JP2009271347A - Font plotting device and information processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To paint out after plotting the outline of a glyph. <P>SOLUTION: The font plotting device includes: a memory for storing a plurality of pixel data showing the position of each pixel specified in a two-dimensional coordinate system; an instruction input means to which a first or second plotting instruction is input; an outline calculating means which specifies pixels through which the outline of the glyph passes as object pixels by using glyph data showing the outline of the glyph; a plotting position calculating means which calculates the coordinates of each object pixel in a two-dimensional coordinate system as a plotting position; an outline plotting means which performs outline plotting processing to write, in the memory, the pixel data showing the pixels through which the outline passes; and a paint-out means which performs paint-out processing to paint out the inside of the outline specified by the data written in the memory after finishing the outline plotting processing on the glyph to which the second plotting instruction is given, when the second plotting instruction is input to the instruction input means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for drawing an outline font.

  An outline font is known as a data format for expressing on a computer the form of a glyph (a visual expression of characters or an abstract expression in which the size and design are normalized from its constituent parts). The outline font is a format that expresses the shape of a glyph as a collection of coordinates and outlines of a reference point. Here, a glyph (hereinafter referred to as a “composite glyph”) that is a combination of glyphs that become parts (hereinafter referred to as “parts glyph”) is used as necessary. Patent Document 1 discloses a technique for drawing a composite glyph. According to Patent Literature 1, after rendering each part glyph on the cache, the rendering result is synthesized on the memory to obtain a composite glyph.

Japanese Patent Application Laid-Open No. 6-067641

Even with the technique described in Patent Literature 1, there are composite glyphs that cannot be drawn by rendering after rendering part glyphs such as white circles and white numerals.
On the other hand, the present invention provides a technique for rendering (filling) after synthesizing outlines of part glyphs.

The present invention provides a first glyph data read from a memory for storing data indicating gradations of pixels arranged in a matrix, and a storage means for storing glyph data indicating the contour of the glyph and the direction of the contour. The data indicating the contour line of the first glyph indicated by is written in the memory, and the data indicating the contour line of the second glyph indicated by the second glyph data read from the storage means is written in the memory. A filling means for filling a pixel inside the contour line among the pixels stored in the memory, and a region surrounded by the two contour lines is set in the direction of the two contour lines; In accordance with the present invention, there is provided a font drawing apparatus having a filling means for executing a filling process for determining whether or not the region is filled.
According to this font drawing device, the first glyph and the second glyph are drawn after the outlines are drawn.

In a preferred aspect, the filling process is a process of setting one row or one column of the matrix as a target line and determining a gradation for each pixel along the target line, wherein the target line and the contour line In other words, the gradation of the pixel may be determined according to a parameter that increases or decreases depending on the direction in which the and intersect.
According to this font drawing apparatus, the gradation of a pixel is determined according to a parameter that increases or decreases according to the direction in which the target line and the contour line intersect.

In another preferable aspect, the parameter may be increased when the target line and the contour line intersect in a certain direction, and may be decreased when the target line and the contour line intersect in another direction.
According to this font drawing device, the gradation of a pixel is determined according to a parameter that increases when the target line and the contour line intersect with each other and decreases when the target line and the contour line intersect with each other. Is done.

The present invention also stacks information for specifying the target glyph, with the storage device storing glyph data indicating the outline of the glyph and the direction of the outline, and the glyph to be drawn as the target glyph. Is a composite glyph composed of a first part glyph and a second part glyph, a stack for stacking information identifying the first part glyph and the second part glyph, and in order from the stack If the information is still stacked on the stack, a contour drawing command for glyph data corresponding to the read information is issued, and the read information when the stack is empty And a control device that issues contour drawing and filling commands for glyph data corresponding to the A first glyph contour line indicated by a first glyph data read out from a memory storing data indicating the gradation of a pixel and a storage unit storing glyph contour and glyph data indicating the direction of the contour. Contour writing means for writing data indicating the contour line of the second glyph indicated by the second glyph data read out from the storage means, and writing the data indicating the second glyph data to the memory; Whether or not the region surrounded by the two contour lines is filled according to the direction of the two contour lines, which is a filling process for filling the pixels inside the contour line among the pixels. An information processing apparatus is provided that includes a font drawing apparatus having a filling unit that executes a filling process for which the determination is made.
According to this information processing apparatus, when a composite glyph composed of the first part glyph and the second part glyph is drawn, the filling is performed after the outlines of the first glyph and the second glyph are drawn. Is called.

1. Configuration FIG. 1 is a diagram showing a hardware configuration of an information display apparatus 1 according to an embodiment of the present invention. The information display device 1 is an example of an information processing device. A CPU (Central Processing Unit) 10 is a control device that controls each element of the information display device 1. A ROM (Read Only Memory) 20 is a non-volatile storage device that stores programs and data necessary for starting and operating the information display device 1. In the present embodiment, the ROM 20 stores glyph data as data relating to fonts. The glyph data is data indicating the outline of the glyph and the direction of the outline (details will be described later). A RAM (Random Access Memory) 30 is a storage device used as a work area when the CPU 10 executes a program. The display body 40 is a device that displays an image according to supplied data, and in this example is an EPD (Electrophoretic Display). EPD is an example of a memory display. A VRAM (Video Random Access Memory) 50 is a storage device used for storing data to be displayed. The display control device 60 is a device that controls the display body 40 according to the data stored in the VRAM 50 under the control of the CPU 10. The input device 70 is a device used for inputting an instruction, data, etc. from a user, such as a button (rewrite button, page feed button, determination button, etc.), keypad, wheel, lever, touch panel, pen device, or the like. The bus 80 is a transmission path used for transmitting data and signals between elements. The bus controller 90 is a device that arbitrates a bus right (right to use a bus) for all devices (modules) connected to the bus 80. The font processor 100 is an apparatus used for drawing a font, and is an example of a font drawing apparatus.

  The CPU 10, ROM 20, RAM 30, VRAM 50, display control device 60, and font processor 100 are directly connected to the bus 80. With this configuration, the CPU 10, the display control device 60, and the font processor 100 can access the memories (ROM 20, RAM 30, and VRAM 50) independently of each other. A signal line between the CPU 10 and the font processor 100 is used for supplying a drawing start command from the CPU 10 to the font processor 100 and supplying a drawing completion notification from the font processor 100 to the CPU 10. A signal line between the CPU 10 and the display control device 60 is used to supply a screen update from the CPU 10 to the display control device 60 (that is, a transfer command to the display body 40). This signal line is unnecessary when a display body that is not a memory display body, such as a liquid crystal display, is used as the display body 40.

  FIG. 2 is a diagram illustrating the configuration of the font processor 100. The main controller 101 controls each element of the font processor 100. The main controller 101 has a register 102. The register 102 is used, for example, for storing an address of data to be read by the main controller 101. The font drawing controller 103 stores information necessary for font drawing, for example, affine transformation parameters. The font drawing controller 103 further stores whether the given instruction is DrawChar or DrawCharFill. DrawChar is a command for instructing execution of the contour drawing process (an example of a first drawing command). DrawCharFill is a command for instructing execution of contour drawing processing and painting processing (an example of a second drawing command). The contour drawing module 104 (an example of a contour drawing means) performs contour calculation processing, drawing position calculation processing, and contour drawing processing when the command DrawChar or the command DrawCharFill is given. First, the contour drawing module 104 calculates the contour of the glyph using the glyph data (contour calculation processing). In addition, the contour drawing module 104 calculates the position of the pixel for drawing the contour (drawing position calculation processing). The contour drawing module 104 further writes data indicating the calculated contour in the work memory 105 (contour drawing processing). When drawing a composite glyph, the contour drawing module 104 writes data indicating the contour of the first glyph into the work memory 105 and then writes data indicating the contour of the second glyph into the work memory 105. The work memory 105 is used as a rendering memory that stores data indicating gradations of pixels that are two-dimensionally arranged in a matrix (in this example, two gradations for filling or not filling). The paint module 106 (an example of paint means) performs paint processing, background composition processing, and transfer processing when an instruction DrawChar is given. First, the filling module 106 fills the inside of the outline drawn by the outline drawing module 104, that is, the area surrounded by the outline (filling process). In the filling process, for an area surrounded by two outlines, whether or not the area is filled is determined according to the directions of the two outlines (details will be described later). The filling module 106 further synthesizes the pixel and the background as necessary (background synthesis processing). The filling module 106 further outputs the generated pixel data (transfer process). The bus interface module 107 inputs and outputs signals and data to and from other elements such as the CPU 10, ROM 20, and RAM 30 via the bus 80. The main bus 108 and the sub bus 109 are transmission paths used for transmitting data and signals between elements.

  A signal line between the contour drawing module 104 and the filling module 106 is used to notify the end of the contour drawing process. A signal line between the font drawing controller 103 and the filling module 106 is used to transmit information such as the bit width and data range of the work memory 105. A signal line between the filling module 106 and the main bus 108 is used for transmission of background data and transmission of the result of the painting process. Although not specifically described, signal lines other than these are also used for transmitting necessary data and commands. In addition, the two work memories 105 are used alternately to increase the processing speed.

  FIG. 3 is a diagram illustrating an appearance of the information display device 1. The information display device 1 has a display surface of the display body 40 and a button group as the input device 70 on the front surface of the housing.

2. Operation Next, the operation of the information display device 1 will be described. Here, first, the configuration of the glyph data will be outlined, and the operation of the information display device 1 will be described in detail after the prior art and the font drawing method of the present embodiment are outlined.

2-1. Configuration of Glyph Data FIG. 4 is a diagram illustrating glyph data. The glyph data includes information used to draw the outline of the glyph. In this example, the glyph data includes a point coordinate as information for specifying an end point and a command for drawing a straight line or a curve as information for specifying a straight line or a curve connecting two end points. D1 to D6 represent points on the contour line. The command Move is a command for moving the point position. The command Move includes the coordinates of the destination point as an argument. The command Line is a command for drawing a straight line (line segment). The command Line includes the coordinates of the end point of the straight line as an argument. Although not used in the example of FIG. 4, the command Curve2 is a command for drawing a quadratic Bezier curve. The command Curve2 includes the coordinates of the end point of the curve and the coordinates of one control point as arguments. The command Curve3 is a command for drawing a cubic Bezier curve. The command Curve3 includes the coordinates of the end point of the curve and the coordinates of two control points as arguments. The instruction EOC indicates the end of glyph data. Point D0 is a predetermined reference point. The command Move (D1) moves the point position from D0 to D1. A straight line is drawn from D1 to D2 by the command Line (D2). A straight line is drawn from D2 to D3 by the command Line (D3). By a command Curve3 (D7, D8, D4), a cubic Bezier curve is drawn from D3 to D4 with D7 and D8 as control points. Points D7 and D8 are not shown. In the same manner, a contour line having an orientation as shown in FIG. 4 is described by the glyph data. In FIG. 4, glyph data is graphically shown to aid understanding, but the glyph data is actually text data or binary data including instructions and point coordinates.

2-2. Font rendering method of the related art and the present embodiment 2-2-1. Method Recommended for True Type Font FIG. 5 is a diagram for explaining a drawing method recommended for the True Type font. Here, an example will be described in which two part glyphs, glyph A and glyph B, are combined to generate a composite glyph. First, the glyph data (FIGS. 5A and 5B) of the glyph A and the glyph B stored in the ROM are combined on a contour data memory provided in advance (FIG. 5C). Thus, the glyph data of the composite glyph is stored in the contour data memory. In FIGS. 5A to 5C, graphics are shown to aid understanding, but what is stored is glyph data, not bitmap data. The arrow in the figure indicates the direction of the contour line.

  Next, a contour line is drawn on the rendering memory using the glyph data of the composite glyph (FIG. 5D). The rendering memory stores bitmap data indicating whether or not to fill each of a plurality of pixels arranged in a matrix. Finally, the inside of the outline is filled in the rendering memory (FIG. 5E). According to this method, it is necessary to provide a memory for contour data separately from the memory for rendering.

2-2-2. Method According to Patent Document 1 FIG. 6 is a diagram illustrating a drawing method according to Patent Document 1. Using the glyph data (FIGS. 5A and 5B) of glyph A and glyph B stored in the ROM, the contour lines of glyph A and glyph B are respectively drawn in the part cache memory provided in advance. (FIGS. 6A and 6B). The part cache memory stores bitmap data. Next, the insides of the contour lines of the glyph A and the glyph B are filled on the part cache memory (FIGS. 6C and 6D). Finally, the part glyph filled in the rendering memory is synthesized (FIG. 6E).

  According to this method, it is necessary to provide a parts cache memory separately from the rendering memory. The part cache memory needs several parts glyphs to be synthesized. For example, to draw a composite glyph that combines three part glyphs, three parts of cache memory are required. In addition, as described below, there are cases where this method cannot accurately draw a composite glyph.

  FIG. 7 is a diagram illustrating a composite glyph that cannot be accurately drawn by the drawing method disclosed in Patent Document 1. FIG. 7D shows the result to be obtained. The theoretical outline for obtaining this display is as shown in FIG. This composite glyph is composed of a part glyph C (FIG. 7A) and a part glyph D (FIG. 7B). However, when the drawing method according to Patent Document 1 is applied to these part glyphs, since the parts glyphs are filled and then combined, the result shown in FIG. 7E is obtained. This is different from the result originally desired.

2-2-3. Method According to the Present Embodiment FIG. 8 is a diagram illustrating a drawing method according to the present embodiment. First, using the glyph data of the glyph A stored in the ROM (FIG. 5A), the outline of the glyph A is drawn in the rendering memory (FIG. 8A). Further, with the glyph A outline drawn in the rendering memory, the glyph B outline is drawn in the rendering memory using the glyph B glyph data (FIG. 5B) (FIG. 8). (B)). That is, the outline of glyph B is overwritten on the outline of glyph A. Finally, the inside of the contour line is filled on the rendering memory (FIG. 8C).

  According to this method, it is not necessary to provide a contour data memory and a parts cache memory in addition to the rendering memory. Also, in the filling process (details will be described later), it is determined whether or not the region surrounded by the two contour lines is to be painted or not according to the direction of the contour line. You can draw accurately.

2-3. Operation of information display device 2-3-1. Overall Operation FIG. 9 is a flowchart showing the operation of the information display apparatus 1. The flow shown in FIG. 9 is triggered by an event for starting font drawing, for example, an event for updating an image displayed on the display body 40. Here, an example will be described in which a glyph to be drawn (hereinafter referred to as “target glyph”) is the composite glyph shown in FIG. This composite glyph is composed of two part glyphs, a glyph A (FIG. 5A) and a glyph B (FIG. 5B). The following processing is performed by the CPU 10 operating according to a control program stored in the ROM 20.

In step S100, the CPU 10 empties the stack. In this example, the stack is a LIFO (Last In First Out), and a storage area is provided on the RAM 30. Further, the CPU 10 initializes the rendering memory.
In step S110, the CPU 10 loads (pushes) the glyph number of the target glyph on the stack. The glyph number is an example of information for specifying glyph data.

In step S120, the CPU 10 acquires (pops) the glyph number from the stack. Since the stack is a LIFO, the newest data is acquired.
In step S130, the CPU 10 determines from the acquired glyph number whether the glyph indicated by the glyph number (hereinafter referred to as “acquired glyph”) is a composite glyph. In this example, the glyph data has a flag indicating whether the glyph is a composite glyph or a simple glyph (non-composite glyph), and the CPU 10 reads the flag of the acquired glyph from the ROM 20 and determines it. When it is determined that the acquired glyph is a composite glyph (S130: YES), the CPU 10 shifts the processing to step S140. When it is determined that the acquired glyph is not a composite glyph (S130: NO), the CPU 10 shifts the processing to step S150.

  In step S140, the CPU 10 loads all the glyph numbers of the part glyphs constituting the acquired glyph on the stack. The glyph number of the part glyph is described in the glyph data. The CPU 10 reads the glyph data of the acquired glyph from the ROM 20. The CPU 10 identifies the part glyphs that form the acquired glyph from the read glyph data, and accumulates the glyph numbers of the part glyphs on the stack. When the glyph number of the part glyph is stacked on the stack, the CPU 10 shifts the process to step S120 again.

In step S150, the CPU 10 reads the glyph data of the acquired glyph.
In step S160, the CPU 10 determines whether the stack is empty. When it is determined that the stack is empty (S160: YES), the CPU 10 shifts the processing to step S180. When it is determined that the stack is not empty (S160: NO), the CPU 10 shifts the processing to step S170.

  In step S170, the CPU 10 issues an instruction DrawChar. That is, the CPU 10 writes the address where the glyph data of the acquired glyph is stored in the register 102 of the font processor 100 together with the instruction DrawChar.

  When receiving the command DrawChar from the CPU 10, the main controller 101 of the font processor 100 causes the font drawing controller 103 to store that the command is DrawChar. Further, the main controller 101 reads the glyph data from the ROM 20 and causes the contour drawing module 104 to draw a contour line according to the glyph data. The operation of the contour drawing module 104 will be described later. The contour drawing module 104 draws a contour line according to the glyph data in the work memory 105. If the received command is DrawChar, the fill module 106 does not perform processing. When the contour drawing is completed, the font processor 100 notifies the CPU 10 of the completion of the contour drawing. When notified of the completion of drawing, the CPU 10 shifts the process to step S120 again.

  In step S180, the CPU 10 issues an instruction DrawCharFill. That is, the CPU 10 writes the address where the glyph data of the acquired glyph is stored in the register 102 of the font processor 100 together with the command DrawCharFill.

  When receiving the command DrawCharFill from the CPU 10, the main controller 101 of the font processor 100 causes the font drawing controller 103 to store that the command is DrawCharFill. Further, the main controller 101 reads the glyph data from the ROM 20 and causes the contour drawing module 104 to draw a contour line according to the glyph data. That is, the contour drawing module 104 writes bitmap data of the contour line according to the glyph data in the work memory 105. When the received command is DrawCharFill, the fill module 106 performs a fill process for filling the area surrounded by the outline in the bitmap data stored in the work memory 105. The operation of the filling module 106 will be described later. When the painting process is completed, the font processor 100 notifies the CPU 10 of the completion of painting. When the completion of painting is notified, the CPU 10 ends the process of FIG.

  Here, a specific operation example will be described by taking as an example the case where the composite glyph of FIG. In this example, the glyph number for the composite glyph is 150, and the glyph numbers for glyph A and glyph B are 100 and 10, respectively. First, the glyph number 150 is stacked on the stack (step S110). The glyph number 150 is acquired from the stack (step S120). Since the glyph of the glyph number 150 is a composite glyph (S130: YES), the glyph numbers 10 and 100 of the part glyphs are stacked on the stack (step S140). Next, the glyph number 100 is acquired from the stack (step S120). Since the glyph with the glyph number 100 (glyph A) is a simple glyph (S130: NO), the glyph data of the glyph A is read (step S150). Since the stack is still not filled with glyph number 10 (S160: NO), the command DrawChar is issued (step S170). Here, the outline of the glyph A is drawn. Next, the glyph number 10 is acquired from the stack (step S120). Since the glyph of the glyph number 10 (glyph B) is a simple glyph (S130: NO), the glyph data of the glyph B is read (step S150). Since the stack is empty (S160: YES), the command DrawCharFill is issued (step S180). Here, the outline of the glyph B is overwritten, the outline of the composite glyph is drawn, and the inside of the outline is further filled.

2-3-2. Operation of Outline Drawing Module 104 In this embodiment, the outline drawing module 104 calculates a contour calculation process for calculating an outline using glyph data, a pixel through which an outline passes, that is, a position where an outline should be drawn. A drawing position calculation process, and a contour drawing process of writing pixel data passing through the outline into the work memory 105. Details of the contour calculation process and the drawing position calculation process are omitted here, but the outline is as follows.

  In the contour calculation process, the contour drawing module 104 generates a command according to a given command (Move, Line, Curve2, Curve3, EOC) and the coordinates of the point. The command generated by the contour calculation process is one of Move, dVector, and EOC. The instructions Move and EOC are as described in the glyph data section. The command dVector is obtained by decomposing the commands Line, Curve2, and Curve3 to a predetermined minimum unit (for example, one pixel), and indicates a difference vector that specifies a pixel through which an outline passes, that is, a point to be filled.

  In the drawing position calculation process, the contour drawing module 104 generates a command and a parameter for specifying a pixel to be written as a contour line in the work memory 105 according to the command generated by the contour calculation process. The command generated by the drawing position calculation process is one of Move, dVector, and EOC. The parameters generated by the drawing position calculation process include the winding number change amount dwn and the stroke stroke. The winding number change amount dwn represents a change in the direction of the contour line. The direction of the contour line is defined by the direction in which the contour line intersects with a certain reference line (for example, a horizontal line passing through the pixel). When the contour line is directed from the bottom to the top with respect to the reference line, dwn = 1, and when the reference line and the contour line are parallel, dwn = 0, and the contour line with respect to the reference line is from top to bottom. Dwn = −1. The stroke stroke indicates that the outline has passed through the pixel. When stroke = 1, it indicates that the outline has passed, and when stroke = 0, it indicates that the outline has not passed.

  FIG. 10 is a flowchart showing the operation of the contour drawing module 104, particularly the contour drawing processing. In step S200, the contour drawing module 104 determines whether the command given from the drawing position calculation process is EOC. When it is determined that the given command is EOC (S200: YES), the contour drawing module 104 proceeds to step S208. When it is determined that the given command is not EOC (S200: NO), the contour drawing module 104 moves the process to step S201.

  In step S201, the contour drawing module 104 determines whether the given command is Move. If it is determined that the given command is Move (S201: YES), the contour drawing module 104 does not perform any processing on the pixel because it is not necessary to access the work memory 105. When it is determined that the given command is not Move (S201: NO), that is, when the command dVector is given, the contour drawing module 104 proceeds to step S202.

  In step S202, the contour drawing module 104 determines whether stroke = 0 and dwn = 0. If it is determined that stroke = 0 and dwn = 0 (S202: YES), it is not necessary to access the work memory 105, and therefore the contour drawing module 104 does not perform any processing on the pixel. When it is determined that stroke = 0 and dwn = 0 are not satisfied (S202: NO), the contour drawing module 104 proceeds to step S203.

In step S <b> 203, the contour drawing module 104 calculates the address of the work memory 105 storing the pixel data from the pixel position.
In step S204, the contour drawing module 104 reads pixel data from the address calculated in step S203 in the work memory 105. In this example, the pixel data includes a stroke stroke (stroke information) and a winding number change amount dwn. In the case of a complex glyph, as well as in the case of a simple glyph, processing may be performed a plurality of times for a certain pixel, for example, when a line intersects one pixel. Therefore, stroke information other than the initial value and the number of turns change dwn are recorded for pixels that have already been processed.

  In step S205, the contour drawing module 104 overwrites the stroke information. When the stroke given from the drawing position calculation process is stroke = 0, the contour drawing module 104 does not change the stroke information of the pixel. When the given stroke is stroke = 1, the contour drawing module 104 changes the stroke information of the pixel to “1”. In step S206, the contour drawing module 104 adds dwn to the amount of change in the number of turns of the pixel. For example, when “2” is stored as the amount of change in the number of turns of the pixel and the given amount of change in the number of turns dwn = + 1, the amount of change in the number of turns of the pixel is “3”. In step S207, the contour drawing module 104 overwrites the data on the work memory 105 with the updated data.

  In step S208, the contour drawing module 104 notifies the paint module 106 that the contour drawing processing has been completed.

2-3-3. Operation of Filling Module 106 FIG. 11 is a flowchart showing the operation of the filling module 106 of the font processor 100. In the present embodiment, the fill module 106 has a function of executing a fill process for filling the inside of the contour line, a background composition process for synthesizing the glyph image and the background, and a transfer process for transferring the generated data to the VRAM 50. The flow in FIG. 11 is started when the contour drawing module 104 is notified of the end of the contour drawing processing in step S208 in FIG.

  In step S300, the filling module 106 initializes the parameter y. Pixels in the bitmap data are specified using the xy coordinate system. In the xy coordinate system, the pixel at the upper left corner of the pixels arranged in a matrix is the origin, the right direction is the positive direction of the x axis, and the lower direction is the positive direction of the y axis. The parameters x and y indicate pixel coordinates. In this example, the fill module 106 initializes the parameter y as y = yMin. yMin is the minimum value of the y coordinate of the area where the font is drawn. Hereinafter, a row specified by the parameter y among a plurality of pixels arranged in a matrix is referred to as a “target row”.

  In step S <b> 301, the filling module 106 determines whether there is a line that is not yet a target line, specifically, whether the parameter y satisfies y ≦ yMax. yMax is the maximum value of the y coordinate of the area where the font is drawn. If it is determined that there is a line that has not yet been processed (S301: YES), the paint module 106 moves the process to step S302. If it is determined that there is no unprocessed line (S301: NO), the filling module 106 ends the process of FIG.

  In step S302, the filling module 106 initializes the parameter wn, that is, substitutes zero for the parameter wn. The parameter wn indicates the winding number. The number of turns increases when the target row and the contour line intersect in a certain direction (for example, upward), and decreases when the target row and the contour line intersect in another direction (for example, downward).

  In step S303, the filling module 106 initializes the parameter x. In this example, the fill module 106 initializes the parameter x as x = xMin. xMin is the minimum value of the x coordinate of the area where the font is drawn. The pixel specified by the parameter x in the target row in the filling process is referred to as “target pixel”.

  In step S304, the filling module 106 determines whether there is a pixel that is not yet a target pixel in the target row, specifically, whether the parameter x satisfies x ≦ xMax. xMax is the maximum value of the x coordinate of the area in which the font is drawn. If it is determined that there is a pixel that is not yet a target pixel (S304: YES), the paint module 106 moves the process to step S306. When it is determined that there is no pixel that is not the target pixel (S304: NO), the paint module 106 moves the process to step S305.

  In step S305, the filling module 106 updates the parameter y. In this example, the filling module 106 updates the parameter y with y = y + 1. When the parameter y is updated, the filling module 106 moves the process to step S301.

  In step S <b> 306, the filling module 106 writes the background data of the target pixel (data indicating the background gradation) in the work memory 105. The background data is read from the RAM 30, for example.

  In step S <b> 307, the filling module 106 acquires the winding amount change amount wdn from the bitmap data (contour data) indicating the contour stored in the work memory 105. Details are as follows. The filling module 106 calculates an address storing data of the target pixel from the parameters x and y. The filling module 106 reads the data of the target pixel from the calculated address. The filling module 106 extracts the winding number change amount wdn from the read data.

  In step S308, the filling module 106 updates the value of the parameter wn as wn = wn + dwn. Since the parameter wn is initialized to zero every time the target row is updated (step S302), the parameter wn is the amount of change in the number of turns in order from the reference point (in this example, the left end point) pixel by pixel. It is a value obtained by integrating wdn.

  FIG. 12 is a diagram illustrating a change in the number of turns wn. FIG. 12A shows a part of bitmap data in which a contour is drawn. In this example, four contour lines are drawn. An arrow written at the top of the matrix indicates the direction of the contour line. FIG. 12B shows a change in the number of turns of the pixels in the second row from the top in the bitmap data of FIG. At the start point (left end point) of processing, zero is given as the initial value of the number of turns wn. Each pixel is processed toward the right, and the number of turns increases or decreases each time a contour line appears.

  Refer to FIG. 11 again. In step S309, the filling module 106 determines whether a condition for filling a pixel is satisfied. Here, a condition that the number of windings wn and the stroke stroke is other than (wn, stroke) = (0, 0) is used as a condition for filling a pixel. If it is determined that the condition for filling the pixel is satisfied (S309: YES), the filling module 106 proceeds to step S310. If it is determined that the condition for filling the pixel is not satisfied (S309: NO), the filling module 106 proceeds to step S311.

  In step S310, the fill module 106 fills the target pixel. That is, the gradation of the target pixel (in the case of color display, the gradation of each color element) is set to a designated value.

  In step S311, the filling module 106 updates the parameter x as x = x + 1. As a result, the target pixel is updated. When the target pixel is updated, the filling module 106 moves the process to step S304.

  Through the above processing, the outline bitmap data stored in the work memory 105 is filled. The filling module 106 transfers the data thus generated to the VRAM 50 via the bus interface module 107 and the bus 80. When the filling process is completed, the font processor 100 notifies the CPU 10 of the completion of the filling process.

3. An example of drawing a plurality of characters In the above, an example of drawing as a single character composite glyph has been described. Here, glyph sets including a plurality of characters “i”, “ro”, “ha”, and “ni” are shown. An example of drawing a series of processes will be described.

  FIG. 13 is a flowchart showing the operation of the information display device 1 when drawing a plurality of characters. The flow shown in FIG. 13 is triggered by an event for starting font drawing, for example, an event for updating an image displayed on the display body 40. A plurality of characters to be drawn is designated by the CPU 10.

In step S500, the CPU 10 empties the stack. The stack is a LIFO, and a storage area is provided on the RAM 30. Further, the CPU 10 initializes the rendering memory.
In step S510, the CPU 10 stacks the glyph numbers of a plurality of glyphs to be processed in a series on the stack in order. In this example, the glyph numbers are stacked on the stack in the order of “ni”, “ha”, “ro”, “i”.

  In step S520, the CPU 10 determines whether there is a glyph to be drawn, that is, whether there is a glyph number stacked on the stack. If it is determined that there is a glyph to be drawn (S520: YES), the CPU 10 shifts the processing to step S530. If it is determined that there is no glyph to be drawn (S520: NO), the CPU 10 shifts the processing to step S580.

In step S530, the CPU 10 reads the glyph number from the stack. Since the stack is a LIFO, it is the latest glyph number that is read.
In step S540, the CPU 10 issues a command DrawChar with the glyph indicated by the read glyph number as the target glyph. The operation of the font processor 100 when the instruction DrawChar is issued is as already described.

  In step S550, the CPU 10 determines whether there is room in the rendering memory. “Rendering memory has room” means that a predetermined condition regarding the size of an unused area in the storage area of the rendering memory is satisfied. As the “predetermined condition”, for example, a condition that the number of glyphs currently written in the rendering memory exceeds a predetermined threshold is used. Alternatively, the threshold value is the number of glyphs written to the rendering memory, with the width of the rendering memory or capacity divided by the width of the longest glyph among all glyphs. The condition of reaching may be used. Further alternatively, a condition that the capacity of a portion of the rendering memory where data has not yet been written becomes smaller than a predetermined threshold value may be used. When it is determined that the rendering memory has a margin (S550: YES), the CPU 10 shifts the processing to step S520. When it is determined that there is no room in the rendering memory (S550: NO), the CPU 10 shifts the processing to step S560.

  In step S560, the CPU 10 reads out dummy data, that is, empty glyph data. In step S570, the CPU 10 issues an instruction DrawCharFill with the dummy data as the data of the target glyph. The reason for reading the dummy data is to prevent malfunction. The operation of the font processor 100 when the instruction DrawCharFill is issued is as described above. When the command DrawCharFill is issued, the CPU 10 initializes the rendering memory, and the process proceeds to step S520.

  In step S580, the CPU 10 reads out dummy data. In step S590, the CPU 10 issues a command DrawCharFill with the dummy data as the data of the target glyph. When the instruction DrawCharFill is issued, the CPU 10 ends the flow of FIG. The reason why the dummy data is loaded and the command DrawCharFill is issued in steps S580 and S590 is because there may be a glyph in which the outline is drawn but not yet filled.

  FIGS. 14-16 is a figure explaining the effect of the process of FIG. FIG. 14 is a diagram showing the size of each glyph and the drawing range on the VRAM 50, that is, the area on the VRAM 50 used by the glyph. In this example, the glyph “i” has a width of 10 pixels and is drawn in the range of 2 ≦ x ≦ 11 on the VRAM 50. The glyphs “RO”, “HA” and “NI” are also as shown in FIG. The four glyphs “I”, “RO”, “HA” and “NI” are drawn on the VRAM 50 in the range where the x coordinate is 2 ≦ x ≦ 54.

  FIG. 15 is a diagram showing the memory access amount when each glyph is drawn individually, that is, when the drawing method according to the present embodiment is not applied. In this example, memory access is performed in units of one word. One word is 32 bits. The left half of the table of FIG. 15 shows access to the work memory 105. On the work memory 105, 2 bits are assigned to one pixel. Since the glyph “i” has a width of 10 pixels, the memory access amount is 1 word. Since the height of the glyph “I” is 9 pixels, memory access of 1 × 9 = 9 words is required. The glyphs “RO”, “HA” and “NI” are also as shown in FIG. A total of 40 words of memory access is required for the work memory 105.

  The right half of the table of FIG. 15 shows access to the VRAM 50. On the VRAM 50, one bit is assigned to one pixel. On the VRAM 50, memory access is performed in units of areas divided for each word, in this example, areas of 0 ≦ x ≦ 31 and 32 ≦ x ≦ 63. For example, since the glyph “i” is drawn in the range where the x coordinate is 2 ≦ x ≦ 11, a memory access of 1 word width × 9 pixels height = 9 words is required. Also, the glyph “ha” is drawn in the range of x ≦ 30 ≦ x ≦ 40, so it spans two areas, and memory access of 2 words wide × 10 pixels high = 20 words is required. The glyphs “RO” and “NI” are also as shown in FIG. A total of 50 words of memory access is required for the VRAM 50. When the access to the work memory 105 and the access to the VRAM 50 are combined, a total of 90 words of memory access is required.

  FIG. 16 is a diagram showing the memory access amount by the drawing method according to the present embodiment. According to this embodiment, four glyphs are accessed as a glyph “Irohani”. In this case, a total of 66 words of memory access are required, 44 words for the work memory 105 and 22 words for the VRAM 50. In this case, the memory access amount is reduced as compared with the case of individual drawing described with reference to FIG.

  As described above, according to the present embodiment, memory access is reduced by handling a plurality of characters like a composite glyph composed of a plurality of glyphs. Since the work memory 105 is often faster than the VRAM 50, the amount of access to the VRAM 50 often contributes more in terms of the time required for memory access. According to the present embodiment, since the access amount to the VRAM 50 is further reduced, the system can be speeded up.

4). Other Embodiments The present invention is not limited to the above-described embodiments, and various modifications can be made. Hereinafter, some modifications will be described. In the description of the modification, common reference symbols are used for elements that are common to the embodiment. Two or more of the modifications described below may be used in combination.

4-1. Modification 1
FIG. 17 is a flowchart showing the operation of the information display apparatus 1 according to the first modification. Instead of the flow of FIG. 9, the flow of FIG. 17 may be used. In the flow of FIG. 17, the processing from step S100 to S150 is common to the flow of FIG. Instead of steps S160-180 in FIG. 9, steps S400-S430 are performed.

  In step S400, the CPU 10 issues an instruction DrawChar. In step S410, the CPU 10 determines whether the stack is empty. When it is determined that the stack is empty (S410: YES), the CPU 10 shifts the processing to step S420. When it is determined that the stack is not empty (S410: NO), the CPU 10 shifts the processing to step S120.

  In step S420, the CPU 10 reads dummy data (empty glyph data). In step S430, the CPU 10 issues a command DrawCharFill with the dummy data as the data of the target glyph. The reason why the dummy data is read in step S420 is to prevent malfunction. The processing of steps S400 to S430 is basically performed in the same manner as the processing of steps S160 to 180 in FIG. 9 although the order is different.

4-2. Modification 2
The format of the glyph data is not limited to that described with reference to FIG. Instructions other than Move, Line, Curve2, Curve3, and EOC may be used. As a function for describing a curve, a Bezier curve of a fourth or higher order may be used, or a curve other than a Bezier curve may be used. In short, any type of data may be used as long as it indicates the outline of the glyph and the direction of the outline. In the embodiment, an example in which the composite glyph is composed of two part glyphs has been described. However, the composite glyph may include three or more part glyphs. The part glyph may be a composite glyph. The glyph data only needs to specify the contour line, and does not need to include the direction of the contour line. Furthermore, although the flow of FIG. 14 has been described as an example used when a plurality of glyphs are drawn, the flow of FIG. 14 may be used when a single simple glyph is drawn.

4-3. Modification 3
The parameter that increases or decreases according to the direction of the contour line is not limited to the number of turns wn described in the embodiment. The winding number wn is a parameter that increases or decreases by 1 according to the direction of the outline, but the unit of increase or decrease may not be 1. In the embodiment, the target row is determined and the processing is advanced in the horizontal direction pixel by pixel for the target row. However, the processing order is not limited to this. The target column may be determined and the processing may be advanced in the vertical direction pixel by pixel for the target column. In this case, the winding amount change amount dwn is different when the contour line is directed from right to left, when the contour line is directed in the vertical direction, and when the contour line is directed from left to right. In short, the parameter that increases or decreases depending on the direction of the contour line is the target line when processing one pixel or one pixel along the target line with one row or one column of the pixel matrix as the target line. Any parameter may be used as long as it increases or decreases according to the direction in which the contour line intersects. Furthermore, as long as it is determined whether to fill a pixel or not using this parameter, any process may be used as the fill process.

4-4. Modification 4
In the embodiment, the contour drawing module 104 has functions of executing contour calculation processing, drawing position calculation processing, and contour drawing processing, that is, functions as contour calculation means, drawing position calculation means, and contour drawing means. However, these functions may be realized by separate modules. The same applies to the filling module 106.

  The hardware configuration of the information display device 1 is not limited to that shown in FIG. An apparatus having any hardware configuration may be used as long as the necessary functional configuration can be realized. The same applies to the font processor 100. In the above-described embodiment, an example in which the information display device 1 is electronic paper has been described. However, any device other than electronic paper, such as a personal computer, a PDA (Personal Digital Assistant), or a mobile phone, may be used as long as it has a necessary function. There may be. In the embodiment, the information display device 1 includes the display device (display body 107), but the display device may be externally attached.

  In the above-described embodiment, the program executed by the CPU 10 includes a magnetic recording medium (magnetic tape, magnetic disk (HDD (Hard Disk Drive), FD (Flexible Disk)), etc.), optical recording medium (optical disk (CD (Compact Disk)). , DVD (Digital Versatile Disk), etc.), magneto-optical recording medium, semiconductor memory (flash ROM, etc.) and the like. The program may be downloaded via a network such as the Internet.

It is a figure which shows the hardware constitutions of the information display apparatus 1 which concerns on one Embodiment. 2 is a diagram illustrating a configuration of a font processor 100. FIG. 1 is a diagram illustrating an appearance of an information display device 1. FIG. It is a figure which illustrates glyph data. It is a figure explaining the drawing method recommended with the True Type font. It is a figure explaining the drawing method by patent document 1. FIG. It is a figure which illustrates the composite glyph which cannot be drawn correctly. It is a figure explaining the drawing method by this embodiment. 3 is a flowchart showing an operation of the information display device 1. 5 is a flowchart showing the operation of the contour drawing module 104. 3 is a flowchart showing the operation of a filling module 106. It is a figure which illustrates change of winding number wn. It is a flowchart which shows the operation | movement which draws a several character. The size of each glyph and the drawing range on the VRAM 50 are shown. Indicates the memory access amount when each glyph is drawn individually. The memory access amount by the drawing method concerning this embodiment is shown. 10 is a flowchart showing an operation of the information display device 1 according to Modification 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Information display apparatus, 10 ... CPU, 20 ... ROM, 30 ... RAM, 40 ... Display body, 50 ... VRAM, 60 ... Display control apparatus, 70 ... Input device, 80 ... Bus, 90 ... Bus controller, 100 ... Font Processor: 101 ... Main controller, 102 ... Register, 103 ... Font drawing controller, 104 ... Outline drawing module, 105 ... Work memory, 106 ... Fill module, 107 ... Bus interface module, 108 ... Main bus, 109 ... Sub bus

Claims (5)

A memory that stores data of a plurality of pixels that are two-dimensionally arranged and whose positions are specified using a two-dimensional coordinate system;
A command input means for inputting a first drawing command for instructing drawing of a glyph outline, or a second drawing command for instructing drawing of a glyph outline and filling of the inside of the outline;
Contour calculation means for specifying, as a target pixel, a pixel through which the glyph contour passes, using glyph data indicating the contour of the glyph that has been commanded to be rendered by the first rendering command or the second rendering command; ,
Drawing position calculating means for calculating the coordinates of the target pixel in the two-dimensional coordinate system as a drawing position;
Contour drawing means for executing contour drawing processing for writing data indicating that the contour line passes through a region of the memory that stores pixel data specified by the drawing position;
When the second drawing command is input to the command input means, the contour drawing process is completed for the glyph commanded to be drawn by the second drawing command, and then specified by the data written in the memory A font rendering device comprising: filling means for performing a filling process for filling the inside of the contour line. The glyph data includes the direction of the contour line,
2. The filling process according to claim 1, wherein in the filling process, whether or not the area is filled is determined in accordance with a direction of the two outlines for the area surrounded by the two outlines. Font drawing device. The filling process is a process in which one row or one column of the matrix is set as a target line, and gradation is determined pixel by pixel along the target line, and the direction in which the target line and the outline intersect The font drawing apparatus according to claim 2, wherein it is a process of determining whether or not the pixel is to be filled according to a parameter that increases or decreases according to. The parameter increases when the target line and the contour line intersect in a certain direction, and decreases when the target line and the contour line intersect in another direction. Font drawing device. A storage device storing glyph data indicating the outline of the glyph;
A stack for stacking information identifying at least one glyph to be drawn;
The information is read in order from the stack, and if the information is still stacked on the stack, a first rendering instruction for glyph data corresponding to the read information is issued, and the stack becomes empty A controller that issues a second rendering command for glyph data corresponding to the read information,
A memory that stores data of a plurality of pixels that are two-dimensionally arranged and each pixel's position is specified using a two-dimensional coordinate system, and a command input for inputting the first drawing command or the second drawing command And a contour that specifies a pixel through which the glyph contour passes as a target pixel using glyph data indicating the contour of the glyph that has been rendered by the first rendering command or the second rendering command. A calculation means; a drawing position calculation means for calculating the coordinates of the target pixel in the two-dimensional coordinate system as a drawing position; and an area for storing pixel data specified by the drawing position in the memory. A contour drawing means for executing a contour drawing process for writing data indicating that the pixel passes through the line; and the second drawing command when the second drawing command is input to the command input means. A font rendering apparatus comprising: a filling unit that performs a filling process for filling the inside of the contour line specified by the data written in the memory after the contour drawing process has been completed for the glyph for which rendering has been commanded by a command And an information processing apparatus.

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