JP2583379B2 - Pseudo three-dimensional image synthesizing apparatus and image synthesizing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pseudo three-dimensional image synthesizing apparatus.

[0002]

2. Description of the Related Art Conventionally, a pseudo three-dimensional image synthesizing apparatus for displaying a three-dimensional image two-dimensionally has been known. For example, video games for three-dimensional images, simulators for airplanes and various vehicles, computer graphics, and the like. CAD
It is widely used in device displays and other applications.

The inventor has been conducting research and development on such a pseudo three-dimensional image synthesizing apparatus for synthesizing and displaying a three-dimensional object having an arbitrary shape as a combined image of a plurality of polygons, as described later. . However, when an image is displayed by this device, two of these polygons are displayed.
It is not necessary to process polygons that cannot be seen from the dimensional display screen, that is, those that correspond to the polygons on the back. Therefore, if the polygons on the back side are excluded from the objects to be processed in advance, the subsequent processing time and the amount of data to be processed are ideally reduced to about １ ／, and in particular, image synthesis for real-time image synthesis. In the device, the burden on hardware can be greatly reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and an object of the present invention is to provide a pseudo three-dimensional image synthesizing apparatus capable of minimizing processing of a polygon corresponding to a back portion on a display screen. To provide.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a plurality of polygons.
A three-dimensional display object represented by a set of
The first and second vertices of the projected polygon are transformed by visual projection
Vertex information including coordinates in the order according to the front and back of each polygon
Image information supply means for outputting and configuring the polygon
Contour point pair where the contour and horizontal scan line intersect
The contour point information including the first and second coordinates of
Contour point calculating means for calculating based on the point information;
Based on the calculation result from the calculation means,
Image synthesizing means for synthesizing a view image composed of
Only, the contour point calculating means is provided by the image information supplying means.
The input second coordinates of the N-th (N is an integer) vertex,
A method of calculating an increase / decrease between the (N + 1) vertex and the second coordinate
On the contour edge connecting the step and the Nth vertex to the (N + 1) th vertex
Constructs the first coordinates of the contour point and the contour point and contour point pair
Means for calculating an increase or decrease between the first coordinate of the contour point to be calculated and
Polygon to be processed based on the calculated increase / decrease result
To determine whether is a back polygon or a front polygon
If it is determined that the step and the back polygon, the back polygon
Output of the contour point information to the image combining means.
And a means for omitting. The present invention
Indicates a three-dimensional display object represented by a set of polygons.
Perspective transformation on a fixed projection plane
Vertex information including the first and second coordinates of the vertices is stored in a table for each polygon.
An image information supply step of outputting in an order according to the back;
The outline and the horizontal scan line that make up the polygon intersect
Contour point information including first and second coordinates of a contour point pair that is a point
Information, the contour points calculated based on the vertex information of each vertex
Calculation step and the calculation result in the contour point calculation step
The view image composed of multiple polygons based on the
Image composing step, the contour point calculating step
Of the input Nth vertex (N is an integer)
Increase / decrease between the second coordinate and the second coordinate of the (N + 1) th vertex
Is calculated, and the contour connecting the Nth vertex and the (N + 1) th vertex is calculated.
The first coordinate of the contour point on the side , and the contour point and the contour point pair
Calculate the increase / decrease between the first coordinate of the contour point to be constituted, and calculate
Polygons to be processed based on the
Judge whether it is a polygon or a front polygon, and
If it is determined to be a gon,
The output of the contour point information is omitted.

[0006]

According to the present invention, the contour point is supplied from the image information supply means.
Vertex information is added to the calculation means in the order corresponding to the front and back of the polygon.
Is entered. That is, the polygons in the table are, for example, counterclockwise (reverse
), And the polygon on the back, for example, clockwise (or vice versa)
Vertex information is input. This vertex information contains
First coordinate of vertex (for example, X coordinate on projection plane), second coordinate
(For example, the Y coordinate on the projection plane). And contour points
The calculating means calculates the polygon based on the input vertex information.
Contour point pair, which is the intersection of the scanning lines of the contour line
The contour point information of (left contour point, right contour point) is obtained. An example
For example, suppose that a polygon has A, B, C, and D vertices.
You. Then, the contour point calculating means calculates, for example, the second coordinates of the vertex A.
And the second coordinate of the vertex B are calculated. Further contour sides
The first coordinates of the contour points on A and B are paired with the contour points.
Of the contour point with the first coordinates is determined. And got
Based on the result of the increase / decrease, the polygon to be processed is
It is determined whether the polygon is a front polygon or a back polygon. So
If it is a back polygon, it will be removed from subsequent processing
You. This makes it possible to improve the efficiency of arithmetic processing.
Both can easily determine the front and back of a polygon.
You.

[0007]

【Example】

[Table of Contents of Examples] Outline of the Invention B: Example B1: Image Information Supply Source * Point of View * Configuration * Function * Auxiliary Data * Communication Memory B2: Field Processor Circuit * Polygon Recognition Number B3: Image Synthesis Device (a ) Storage circuit a-1. Field memory * Data write order * Word configuration a-2. Associated data memory (b) Line buffer (c) Line processor circuit * Data read unit * Data write unit * Free space detection unit * Specific example of filling operation (d) Comparison between this embodiment and conventional device C: Specific example C1: First specific example (a) Specifications (b) Dual-port RAM (c) Image information supply source (d) Field processor circuit * Configuration * Operation (e) Field memory (f) Line buffer (g) Line processor circuit * Contour point information reading * Filling process * Filling operation specific example * Free pixels * Polygon displayable number * Dual port RAM C2: Second specific example * Complete discontinuous type * Semi-discontinuous type [Embodiment] Next, a preferred embodiment of the present invention will be described with reference to the drawings.

A: Outline Description The present invention relates to an apparatus capable of synthesizing and outputting an image signal for CRT display in real time based on various graphic information supplied from the outside.

FIG. 2 shows a preferred example of a pseudo three-dimensional image synthesizing apparatus using the present invention. The apparatus of this embodiment includes an image information supply source 10, a field processor circuit 1
2 and an image synthesizing device 14.

The image information supply source 10 handles three-dimensional stereoscopic information, performs various conversions such as rotation, translation, and perspective projection on the three-dimensional information, and converts the three-dimensional information to be displayed into two-dimensional graphic combination information. And outputs this as pseudo three-dimensional information.

The pseudo three-dimensional information includes, for example, a color code and other accompanying data in addition to the shape, position, and priority of the figure.

The field processor circuit 12 generates a CR based on the pseudo three-dimensional information thus output.
The outline of each figure displayed on T is calculated. Then, the outline points of each polygon are sequentially output as outline point information together with the corresponding accompanying data.

The image synthesizing device 14 calculates and outputs a pseudo three-dimensional image signal for CRT display in real time based on the contour point information thus output.

B: Embodiment FIG. 1 shows a preferred example of an airplane operation simulator formed by using the pseudo three-dimensional image synthesizing apparatus.

B1: Image Information Supply Source In this embodiment, the image information supply source 10 calculates simulation images under various flight conditions during flight, and uses the simulation images as combination information of a plurality of figures. The signal is output to the field processor circuit 12 via the communication memory 28. * Focus point By the way, in order to increase the reality of the image output from the image information supply source 10, it is more advantageous to handle more information.

On the other hand, in order to increase the speed of the image information supply source 10, the smaller the amount of information to be handled, the more advantageous.

Therefore, in order to increase the reality of the signal output from the image information supply source 10 and to make it possible to increase the speed, it is necessary to devise signal processing for obtaining a more realistic image with a small amount of information. There is.

For this purpose, information having low utility may be sequentially deleted as necessary from the pseudo three-dimensional information output from the image information supply source 10. From such a viewpoint, the present applicant has studied the following four points. Point 1 Among the information on the three-dimensional object, the least useful information relates to the inside of the object.

This is because the inside of the object is invisible and can be ignored unless the object is translucent.

Therefore, it is understood that what is handled as three-dimensional image information is sufficient if it is limited to information on the object surface. Point 2 Also, if you endure that information in the surface details of the object is lost, the surface shape of the object can be simplified by considering it as an aggregate consisting of a combination of "planar figures".

Therefore, if the information on the surface of the object is limited to only "planar figures" consisting of figure shapes and color information, the amount of information to be handled can be further reduced. Point 3 The information on the graphic shape narrowed down at the point 2 is further limited to a simplified graphic shape according to some rule, such as a circle, an ellipse, or a polygonal system, so that the information to be handled is further reduced. It is possible to do. Point 4 The simplified graphic shape at the point 3 is a circle,
Ellipses, polygons, etc. are possible. However, when such a plurality of graphic shapes are appropriately selected and used, not only the entire circuit becomes complicated, but also new information of "selection of graphic type" is required.

Therefore, it is preferable to limit the types of figures used for such a combination display to any one of a circle, an ellipse and a polygon.

For this reason, when considering each of these figures from the viewpoint of displaying a combination of arbitrary figures, a polygon is the most advantageous in terms of flexibility.

The image information supply source 10 of the embodiment is formed based on such a viewpoint, and sequentially calculates and outputs each three-dimensional object as combination information of a plurality of polygons.

In this manner, the image information supply source 10 of the embodiment can calculate and output information necessary for synthesizing a more realistic image signal at a high speed. * Configuration Hereinafter, a specific configuration of the image information supply source 10 of the present embodiment will be described in detail.

In the embodiment, the image information supply source 10
Includes an operation unit 20, a main CPU circuit 22, a three-dimensional information memory 24, and a three-dimensional operation circuit 26.

The operation section 20 is formed in exactly the same manner as the cockpit of an actual airplane, and its operation content is converted into an electric signal via a switch or a variable resistor and output to the main CPU circuit 22. Have been.

The main CPU circuit 22 is a central part of the operation as a simulator, and based on a signal output from the operation unit 20, data representing the flight position of the airplane.
And outputs it to the three-dimensional operation circuit 26.

The main CPU circuit 22 outputs various status signals output from the three-dimensional arithmetic circuit 26, for example, "the airplane has collided with another object", "the airplane has entered turbulence", and The information such as "the destination has been reached" is received, and the situation data corresponding to the information is calculated and output to the three-dimensional calculation circuit 26.

In the three-dimensional information memory 24, every object is represented as a polyhedron, three-dimensional coordinate data representing each vertex of the polyhedron, and a polygon representing each surface of the polyhedron as a connection of each vertex. Data is written and stored. Here, each of the polyhedral data is represented using a fixed coordinate system.

The three-dimensional arithmetic circuit 26 calculates the current position of the airplane calculated by the main CPU circuit 22,
With reference to various polyhedral data stored in the three-dimensional information memory 24, the scene seen from the airplane is calculated. Then, the scene is output to the communication memory 28 as a combination of graphic information. * Operation In the embodiment, such calculation of polygon information is performed according to the following procedure.

As shown in FIG. 3, the three-dimensional arithmetic circuit 26 of the embodiment assumes a moving coordinate system having the origin at the airplane.
In the figure, the right direction is set to the X coordinate, the downward direction is set to the Y coordinate, and the forward direction is set to the z coordinate.

When the main CPU circuit 22 outputs the moving coordinates indicating the current position of the airplane, the three-dimensional operation circuit 26 reads out predetermined polyhedral data from the three-dimensional information memory 24.

In the embodiment, the information written in the three-dimensional information memory 24 is represented by using a fixed coordinate system. Therefore, the three-dimensional operation circuit 26 converts the information read from the memory 24 into the moving coordinate system. It is necessary to convert to coordinate data.

This conversion can be realized by a combination of two calculation elements of rotation and translation of coordinates. In the process of this conversion, information (z <0) that is found to be out of the field of view of the pilot. Etc.) are removed. The status data obtained by the conversion is output to the main CPU circuit 22.

The coordinate-converted polyhedral information is
Next, assuming that the display screen is on the plane of z = 0, perspective projection transformation is performed toward the viewpoint of z <0.

By such perspective projection conversion, each polyhedron data is represented as a set of point information obtained by converting the coordinates of each vertex of the polyhedron into two dimensions of X and Y. In performing such perspective projection transformation, the distance between the viewpoint and each vertex coordinate of the polyhedron is determined.

Then, the two-dimensional point information (the coordinates of the vertices of the polyhedron) obtained by the perspective projection transformation is classified for each polygon representing the surface of the polyhedron, and the classified polygon is the visual field of the pilot, that is, the visual field of the screen. Check if you enter.

In the present embodiment, the field processor circuit 12 and the image synthesizing device 14 have their receiving coordinate ranges set somewhat wider than the field of view.

For this reason, the three-dimensional arithmetic circuit 26 checks the obtained information for each polygon, removes polygons that do not enter the visual field at all, and partially enters the visual field but leaves the rest beyond the acceptance coordinate range. Such a polygon is appropriately deformed so as to fall within the receiving coordinate range.

Thereafter, the three-dimensional arithmetic circuit 26 determines a representative value of the distance from the viewpoint to the polygon that falls within the receiving coordinate range.

Then, the polygons are output to the communication memory 28 as polygon information having a higher priority in order from the polygon having the smaller representative value. * Accompanying data At this time, each polygon information output to the communication memory 28 includes not only two-dimensional coordinate data (X, Y) of each vertex of the polygon, but also accompanying data. Is included.

As the accompanying data, for example, a polygonal color code, luminance information, a z-axis coordinate value useful for synthesizing with other images, and the like can be considered. Also, besides this,
For example, if the inclination of the polygon is given as accompanying data, it is possible to determine the brightness of the polygon by the subsequent arithmetic processing based on the relationship between the inclination of the surface and the direction of light.

In the present embodiment, for the sake of simplicity, the following description will be made on the assumption that a color code is output as accompanying data.

As described above, the image information supply source 10 of the embodiment converts a scene in the field of view of the pilot into a combination of a plurality of pieces of polygon information, and sequentially communicates the polygon information in descending order of priority. 28. * Communication memory The communication memory 28 functions as an interface between the image information supply source 10 and the field processor circuit 12, and the polygon information output from the image information supply source 10 Are output to the field processor circuit 12 in descending order of priority.

B2: Field Processor Circuit The field processor circuit 12 functions as contour point information calculation means, and performs CRT based on input polygon information.
The polygon outline displayed above is calculated and output.

In the embodiment, the image information source 10
The polygon information output in descending order of priority from CRT
Is updated in synchronization with the field scan (scanning to the odd field or the even field).

For this reason, the field processor circuit 12 of the embodiment operates with the field scanning time as one cycle, and stores the polygon information input during this period in the internal register in the descending order of priority.

Therefore, assuming that polygon information representing polygons A, B, and C is sequentially output from the image information supply source 10, for example, as shown in FIG. The circuit 12 first determines the highest priority figure A
X, Y coordinate data representing each vertex a1, a2, a3, a4 of
The associated data (color code) of the figure and the polygon data of the figure A are read out and stored in its internal register.

Then, based on the vertex coordinate data included in the polygon information read in this way, the calculation of the outline point position where the outline of the polygon A intersects each horizontal scanning line of the CRT is performed.

By the way, assuming that a figure intersecting with a certain scanning line exists, at least two contour points of the figure exist on this scanning line (excluding the vertices of the polygon). . These two contour points are defined as “left contour point” and “right contour point” according to their positions, and both are defined as “contour point pair”.

Normally, there are only one set of such contour point pairs on the left and right when considering one figure, but there may be a plurality of sets of special concave polygons.

Field Processor Circuit 12 of Embodiment
Summarizes the contour point positions obtained by the calculation as contour point pairs for each scanning line.

Then, the contour point information including each contour point pair obtained in this way and the accompanying data of the figure is output to the image synthesizing device 14.

Thereafter, the field processor circuit 12
Calculates the outline point information for polygons B and C in the same manner, and outputs the obtained outline point information to the image synthesizing device 14.

As described above, from the field processor circuit 12 of the present embodiment, the contour point information including the contour point pairs of the polygons A, B, and C and the accompanying data has a high priority. They are sequentially calculated and output in order. * Polygon Recognition Number The field processor circuit 12 of the present embodiment corresponds to each of the polygons A, B, and C when the associated data memory 44 is provided in the storage circuit 32 described later. It is necessary to output a polygon identification number to the storage circuit 32 together with the contour point pair and the associated data.

B3: Image Synthesizing Apparatus The image synthesizing apparatus 14 of the present invention is based on the contour point information of each of the polygons A, B, and C input in the order of priority, and outputs the image signal for CRT display. Is synthesized and output.

In the present invention, the image synthesizing device 14
Includes a storage circuit 32, a line processor circuit 34, and a line buffer 36. (A) Storage circuit a-1. Field Memory In this embodiment, the storage circuit 32 functions as contour point information storage means and is usually formed using a field memory 42. Then, contour point information of all polygons displayed on one screen of the CRT is stored.

FIG. 4B is a conceptual diagram of the field memory 42. The memory space of the field memory 42 corresponds to the scanning lines in one-to-one correspondence with the scanning lines constituting one screen. It is divided into a number of horizontal scanning storage areas equal to the number, and each storage area is given an address corresponding to the Y coordinate.

Accordingly, the contour point information of each of the polygons A, B, and C output from the field processor circuit 12 is represented by Y
The data is sequentially written and stored in a free area in the horizontal scanning storage area corresponding to the coordinates. * Data writing order The apparatus of the present embodiment uses the writing order of the contour point information to the horizontal scanning storage area to indicate the priority of each of the polygons A, B, and C.

That is, the field processor circuit 12 of the embodiment outputs the contour point information in the order of the polygons A, B, and C having the highest priority. Therefore, in each horizontal scanning storage area in the field memory 42 of the embodiment, first, the outline point information of the polygon A having the highest priority is written, and then the outline points of the polygons B and C are written in this order. Point information is sequentially written.

Therefore, for example, taking a horizontal scanning storage area designated by Y = 20 as an example, this storage area contains
The respective contour point information of the polygons A, B and C are written in ascending order of address. * Word configuration By the way, when attention is paid to the contour point information of each polygon written in this way, each of these contour point information is represented by the X coordinate XL of the left contour point and the X coordinate XR of the right contour point. And accompanying data of polygons.

The writing of such polygonal information can be performed in any word configuration of each horizontal scanning storage area, but the following three practical word configurations are considered. Can be

One word is used to store one piece of contour point information, and all of the left contour point, right contour point, and associated data constituting the contour point information are stored in one word.

Two words are used for storing one contour point information. Then, the left contour point and the right contour point are assigned to each word, and the accompanying data is divided into two equal parts and assigned to each word.

Three words are used to store one piece of contour point information. Then, the left contour point, the right contour point and the accompanying data are stored in each word.

In this embodiment, any of the above word structures can be employed, but it goes without saying that the smaller the number of words used, the faster the data access. Further, the method of writing the contour point information by the field processor circuit 12 differs depending on which of the above word configurations is adopted.

First, when the word configuration is adopted, three writing methods are conceivable.

First, as a first method, there is a method in which, in the process of calculating the contour points of one polygon, a contour point pair is sequentially written from the contour point information obtained.

In this case, a memory for temporarily storing one contour point is required. Then, the contour points obtained first are temporarily stored in this memory, and when the other contour point forming a pair with this contour point is obtained, both contour points are written and stored as a contour point pair.

As a second method, there is a method using read-modify-write (read, correction, write-back).

According to this method, when one contour point of a contour point pair is determined in the polygon contour point calculation process, the data is immediately written together with the accompanying data. Then, when the other contour point of the contour point pair is obtained, the previously written contour point is read out, and the writing is performed again with the newly obtained contour point.

Note that the accompanying data may be written at this time or at another time.

The third method differs from the above two methods in the procedure itself for obtaining the outline points of one polygon. Starting from the maximum point or minimum point as the starting point, find the left and right contour points simultaneously,
This is a method of writing with accompanying data. In this method, the circuit for calculating the contour points becomes slightly complicated.

When the above word structure is adopted, the field processor circuit 12 immediately writes the contour points each time a contour point is obtained in the process of calculating the contour points of one polygon. . In particular, when the word configuration is adopted, it is necessary to write only the accompanying data separately from the contour points in the corresponding word. a-2. By the way, focusing on the accompanying data, as described above, this accompanying data is basically written and stored in the field memory 42 together with the contour point pairs. You.

However, since the storage structure of the accompanying data in the field memory 42 is redundant, when the number of bits of the accompanying data is large, the dedicated accompanying data memory 4 is used.
4 is preferably provided separately.

In this case, the field processor circuit 12
Outputs a polygon recognition number as contour point information in addition to the contour point pair and the accompanying data.

Then, the associated data is written into the associated data memory 44 using the polygon identification number as an address.

On the other hand, a polygon identification number is written in the field memory 42 instead of the accompanying data.

Normally, as the accompanying data, there are many simple data having a small number of bits such as color information and luminance information. In such a case, the need for the accompanying data memory 44 is small. No.

However, such additional data includes, for example, z-axis coordinate values used for synthesizing polygons and other information related to special functions, in addition to the color information and the like. In such a case, the number of bits constituting the accompanying data becomes extremely large, and a dedicated accompanying data memory 44 is required. (B) Line Buffer The line buffer 36 has an associated data storage area corresponding to the number of pixels for at least one horizontal scan, and the associated data included in the contour point information is written and stored in each storage area. It is formed to be possible.

FIG. 5A and FIG. 6A show the format of the line buffer 36 of the embodiment.

In the line buffer 36 of the embodiment, the line processor circuit 34 described later synchronizes with the horizontal scanning signal and outputs each contour point information (associated data, left contour) from the horizontal scanning storage area corresponding to the vertical scanning position. When the point position XL and the right contour point position XR) are read out, the associated data included in each contour point information is sequentially written and stored at addresses surrounded by the contour point pair (XL, XR).

Therefore, for example, if the accompanying data of polygons A, B, and C represent red, blue, and yellow color codes, respectively, Red, blue and yellow color codes will be written respectively. (C) Line Processor Circuit The line processor circuit 34 sequentially synchronizes the outline point information of each polygon from a predetermined horizontal scanning storage area in the field memory 42 in order of the priority in synchronization with the horizontal scanning of the CRT. Read.

Then, the accompanying data is sequentially written and stored in a storage area in the line buffer 36 surrounded by the left contour point position XL and the right contour point position XR of the read contour point information.

In the present invention, the line processor circuit 34 includes a data reading section 46 and a data writing section 48.
And a free space detection unit 50. * Data reading unit The data reading unit 46 sequentially reads contour point information of each polygon from the horizontal scanning storage area corresponding to the vertical scanning position according to the priority in synchronization with horizontal scanning. put out.

For example, assuming that horizontal scanning is performed on the line of Y = 20 shown in FIG.
Reads the outline point information of the polygon A first from the horizontal scanning storage area of Y = 20 in the field memory 42, and then sequentially reads the outline point information in the order of the polygons B and C. * Data writing section Each time the contour point information is read, the data writing section 48 stores the associated data in the storage area of the line buffer 36 surrounded by the contour point pair (XL, XR). Are sequentially written.

At this time, the writing of data into the line buffer 36, that is, the filling processing of the accompanying data is performed as follows.
Since the reading is performed according to the reading order of the contour point information, accompanying data having a high priority is written into the line buffer 36 first.

Accordingly, the additional data to be written later on the line buffer 36 has its empty area (hereinafter referred to as an empty pixel) so as not to be overwritten on the previously written auxiliary data. Need to be done only for * Empty area detection unit However, if such empty pixel detection in the line buffer 36 is performed by using a so-called read-modify-write method, the speed of the entire circuit cannot be extremely increased. .

Therefore, the line processor circuit 3 of the present invention
Reference numeral 4 uses the free area detection unit 50 to detect a free pixel in the line buffer 36 at high speed during horizontal scanning.

FIGS. 5 (B) and 6 (B) show the format of the empty area detecting section 50. The detecting section 50 determines that the corresponding pixel in the line buffer 36 is empty. Set to "0" if it is a pixel,
If the pixel is a solid pixel, it is set to “1”.

Each time the outline point information is read out based on the empty pixel information detected by the empty area detection section 50, the data writing section 48 sets the left outline point position XL.
And the associated data is sequentially written to the empty pixels in the line buffer 36 surrounded by the right outline point position XR.

At the same time, the empty area detecting section 50 detects that new accompanying data has been written in the empty pixels surrounded by the left outline point position and the right outline point position. * Specific Example of Filling Operation Accordingly, for example, the line of Y = 20 shown in FIG. 4 is horizontally scanned, and at this time, the contour point information of each of the polygons A, B, and C includes
Assuming that the red, blue, and yellow color codes are respectively included as accompanying data, the line processor circuit 34 starts from the horizontal scanning storage area of Y = 20 in the field memory 42. The outline point information of the polygon A is read.

Then, as shown in FIG. 6 (A), the memory area of the line buffer 36 surrounded by the left contour point position XLA and the right contour point position XRA included in the contour point information is firstly stored in red color. -Fill with code. At the same time, as shown in FIG.
Detects an area other than the area surrounded by the left contour point position XLA and the right contour point position XRA as the current empty pixel in the line buffer 36.

When the filling processing of the polygon A is completed in this way, the field processor circuit 34
Next, the contour point information of the polygon B having the highest priority is read out in the same manner, and the memory area surrounded by the left contour point and the right contour point position XLB, XRB included in the contour point information is shown in FIG. Fill with blue color code as shown in.

At this time, the line processor circuit 34
The red color already written in the line buffer 36
This is performed only on the empty pixels (FIG. 6 (B)) detected by the empty area detection unit 50 so as not to be overwritten on the data.

The empty area detecting section 36 similarly detects a new empty pixel area in the line buffer 36 in real time based on such a write operation as shown in FIG. 5B.

When the painting process for the polygon B is completed, the painting process for the polygon C is performed in the same manner.

As described above, the line processor circuit 34 of this embodiment combines the image signals for one horizontal scan by using the line buffer 36.

Then, the line buffer 3
The image signal for horizontal scanning synthesized in 6 is input to the color palette memory 38 in synchronization with the horizontal scanning of the CRT, where it is converted into a specific color signal based on the color code. , CRT 40.

The line processor circuit 34 of the embodiment repeatedly writes and outputs the image signal to and from the line buffer 36 in synchronization with the horizontal scanning of the CRT. The simulation image output from 10 is satisfactorily displayed as polygon combination information. (D) Comparison between the present embodiment and the conventional apparatus In the apparatus of the present embodiment, the so-called accompanying data read and
This eliminates the need for a modify / write operation.

That is, in the image synthesizing apparatus using the bitmap display system, the outline of the image is set in the bitmap memory, and then the outline is filled with desired accompanying data. "Filling work" is required.

However, assuming a case where such a filling process is performed in order from the graphic having the highest priority using the conventional apparatus, the information which has been written first and has the higher priority can be obtained.
It is necessary to perform a time-consuming operation called read-modify-write every time so as to prevent erasure with low-priority information to be written later, and image synthesis cannot be performed in a short time.

In particular, such read-modifying
When the light processing is performed, the painting operation often cannot follow a change in the image, and there is a problem that a real-time display of a fast-moving moving image or the like cannot be obtained.

Further, such a filling operation can be performed at a high speed by using a large-capacity bus line. However, this causes a problem that the capacity of the bus line and other members becomes too large compared to the amount of information to be handled, and the entire device becomes large and expensive.

On the other hand, the image synthesizing apparatus of the embodiment uses the empty area detecting section 50 to detect an empty area in the line buffer 36, and fills out the accompanying data. For this reason, it is not necessary to perform the time-consuming operation of read-modify-write at the time of performing the filling processing of the accompanying data as in the conventional apparatus, and it is possible to perform the image synthesis at a high speed. .

In particular, when read-modify-write of accompanying data is not performed, the amount of data calculation when performing image composition is extremely small. Therefore, it is possible to combine image signals in real time without increasing the capacity of the bus line. In the device of the present embodiment, the capacity of the memory to be used can be reduced.

That is, in the conventional apparatus, a bit map memory for storing accompanying data corresponding to the total number of pixels of at least one screen is required.

However, in the apparatus according to the present embodiment, instead of the bit map memory, roles are shared by using a field memory for storing image information for one screen and using a line buffer for filling work. I have.

Since the field memory has no correspondence with the pixels, the capacity is smaller than that of the bit map memory. On the other hand, although the line buffer has a correspondence with the pixel, the capacity may be one or two scanning lines.

Therefore, the total capacity of the memory can be made smaller than that of the bit map memory. The apparatus according to the present embodiment can satisfactorily combine and output image signals without dropping images with high priority.

That is, as an apparatus that does not use the read-modify-write method, there is known an apparatus that performs a filling process in order from a figure having a lower priority than in the past.

In such a conventional apparatus, if the data writing time is insufficient for some reason, the graphic having the highest priority cannot be written into the memory, and as a result, the graphic having the lower priority is displayed on the CRT screen. However, there is a serious drawback in that only the image with the highest priority may be displayed.

On the other hand, in the apparatus of this embodiment, the field
The outline point information of the polygons A, B, and C is sequentially written and stored in the horizontal scanning storage area of the field memory 42 in the order of the priority, and the thus written outline point information is stored in a line processor. The circuit 34 is formed so as to sequentially read data in descending order of priority.

Therefore, even if the data write / read time is insufficient for some reason, it is possible to satisfactorily synthesize and output the image signal without dropping the graphic having the highest priority. The apparatus of the present embodiment can synthesize and output a pseudo three-dimensional image with high reality in real time.

That is, the apparatus of this embodiment handles the surface shape of a three-dimensional object as a set of a plurality of polygons in order to display a pseudo three-dimensional image.

Therefore, according to the present embodiment, as described above, it is possible to synthesize and output a pseudo three-dimensional image having higher reality with less information and memory capacity in real time.

C: Specific Example Next, a specific example of the apparatus of the present invention will be described in detail.

C1: First Specific Example The apparatus according to the embodiment uses the horizontal scanning line 1 based on the following specifications.
It is formed so that 64 polygons can be displayed in the vicinity. (A) Specifications (a) CRT (Interface) Number of pixels 576 x 448 (576 x 224 / field) Number of scanning lines 525 (262.5 / field) Vertical synchronization frequency 60.015Hz ( (Vertical cycle 16.663ms) Horizontal sync frequency 15.754KHz (horizontal cycle 63.477μs) Dot clock frequency 12.288MHz (b) Polygon display number (1 screen) 1.024 (c) Polygon display number (horizontal) 64 (d) Input Information coordinate range 0 ≤ X ≤ 4095, 0 ≤ Y ≤ 2047 (E) Display coordinate range 2048 ≤ X ≤ 2623, 1024 ≤ Y ≤ 1471 (0 ≤ X ≤ 575, 0 ≤ Y ≤ 447 on the circuit. (B) Dual port RAM Also, each memory of the device of the present embodiment, for example, a communication
A so-called dual-port RAM, in which data writing by a preceding processor and reading of data by a subsequent processor are performed independently, is used for the section memory 28, field memory 42, and line buffer 36. Is preferred.

Each of these dual-port RAMs used in this embodiment has a storage capacity twice as large as that required for the write and read operations, and the memory space is equally divided into two storage areas. Have been.

Each storage area thus divided into two equal parts is formed so as to be alternately accessed by a preceding processor and a succeeding processor at regular intervals.

Therefore, in this dual port RAM, when data is written in one storage area, the written data is read from the other storage area. If data is being read from one storage area, new data is written to the other storage area.

Table 1 shows the switching cycle of the storage area for each memory.

[Table 1] (C) Image Information Supply Source In this embodiment, the image information supply source 10 sequentially outputs polygon information in descending order of priority in synchronization with CRT field scanning.

For example, when the image shown in FIG. 4A is displayed on a CRT, polygon information is sequentially output in the order of figures A, B, and C according to the priority.

Each piece of polygon information output in this way includes its accompanying data and each vertex coordinate data (X, Y) of the polygon.

In the embodiment, it is assumed that the accompanying data includes a color code representing a display color of a polygon. This color code functions as a color signal read address of the color palette memory 38.

The vertex coordinate data of each polygon is
As shown in FIG. 7 (A), a1,
It is necessary to output counterclockwise in the order of a2, a3, and a4.

This is for causing the field processor circuit 12 to exhibit the function of removing the inverted polygon, as will be described later.

In this way, as shown in FIGS. 7 (B) and 7 (C), polygon information of polygons A, B and C is written in communication memory 28 in accordance with the priority order. Will be. (D) Field Processor Circuit FIG. 8 shows the field processor circuit 12 of this embodiment.
Is shown. The field processor circuit 12 of the embodiment has a preprocessing circuit 52, a division circuit 54, a line segment circuit 56, and a contour point buffer 5.
8, including a contour point counter 60.

The pre-processing circuit 52 converts the polygon information written in the communication memory 28, for example, as shown in FIG.
Reading is performed sequentially in the order of B and C.

Then, the read polygon information is arranged into information on each side constituting the polygon and output to the line segment circuit 56. At this time, the division circuit 54 is used to calculate the inclination of each side of the polygon.

The line segment circuit 56 first calculates a contour point pair group of the polygon A having the highest priority based on the data input from the preprocessing circuit 52, and then calculates the polygon B , C in order of contour point pairs.

Then, the calculated contour point pair is color-coded.
The data is sequentially written into the field memory 42 as contour point information together with the data.

Here, the contour point buffer 58
Is used to temporarily store previously obtained contour points in order to obtain a contour point pair.

The contour point counter 60 is used as a group of registers for counting the number of contour points for each horizontal scanning line.

Therefore, the contour point counter 60 can be regarded as a counter for a pair of contour points displayed on one horizontal scanning line by dividing the count value by 2. this is,
It is nothing more than a write pointer to each horizontal scan storage area of the field memory 42.

The least significant bit of the count value is
It can be used as a flag indicating whether a contour point pair consisting of a left contour point and a right contour point has been completed, or whether the contour point pair is only half-cut. Operation FIGS. 9 to 13 show flowcharts of the field processor circuit 12. As shown in FIG.

In this flowchart, the following various variables are used. Many of the upper case variables represent actual registers, and the lower case variables represent numerical values appearing on the bus line. ing. X, Y: X, Y coordinate values of each vertex included in the polygon information. X0, Y0: First vertex coordinate value of the polygon. X _1, Y _1: start side (as directed segment) coordinate values X _2, Y _2: a side end point (as directed segment) coordinates Q (Quotient): division result, the quotient. That is, gradient of side X, Y: coordinate value of contour point YE (Y End): Y coordinate value of plot end point of side XV (X Visible): X of contour point on display screen
Coordinate value BR (Buffer): contour point buffer corresponding to scanning line number R. CR (Counter): A contour point counter corresponding to the scanning line number R.

First, FIG. 9 is a flowchart showing the entire operation of the field processor circuit 12. This field processor circuit 12 performs a new field scan. Each time, a predetermined field processing operation is repeated.

FIG. 10 shows the field processing operation shown in FIG.

In the apparatus of this embodiment, first, a new field scan is started, and at the same time, the count values C0, C1, C2, and C3 of the counter 60 set corresponding to each of the 224 horizontal scanning lines are set.
... Clear C223 to 0.

Then, the polygon information is read one by one from the communication memory 28 in the descending order of priority.
A predetermined polygon processing operation is performed.

That is, the apparatus according to the embodiment reads out all contour point pairs of the polygon based on the polygon information. Then, each contour point pair is combined with a color code, and is written and stored in the field memory 42 as contour point information.

For example, assuming a case where polygon information as shown in FIG. 7C is stored in the communication memory 28, first, the above-described processing is performed on the polygon A, and When the processing is completed, the same processing is sequentially performed on the polygon B and the polygon C.

When the processing for all polygons is completed, an end code is written in each horizontal scanning storage area in the field memory 42, as indicated by hatching in FIG. 4 (B). Specifically, P = 0, 1, 2,... 223
The end code is written using the combination of the counts C0, C1, C2, and C223 of the counter 60 as an address.

FIG. 11 is a flowchart showing the processing operation of one polygon shown in FIG.

In the embodiment, for example, when the processing operation for the polygon A is started, the X and Y coordinates of the first vertex a1 of the polygon A are read, and then the X and Y coordinates of the vertex a2 are read. .

Here, X0, Y0, X1, Y1, X2, Y2
Are set using actual registers, and when a value is set in X2 or Y2, the original value is automatically set in X1 and Y1, respectively. At this time, the original values of X1 and Y1 automatically disappear.

Thus, the X of the vertex coordinates a1 and a2
When the Y coordinate is read, the processing operation of one side a1, a2 is performed based on the read information.

Such an operation is described by each side a1 a2, a
2 Performs sequentially on a3, a3 a4, a4 a1.

Although not shown in FIG. 11, the accompanying data (color code) is read out in the same manner as the X and Y coordinates.
Set in a dedicated register.

FIG. 12 shows the processing operation of one side shown in FIG.

First, the apparatus according to the embodiment determines whether or not both ends of the target side have the same Y coordinate (step 120). If the Y coordinates of both ends match, it is determined that there is no need to plot this side, and the processing operation for this side is stopped. Next, the apparatus of the embodiment determines whether or not the Y coordinate of the target side is outside the screen at all points (steps 121 and 122).

Even if the target side is within the reception coordinate range, if the Y coordinate of all points constituting the side is outside the screen, there is no need to plot this side. Judgment is made, and the processing operation for this side is terminated (first stage of clipping).

Next, the apparatus of the embodiment calculates the slope Q of the target side (step 123).

At this time, the slope of the side is actually obtained by dividing it into two parts, an integer part and a remainder, but in FIG.
In order to simplify the description of the algorithm, the slope Q is regarded as a real number.

In this way, the expression representing the target side is set as follows.

(Equation 1) Next, it is determined from which end of the target side the calculation of the contour point is started (step 124). For this reason, it is first determined whether the Y coordinate of the both ends of the side, Y1, Y2, is larger, and the calculation start point of the contour point is initialized so that the calculation of the contour point is always performed in the increasing direction of the Y coordinate. .

Next, the calculation of the X coordinate of the point where the target side intersects each horizontal scanning line, that is, the contour point, is sequentially performed from the calculation start end to the calculation end end.

For example, taking the side a1, a2 shown in FIG. 4A as an example, first, the X coordinate which intersects the side a1, a2 with the horizontal scanning line of Y = 6 is obtained (step 125). Next, contour points intersecting with the horizontal scanning lines of Y = 8 and Y = 10 are sequentially obtained.

Then, when the Y coordinate of the horizontal scanning line becomes the Y coordinate YE set as the measurement end point, the contour point calculation operation for this side a1 a2 is ended (step 126).

It is to be noted that Y intersecting the target side a1 a2
If the coordinates are outside the screen, it is not necessary to find a contour point, so that the operation of calculating the contour point at that position is not performed (second stage of clipping) (step 127,
128).

In this embodiment, the scanning of the even field and the scanning of the odd field are performed alternately.

Therefore, in the apparatus of the embodiment, it is determined whether the current scanning is an even field or an odd field.
In the case of an even field, an even horizontal scanning line (Y =
0, 2, 4,...), And in the case of an odd field, an odd horizontal scanning line (Y = 1, 3, 3)
(5,...) Are calculated (step 129).

FIG. 13 shows the processing operation (step 125) of the contour points shown in FIG.

The apparatus of this embodiment first obtains a new XV coordinate with the origin at the upper left corner of the CRT screen (step 13).
0). This new XV coordinate is a value obtained by subtracting 2048 from the original X coordinate.

If the original X coordinate is outside the screen, XV = 0, XV so that it is displayed at both ends of the screen.
= 575 (3rd clipping)
Stages).

The new XV coordinate itself obtained in this manner becomes the X coordinate of the contour point calculated by the field processor circuit 12 of the embodiment.

When the contour point is obtained in this way, an address R for writing the contour point is calculated (step 131). Here, the function int (X) is
Represents the largest integer not exceeding X, and (y-102
4) represents a new Y coordinate having the origin at the upper left corner of the screen.

When the count value CR of the counter 54 is an even number, only one of the contour point pairs has been obtained. For this reason, the determined contour point is temporarily stored in the buffer 52 as BR until the next contour point is determined next, and the count value CR of the counter 54 is incremented (step 134).

When CR is an odd number, both contour points are aligned. In this case, the contour point XV is stored in the horizontal scanning storage area in the field memory 42 as specified by the address R. At this time, the contour point BR already determined and the accompanying data stored in the dedicated register are also stored in the horizontal scanning storage area at the same time. And
The count value CR of the counter 54 provided corresponding to the area is incremented (steps 132 and 13).
3).

The apparatus of this embodiment is for displaying a three-dimensional stereoscopic image as a pseudo three-dimensional image on two dimensions.

Incidentally, the vertex coordinates of the polygon information on the three-dimensional surface side output from the image information supply source 10 are given in a counterclockwise direction. However, on the contrary, the polygon located on the back side of the three-dimensional object is output as the inverted polygon information to which the vertex coordinates are given clockwise.

For this reason, the apparatus according to the embodiment compares the increase / decrease of the Y coordinate and the magnitude of the contour point, and removes the inverted polygon information (step 135). This will be described in more detail with reference to FIG.

In step 124 of the processing of one side, Y1 and Y2 are compared to determine the operation start point. Here, the processing branches again due to the magnitude relationship between Y1 and Y2. This does not mean that the same comparison operation is repeated, but the hardware stores the comparison result as a 1-bit flag in step 124, and this flag causes the branch of step 135 to occur. Absent.

Y1 and Y2 are output in the order output from the image information supply source 10, with Y1 being first and Y2 being later (except when Y1 is the last vertex, Y2 is the first vertex).
Since the order of the vertices is counterclockwise, if Y1 <Y2, as shown in FIG.
V is a left contour point, and BR determined in the past is a right contour point. At this time, if XV <BR, the polygon is a “front”, and otherwise, as shown in FIG. Conversely, if Y1 ≧ Y2, XV is the right contour point and BR is the left contour point, as shown in FIG. At this time, if XV> BR, this polygon is a “table”; otherwise, as shown in FIG.
"Turn it over." In this way, increase / decrease of the Y coordinate,
The inverted polygon can be determined from the size of the contour point.

If it is determined that the polygon has been turned inside out, the contour point pair currently being searched for must be invalidated. For this purpose, one of the contour point pairs B
Since only R is used, the count value CR of the counter 60 may be decremented to invalidate the value.

In this embodiment, the preprocessing circuit 46
The division circuit 48 handles all the operations shown in FIGS. 9 to 11 and all the parts except for the steps 129, 127 and 125 in FIG. The point counter 54 handles the operations of steps 129, 127 and 125 in FIG. 12 and all the operations shown in FIG.

In the above-mentioned flowchart, the case where serial processing is performed for the sake of simplicity is described as an example. However, parallel processing and pipeline processing are introduced as necessary to achieve high-speed processing. It is also possible to achieve the conversion. (E) Field Memory In the present embodiment, the storage circuit 32 comprises only the field memory 42, and does not have the accompanying data memory 44. This is because the associated data to be handled is data having a relatively small number of bits, such as a color code, as described above.

This field memory 42 stores the outline point information of all polygons represented in one field, and in the embodiment, 28 bits × 2 ¹⁵ (32K).
It is composed of a word RAM.

As described above, this field memory 42 is formed as a dual-port RAM so as to have twice the capacity of the actual work area. For this reason, one work area has half of the total capacity, ie, 2
There is a capacity of 8 bits × 2 ¹⁴ (16k) words.

Further, in this embodiment, the CRT alternately displays even and odd fields by interlaced scanning. Therefore, the memory space of the field memory 42 is, as shown in FIG.
Each of the scanning lines (Y = 0, 2, 4,...) Or the odd-numbered scanning lines (Y = 1, 3, 5,...) Is divided into blocks corresponding to one-to-one. .

Here, as described in the specification, since the number of Y coordinates constituting one frame screen is 448 on the circuit configuration, the odd field or the even field is used.
The number of scanning lines in the field is 224. The maximum number of polygons displayed on one horizontal scanning line is 64.

Therefore, assuming that one piece of contour point information (consisting of a contour point pair and a color code) is stored in one word, it is actually used in the field memory 42 of the embodiment. The working area is 28 bits × 14336 (= 64 × 224) words.

In FIG. 14, this field memory 42
The format of the contour point information written in the table is shown. Each contour point information comprises a total of 28 bits of data including an 8-bit color code, a 10-bit left contour point X coordinate XL, and a 10-bit right contour point X coordinate XR.

Each piece of contour point information sequentially output from the field processor circuit 12 is stored in the horizontal scanning storage area designated by the Y coordinate included in the contour point information in accordance with its priority order, with the address having the smallest address. , And an end code is written at the end of this storage area.

However, when the horizontal scanning storage area is completely filled with 64 pieces of contour point information, the end code is not written.

Further, the field memory 42 of the embodiment is
As shown in FIG. 15, writing and reading of data are controlled according to a 3 MHz clock. That is, data is written when the clock of the data output from the field processor circuit 12 is at the H level, and reading of the written data is performed when the clock is at the L level.

The field memory may store half or only a part of the video screen instead of the entire video screen. (F) Line Buffer FIGS. 5 (A) and 6 (A) show the line buffer 3
A format of 6 is shown. The line buffer 36 has addresses from 0 to 575 corresponding to each pixel constituting one scanning line, and each address is assigned an 8-bit storage area for storing associated data. .

In the embodiment, the line buffer 36
Is formed using a dual-port RAM having two storage areas with a memory capacity of 8 bits × 576 words.

Each time the contour point information is read from the field memory 42, the storage area surrounded by the left contour point XL and the right contour point XR is filled with the accompanying data.

The apparatus of the embodiment is formed so as to perform this filling process only on the empty area of the line buffer 36 as described later. (G) Line Processor Circuit FIG. 16 shows a detailed configuration of the line processor circuit 34 of the present embodiment.

The line processor circuit 34 reads out polygon outline point information from a predetermined horizontal scanning storage area in the field memory 42 in synchronization with horizontal scanning of the CRT, and outputs an image for horizontal scanning via the line buffer 36. The signal is synthesized and output. * Reading of contour point information In the embodiment, this line processor circuit 34
A line counter 70 for outputting a selection signal of a corresponding scanning line in synchronization with the horizontal scanning of the RT, and a priority number counter 72 for generating a priority number in order from 0,
The output of each of these counters is used as a read address as a field.
Output to the field memory 42.

Here, the output of the line counter 70 and the priority number counter 72 is cleared each time the control circuit 74 outputs a field scan start pulse and a horizontal scan start pulse.

As a result, the contour point information is sequentially read from the horizontal scanning storage area designated by the selection signal (Y coordinate data) output from the line counter 72 in descending order of priority.

At this time, the left contour point position XL, the right contour point position xR, and the color code included in each read contour point information are temporarily latched by the latch circuit 76, respectively. Each time the contour point information is latched in the latch circuit 76, the memory area of the line buffer 36 surrounded by the left contour point position XL and the right contour point position xR is filled with the accompanying data. I will go.

The line processor circuit of the embodiment reads out new polygon outline point information every time such a filling process is completed, and performs the same filling process on the line buffer 36.

Therefore, assuming that the contour point information is sequentially read out from the horizontal scanning storage area of Y = 20 shown in FIG. 4, the line buffer 36 is composed of the accompanying data of the polygons A, B and C. The filling process is sequentially performed.

At this time, the filling of the line buffer 36 is performed in accordance with the reading order of the outline point information.
Data will be written first.

Therefore, the additional data to be written later on the line buffer 36 needs to be performed only on the empty pixels so that the additional data is not overwritten on the previously written additional data. is there.

However, as described above, if the empty pixels in the line buffer 36 are detected by using the so-called read-modify-write technique, the speed of the entire circuit cannot be greatly increased.

The characteristic feature of the present invention is that the line buffer 3
6 is to perform a process of filling the line buffer 36 with accompanying data without performing a read-modify-write operation.

For this reason, the apparatus according to the present embodiment includes
A data writing circuit 78 is provided. An empty pixel in the line buffer 36 is detected in real time, and every time the contour point information is latched in the latch circuit 76, the line buffer 3 surrounded by the contour point pair is detected.
Attachment data is written to empty pixels in 6.

In the embodiment, this circuit 78 includes a flip-flop group 80, a priority encoder 82, a latch circuit 84, a decoder 86, a comparison circuit 88, and an age block.
G.

The flip-flop group 80 is composed of 576 flip-flops corresponding to all the pixels on one horizontal scanning line on a one-to-one basis.

FIGS. 5 (B) and 6 (B) show the format of the flip-flop group 80, and the 576 flip-flops constitute one scanning line. Addresses from 0 to 575 are assigned to the corresponding pixels.

Each flip-flop is set to “0” when the corresponding pixel is an empty pixel, and is set to “1” when the corresponding pixel is a solid pixel.
The output of each flip-flop is output to the priority encoder 82.

Priority encoder 82 outputs 576 output from flip-flop group 80 in this manner.
The vacant pixel information and the left contour point X coordinate (XL) of the polygon output from the latch circuit 76 are collated.

Then, among the blank pixels, the one whose X coordinate is equal to or larger than the left contour point X coordinate (XL) and the smallest is detected at high speed, and this detection result is referred to as “X of the pixel to be written next. Output as "coordinates". Then, the X coordinate value is output to the line buffer 36 via the latch circuit 84 as a “write address”.

As a result, the polygonal data latched by the latch circuit 76 is written into the empty pixel of the line buffer 36 specified by the write address.

At the same time, the output of the priority encoder 82 is fed back to the decoder 86 via the latch circuit 84. Then, the flip-flop designated by the X coordinate value is set from the empty pixel display state “0” to the pixel filling state “1”.

As described above, in the apparatus of the embodiment, the line buffer 36 and the flip-flop group 80 operate in conjunction with each other, and as a result, the line buffer 36 is sandwiched between the left contour point XL and the right contour point XR. The empty pixels that have been filled will be filled with the new accompanying data.

The filling of the area surrounded by the set of contour points (XL, XR) is completed in the following cases. First, the process ends when there is no “empty pixel” to the right of the left contour point.

In this case, "no empty pixel" is sent from the priority encoder 82 to the orgate 90.
Is output at the H level which indicates the state of. The process is also terminated when the detected empty pixel is equal to the right contour point or when the detected empty pixel exists on the right side of the right outline point. In order to detect such a case, a comparison circuit 88 is used in the apparatus of the embodiment.

That is, the comparison circuit 88 is connected to the latch circuit 7
6 is compared with the “X coordinate of the pixel to be written next” output from the latch circuit 84, and the X coordinate output from the latch circuit 84 is output from the latch circuit 76. When the X coordinate becomes equal to or exceeds the X coordinate, an "H level signal" indicating the end of the painting operation is output to the OR gate 90.

The detection of the end by the comparing circuit 88 can be used to remove the inverted polygon. That is, if an inverted polygonal contour point pair arrives, then left contour point ≧ right contour point. In this case, even if a vacant pixel exists to the right of the left contour point, the vacant pixel will always be located to the right of the right contour point. As a result, the painting operation ends without painting any pixel. . However, in this embodiment, as shown in step 135 of FIG.
Since the inside-out polygon has already been completely removed in step 2, the line-processing circuit 34 does not actually remove the inside-out polygon.

The orgate 90 outputs the H-level signal output in this way to the control circuit 74 as a painting end signal. Thereby, the control circuit 74
Increments the output of the priority number counter 72. The apparatus according to the embodiment increments the output of the priority number counter 72 every time the filling operation based on the contour point information of one polygon is completed in this manner, and similarly performs the reading and painting operation of the next contour point information. To do. * Specific Example of Filling Operation Therefore, for example, assuming that contour point information is read in the order of polygons A, B, and C from a horizontal scanning storage area in a field memory specified by using Y = 20 as an address, The filling process based on the read contour point information is performed as follows.

That is, before the reading of the contour point information from the horizontal scanning storage area is started, the line buffer 36 is used.
Each pixel in is a free area. Therefore, in this state, the flip-flops 80 are all set to “0”.

In this state, when the outline point information of the polygon A having the highest priority is read out and latched in the latch circuit 76, the associated data, that is, the red color code is read out. As shown in FIG. 6A, data is sequentially written in a storage area (X area where XLA ≦ X <XRA) in the line buffer 36 surrounded by the contour point pairs XLA and XRA.

At the same time, the contour point pairs XLA and XRA
The flip-flops in the flip-flop group 80 surrounded by are set to "1" sequentially as shown in FIG. 6 (B).

When the color code filling processing of the polygon A is completed, a fill end signal is output from the OR gate 90, the priority counter 72 is incremented by one, and then the contour points of the polygon B are Reading of information is started.

When the outline point information of polygon B is read, the outline point information is similarly latched in latch circuit 16.

In this state, flip-flop group 8
0 is the line buffer 30 as shown in FIG.
It is detected that a region surrounded by XLA and XRA in the inside has been filled.

Therefore, the line processor circuit 3 of the embodiment
Reference numeral 4 indicates the associated data, that is, the blue color code, sequentially in a free area (X area where XLB ≦ X <XLA) in the line buffer 36 surrounded by the contour point pairs XLB and XRB. I will write.

At the same time, the device of this embodiment sequentially sets the flip-flops in the area surrounded by XLB and XLA in the flip-flop group 80 to "1".

As a result, when the painting process of the polygon B is completed, the color codes of the polygons A and B are written in the line buffer 36 as shown in FIG. In addition, the flip-flop group 80 detects a filled area in the line buffer 36 as shown in FIG. 5B.

At the same time, a filling end signal is input into the control circuit 74, and the reading and filling of the next polygon C are performed in the same manner.

At this time, the contour point pair XLC and X
Since there is no free area in the area surrounded by RC, the accompanying data is not written.

As described above, the line processor circuit 34 of the present embodiment can satisfactorily write and write the horizontal scanning image signal into the line buffer 36 for each horizontal scanning in synchronization with the horizontal scanning of the CRT. Can be.

The apparatus according to the embodiment converts the color code written in the line buffer 36 into C
Address “0”, “1”,... In synchronization with the horizontal scanning of RT
The data is sequentially output to the color palette memory 38 in the order of “575”. Thereby, the color palette memory 38
Thereafter, a video signal for displaying the polygons A and B in the designated color is output to the CRT 40.

Therefore, if such operations are repeated in synchronization with horizontal scanning, a desired image signal can be displayed on the CRT 40 in real time based on the polygon information output from the image information supply source 10. Becomes possible. * Processing of Empty Pixels As described above, when all the filling processing for one horizontal scanning line is completed, the line buffer 36
In some cases, empty pixels (empty storage areas) remain in the area.

[0231] Such an empty pixel is
It is a point located outside of all polygons, and therefore, for such an empty pixel, information indicating that no polygon exists must be output to the color palette memory 38.

As such a method, the following three methods can be considered. Prior to writing data, the line buffer 36 is initialized in advance. All the contents of the flip-flop group 80 are serially output in synchronization with the output of the image signal. After all horizontal scanning lines have been filled,
All empty pixels in the line buffer 36 are filled with empty pixel information.

[0233] Of these methods, the third method can be adopted relatively easily. * Possible number of polygons to be displayed In addition, using the line processor circuit 34 of the embodiment, 1
We examined how many polygons can be displayed on a horizontal scanning line.

As a result of this study, assuming that writing is performed in the line buffer 36 with a cycle of a 12 MHz dot clock (clock serving as a reference for determining a pixel display cycle), 203 or more per horizontal scanning line is calculated. It was confirmed that the polygon can be displayed in real time. * Dual-port RAM The line buffer 36 of the embodiment is formed using the dual-port RAM as described above, and its memory space is divided into two storage areas.

Therefore, the line buffer 36 stores data from the line processor circuit 36 in one of its storage areas.
When data is being written, data is being read from the other storage area, and when data is being read from one storage area, the other is being read. In the storage area of the line processor circuit 14
Data is written.

Each part of the line processor circuit 34 shown in FIG. 16 and the line processor circuit 3 shown in FIG.
4 correspond to the data reading unit 46, the data writing unit 48, and the empty area detecting unit 50 as follows.

That is, the line counter 70 and the priority number count 72 controlled by the control circuit 74 function as the data reading section 46.

The latch circuit 76 and a part of the empty space detection / data writing section 78, such as the priority encoder 82, the latch circuit 84, the comparison circuit 88, and the gate 90, function as the data writing section 48. Further, a part of the free space / data writing circuit 78, for example, the flip-flop group 80, the decoder 86, etc.
Function as

C2: Second Specific Example-Another Embodiment of Field Memory 42- In the present invention, the field memory 42 is provided with a plurality of horizontal scanning storage areas corresponding to each horizontal scanning line. .

In such a horizontal scanning storage area, as shown in FIG. 4B, the memory space in the field memory 42 is simply divided equally into a number of unit blocks corresponding to the total number of scanning lines. It is also possible to set.

However, in this case, the memory capacity of each block is fixed, and the number of polygons that can be displayed on one horizontal scanning line is limited by the memory capacity of each block. For this reason, a situation often occurs that one block is overflowing, but a lot of free space exists in another block, and the efficiency of memory utilization is low. There's a problem.

In order to solve such a problem, it is preferable that each horizontal scanning storage area is of a completely discontinuous type or a semi-discontinuous type, and its memory capacity is formed so as to be set flexibly. Completely discontinuous Figure 17, fully discontinuous Fi formed in this way - is the preferred example of Rudomemori 42. In the figure, the memory image of the field memory 42 has a memory capacity per screen of 16384 (= 2 ¹⁴ ) words, and the number of scanning lines excluding blanking is 224 lines / field.
It is drawn as Ludo.

Each word of the field memory 42 contains an item indicating "next address", and the subsequent line processor circuit 34 continuously outputs one line of contour point information. It is possible to read it out.

By the way, the field memory 42 of the embodiment
Since there are 16384 (= 2 ¹⁴ ) words per screen, a 14-bit address is required to specify the next read address.

Therefore, when the memory space of 8, 10, 10, or 14 bits is allocated to each of the accompanying data, the left contour point, the right contour point, and the next address, 42 bits per word are obtained. Memory space is required.

In order to write data in such a field memory 42, the field processor circuit 12 has a one-to-one correspondence with the horizontal scanning lines of each CRT.
It is necessary to provide 224 slave pointers and one master pointer.

Here, each slave pointer is:
It is used to designate an address in the same horizontal scanning storage area where the contour point information is to be written next.

The master pointer is used to set an address to be written in the "next address" column of the word specified by the slave pointer.

For this reason, the address output by the master pointer is controlled so as to be the youngest address in an area in which data has not been specified by each slave bus pointer and data has not yet been written. You.

Next, an operation of writing contour point information performed using the slave pointer and the master pointer will be described.

First, before writing data, a slave pointer and a master pointer are initialized.
Thus, the slave pointer designates the head address 0, 1, 2,... 223 of the corresponding horizontal scanning storage area. Also, the master pointer is at address 2
Specify 24.

Subsequently, when the output of the contour point information by the field processor circuit 12 is started, the computed contour point information is stored in the horizontal scanning storage area specified by the y coordinate as follows. Is written according to a simple procedure.

First, the field processor circuit 12
When the first contour point information on the line is calculated, the write address of the field memory 42 is specified by the slave pointer corresponding to the y coordinate of the contour point information.

Then, the calculated contour point information is written in the “associated data”, “left contour point”, and “right contour point” fields of the designated address, respectively. -The "Next Address" column of the
The address “224” indicated by the pointer is written.

Next, the slave pointer is switched so as to indicate the same address "224" as the address of the master pointer written in the "next address" column. The address output by the pointer also increases to “225”.

As a result, when the contour point information of the same line is calculated next time, the slave pointer is set to the “associated data”, “left contour point” of the word specified by the address 224. Write the contour point information in each field of "Right contour point",
Further, the address of the master pointer currently displayed in the column of “next address” is written.

After the writing is completed, the slave pointer newly designates the address of the master pointer written in the "next address" column, and the master pointer is linked with this. The address output by-is incremented by one.

In the field memory 42 of the embodiment, when the writing of the contour point information of the entire polygon is completed, the end code is added to the address indicated by each slave pointer.
Write the code.

With the above configuration, each horizontal scanning storage area is treated as a series of storage areas linked by the address written in the "next address" column of each word.

Therefore, for example, the line processor circuit 3
Assuming that the contour point information is read out from the horizontal scanning storage area corresponding to the scanning line m, the contour point information written in the horizontal scanning storage area starts from the address m of the field memory and starts at the next address. Is read in a potato vine system by the time the end code is detected.

As described above, the field memory 4 of the embodiment is
In 2, a series of storage areas linked by an address written in the “next address” column of each word starting from the storage area specified by the address m is defined as a horizontal scanning storage area corresponding to the horizontal scanning line m. Will be set.

FIG. 18 shows an example of a data reading section of the line processor circuit 34 used for the field memory 42 constructed as described above.

In the figure, members corresponding to those of the first embodiment are denoted by the same reference numerals and description thereof is omitted.

In the embodiment, each of the line processor circuits 34 includes a line counter 70 for outputting a selection signal (Y coordinate data) of a corresponding scanning line in synchronization with the horizontal scanning of the CRT, and a 0 for the scanning line. An address specifying circuit 71a that outputs 6-bit information for address specification.
The outputs of both multiplexers are used as the leading word read address in the horizontal scanning storage area.
The data is output to the field memory 42 via the latch circuit 71c.

As a result, starting from the first word in the horizontal scanning storage area designated by the selection signal (Y coordinate data),
Reading of the contour point information is started.

At this time, the apparatus according to the embodiment uses this read word.
The 14-bit next address written in the "next address" column of the command is simultaneously output and input to the multiplexer 71b.

Then, the multiplexer 71b automatically selects the next address read from the field memory 42 and outputs it to the latch circuit 71c.

Therefore, assuming that, for example, a selection signal of the scanning line m is output from the line counter 70 of the line processor circuit 34, the horizontal scanning storage area m starts at the address m of the field memory 42. As a result, the contour point information is sequentially read in a vine-like manner while referring to the "next address" column until the end code is detected. If the memory capacity of the horizontal scanning storage area can be completely flexibly set as shown in FIG. 17, it is necessary to allocate 14 bits to the "next address" column. The configuration unit of the field is increased from 28 bits to 42 bits, and the total capacity of the field memory 42 is reduced
There is a problem that it increases 1.5 times.

In order to solve such a problem, it is preferable that the storage capacity of the horizontal scanning storage area is of a semi-discontinuous type.

FIG. 19 shows an example of such a field memory 42.

In this embodiment, the field memory 42
This memory space is equally divided for each sector block composed of a plurality of words.

It is necessary to set the number of divisions to at least the number of all scanning lines.
It is divided into 24 sectors-blocks.

The last word of each sector block is assigned to the “next sector address”.

In the figure, the sector address is
This is an address for designating each sector block, and is expressed as a value obtained by dividing the head address of each sector block by the number of words in the sector block.

In this embodiment, the capacity of one field of the field memory is set to 16384 (= 2 ¹⁴ ) words, and
The number of words per sector block is set to 16 (= 2 ⁴ ). As a result, the sector block for one screen is 1
024 (= 2 ¹⁰ ), and the sector address is 0 to 10.
23.

Next, an operation of writing contour point information in the field memory 42 thus formed will be described.

In order to perform such a writing operation, it is necessary to prepare 224 slave pointers corresponding to the number of scanning lines and one master pointer in the field processor circuit 12. .

In this embodiment, a plurality of words exist in each sector block. For this reason, while the slave pointer provided for each scanning line indicates the address assigned to each word,
It should be noted that the master pointer indicates a sector address assigned to each sector-block.

The field processor circuit 12
When the calculation of the contour point information is started, the slave pointer and the master pointer are initialized.

As a result, each of the slave pointers is set to the start address 0, 1 of the sector block 0, 1, 2,.
, 3568, and the master pointer indicates the sector address 224.

Subsequently, when the output of the contour point information is started, each piece of the contour point information is stored in a slice corresponding to the Y coordinate.
Are sequentially written to the empty word specified by the pointer. The slave pointer increments the address each time the writing of the contour point information is completed, and designates the next empty word.

Thus, the writing of the contour point information to each sector block proceeds in the same manner as in FIG. 4 (B).

By the way, in the case where the slave pointer designates the last word of a certain sector block and the contour point information to be written is output, the following processing is performed.

First, the value output by the master pointer, for example, 224, is written as the “next sector address” at the address indicated by the slave pointer.

Then, the head address of the sector block specified by the master pointer is set in the slave pointer, and at the same time, the sector address output by the master pointer increases by one.

Thereafter, the above-described contour point information is sequentially written at the address newly designated by the slave pointer, and each time the address of the slave pointer is incremented by one.

With the above configuration, according to the field memory 42 of the embodiment, the number of bits per word can be significantly reduced as compared with the field memory 42 shown in FIG. Becomes possible.

FIG. 20 shows an example of a data reading section of the line processor circuit 34 used for such a semi-discontinuous field memory 42.

The line processor circuit 34 includes a line counter 70, an address designation circuit 71a, a multiplexer 71b, a latch circuit 71c, and an intra-sector selection counter 71d.

The semi-discontinuous field memory 42 comprises:
It has sector addresses from 0 to 1023, and each of these sector addresses is specified by the upper 10 bits of the read address output from the latch circuit 71.

In this embodiment, the head sector address of the horizontal scanning storage area of the scanning line is synchronized with the horizontal scanning of the CRT, and the line counter 70 and the address designation circuit 7 are used.
1a.

The read word designation signal in each designated sector is sequentially output from the intra-sector selection counter 71d.

In the embodiment, one sector has 16 words.
It is composed of Therefore, the intra-sector selection counter 71d repeatedly outputs a total of 16 word designation addresses for each word from 0 to 15.

The in-sector selection counter 71d becomes "0" at the start of horizontal scanning. In addition, the latch 71c
It outputs a sector address, and updates the stored contents only when the in-sector selection counter 71d becomes "0". The multiplexer 71b selects the output of the line counter 70 and the 2-bit "0" designating the address 0 only at the start of horizontal scanning.

The line counter 70 becomes "0" at the start of the field scan.

The reading of the horizontal scanning storage area in the embodiment is performed as follows.

First, at the start of horizontal scanning, it is assumed that the line counter 70 has output the selection signal m for the horizontal scanning storage area corresponding to the scanning line m.

The output m of the line counter 70 plus 2-bit "0" is read into the latch 71c via the multiplexer 71b and output as a sector address.

At the same time, the intra-sector selection counter 7
1d is cleared to "0". As a result, a 14-bit address 16 is input to the address input of the field memory 42.
m is input.

This is the head address of the horizontal scanning storage area corresponding to the scanning line m, and the first contour point information is read from the field memory 42.

Thereafter, each time the processing of the contour point information is completed, the in-sector selection counter 71d counts up to 1, 2,..., 14 while keeping the sector address output from the latch 71c, and the second, third .., The fifteenth contour point information is read.

When the value output from the intra-sector selection counter 71d becomes 15, the "next sector address" is read from the field memory 42 in place of the contour point information, and is passed through the multiplexer 71b to the latch 71c. To enter.

Subsequently, when the intra-sector selection counter 71d counts, the output value becomes "0" again.
At the same time, the latch 71c outputs the next sector address.

As described above, the reading of the contour point information is performed continuously within the sector, but when the reading of one sector is completed, the reading is performed in a sweet potato manner with reference to the "next sector address".

This read operation is continued until the end code is detected.

[0306]

According to the present invention, the front and back sides of polygons are determined by the contour point calculating means, and the back side polygons are not output as contour point pairs. Therefore, it is not necessary to perform the processing of the back polygon in the subsequent processing, so that the load on hardware can be greatly reduced. As a result, it is possible to increase the speed of hardware processing, reduce the size of hardware, and improve image quality.

[Brief description of the drawings]

FIG. 1 is an overall explanatory diagram of a simulation device formed using an image synthesizing device of the present invention.

FIG. 2 is an overall block diagram of an image display device formed by using the present invention.

FIG. 3 is an explanatory diagram showing an example of a moving coordinate system used in an image information supply source.

FIG. 4 is an explanatory diagram showing a relationship between contour point information and a field memory;

FIG. 5A is a schematic explanatory diagram of a line buffer used in the present invention, and FIG. 5B is a schematic explanatory diagram of a free area detection unit used in the present invention.

FIG. 6A is a schematic explanatory diagram of a line buffer used in the present invention, and FIG. 6B is a schematic explanatory diagram of a free area detection unit used in the present invention.

FIG. 7 is an explanatory diagram showing the structure of a communication memory.

FIG. 8 is an explanatory diagram showing a specific configuration of a field processor circuit.

FIG. 9 is a flowchart showing the operation of the field processor circuit shown in FIG.

FIG. 10 is a flowchart showing an operation of the field processor circuit shown in FIG. 8;

FIG. 11 is a flowchart showing the operation of the field processor circuit shown in FIG.

FIG. 12 is a flowchart showing the operation of the field processor circuit shown in FIG.

FIG. 13 is a flowchart showing the operation of the field processor circuit shown in FIG.

FIG. 14 is an explanatory diagram of contour point information used in the embodiment.

FIG. 15 is an explanatory diagram showing read / write timings for a field memory.

FIG. 16 is a block diagram showing a first specific example of the line processor circuit shown in FIG. 1;

FIG. 17 is an explanatory diagram showing another specific example of the field memory shown in FIG. 1;

18 is an explanatory diagram of a line processor circuit used for the field memory shown in FIG.

FIG. 19 is an explanatory view showing another specific example of the field memory shown in FIG. 1,

20 is an explanatory diagram of a line processor circuit used for the field memory shown in FIG.

FIG. 21 is a schematic explanatory diagram illustrating an example of back surface removal according to the present embodiment.

[Explanation of symbols]

 Reference Signs List 10 Image information supply source 12 Field processor circuit 14 Image synthesis device

Claims (2)

(57) [Claims] 1. A three-dimensional image represented by a set of a plurality of polygons
Perspective projection transformation of the display object on a predetermined projection plane
Vertex information including the first and second coordinates of the vertices of the polygon is
Image information supply means to output in order according to the front and back of Rigon
The horizontal scanning line intersects the contour line forming the polygon.
Points including the first and second coordinates of the contour point pair
A contour that calculates information based on the vertex information of each vertex
Point calculation means, and a plurality of polygons based on calculation results from the contour point calculation means.
Image synthesis means for synthesizing a view image formed by a gon
Wherein the door, the contour point calculating means, input from the image information supply means
The second coordinate of the N-th (N is an integer) vertex and the (N +
Means for calculating an increase or decrease between the first coordinate of the vertex and the second coordinate;
A contour on the contour side connecting the Nth vertex and the (N + 1) th vertex
A first coordinate of a point and a ring forming the contour point and the contour point pair
Means for calculating an increase or decrease between the first coordinates of the section point and the first coordinates;
Polygons to be processed based on the
Means for determining whether it is a Rigon or a table polygon;
If it is determined to be a back polygon,
Output of the outline point information to the image synthesizing means is omitted.
Pseudo three-dimensional image synthesizing apparatus comprising:
Place. 2. A perspective projection transformation of a three-dimensional display object represented by a set of a plurality of polygons onto a predetermined projection plane, and vertex information including first and second coordinates of the vertices of the projected polygon are converted into each polygon. Image information supplying step of outputting in the order according to the front and back of the contour point information, and contour point information including first and second coordinates of a contour point pair which is a point where a contour line and a horizontal scanning line constituting the polygon intersect, A contour point calculating step of calculating based on vertex information of each of the vertices; and an image synthesizing step of synthesizing a view image composed of a plurality of polygons based on a calculation result of the contour point calculating step, In the point calculation step, an increase / decrease between the input second coordinates of the Nth (N is an integer) vertex and the second coordinates of the (N + 1) th vertex is calculated, and the Nth vertex and the (N + 1) th vertex are calculated. ) On the contour edge connecting the vertices An increase / decrease between the first coordinate of the contour point and the first coordinate of the contour point forming the contour point and the contour point pair is calculated, and the polygon to be processed is a back polygon based on the calculated increase / decrease result. An image composition method comprising: determining whether there is a front polygon or a front polygon, and omitting the output of the contour point information for the rear polygon if the rear polygon is determined.