WO2014174569A1

WO2014174569A1 - Font drawing device

Info

Publication number: WO2014174569A1
Application number: PCT/JP2013/061771
Authority: WO
Inventors: 前川　拓也
Original assignee: 三菱電機株式会社
Priority date: 2013-04-22
Filing date: 2013-04-22
Publication date: 2014-10-30
Also published as: TW201441838A

Abstract

A first storage unit (1) temporarily holds pass data unique to a character code. A second storage unit (2) temporarily holds pass data which was position-adjusted by grid fitting after scaling the pass data to a character drawing size. When drawing a character, if the pass data exists in the second storage unit (2), a drawing processing unit (3) performs a drawing using the pass data, and if the pass data does not exist in the second storage unit (2), the drawing processing unit (3) performs drawing processing including the grid fitting using the pass data in the first storage unit (1).

Description

Font drawing device

The present invention relates to a font drawing apparatus for drawing a character of at least one of a stroke font and an outline font.

A drawing processing speed-up technique by caching character data has existed conventionally. For example, bitmap data obtained by expanding vector data of glyphs, or linear approximation data generated in the middle of expansion is cached, There has been a technique of drawing characters without performing the same character drawing processing after the second drawing (see, for example, Patent Document 1).

JP 7-306669 A

However, when a bitmap is used, the memory capacity required for the cache is proportional to the square of the character size to be drawn, which causes a problem that the required memory capacity becomes enormous. In addition, when using the linear approximation data cache, there is a problem that even if the characters have the same character code, if the character width and height to be drawn are different, a cache miss occurs, and it is necessary to perform grid fitting processing that requires processing again. there were.

The present invention has been made to solve such a problem, and an object of the present invention is to obtain a font drawing apparatus capable of speeding up character drawing processing while reducing the memory capacity to be used.

The font drawing device according to the present invention is a font drawing device that draws characters of at least one of a stroke font and an outline font, and that temporarily holds unique path data for the character code of the font. 1 storage unit, the second storage unit that temporarily stores the path data that has been scaled to the size of the character to be drawn and then adjusted by grid fitting, and the character pass data when drawing the character It is determined whether there is path data to be stored in the second storage unit. If it exists, drawing is performed based on the path data in the second storage unit, and if there is no path data in the second storage unit, the first is stored. And a drawing processing unit that performs drawing processing including grid fitting using the path data of the storage unit.

In the font drawing device according to the present invention, when the character is drawn, if the pass data exists in the second storage unit, drawing is performed using the pass data, and if the pass data does not exist in the second storage unit, the first drawing is performed. Since the drawing processing including grid fitting is performed using the path data of one storage unit, the character drawing processing can be speeded up while reducing the memory capacity to be used.

It is a functional block diagram of the font drawing apparatus which concerns on this invention. It is a hardware block diagram by the font drawing apparatus of Embodiment 1 of this invention. It is explanatory drawing of a grid fitting. It is explanatory drawing of an outline font and a stroke font. It is a flowchart which shows operation | movement of the font drawing apparatus of Embodiment 1 of this invention. It is explanatory drawing which shows the management information in the font drawing apparatus of Embodiment 1 of this invention. It is explanatory drawing at the time of implementing a grid fitting process only about the axis | shaft in which the path data does not exist in the cache in the font drawing apparatus of Embodiment 1 of this invention. It is a flowchart which shows the rendering process in the font drawing apparatus of Embodiment 1 of this invention. It is a hardware block diagram which shows the font drawing apparatus of Embodiment 2 of this invention.

Hereinafter, in order to explain the present invention in more detail, modes for carrying out the present invention will be described with reference to the accompanying drawings.
Embodiment 1 FIG.
FIG. 1 is a functional block diagram of a font drawing apparatus according to this embodiment.
The font drawing apparatus according to the present embodiment is a drawing apparatus that draws characters of at least one of a stroke font and an outline font, and includes a first storage unit 1, a second storage unit 2, and a drawing process. Part 3 is provided.

The first storage unit 1 is a storage unit that temporarily holds unique path data for a character code. The second storage unit 2 is a storage unit that temporarily holds path data that has been scaled to a character size to be drawn and then subjected to position adjustment by grid fitting. The drawing processing unit 3 determines whether path data matching the path data of the character exists in the second storage unit 2 when drawing a character based on the input drawing parameters. A processing unit that performs drawing based on the path data in the second storage unit 2 and performs a drawing process including grid fitting using the path data in the first storage unit 1 when the data does not exist in the second storage unit 2 It is.

FIG. 2 is a hardware configuration diagram of the font drawing apparatus according to this embodiment. As shown in the figure, the font drawing apparatus includes an arithmetic processor 101, a main memory 102, an auxiliary storage device 103, and an output device 104. The arithmetic processor 101 is a processor for performing arithmetic processing represented by a CPU or the like. The main memory 102 forms a work area for the arithmetic processor 101 to perform arithmetic processing, and realizes a first storage device 102a and a second storage device 102b. The first storage device 102a is a cache memory corresponding to the first storage unit 1 in FIG. 1, and holds path data that depends only on the character code. The second storage device 102b is a cache memory corresponding to the second storage unit 2 in FIG. 1, and holds path data that has been subjected to position adjustment by grid fitting after scaling to the character size to be drawn. The auxiliary storage device 103 is a storage device including a hard disk device or a semiconductor memory for storing the application program 103a, data (not shown), and the like. The output device 104 is an output device such as a display for displaying a character drawing result.

1 is realized by the arithmetic processor 101 loading the application program 103a from the auxiliary storage device 103 to the main memory 102 and executing it. That is, after the application program 103a is copied onto the main memory 102, it is executed by the arithmetic processor 101 to execute path data generation processing, instruction control, and the like.

The present invention is a technique for speeding up character drawing processing in an apparatus for drawing characters using a grid fitting technique that dynamically performs hinting processing. Hinting processing is an optimization technique for rasterizing font outline information (path data) into a bitmap image. As shown in FIG. 3, the position of the path data is dynamically changed with respect to the display grid. The method of correcting to is grid fitting. In the present invention, attention is paid to a character drawing process using the grid fitting process. The path data refers to character outline information as shown in FIG. 4, and is represented by a set of point coordinate and line type flag data connecting points. There are two types of methods for storing the shape of the path data, and there are stroke fonts that are formed only by the character framework, in addition to outline fonts that imitate the outline of the characters. A description will be given below of a drawing process using a cache for the purpose of reducing the amount of calculation required for the internal grid fitting process and speeding up the drawing process of the path data.

FIG. 5 is a flowchart of the character drawing process performed by the font drawing apparatus according to this embodiment.
When drawing one character, as main inputs related to the present invention, a character code, a character size, and a drawing parameter such as an X-axis / Y-axis magnification for scaling such as a vertical double-width or horizontal double-width character are specified. . Based on such parameters, the drawing processing unit 3 first searches the second storage unit 2 for characters having the same parameters in step ST1. The second storage unit 2 has path data that has been enlarged to a drawing character size including scaling, and has been subjected to position adjustment by grid fitting. By hitting this cache, calculation by grid fitting is performed. Processing can be omitted. If there is no path data in which the width and height of the drawing character size match, but the width and height can be acquired from different cache data, the data is acquired and the rendering process in step ST11 is performed. Migrate to

On the other hand, if desired path data cannot be acquired, the presence or absence of path data with the same character code is searched from the first storage unit 1 in step ST2. The path data included in the first storage unit 1 is obtained by normalizing glyph path data loaded from font data, and is unique to the character code. If the desired storage data does not exist in the first storage unit 1, a process of acquiring the path data from the font data in step ST 3 and a normalization process of the path data are performed in step ST 4, and the first storage unit Register to 1. It is assumed that the font data is held in advance by the drawing processing unit 3 or stored in an external storage device.

Subsequently, in step ST5 and step ST6, it is searched whether there exists path data having the same width or height of the scaled drawing character size. If the path data does not exist, in step ST7, the normalized path data is enlarged according to the designated character size and the X-axis / Y-axis magnification. Then, after the path data is enlarged, a grid fitting process is performed in step ST8, and the path data after the position adjustment and management information relating to the grid fitting are held in step ST10. In the management information, as shown in FIG. 6, the character code, the line type flag data, the drawing character size, and the path data storage destination address corresponding to the character size are held as a set, and the management information is referred to. Pass data after grid fitting. The management information shown in FIG. 6 may be stored in the drawing processing unit 3 or stored in any device accessible by the drawing processing unit 3.

Also, the grid fitting process used in the present invention employs a method capable of separately processing the horizontal line and vertical line fitting processes as described in Japanese Patent Application Laid-Open No. 2010-170097. As a result, when there is path data that is equal only in one of the width and the height, the grid fitting process is performed only for the axis for which no path data exists in the cache in step ST9. The above example is shown in FIG. In FIG. 7,

characters

701 and 702 are characters having character sizes of 16 dots and 32 dots, respectively, and the characters are drawn by specifying the enlargement ratio of the X axis and the Y axis in addition to the character size. A character 703 draws a character having a character size of 16 dots while designating a character having a character size of 32 dots as a character having a character size of 32 dots. It is assumed that drawing is performed with the enlargement ratio specified as 1 for both the axis and the Y axis. As a result, the widths of the drawn

characters

703 and 704 are both equal to 32 dots. At this time, since the coordinate values after the grid fitting process in the X direction are equal, the grid fitting process may be applied only for the Y coordinate. Then, after obtaining the pass data after the grid fitting process, the pass data is input to the rasterizer in step ST11 to perform rendering. The flow of the rendering process is described in FIG. 8. Characters are obtained by straight line division processing (step ST 111) of curve data, intersection point calculation processing of path data and scan lines (step ST 112), and painting processing (step ST 113). Draw.

The above two-stage cache mechanism reduces the number of grid fitting processes and draws at high speed. In addition, this method uses pass data as a cache target, and the memory capacity required to store the pass data does not depend on the size of the character to be drawn. The capacity can be reduced.

As described above, according to the font drawing apparatus of the first embodiment, the font drawing apparatus that draws characters of at least one of the stroke font and the outline font is unique to the character code of the font. A first storage unit that temporarily stores correct path data, a second storage unit that temporarily stores path data that has been scaled to the character size to be drawn and then adjusted by grid fitting, and a character When drawing, it is determined whether there is path data matching the character path data in the second storage unit. If there is, the drawing is performed based on the path data in the second storage unit, and the second storage unit A rendering processing unit that performs rendering processing including grid fitting using the path data in the first storage unit Because it was example, while reducing the memory capacity to be used, it is possible to speed up the character rendering process.

Further, according to the font drawing apparatus of the first embodiment, the drawing processing unit performs the grid fitting process of the pass data independently in the X-axis direction and the Y-axis direction, so the width and height are equal. By referring to the corrected path data on the X-axis and Y-axis, respectively, the grid fitting process can be omitted and the speed can be increased.

Embodiment 2. FIG.
The second embodiment is an example in which the drawing processing unit 3 includes a hardware processing unit, and the hardware processing unit performs drawing using the path data in the second storage unit. Since the functional block diagram is the same as that of FIG. 1, description will be made using the configuration of FIG.

FIG. 9 is a hardware configuration diagram of the font rendering apparatus according to the second embodiment. The illustrated font drawing apparatus uses an H / W graphics engine capable of vector graphics processing, and the graphics engine 201 refers to the video memory 202 as compared with the configuration of the first embodiment shown in FIG. The difference is that the characters are drawn. In addition, a second storage device 102 b that holds path data that has been subjected to position adjustment by grid fitting is arranged in the video memory 202 and used as input data for the graphics engine 201. As a result, the grid fitting process is not performed at the time of a cache hit, and the character rendering process can be immediately performed by H / W. Since other configurations are the same as those of the first embodiment shown in FIG. 2, the same reference numerals are given to corresponding portions, and description thereof will be omitted.

As described above, according to the font rendering apparatus of the second embodiment, the rendering processing unit includes the hardware processing unit, and the hardware processing unit performs rendering using the path data in the second storage unit. Therefore, higher speed can be achieved.

In the present invention, within the scope of the invention, any combination of the embodiments, or any modification of any component in each embodiment, or omission of any component in each embodiment is possible. .

As described above, the font drawing apparatus according to the present invention relates to a font drawing apparatus that draws characters of stroke fonts and outline fonts, and is suitable for outputting a character drawing result to a display or a printer.

1. 1st storage unit, 2nd storage unit, 3 drawing processing unit, 101 arithmetic processor, 102 main memory, 102a 1st storage device, 102b 2nd storage device, 103 auxiliary storage device, 103a application program, 104 output Device, 201 graphics engine, 202 video memory.

Claims

In a font drawing device that draws characters of at least one of a stroke font and an outline font,
A first storage unit that temporarily stores unique path data for the character code of the font;
A second storage unit that temporarily holds path data that has been subjected to position adjustment by grid fitting after scaling to the character size to be drawn;
When drawing a character, it is determined whether there is path data that matches the path data of the character in the second storage unit. If there is, the drawing is performed based on the path data in the second storage unit. A font rendering apparatus comprising: a rendering processing unit that performs rendering processing including the grid fitting using path data of the first storage unit when it does not exist in the second storage unit.
The font drawing apparatus according to claim 1, wherein the drawing processing unit performs grid fitting processing of path data independently in the X-axis direction and the Y-axis direction.
2. The font drawing apparatus according to claim 1, wherein the drawing processing unit includes a hardware processing unit, and the hardware processing unit performs drawing using the path data of the second storage unit.