JP2009134773A - Drawing method, image generation device and electronic information apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique that can inexpensively draw lines with less aliasing. <P>SOLUTION: From two vertex coordinates given to a line 66 to be drawn, an edge function is calculated. The gradient of the edge function is next determined. If an acute angle between the line 66 to be drawn and the x-axis of a drawing plane coordinate system is not larger than 45°, functions of two shift lines 68 to which the line 66 to be drawn is translated by 0.5d and -0.5d along the y-axis are calculated, where (d) is the width of one pixel. If the acute angle between the line 66 to be drawn and the y-axis of the drawing plane coordinate system is larger than 45°, functions of two shift lines to which the line 66 to be drawn is translated by 0.5d and -0.5d along the x-axis are calculated. Sub pixels included in a parallelogram abcd whose vertices are four start points and end points of the two shift lines 68 are next counted, and a pixel value of each pixel is set accordingly. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a drawing method, an image generation apparatus, and an electronic information device that generate drawing data in pixel units.

  With the remarkable progress of computer graphics technology and image processing technology used in fields such as computer games and digital broadcasting in recent years, it is possible to display a three-dimensional image or the like on a more precise screen. A polygon representing an object in a three-dimensional space, a two-dimensional image input by a user, and the like are sent to a display device or the like as digital image information in units of pixels.

  In order to represent an image that was originally analog information or a line segment connecting known vertex coordinates in pixel units, depending on the required processing speed, drawing accuracy, and ease of implementation in hardware, etc. A method is selected.

  Since the pixel is a discrete array, when the figure to be drawn is converted to pixel data, the outline of the pixel constituting the figure appears on the image and is displayed in a jagged shape called jaggy, or a thin line May occur, or the phenomenon may occur. These phenomena are generally called aliasing, and an anti-aliasing technique has been devised such as rendering with a higher resolution in order to reduce this phenomenon (see Non-Patent Document 1, for example).

Hardware Acceleration for Spatial Selections and Joins, Chengyu Sun et.al., UCSB Technical Report (2002-17).

  However, although anti-aliasing can reduce aliasing, there may be a problem that the overall impression, such as the thickness of the line, differs from the shape you originally intended to draw, and by increasing the resolution. The present inventor has recognized that the calculation load due to the anti-aliasing process itself increases and may be a barrier to high-speed drawing.

  The present invention has been made in view of such problems, and an object thereof is to provide a technique capable of generating drawing information having a desired drawing shape and inconspicuous aliasing. Yet another object is to provide an anti-aliasing technique that is advantageous in terms of computational load and processing speed.

  One embodiment of the present invention relates to a drawing method. In this drawing method, an area having a width that is an integral multiple of the pixel size in either the horizontal direction or the vertical direction of the display screen with the drawing target line as the center is set as the drawing area of the drawing target line. The pixel value of the pixel is determined according to the ratio of the display area of the pixel included in the drawing area.

  Here, the “pixel display area” is an area of each eye that can display pixel values such as color and density when a digitized image is represented in pixel units. The area changes depending on the resolution.

  Another embodiment of the present invention also relates to a drawing method. This drawing method includes a line to be drawn, two parallel lines obtained by shifting the line by a predetermined width in either the horizontal direction or the vertical direction of the display screen, and the two lines. An area having the end point of the parallel line as an apex is defined as a drawing area of the drawing target line, and a pixel value of the pixel is determined according to a ratio of a pixel display area included in the drawing area. To do.

  Another embodiment of the present invention also relates to a drawing method. This drawing method includes a line to be drawn, two parallel lines obtained by shifting the line by a predetermined width in either the horizontal direction or the vertical direction of the display screen, and the two lines. Determining a region having the end point of the parallel line as a vertex as a drawing region of the drawing target line, and a rectangular scanning region including the drawing region and including at least a part of a boundary line of the drawing region as a boundary line Setting, and scanning the scanning area in units of sub-pixels obtained by virtually dividing a display area of pixels by a predetermined number to obtain the number of sub-pixels included in the drawing area; And setting a pixel value of the pixel according to a ratio of the number of subpixels included in the drawing area among subpixels included in the pixel.

  Yet another embodiment of the present invention relates to an image generating apparatus. The image generation apparatus includes: a drawing information acquisition unit that reads information on an image to be drawn; a drawing data generation unit that generates drawing data expressed in pixel units by pixel values based on the image information; and the drawing data A drawing data storage unit, and the drawing data generation unit, when expressing the drawing target line included in the image information in units of pixels, with the drawing target line as a center, An area having a width that is an integral multiple of the pixel size in either the horizontal direction or the vertical direction is defined as the drawing area of the line to be drawn, and the pixel display area is included in the drawing area. The pixel value of the pixel is set.

  The pixel value setting factor in the drawing data generation unit may appropriately include attributes added in general rendering processing such as shadows and textures.

  Still another embodiment of the present invention also relates to an image generation apparatus. The image generation apparatus includes: a drawing information acquisition unit that reads information on an image to be drawn; a drawing data generation unit that generates drawing data expressed in pixel units by pixel values based on the image information; and the drawing data A drawing data storage unit that stores the drawing target line when the drawing target line included in the image information is expressed in units of pixels, and displays the line. The drawing target line includes an area having two parallel lines shifted by a predetermined width in either the horizontal direction or the vertical direction of the screen as a boundary line, and having vertexes at the end points of the two parallel lines. The pixel value of the pixel is set according to the ratio of the pixel display area included in the drawing area.

  It should be noted that any combination of the above-described constituent elements and a representation of the present invention converted between a method, an apparatus, a system, a computer program, etc. are also effective as an aspect of the present invention.

  According to the present invention, line drawing with reduced aliasing can be realized while maintaining a desired shape.

It is a block diagram of the image generation apparatus in this Embodiment. It is a block diagram of the drawing block in this Embodiment. It is a block diagram of the rasterizer in this Embodiment. It is a figure explaining the method of producing | generating the pixel information at the time of a triangle drawing per pixel. It is a figure explaining the method of producing | generating the pixel information at the time of a triangle drawing per subpixel. It is a figure explaining the method of the diamond rule in line drawing. It is a figure explaining the case where the method of the diamond rule in line drawing is performed per subpixel. It is a figure explaining the method of producing | generating pixel information at the time of line drawing in this Embodiment. It is a flowchart which shows the procedure which produces | generates pixel information at the time of line drawing in this Embodiment. It is a figure explaining the scanning method of the sub pixel unit in this Embodiment. It is a figure explaining the internal / external determination method of the pixel at the time of triangle drawing, or a subpixel. It is a figure explaining the method of applying the method at the time of a triangle drawing regarding the inside / outside determination of the sub pixel in this Embodiment.

  FIG. 1 is a configuration diagram of an image generation apparatus 200 according to the present embodiment. The image generation apparatus 200 is configured by connecting a drawing block 100, a control block 110, and an input / output block 120 via a bus 150, and a storage device 130 and a display device 140 are connected to the input / output block 120. The input / output block 120 may be configured to acquire data necessary for drawing from the outside by communicating with another device via a network.

  The control block 110 is a block that controls the entire image generation apparatus 200. The synchronization management of data transfer between the inside of the image generation apparatus 200 and external peripheral devices such as the storage device 130 and the display device 140, the image generation apparatus Processing of interruption from each unit in the 200, management of a timer, and the like are performed.

  The input / output block 120 reads the three-dimensional model information and various parameters stored in the storage device 130 and provides them to the drawing block 100. The input / output block 120 may receive data necessary for drawing from an external device via a network and provide the data to the drawing block 100. The input / output block 120 displays the drawing data output from the drawing block 100 on the display device 140.

  The drawing block 100 performs rendering processing that generates drawing data based on the three-dimensional model information given from the input / output block 120 and writes the drawing data in the frame buffer.

  FIG. 2 is a configuration diagram of the drawing block 100. The rasterizer 10 receives the drawing primitive vertex data from the input / output block 120. The drawing primitive is generally a triangle, and the rasterizer 10 performs view conversion that converts a triangle in the three-dimensional space into a triangle on the drawing plane by projection conversion, and further converts the triangle on the drawing plane to the horizontal of the drawing plane. While scanning along the direction, raster processing is performed to convert the pixel into a quantized pixel for each column. The rasterizer 10 develops the rendering primitive into pixels, and pixel information including RGB color values, α values, and Z values is calculated for each pixel.

  The rasterizer 10 generates a pixel area having a predetermined size along the scanning line (hereinafter referred to as a drawing target area) and supplies the pixel area to the subsequent drawing arithmetic unit 20. The drawing operation unit 20 includes a shader unit 30 and a texture unit 50, and performs processing while using the memory 40. In the memory 40, a frame buffer and a texture buffer are provided. Note that the frame buffer and the texture buffer may be provided in a single memory, or may be provided in physically separate memories.

  The drawing target areas supplied from the rasterizer 10 to the drawing calculation unit 20 are stacked in a queue, and the shader unit 30 sequentially processes the drawing target areas stacked in the queue.

  The shader unit 30 performs a shading process based on the pixel information calculated by the rasterizer 10, determines a pixel color after texture mapping based on the texel information obtained by the texture unit 50, and stores in the memory 40. Write drawing data to the frame buffer. The shader unit 30 further performs processing such as fogging and α blending on the drawing data held in the frame buffer, obtains a final drawing color, and updates the drawing data in the frame buffer. The drawing data stored in the frame buffer is read by the input / output block 120 and output to the display device 140.

  The texture unit 50 receives an input of a parameter for designating texture data from the shader unit 30, calculates an address of the texture data, and requests necessary texture data from the texture buffer in the memory 40. The texture unit 50 caches the texture data read from the texture buffer, performs filter processing such as bilinear interpolation and trilinear interpolation, and outputs the result to the shader unit 30.

  FIG. 3 is a configuration diagram of the rasterizer 10. The rasterizer 10 includes a vertex data reading unit 12 that receives the vertex data of a drawing primitive from the input / output block 120, a view conversion unit 14 that converts the vertex data of the drawing primitive into vertex data of a drawing plane coordinate system by view conversion, and a drawing plane. A setup processing unit 16 that calculates a function (hereinafter referred to as an edge function) that represents a line segment that connects the upper vertex coordinates, or sets a scanning area used in a DDA process performed later, and an edge function The acquired drawing shape such as a triangle is scanned in the horizontal direction of the drawing plane and subjected to DDA (Digital Differential Analyzer) processing or the like for each column, so that an RGB color is applied to each side of the drawing shape and each pixel included in the drawing shape. A pixel information generation unit 18 that acquires pixel information including a value, an α value, and a Z value; The drawing target region including the resulting the pixel information to the rendering operation unit 20 including supplying pixel information sending unit 19.

  Next, the operation in the pixel information generation unit 18 of the rasterizer 10 will be described. First, in order to describe the present embodiment, general operations will be described. 4 and 5 are diagrams for explaining processing performed in the pixel information generation unit 18 for the triangle from which the vertex data and the edge function of the drawing plane coordinate system are obtained. FIG. 4 is a diagram illustrating processing in units of pixels. Reference numeral 5 denotes processing in units of subpixels obtained by virtually dividing each pixel. In these drawings, the display area of 1 pixel is indicated by a solid line, and the area of 1 subpixel is indicated by a broken line.

  In the pixel unit processing shown in FIG. 4, for example, the first row and the second row from the top are sequentially scanned in the horizontal scanning direction 60 to determine whether each pixel is inside the triangle 62 or not. Do. In FIG. 4, pixels determined to be inside the triangle 62 are represented by black circles, and pixels determined to be outside are represented by white circles. Thereafter, the same display is performed in FIGS. 5 to 7 and FIG. After the inside / outside determination, the RGB color value and Z value of each pixel are calculated by performing linear interpolation for each pixel existing inside the triangle 62 with the side of the triangle 62 as an end point. In the pixel unit processing as shown in FIG. 4, since all processing is performed in discrete pixel units, the difference between the pixel existing inside the triangle 62 and the pixel existing outside is significant, and jaggies and the like Alias is conspicuous.

  FIG. 5 shows a case where each pixel is virtually divided into four in the vertical and horizontal directions, and one pixel is 16 subpixels. At this time, scanning is sequentially performed in the scanning direction 60 for each row of subpixel units, and the inside / outside determination of the subpixel with respect to the triangle 62 is performed. Then, of the 16 subpixels included in each pixel, the number of subpixels existing inside the triangle 62 is totaled, and the ratio of the number is calculated as an α value for each pixel. For example, if three sub-pixels of a sub-pixel constituting a certain pixel exist inside the triangle 62, the α value of that pixel is 3/16.

  This α value is used in the α blending process in the shader unit 30 at the subsequent stage. For example, in a display area of pixels extending inside and outside the triangle 62, when the pixel value of the inner part of the triangle 62 is A and the pixel value of the outer part is B, the pixel value of the pixel is αA + (1−α) B For example, the two pixel values A and B are internally divided at a ratio of (1-α): α and mixed. Since the pixel value of each pixel is adjusted by the positional relationship with the triangle 62 by this blending process, the difference from the pixel outside the triangle 62 is compared with the case of FIG. Is relaxed and aliases are not noticeable. The rasterizer 10 generates both information by scanning in units of pixels and information by scanning in units of sub-pixels as shown in FIGS. 4 and 5, and performs α blending processing according to the display contents and the status of the apparatus. The shader unit 30 can also determine whether to do this.

  Next, an example of a method for generating pixel information for a line segment (hereinafter referred to as a drawing target line) from which vertex data and an edge function of the drawing plane coordinate system are obtained will be described with reference to FIG. FIG. 6 is a diagram for explaining a diamond rule (Diamond-Exit Rule) which is one of the methods used for generating pixel information of a drawing target line. The diamond rule virtually generates a diamond-shaped quadrangle (hereinafter simply referred to as diamond 64) having the center of each pixel as the center point and the midpoint of the pixel side as a vertex, and the drawing target line 66 is the diamond 64. Is a process of determining the pixels constituting the drawing target line 66 depending on whether or not they cross. As shown in the figure, since the pixels determined to constitute the drawing target line 66 are discrete, the difference between the pixel and the other pixels is the same as described with reference to FIG. 4 in the case of a triangle. Becomes noticeable, and aliases such as jaggy are more noticeable.

  Here, a case is considered in which the alias of the drawing line is to be reduced by using the sub-pixel unit scanning function introduced in the case of the triangle described above. FIG. 7 is a diagram illustrating an aspect when a scanning method in units of subpixels is introduced in drawing a line by the diamond rule. This figure also shows an example in which each pixel is divided into four in the vertical direction and the horizontal direction, and one pixel is 16 subpixels. When the above diamond rule is applied to each subpixel, it is determined that the subpixel having the diamond that the drawing target line 66 crosses constitutes the line, and the other subpixels are not related to the line.

  Here, if it is assumed that one pixel is 16 subpixels in the diamond rule processing in units of pixels shown in FIG. 6, all of the 16 subpixels determined to constitute the drawing target line 66 are drawn. It is determined that the target line 66 is configured. Compared to that, in the processing in units of subpixels in FIG. 7, the number of subpixels determined to constitute the drawing target line 66 among the subpixels included in one pixel is extremely small, and the α value is used as information in units of pixels. As a result, the overall value becomes small. For this reason, the drawing data obtained as a result of the α blending in the shader unit 30 appears to be a thin line, a thin line, or a discontinuous line as compared with the pixel unit processing in FIG. Sometimes. Therefore, the present inventor has recognized that when the shader unit 30 is subjected to the α blending process to reduce the alias, a problem that the impression of the drawn line itself changes easily occurs.

  Processing operations performed in the setup processing unit 16 and the pixel information generation unit 18 of the rasterizer 10 of the present embodiment to overcome the above-described problem will be described below.

  FIG. 8 is a diagram for explaining processing performed in the pixel information generation unit 18 for the line from which the vertex data and the edge function of the drawing plane coordinate system are obtained in the present embodiment. This figure shows an example in which each pixel is divided into four in the vertical and horizontal directions, and one pixel is 16 subpixels. However, the number of subpixels is not limited to this, and the desired calculation cost, accuracy, etc. The method of this embodiment can be applied in any case. As shown in the figure, in the present embodiment, the line is considered as a region having a predetermined width, and the inside / outside determination of the subpixel is performed on the region. Specifically, two shift lines 68 formed by translating the drawing target line 66 for which the edge function has been calculated in the axial direction of the drawing plane coordinate system, and two lines parallel to the moving direction (hereinafter referred to as end points). The parallelogram abcd formed by “side” is defined as the region.

  FIG. 9 is a flowchart showing a procedure of processes performed in the setup processing unit 16 and the pixel information generation unit 18 of the present embodiment. First, an edge function is calculated from the two vertex coordinates given for the drawing target line 66 (S10). Next, the inclination of the edge function is determined, and when the acute angle between the drawing target line 66 and the x axis of the drawing plane coordinate system is 45 ° or less (Y in S12), the drawing target line 66 is 0.5d in the y-axis direction. And the function of the two shift lines 68 translated by −0.5d is calculated (S14). Here, d indicates the width of the display area of 1 pixel. The diagram shown in FIG. 8 shows a case where the acute angle formed between the drawing target line 66 and the x-axis is 45 ° or less and the drawing target line 66 is translated in the y-axis direction. On the other hand, when the acute angle formed by the drawing target line 66 and the x-axis of the drawing plane coordinate system is greater than 45 ° (N in S12), the drawing target line 66 is translated by 0.5d and −0.5d in the x-axis direction. A function of the two shifted shift lines 68 is calculated (S16).

  Hereinafter, when the acute angle between the drawing target line 66 and the x axis of the drawing plane coordinate system is 45 ° or less (Y in S12), the x axis is called the major axis and the y axis is called the minor axis with respect to the drawing target line 66. . On the other hand, when the acute angle between the drawing target line 66 and the x axis of the drawing plane coordinate system is greater than 45 ° (N in S12), the x axis is called the minor axis and the y axis is called the major axis.

  Next, a scanning region for detecting subpixels included in the parallelogram abcd having the four starting points and the ending points of the two shift lines 68 is set (S18), and the scanning region is scanned. The inside / outside determination of the subpixel is performed (S20). The scanning method will be described later.

  Thereafter, as in the case of the triangle processing at the time of introducing the sub-pixel described above, the ratio of the number of sub-pixels existing inside the parallelogram abcd among the sub-pixels belonging to each pixel is calculated as an α value. By using this α value, the α blending process in the shader unit 30 is performed, so that the width is about d, that is, one pixel, and based on pixel information generated without introducing a subpixel by a diamond rule or the like. It is possible to draw a line having the same color as the drawn line and having reduced alias.

  Next, the sub-pixel unit scanning method in the present embodiment performed in S18 and S20 of FIG. 9 will be described.

  FIG. 10 is a diagram for explaining a scanning method in units of subpixels in the present embodiment. First, as shown in S18 of FIG. 9, the scanning region ABCD is set in a rectangular shape circumscribing the parallelogram abcd and having sides parallel to the x axis and the y axis of the drawing plane. In the present embodiment, of the sides of the parallelogram abcd, the edges ad and bc that connect the end points of the two shift lines 68 are the axes in the shift direction of the drawing target line 66, that is, the y axis that is the minor axis. Since they are parallel, a part of the boundary line of the scanning area ABCD, that is, AD and BC coincide with the edges ad and bc, respectively. Similarly, in the drawing target line whose minor axis is the x-axis, the scanning region coincides with the end side.

  Next, the scanning area ABCD is sequentially scanned, for example, in the horizontal scanning direction 60 for each row of subpixels, similarly to the above-described inside / outside determination for the triangle. As described above, since the scanning region ABCD coincides with the edge sides ad and bc, the sub-pixels outside the edge sides ad and bc are not scanned. Therefore, in the scanning performed here, it is only necessary to determine whether the subpixel is inside the two sides ab and dc.

  For the subpixels on the two sides ab and dc, if the subpixel on one side is determined to be internal, the subpixel on the other side is external, for example, the width of the drawing line is further increased to d Set rules that are close to each other. Similarly, for the subpixels on the two sides ad and bc, a rule is set such that if a subpixel on one side is determined to be internal, a subpixel on the other side is determined to be external. As a result, a line closer to the original length of the drawing target line can be drawn, and when a plurality of lines are continuous, it is possible to prevent the sub-pixels of the connection portion from being double counted.

  Next, a description will be given of an operation principle that easily realizes the scanning method for determining the inside / outside of a subpixel with respect to the parallelogram abcd according to the present embodiment by applying the inside / outside determination function used for a triangle. .

  First, in order to understand the present embodiment, an inside / outside determination process for a triangle will be described. FIG. 11 is a diagram for explaining a pixel or sub-pixel inside / outside determination method when a drawing target is a triangle. Here, the lines representing the triangular edge functions are denoted as e, f, and g, and the coordinates on the drawing plane are (x, y). In the following description, it is assumed that inside / outside determination is performed in units of subpixels in order to maintain consistency with the present embodiment. First, a bounding box for scanning, that is, a scanning area is set. The circumscribed rectangle of the triangle formed by the lines e, f, and g is the rectangle EFGH. Here, if the triangle protrudes from a drawable region such as an image display region in the display device, the pixel information of the protruding portion is not necessary for display, and thus scanning is not performed. As shown in FIG. 11, when a predetermined drawable area (hereinafter referred to as a scissoring area) is sx0 ≦ x ≦ sx1, sy0 ≦ y ≦ sy1, the scanning area for the triangle is the circumscribed rectangle EFGH and the above-described area. This is a rectangle EIJH that is a common area with the scissoring area.

  When the scanning region is set, for example, scanning is performed in units of subpixels sequentially in the negative direction of the y axis on the scanning line parallel to the x axis from the intersection of the edge functions e and f. For example, as indicated by the scanning line 70, the sub-pixel is scanned from the line f in the positive direction of the x-axis, and the scanned sub-pixel is determined to exist inside the triangle. When the scanning position reaches the line e, the next lower pixel row is similarly scanned. If this process is repeated, before reaching the line e, a line reaching the side IJ of the scanning area EIJH, that is, the boundary line of the scissoring area appears. At this time, as indicated by the scanning line 72, when the side IJ is reached, scanning is shifted to the next scanning line.

  In the above-described determination of the inside / outside of the subpixel with respect to the triangle, the numerical value indicating the scissoring area set in advance, sx0, sx1, sy0, and sy1, and the edge functions of the lines e, f, and g that form the sides of the triangle are used. Based on this, a scanning region is set, and the inside / outside determination of the subpixel is performed. Next, a case where subpixels included in the parallelogram abcd in the present embodiment are detected using the inside / outside determination function for the triangle will be described.

  FIG. 12 is a diagram for explaining a technique for applying the technique at the time of drawing a triangle regarding the determination of the inside / outside of the subpixel in the present embodiment. First, the edge function corresponding to the two shift lines 68 forming the two sides ab and dc of the parallelogram abcd is expressed as two of the three lines constituting the sides of the triangle shown in FIG. Set as a function of f. For the remaining line g, for example, the same function as one side of the boundary line of the scissoring region is given. In FIG. 12, a function y = sy1 is given. On the other hand, since the functions that give ad and bc that are the edges are constants for x, the constants are lines parallel to the y-axis that is the minor axis among the boundary lines of the scissoring region, that is, x = sx0 and x = Set as sx0 and sx1 of sx1.

  As a result, the scanning area is automatically determined as a rectangle ABCD. Accordingly, in scanning in units of subpixels with respect to the parallelogram abcd, a scanning line 74 having a start point on the side ab has an end side bc as an end point, and a scan line 76 having an end point on the side dc has an end side ad. The starting point. In other words, when scanning a row of subpixels that crosses the edge, no scanning is performed outside the edge, and the same processing as in the case of a triangle is performed on the two lines e and f. For example, as a result, subpixels existing in the parallelogram abcd are detected. The case where the minor axis is the y axis has been described above with reference to FIG. 12, but the same applies to the case where the minor axis is the x axis. Specifically, the line g is set as, for example, x = sx1, and the constant for y on the edge side is set as a part of the function that gives the boundary line of the scissoring region, y = sy0 and y = sy1, sy0 and sy1. That's fine.

  Here, as described above, for the subpixels located on both ends ad and bc, for example, if it is determined that the subpixel on one end ad is intrinsic to the parallelogram, the subpixel on the other end bc Provides rules such as determining whether the person is outside. As a result, it is possible to prevent double counting of sub-pixels at connection portions of a plurality of lines. In this embodiment, when a plurality of lines having the same minor axis are continuous, the functions representing the edges coincide with each other as a constant of x or a constant of y. Unevenness due to the end of the line no longer appears.

  In FIG. 12, the constants for x representing the edge sides ad and bc are set as sx0 and sx1 of x = sx0 and x = sx1 representing the two sides of the boundary line of the scissoring region. However, if the boundary line of the original scissoring region that is set in advance exists inside the parallelogram abcd from at least one of the end sides, the boundary line is outside the original scissoring region of the parallelogram abcd. There is no need to scan the area. In this case, as described in the case of the triangle shown in FIG. 11, the parallelogram abcd is cut by the boundary line, and an area surrounded by the boundary line and a part of the scanning area ABCD shown in FIG. This becomes a regular scanning area. Also at this time, the end side is merely translated inward of the parallelogram abcd, and the functions and effects of the present embodiment can be obtained in the same manner.

  According to the present embodiment described above, by calculating an area in consideration of a desired line width in advance and performing an inside / outside determination process in units of subpixels, aliases are reduced and line width and color tone are not impaired. Line drawing is possible. In addition, since the area is configured by a function that can be easily obtained simply by translating the drawing target line from which the edge function is obtained in the axial direction, there is no need to newly install a divider or the like, Furthermore, because the edge is parallel to the axis of the drawing plane, the hardware functions generally used for drawing triangles etc. can be used as they are for setting the scanning area. This can be realized and the calculation load does not increase. Furthermore, in the case of a drawing line with a configuration in which multiple lines with the same minor axis are connected, the edges of the lines are parallel to each other. can do.

  The present invention has been described based on the embodiments. Those skilled in the art will understand that the above-described embodiment is an exemplification, and that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are also within the scope of the present invention. is there.

  In the present embodiment, the configuration mainly regarding the three-dimensional graphics processing has been described, but the operation of the rasterizer 10 is the same also in the two-dimensional graphics processing. The drawing target line is not limited to a straight line, and the same processing can be applied to a curve. Furthermore, the width of the region generated by shifting the drawing target line, such as a parallelogram, does not have to be the width of the display region of 1 pixel, and may be set as appropriate according to the user input. Also in these modified examples, first, an area having a desired shape and width is generated, and the inside / outside determination for each subpixel is performed using the inside / outside determination function of the triangle, and the information for each pixel is based on the result. By acquiring the above, it is possible to draw a line with a small number of aliases while minimizing the influence on the shape, hue, etc., without increasing the mounting cost and processing load.

  10 rasterizer, 12 vertex data reading unit, 14 view conversion unit, 16 setup processing unit, 18 pixel information generating unit, 19 pixel information sending unit, drawing operation unit, 66 drawing target line, 68 shift line, 100 drawing block, 120 input Output block, 200 image generation device.

Claims (13)

A drawing method in an image generation apparatus including a drawing data generation unit, wherein the drawing data generation unit includes:
Display the pixel by setting an area with a width that is an integer multiple of the pixel size in the horizontal or vertical direction of the display screen around the line to be drawn as the drawing area of the line to be drawn. According to the proportion of the area included in the drawing area, determine the pixel value of the pixel ,
The ratio of the display area of the pixel included in the drawing area depends on the number of subpixels included in the drawing area among the subpixels obtained by virtually dividing the display area of the pixel by a predetermined number. Decide
When obtaining the number of subpixels included in the drawing area, it is assumed that a subpixel including one of a pair of opposing borders of the drawing area is included in the drawing area, and a subpixel including the other is drawn in the drawing area. A drawing method characterized in that it is determined to be outside a region . A drawing method in an image generation apparatus including a drawing data generation unit, wherein the drawing data generation unit includes:
Includes two parallel lines including a drawing target line, and the lines are shifted by a predetermined width in either the horizontal direction or the vertical direction of the display screen, and the end points of the two parallel lines Is determined as the drawing area of the line to be drawn, and the pixel value of the pixel is determined according to the ratio of the display area of the pixel included in the drawing area ,
The ratio of the display area of the pixel included in the drawing area depends on the number of subpixels included in the drawing area among the subpixels obtained by virtually dividing the display area of the pixel by a predetermined number. Decide
When obtaining the number of subpixels included in the drawing area, it is assumed that a subpixel including one of a pair of opposing borders of the drawing area is included in the drawing area, and a subpixel including the other is drawn in the drawing area. A drawing method characterized in that it is determined to be outside a region .   3. The drawing area according to claim 2, wherein the two parallel lines shifted and the two line segments respectively connecting the start points and the end points of the two parallel lines are used as a boundary line. The drawing method described. A drawing method in an image generation apparatus including a drawing data generation unit, wherein the drawing data generation unit includes:
Includes two parallel lines including a drawing target line, and the lines are shifted by a predetermined width in either the horizontal direction or the vertical direction of the display screen, and the end points of the two parallel lines A step of defining a region having a vertex as a drawing region of the drawing target line;
Setting a rectangular scanning area including the drawing area and including at least a part of a boundary line of the drawing area as a boundary line;
Scanning the scanning area in units of subpixels obtained by virtually dividing a display area of pixels by a predetermined number to obtain the number of subpixels included in the drawing area;
Setting a pixel value of the pixel according to a ratio of the number of subpixels included in the drawing area among the subpixels included in each pixel;
When obtaining the number of subpixels included in the drawing area, it is assumed that a subpixel including one of a pair of opposing borders of the drawing area is included in the drawing area, and a subpixel including the other is drawn in the drawing area. A step of determining that the object is outside the area, and a drawing method characterized by executing . A drawing method in an image generation apparatus including a drawing data generation unit, wherein the drawing data generation unit includes:
Small area unit smaller than the pixel display area for a parallelogram parallel to the straight line having a predetermined width in either the horizontal or vertical direction of the display screen, including the straight line to be drawn from which the vertex data was obtained The inside / outside determination is performed to evaluate the degree of the display area of the pixel existing in the parallelogram, and the pixel value of the pixel is determined based on the degree .
The ratio of the display area of the pixel included in the drawing area depends on the number of subpixels included in the drawing area among the subpixels obtained by virtually dividing the display area of the pixel by a predetermined number. Decide
When obtaining the number of sub-pixels included in the drawing area, it is assumed that a sub-pixel including one of a pair of opposing borders of the drawing area is included in the drawing area, and a sub-pixel including the other is drawn in the drawing area. A drawing method characterized in that it is determined to be outside a region . A drawing information acquisition unit that reads information of an image to be drawn;
A drawing data generation unit that generates drawing data expressed in pixel units by each pixel value based on the information of the image;
A drawing data storage unit for storing the drawing data;
When the drawing data generation unit expresses a drawing target line included in the image information in units of pixels, the drawing data generation unit has pixels in either the horizontal direction or the vertical direction of the display screen around the drawing target line. An area having a width that is an integral multiple of the size of is defined as the drawing area of the line to be drawn, and the pixel value of the pixel is set according to the ratio of the pixel display area included in the drawing area ,
The drawing data generation unit
The ratio of the display area of the pixel included in the drawing area is determined according to the number of subpixels included in the drawing area among the subpixels obtained by virtually dividing the display area of the pixel by a predetermined number. Decide
When obtaining the number of subpixels included in the drawing area, it is assumed that a subpixel including one of a pair of opposing borders of the drawing area is included in the drawing area, and a subpixel including the other is drawn in the drawing area. An image generating apparatus, characterized in that it is determined to be outside a region . A drawing information acquisition unit that reads information of an image to be drawn;
A drawing data generation unit that generates drawing data expressed in pixel units by each pixel value based on the information of the image;
A drawing data storage unit for storing the drawing data;
The drawing data generation unit includes the drawing target line when expressing the drawing target line included in the image information in units of pixels, and the drawing data generation unit includes either the horizontal direction or the vertical direction of the display screen. A region including two parallel lines shifted by a predetermined width as a boundary line and having an end point of the two parallel lines as a vertex is defined as a drawing region of the drawing target line, and a pixel display region is Set the pixel value of the pixel according to the percentage included in the drawing area ,
The drawing data generation unit
The ratio of the display area of the pixel included in the drawing area is determined according to the number of subpixels included in the drawing area among the subpixels obtained by virtually dividing the display area of the pixel by a predetermined number. Decide
When obtaining the number of subpixels included in the drawing area, it is assumed that a subpixel including one of a pair of opposing borders of the drawing area is included in the drawing area, and a subpixel including the other is drawn in the drawing area. An image generating apparatus, characterized in that it is determined to be outside a region . The drawing area defined by the drawing data generation unit uses the two parallel lines shifted and the two line segments connecting the start points and the end points of the two parallel lines as boundary lines. 8. The image generation apparatus according to claim 7 , wherein The drawing data generation unit sets a rectangular scanning area including the drawing area, and scans the scanning area in the horizontal direction and the vertical direction of the display screen in units of subpixels. 9. The image generation apparatus according to claim 7, wherein a sub-pixel included in the drawing area is detected. The image generation apparatus according to claim 9 , wherein the drawing data generation unit sets the scanning region so that a part of a boundary line thereof coincides with a part of a boundary line of the drawing region. The drawing data generation unit performs the shift in the vertical direction when the acute angle formed by the line to be drawn and the horizontal direction of the display screen is within a predetermined angle, and performs the shift when the acute angle is larger than the predetermined angle. the image generating apparatus according to claim 7, characterized in that it is carried out in the horizontal direction 10. 7. An electronic apparatus comprising: the image generation apparatus according to claim 6; and a control unit that controls the image generation apparatus, wherein an image generated by the image generation apparatus is displayed on a display device under the control of the control unit. Information equipment. 8. An electronic apparatus comprising: the image generation device according to claim 7; and a control unit that controls the image generation device, wherein an image generated by the image generation device is displayed on a display device under the control of the control unit. Information equipment.

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