JPH0683977A - Plotting system - Google Patents

Abstract

PURPOSE:To provide a Z buffer and a newly provided Z register switching mechanism on the plotting system merging plural images by means of Z information, to make the transmission and plotting on the image buffer after plotting on the Z buffer, to make an effective use of a Z buffer, and to enable the high- speed drawing of an image. CONSTITUTION:Three-dimensional data (or image information) passed from a host are developed and written in image buffers 1-3. A value Z of each part of the image is written in Z buffers 1-3 or the value Z of the entire image is written in a Z register 14. When there is an unused Z buffer, the three- dimensional data (or image information) are developed and used for plotting. A merge circuit 15 synthesizes the image taken out from the image buffers 1-3 based on the value Z of Z buffers 1-3 (or the Z register 14) and the synthesized synthesis picture is designed to be displayed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drawing system for merging a plurality of images using Z information.

[0002]

2. Description of the Related Art Conventionally, in the case of performing two-dimensional graphics display, a workstation or terminal has provided a hidden surface erasing function using a Z buffer. The Z buffer compares the depth direction (Z direction) information of the figure to be drawn to detect the front-back relationship with the already drawn figure. I erased the shaded parts (hidden surface removal).

Further, as shown in FIG. 3, a plurality of drawing units 21, 22, 23 are separately provided in the image buffer 1,
Using the Z information in the Z buffer, the Z merge circuit 24 reads the three-dimensional figures drawn in a few steps and synthesizes them.
It consists of two screens.

In FIG. 3, figures drawn by the drawing unit 21 for drawing the background, the drawing unit 22 for drawing the car 1, and the drawing unit 23 for drawing the car 2 are combined by the Z merge circuit 24 and combined. Display the composite screen. In this way, even a complicated screen can be created at a higher speed than in the case of drawing by one drawing unit by sharing and expanding and drawing by the plurality of drawing units 21, 22, 23. The configuration and operation of FIG. 3 will be briefly described below.

FIG. 3 shows an explanatory view of the prior art. In FIG. 3, the drawing unit 21 has an image buffer 1 and a Z buffer 1, expands the three-dimensional data to be drawn and draws it in the image buffer 1, and writes the Z value of each pixel at that time into the Z buffer 1. It is a thing.

The drawing unit 22 includes an image buffer 2
Similarly, it has a Z buffer 2 and similarly develops and draws three-dimensional data and writes Z values.

The drawing unit 23 includes an image buffer 3
Similarly, it has a Z buffer 3 and similarly develops and draws three-dimensional data and writes Z values.

The Z-merge circuit 24 is provided in the image buffer 1
And Z buffer 1, image buffer 2 and Z buffer 2,
Z merge based on image buffer 3 and Z buffer 3,
That is, the pixel existing first is displayed to perform the shadow processing.

The composite screen 25 is a screen after being composited by the Z merge circuit 24. Next, the operation will be described. (1) The drawing unit 21 develops the three-dimensional data passed from a host (not shown) and draws it in the image buffer 1 and writes the Z value of each pixel in the Z buffer 1.
Similarly, the drawing units 22 and 23 also draw in the image buffers 2 and 3 and write the Z value of each pixel in the Z buffers 2 and 3.

(2) The image buffers 1, 2, 3 having the previous (smaller) Z value read out from the Z buffers 1, 2, 3 by the Z merge circuit 24 for each pixel.
The reading of the image from which is repeated for all pixels to generate a composite image.

Due to the above, here, as shown in the figure,
Background, car 1 and car 2 are displayed with the previous images (car 2 with small Z value (Z value is "10")), then car 1 with small Z value (Z value is "20"), next A background with a small Z value (Z value "200") is displayed on.

[0012]

Conventionally, a plurality of drawing units 21, 22, 23 are arranged in parallel as shown in FIG.
The dimensional data is written in the image buffers 1, 2, 3 and the Z buffers 1, 2, 3 respectively, and the Z merge circuit 24
However, the drawing process can be performed at high speed by displaying the foremost figure (pixel) among these and performing the shading process while leaving the latter figure as the non-drawing. However, a usage example in which a plurality of objects move around in the background as shown in FIG. 3 is often used in simulations, and complicatedly, an image in which the background is completed in advance is prepared as a pattern, and transferred and drawn according to the situation. May be used. In such a case, if the Z buffer values are all set to be the same, the same value (here, the background Z value = 200) is written to the Z buffer having a large number of pixels, and the large capacity Z buffer is effective. There was a problem that I could not say that I was using it.

In order to solve these problems, the present invention has a switching mechanism of a Z buffer and a newly provided Z register, and after drawing in the Z buffer, transfer drawing is performed in the image buffer to effectively use the Z buffer. The aim is to enable high-speed drawing of the image.

[0014]

[Means for Solving the Problems] Means for solving the problems will be described with reference to FIG. In FIG. 1, image buffers 1, 2, and 3 are used to develop and draw an image.

The Z buffers 1, 2, and 3 are for writing the Z value of each portion (for example, each pixel) of the image. The Z register 14 writes the Z value of the entire image.

The merge circuit 15 synthesizes the images drawn in the plurality of image buffers 1, 2 and 3 based on the Z value.

[0017]

According to the present invention, as shown in FIG. 1, the three-dimensional data (or image information) passed from the host is expanded and drawn in the image buffers 1, 2, and 3 and each part of the image (for example, each Pixel) Z value is Z buffer 1,
2, 3 or the entire Z value of the image is written in the Z register 14, and when there is an unused Z buffer 1, it becomes 3
The dimensional data (or image information) is used for development / drawing, and the merge circuit 15 uses one of the image buffers 1, 2 and 3 based on the Z value of the Z buffers 1, 2 and 3 (or Z register 14). Combine the retrieved images,
This composited composite image is displayed.

At this time, the image is expanded and drawn in the unused Z buffer 1, the image after drawing is transferred to the image buffer 1 and written, and the Z value is set in the Z register 14 to perform high speed drawing. I have to.

Therefore, a switching mechanism for the Z buffers 1, 2 and 3 and the newly provided Z register 14 is provided, and after drawing in the Z buffer 1 and transferred to the image buffer 1, the memory resources called the Z buffer are effectively used. It is possible to achieve high speed drawing of an image.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the construction and operation of an embodiment of the present invention will be described in detail with reference to FIGS.

FIG. 1 shows a block diagram of an embodiment of the present invention.
In FIG. 1, the drawing unit 11 develops three-dimensional data (or image information) passed from a host (not shown), draws it in the image buffer 1, and writes the Z value of each pixel at that time into the Z buffer 1. The image information such as the background image is drawn in the Z buffer 1, and the image information such as the drawn background image on the Z buffer 1 is transferred to the image buffer 1 at high speed.

The drawing unit 12 develops three-dimensional data (or image information) passed from a host (not shown) and draws it in the image buffer 2 and writes the Z value of each pixel at that time into the Z buffer 2. Is.

The drawing unit 13 develops three-dimensional data (or image information) passed from a host (not shown) and draws it in the image buffer 3 and writes the Z value of each pixel in the Z buffer 3 at that time. Is.

The image buffers 1, 2, and 3 are for expanding and drawing the image information. Z buffer 1,
Reference numerals 2 and 3 store the Z value of each pixel of the image information. When performing the shading processing of the image information, a pixel having a small Z value (front) of the Z buffers 1, 2 and 3 is taken out from the image buffers 1, 2 and 3 and image-synthesized to perform the shading processing. It is a thing.

The Z register 14 stores the Z value of the entire image drawn in the image buffer 1. This is to set in the Z register 14 when the Z value of the image drawn in the image buffer 1 is the same so as to efficiently use the memory resources, and to develop and draw the three-dimensional data in the unused Z buffer 1. Then, this is transferred to the image buffer 1, and as a result, high-speed drawing is possible.

The Z-merge circuit 15 is for performing shading processing, and includes the Z-buffers 1, 2, 3 or the Z-register 1.
The image of the smallest (front) pixel of the Z-values fetched from No. 4 is read from the image buffers 1, 2, and 3 and image-synthesized.

The composite screen 16 is a composite screen after being composited by the Z merge circuit 15. Here, the drawing unit 11 draws the background in the image buffer and the Z value is "200". The drawing unit 12 draws the car 1 in the image buffer and the Z value is "20" as shown in the background. The drawing unit 13 draws the car 2 in the image buffer, and the Z value is "10" and the background is "255" as shown in the figure. Then, it is assumed that the Z register 14 is provided in the drawing unit 11.

The operation in this state will be described in detail with reference to FIG. In FIG. 2, in step S1, the host sends a Z register use notification to the drawing unit 11.

In S2, the drawing unit 11 designates the output of the Z value write Z value register, and switches (sets) the state in which writing to the Z register 14 is enabled. In S3, the host notifies the drawing unit 11 of the drawing instruction.

In step S4, the three-dimensional data (or image information) delivered by the notification in step S3 is analyzed and drawn in the image buffer 1. Here, the background is drawn in the image buffer 1 and the Z register 14 is set to 1 as a whole.
For example, as shown in the Z register 14 of FIG.
Write as Z value "200".

In step S5, the host notifies the drawing unit 12 of the drawing instruction. In S6, the three-dimensional data (or image information) passed by the notification in S5 is analyzed and drawn in the image buffer 2, and the Z value of each pixel is written in the Z buffer 2. Here, as shown in FIG.
Image is expanded and drawn in the image buffer 2, and the Z value is written in the Z buffer 2 as shown.

In step S7, the host notifies the drawing unit 13 of the drawing instruction. In S8, the three-dimensional data (or image information) passed by the notification in S6 is analyzed and drawn in the image buffer 3, and the Z value of each pixel is written in the Z buffer 3. Here, as shown in FIG.
Image is developed and drawn in the image buffer 3, and the Z value is written in the Z buffer 3 as shown.

In step S9, the host notifies the drawing unit 12 of a drawing instruction (background). This is an unused Z
The drawing unit 11 is notified to the buffer 1 to draw another background.

In step S10, the drawing unit 11 to which the background (image) is transferred in step S9 analyzes the background in the Z buffer and draws it. In S11, the Z merge circuit 15 is provided with: • image buffer 1, Z register 14 • image buffer 2, Z buffer 2 • image buffer 3, Z buffer 3 among Z register 14, Z buffer 2, Z buffer 3
The smallest (front) pixel of the Z values extracted for each pixel from is determined, the image of the determined pixel is read from the corresponding one of the image buffers 1, 2, 3 and merged to obtain the previous image. Is displayed, and the image at the back is hidden.

In step S12, the image synthesized in step S11 is displayed on a display (not shown). Next, S13
The host notifies the drawing unit 12 of the drawing instruction (switching the background).

In S14, the Z drawn by the drawing unit 11 in S15 in response to the background switching instruction in S13.
The background (image) is taken out from the buffer 1 and transferred to the image buffer 1 at high speed. This allows the Z buffer 1
Therefore, the background (image) is drawn in the image buffer 1 at high speed.

In step S16, Z merge is performed. This is because the Z merging circuit 15 has: • image buffer 1 and Z register 14 • image buffer 2 and Z buffer 2 • image buffer 3 and Z buffer 3 among Z register 14, Z buffer 2 and Z buffer 3
The smallest (front) pixel of the Z values extracted for each pixel from is determined, the image of the determined pixel is read from the corresponding one of the image buffers 1, 2, 3 and merged to obtain the previous image. Is displayed, and the image at the back is hidden.

In step S17, the image combined in step S16 is displayed on a display (not shown). As mentioned above,
Here, the background is drawn in the image buffer 1, and the entire Z value (here, "200") at that time is written in the Z register 14, and the other image buffers 2 and 2 and the image buffers 3 and Z buffers are written. The cars 1 and 2 are drawn on 3 respectively, and in this state, the Z-merged composite screen 16 is displayed as shown in the figure. This composite screen 16
While the is being displayed, the next background is drawn in the Z buffer 1 (S10), then the Z buffer 1 is transferred at high speed to the image buffer 1 for merging, and the composite screen 16 having a new background is displayed. To quickly generate and display. Because of these, the Z buffer 1 is provided by providing the Z register 14.
Is effectively used, which is used for the next background analysis / drawing, and the backgrounds can be merged and displayed at high speed.

[0039]

As described above, according to the present invention,
In addition to the Z buffers 1, 2, and 3, a new Z register 14 is provided, and a structure is adopted in which after drawing in the Z buffer 1 and then transferring and drawing in the image buffer 1, the memory resource called the Z buffer is effectively used. It is possible to draw the image in the unused Z buffer in advance,
This can be transferred to the image buffer for high speed drawing.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is an operation explanatory diagram of the present invention.

FIG. 3 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 11, 12, 13: Drawing unit 14: Z register 15: Z merge circuit 16: Composite screen

Claims (2)

[Claims] 1. In a drawing method for merging a plurality of images using Z information, an image buffer for drawing an image and a Z value for writing a Z value of each part (for example, each pixel) of the image are written.
Z to write the buffer and optionally the overall Z value of the image
It comprises a register (14) and a merge circuit (15) for synthesizing images drawn in a plurality of image buffers based on Z values, and develops three-dimensional data (or image information) passed from the host. The Z value of each portion (for example, each pixel) of the image is written in the image buffer and the Z value is set to the Z value.
The Z value of the buffer or the entire image is written in the Z register (14), and when there is an unused Z buffer, three-dimensional data (or image information) is used for development / drawing, and the merge circuit (15) is used. ) Composes the images taken out from the image buffer based on the Z value of the Z buffer (or Z register (14)), and displays the composited image. 2. A structure in which an image is expanded and drawn in the unused Z buffer, transferred to the image buffer and written, and a Z value is set in the Z register (14) to perform high speed drawing. The drawing method according to claim 1, wherein: