more (Yes), then the process proceeds to step S407. In the case where x ₂ is determined to be _{x 1} is smaller than (No), then the process proceeds to step S408.
Step S407: determining either the greater of _{y 1} and _{y 2.}

In the case where y ₂ is determined to be _{y 1} or more (Yes), then the process proceeds to step S409. In the case where y ₂ is determined to be _{y 1} is less than (No), then the process proceeds to step S410.
Step S408: determining either the greater of _{y 1} and _{y 2.}

In the case where y ₂ is determined to be _{y 1} or more (Yes), then the process proceeds to step S411. In the case where y ₂ is determined to be _{y 1} is less than (No), then the process proceeds to step S412.

  Step S409: Drawing the first quadrant when the second point is in the first quadrant when the first point is the origin.

  Step S410: When the first point is the origin, the second quadrant is drawn when the second point is in the second quadrant.

  Step S411: When the first point is set as the origin, the third quadrant is drawn when the second point is in the third quadrant.

  Step S412: When the first point is set as the origin, the fourth quadrant is drawn when the second point is in the fourth quadrant.

  Step S413: It is determined whether a flag is set. If it is determined that the flag is set (Yes), the process ends. If it is determined that the flag is not set (No), the process proceeds to step S414.

  Step S414: It is determined whether or not the three points acquired by executing Step S401 are the last three points.

For example, the coordinate points given to the curve drawing process are (a ₁ , b ₁ ), (a ₂ , b ₂ ), (a ₃ , b ₃ ), (a ₄ , b ₄ ), (a ₅ , b ₅ ) Is the last three points (a ₃ , b ₃ ), (a ₄ , b ₄ ), (a ₅ , b ₅ ) or not. Determine whether.

  If it is determined that there are the last three points (Yes), the process proceeds to step S415. If it is determined that it is not the last three points (No), the process proceeds to step S401.

  Step S415: A flag is set and three points are set in reverse.

For example, when the last three points are set in the order of (a ₃ , b ₃ ), (a ₄ , b ₄ ), (a ₅ , b ₅ ), the last three points are set to (a ₅ , b ₅ ), (a ₄ , b ₄ ), and (a ₃ , b ₃ ) are changed in order. This is to prevent (a ₄ , b ₄ ) and (a ₅ , b ₅ ) from being rendered.

When three points are picked up in order (see step S401), the drawing is performed between the first point and the second point, and between the second point and the third point. Is not drawn. Finally, in order to prevent the last section (between (a ₄ , b ₄ ) and (a ₅ , b ₅ )) from being drawn, the points (a ₃ , b ₃ ) and the points (a ₅ , b ₅ ) is replaced and the last section is drawn.

  In the present embodiment, the last three points are set in reverse, but “process of step 414” is changed to “process of determining whether or not the three acquired points are before the middle of the line”. Also good. In this case, if it is determined that the three acquired points are before the middle, three points are extracted in order from the first point (see step S401), and the three acquired points are before the middle. If it is determined that it is not, three points are extracted in reverse order from the last point.

Figure 27 shows the correspondence between parameter values of ^{tan -1} and ^{tan -1.} The value of tan ⁻¹ is an angle (degree), and the argument of tan ⁻¹ is dy / dx. The angle θ is indicated by (no × 360) / 56.

By using the table showing the correspondence between the argument tan ^-1 values and ^{tan -1,} is no longer necessary to perform calculation of ^{tan -1.} However, the value of tan ⁻¹ is 0 to 180 ° (only the first quadrant and the second quadrant), and an argument of tan ⁻¹ corresponding to 180 ° <tan ⁻¹ <360 is obtained by calculation. For example, since the straight line passing through (0, 0) and (10, 5) is dy / dx = 0.5 (dy = 5, dx = 10), it can be seen that it is between no4 and no5. In this embodiment, if the smaller no is selected, no = 4. Also, since the straight line passing through (0, 0) and (−10, −5) is dy / dx = 0.5 (dy = 5, dx = 10), no = 4, but in the third quadrant Since it is a value, 28 is added and no = 32. That is, Θ ₁ = tan ⁻¹ ((y ₂ −y ₁ ) / (x ₂ −x ₁ )) corresponds to obtaining an angle between a straight line passing through the first point and the second point and a horizontal line. If it is allowed to reduce the accuracy, it can be replaced with determining the table no.

The value of (y ₂ −y ₁ ) / (x ₂ −x ₁ )) obtained from the table is designated as no _1, and the value of (y ₃ −y ₂ ) / (x ₃ −x ₂ )) is represented in the table. If the obtained value is no ₂ , the calculation of a = round (((Θ ₂ −Θ ₁ ) × 28) / (2 × Π)) is a = round (abs (no ₂ −no ₁ ) / 2) Can be replaced.

  Hereinafter, a specific description will be given with reference to FIGS.

FIG. 1 shows curves through (0,0), (7,4), (10,10). The value of no ₁ is 4. This is because (4-0) / (7-0) = 0.571. The value of no ₂ is 9. This is because (10-4) / (10-7) = 2. The angle pattern a is 3 (a = round (abs (9-4) / 2)).

FIG. 2 shows curves through (0,0), (7,4), (13,16). The value of no ₁ is 4. This is because (4-0) / (7-0) = 0.571. The value of no ₂ is 9. This is because (16-4) / (13-7) = 2. The angle pattern a is 3 (a = round (abs (9-4) / 2)).

FIG. 3 shows curves through (0,0), (7,4), (12,17). The value of no ₁ is 4. This is because (4-0) / (7-0) = 0.571. The value of no ₂ is 10. This is because (17-4) / (12-7) = 2.6. The angle pattern a is 3 (a = round (abs (10−4) / 2)).

FIG. 4 shows curves passing through (0,0), (7,4), (14,16). The value of no ₁ is 4. This is because (4-0) / (7-0) = 0.571. The value of no ₂ is 15. This is because (14-4) / (6-7) = − 10. The angle pattern a is 6 (a = round (abs (15-4) / 2)).

  When a table is used in this way, the angle pattern can be obtained without calculating a complicated trigonometric function.

  FIG. 18 shows the first quadrant drawing processing procedure executed in step S409.

  Hereinafter, the first quadrant drawing processing procedure will be described step by step with reference to FIG.

  Step S501: It is determined whether or not the control sequence acquired in step S405 is over.

  If it is determined that the control sequence is finished (Yes), the process ends. If it is determined that it is not the end (No), the process proceeds to step S502.

  Step S502: The process branches according to the value of the control string (values “0” to “7”: see FIG. 13).

  If the control value is “0”, the process proceeds to step S503. If the control value is “1”, the process proceeds to step S504. If the control value is “2”, the process proceeds to step S505. If the control value is “3”, the process proceeds to step S506. If the control value is “4”, the process proceeds to step S507. If the control value is “5”, the process proceeds to step S508. If the control value is “6”, the process proceeds to step S509. If the control value is “7”, the process proceeds to step S510.

  Step S503: The value of x that controls the value in the x direction is increased by one. The process proceeds to step S511.

  Step S504: The value of x that controls the value in the x direction is increased by 1, and the value of y that controls the value in the y direction is increased by 1. The process proceeds to step S511.

  Step S505: The value of y for controlling the value in the y direction is incremented by one. The process proceeds to step S511.

  Step S506: The value of x that controls the value in the x direction is decreased by 1, and the value of y that controls the value in the y direction is increased by 1. The process proceeds to step S511.

  Step S507: The value of x that controls the value in the x direction is decreased by one. The process proceeds to step S511.

  Step S508: The value of x that controls the value in the x direction is decreased by 1, and the value of y that controls the value in the y direction is decreased by 1. The process proceeds to step S511.

  Step S509: The value of y for controlling the value in the y direction is decreased by one. The process proceeds to step S511.

  Step S510: The value of x that controls the value in the x direction is incremented by 1, and the value of y that controls the value in the y direction is incremented by 1. The process proceeds to step S511.

  Step S511: The point (x, y) calculated in steps S503 to S510 is converted into drawing data. For example, the point (x, y) is plotted.

  FIG. 19 shows the second quadrant drawing processing procedure executed in step S410.

  The second quadrant is y-axis symmetric with respect to the first quadrant. Accordingly, the difference between the first quadrant drawing processing procedure (see FIG. 18) and the processing procedure is only that the increase / decrease in x according to the control value is reversed, and thus the description of steps S601 to S611 is omitted.

  FIG. 20 shows the third quadrant drawing processing procedure executed in step S411.

  The third quadrant is symmetric with respect to the first quadrant. Accordingly, the difference in the processing procedure from the first quadrant drawing processing procedure (see FIG. 18) is that the increase / decrease in x and the increase / decrease in y in accordance with the control values are respectively reversed, so that Steps S701 to S711 are explained. Is omitted.

  FIG. 21 shows the fourth quadrant drawing processing procedure executed in step S412.

  The fourth quadrant is x-axis symmetric with respect to the first quadrant. Accordingly, the difference between the first quadrant drawing processing procedure (see FIG. 18) and the processing procedure is only that the increase / decrease in y according to the control value is reversed, and thus the description of steps S801 to S811 is omitted.

  FIG. 22 shows coordinate data, scaled data, and quantized data.

  This is a result of scale processing and quantization processing of vector data (see FIG. 9).

  FIG. 23 shows the result of rendering based on the quantized data shown in FIG.

  The result of rendering quantized data (see FIG. 22) by rendering data conversion processing (see FIG. 15) is shown. Characters can be drawn with high quality by curve drawing.

  FIG. 24 shows a procedure for editing the table.

  FIG. 25 shows the line pattern after changing the display points.

  FIG. 26 shows the curve drawing table after the display point is changed.

  The table editing procedure will be described step by step with reference to FIGS. 1, 12, and 24 to 26.

  Step S901: A control sequence passing through three points is called up, and a line pattern is displayed on the editing screen. The line pattern displayed on the editing screen is shown in FIG. 1, for example. A line pattern passing through two points is displayed on the editing screen.

  Step S902: The displayed line pattern is changed while viewing the screen. For example, the line pattern shown in FIG. 1 is edited to the line pattern shown in FIG.

  Step S903: Of the changed line patterns, only the line pattern passing through the first point and the second point is indicated by the control string, and the table is rewritten. The 1990th control sequence {0, 0, 1, 0, 1, 1, 1} of the curve table shown in FIG. 12 is replaced with the 1990th control sequence {0, 1, 0 of the curve table shown in FIG. , 1, 0, 1, 1}.

  Thus, the contents of the curve table can be changed. However, the change result affects all cases where the angle of the straight line passing through the first point and the second point and the straight line passing through the second point and the third point are divided into the same angle pattern.

  The display procedure of the present invention has been described above with reference to FIGS. 14 to 21 and FIG.

  For example, in the examples of FIGS. 14 to 21 and 24, steps S401 to S404 are “at least one of the first point and the second point with respect to the given first point, second point and third point. Step S405 corresponds to “a step of determining the first positional relationship between one and the third point”, and “step S405 is a pattern of at least one line prepared in advance and passes through the first point and the second point at least. Corresponding to “Step of selecting one line pattern corresponding to the determined first positional relationship from one line pattern”, Steps S409 to S412 are performed according to “Selected line pattern. , “Displaying a line passing through the first point and the second point on the display device”. However, the examples of FIGS. 14 to 21 and FIG. 24 merely show an example of the display procedure of the present invention. As long as each step mentioned above is performed, the display procedure which has arbitrary steps may be included in the scope of the present invention.

  According to the program and the recording medium of the present invention, a pattern of at least one line passing through the first point and the second point can be obtained without calculating a trajectory of the line passing through the first point and the second point. By selecting a pattern of one line corresponding to the determined positional relationship, a line passing through the first point and the second point can be displayed. Therefore, it is not necessary to calculate the trajectory of the line passing through the first point and the second point, which requires complicated calculations, and the line passing through the first point and the second point can be displayed at high speed.

  In the above-described embodiment, the case where characters are displayed has been described as an example, but the present invention is not limited to this. The present invention can be applied to a case where a graphic is displayed instead of or in addition to a character. In this case, a graphic display program is used instead of the character display program 41 or in addition to the character display program 41, and graphic data is used instead of the character data 42 or in addition to the character data 42. That's fine. The graphic display program can also include the same steps as the character display program 41. The graphic includes, for example, a part of a character, a pattern, a symbol, and the like.

  As mentioned above, although this invention has been illustrated using preferable embodiment of this invention, this invention should not be limited and limited to this embodiment. It is understood that the scope of the present invention should be construed only by the claims. It is understood that those skilled in the art can implement an equivalent range based on the description of the present invention and the common general technical knowledge from the description of specific preferred embodiments of the present invention. Patents, patent applications, and documents cited herein should be incorporated by reference in their entirety, as if the contents themselves were specifically described herein. Understood.

  According to the display device, the program, and the recording medium of the present invention, the pattern of at least one line passing through the first point and the second point without obtaining the trajectory of the line passing through the first point and the second point by calculation. A line passing through the first point and the second point can be displayed by selecting one line pattern corresponding to the determined positional relationship. Therefore, it is not necessary to calculate the trajectory of the line passing through the first point and the second point, which requires complicated calculations, and the line passing through the first point and the second point can be displayed at high speed.

  In the present invention, a curve connecting the three points is drawn using a table indicating the correspondence between the pattern of lines passing through the first point and the second point and the positional relationship between the three points. Therefore, a curve can be drawn only by reading the table, and no complicated calculation occurs. As a result, a line passing through the first point and the second point can be drawn at high speed.

  Further, the angles of the straight line passing through the first point and the second point and the straight line passing through the second point and the third point are classified and tabulated. As a result, the capacity can be reduced.

  Furthermore, only when the second point is in the first quadrant, the straight line passing through the first point and the second point and the angle of the straight line passing through the second point and the third point are classified and tabulated. Therefore, the number of combinations of the three points can be reduced. As a result, the capacity can be further reduced.

It is a figure which shows an example of the curve which passes along three points. It is a figure which shows another example of the curve which passes along three points. It is a figure which shows another example of the curve which passes along 3 points | pieces. It is a figure which shows another example of the curve which passes along 3 points | pieces. It is a figure which shows another example of the curve which passes along 3 points | pieces. It is a figure which shows another example of the curve which passes along 3 points | pieces. It is a figure which shows the area | region 1-the area | region 28 allocated around the 2nd point. It is a figure which shows the structure of the character display apparatus 100 of embodiment of this invention. It is a figure which shows an example of the character data. It is a figure which shows an example of a display of the character data. It is a figure which shows an example of the straight line table. It is a figure which shows an example of the curve table. It is a figure which shows the value which a control row | line has. It is a flowchart which shows a character display process procedure. It is a flowchart which shows the drawing data conversion process procedure performed by step S104. It is a flowchart which shows the straight line drawing process procedure performed by step S203. It is a flowchart which shows the curve drawing process procedure performed by step S204. It is a flowchart which shows the 1st quadrant drawing process procedure performed by step S409. It is a flowchart which shows the 2nd quadrant drawing process procedure performed by step S410. It is a flowchart which shows the 3rd quadrant drawing process procedure performed by step S411. It is a flowchart which shows the 4th quadrant drawing process procedure performed by step S412. It is a figure which shows coordinate data, scaled data, and quantized data. It is a figure which shows the result drawn based on the quantization data shown by FIG. It is a flowchart which shows the edit processing procedure of a table. It is a figure which shows the pattern of the line after changing a display point. It is a figure which shows the curve drawing table after changing a display point. is a diagram showing the correspondence between argument tan ^-1 value and ^{tan -1.} It is a figure which shows an example of the area | region allocated around the 2nd point.

Explanation of symbols

10 Input device 20 Control unit 21 CPU
22 Main memory 30 Display device 40 Auxiliary storage device 41 Character display program 42 Character data 43 Line table 44 Curve table 100 Character display device 1

Claims (9)

A display device for displaying lines;
A display device comprising: a control unit that controls the display device;
The control unit has a first positional relationship between at least one of the first point and the second point and the third point with respect to the given first point, second point, and third point. Decide
A pattern of at least one line prepared in advance, and one pattern corresponding to the determined first positional relationship among at least one line pattern passing through the first point and the second point Select the line pattern,
A display device that displays a line passing through the first point and the second point on the display device in accordance with the selected line pattern. A holding unit that holds pattern information indicating a correspondence relationship between the first positional relationship and the line pattern;
The display device according to claim 1, wherein the selection of the line pattern is performed with reference to the pattern information held in the holding unit. The first positional relationship is determined according to an angle between a first straight line connecting the first point and the second point and a second straight line connecting the second point and the third point. Item 4. The display device according to Item 1. The control unit determines a second positional relationship between at least one of the first point and the second point and the fourth point with respect to the first point, the second point, and the fourth point. And
The control unit selects one line pattern corresponding to the determined second positional relationship from the at least one line pattern,
A plurality of areas are allocated around the second point,
The third point and the fourth point are given to the same region of the plurality of regions,
The display device according to claim 3, wherein a pattern of one line corresponding to the selected first positional relationship and a pattern of one line corresponding to the selected second positional relationship are the same. . The display device according to claim 1, wherein the first point is given to an origin and the second point is given to a first quadrant. A plurality of areas are allocated around the second point,
The third point is given to one of the plurality of regions;
The display device according to claim 1, wherein one of the plurality of regions and a region different from the one region have different sizes. A plurality of areas are allocated only to a part around the second point,
The display device according to claim 1, wherein the third point is given to one of the plurality of regions. A program for causing an information display device having a display device for displaying a line to execute display processing,
The display process includes
Determining a first positional relationship between at least one of the first point and the second point and the third point with respect to the given first point, second point and third point;
A pattern of at least one line prepared in advance, and one pattern corresponding to the determined first positional relationship among at least one line pattern passing through the first point and the second point Selecting a line pattern;
Displaying a line passing through the first point and the second point on the display device in accordance with the selected line pattern. A recording medium readable by an information display device having a display device for displaying lines,
The recording medium records a program for causing the information display device to execute display processing,
The display process includes
Determining a first positional relationship between at least one of the first point and the second point and the third point with respect to the given first point, second point and third point;
A pattern of at least one line prepared in advance, and one pattern corresponding to the determined first positional relationship among at least one line pattern passing through the first point and the second point Selecting a line pattern;
And displaying a line passing through the first point and the second point on the display device in accordance with the selected line pattern.

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