JPH0937044A - Graphics system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the communication processing of drawing information between a host computer and a graphic controller form being complicated and to reduce the occurrence of delay in communication. SOLUTION: The graphic controller is provided with plural reception buffers 31 -3n and managing data 6 for specifying the respective reception buffers and corresponding to a request from a task. The host computer checks whether the reception buffer at the set input pointer position is free or not based on the position relation of input and output pointers. When it is free, the drawing information is written in the reception buffer and the input pointer is advanced for one. When the drawing processing completion of a firmware 4 is reported, the graphic controller checks whether there is the drawing information in the reception buffer at the set output pointer position based on the position relation of input and output pointers. When there are data, the drawing information is read out from the reception buffer and the output pointer is advanced for one.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a graphics system using a computer, and more particularly to a communication algorithm for drawing information between a computer and a graphics controller.

[0002]

2. Description of the Related Art FIG. 6 is a block diagram of a device for explaining a conventional communication system. The host computer side exclusively controls the drawing information (drawing command and drawing data) from the plurality of tasks 1 ₁ to 1 _n by the driver 2 and sequentially transmits the drawing information to the graphic controller side.

On the graphic controller side, the firmware 4 receives a drawing command, the drawing data is received by the reception buffer 3, and the received drawing data is drawn by the firmware 4 according to the drawing command.
Visualize on the CRT display device 5.

The graphic controller notifies the host computer side of the completion of the drawing process of the firmware 4 (or the ready of the receiving buffer 3) by means of an interrupt or the like, and the host computer side receives the notification of the completion of the drawing process and then executes the next drawing command. And send the drawing data.

[0005]

In the conventional communication method, since only one drawing data reception buffer is prepared on the graphic controller side, the host computer side and the graphic controller side each send and receive one drawing information. It will wait for the drawing process.

Therefore, the host computer side needs to exclusively control the drawing request from the task by the driver 2, and the task is delayed and the processing is delayed.

Further, the graphic controller side needs to notify the host computer side of the completion of the drawing process by the firmware or the ready of the reception buffer by an interrupt, and a complicated process for accepting the interrupt from the driver of the host computer side is required. Will be needed.

[0008]

According to the present invention, a plurality of receiving buffers are provided, and receiving buffer management data having a data string that can identify each receiving buffer in association with each receiving buffer is provided. Processing for storing the drawing data in the reception buffer and advancing the input pointer position by one if the reception buffer at the input pointer position that is cyclically set for the data string of the management data Provide means.

If there is data in the reception buffer at the output pointer position that is cyclically set for the data string of the management data in sequence, the graphic controller performs drawing processing of the drawing data in the reception buffer and advances the output pointer position by one. Provide processing means.

The number of receive buffers is greater than or equal to the number of tasks,
Alternatively, use a small number.

The management data has at least data that can specify the position of each reception buffer as a data string.

By cyclically setting the input pointer position and the output pointer position with respect to the management data by sequential feeding and storing and retrieving the data, the computer side checks the vacancy of the receiving buffer and the graphic controller side by the relation between the pointer positions. Make it possible to check the existence of data.

[0013]

FIG. 1 shows an embodiment of the present invention. 6 is different from FIG. 6 in that a plurality of reception buffers 3 _{1 to} 3 _n are provided on the graphic controller side and the reception buffer management data 6 is provided.

The reception buffers 3 _{1 to} 3 _n are assigned as storage areas of a memory on the graphic controller side. The assigned number may be equal to the number n of tasks on the host computer side, or may be a plurality smaller than n. If the number is smaller than n, the number is set appropriately according to the expected number n of tasks and the frequency of graphic processing requests. For example, 10 receive buffers are provided for 50 tasks, and exclusive control by the driver is performed. I do.

The reception buffer management data 6 has a data string for individually specifying each of the reception buffers 3 _{1 to} 3 _n , and at least each data has information for specifying a storage area of the reception buffer (for example, storage area of each reception buffer). Start address)
Is held.

Further, one input pointer and one output pointer can be set in the management data 6. The input pointer is set by the host computer side, and which reception buffer to which the drawing information from the task is to be transmitted is set at the data string position of the management data 6. This position setting is carried out in a sequential and cyclic manner with the drawing pointer being sent to one receiving buffer and the next receiving buffer being the input pointer position.

The output pointer is set by the graphic controller side, and which drawing information in the reception buffer is to be drawn is set at the data string position of the management data 6. This setting is carried out in a sequential and cyclic manner with the next receiving buffer as the output pointer position when drawing information is taken out from one receiving buffer.

A communication process using the plurality of reception buffers 3 _{1 to} 3 _n and the management data 6 will be described in detail below.

FIG. 2 shows a flowchart for receiving buffer management on the host computer side. When transmitting drawing information to the reception buffers 3 _{1 to} 3 _n , the host computer side first compares the current positions of the input pointer and the output pointer with respect to the data string in the management buffer 6, and the input pointer becomes the output pointer. It is checked whether it is one before (S1).

This check determines whether or not the receive buffers 3 _{1 to} 3 _n have a free space. That is, since the input pointer and the output pointer are set in a forward and cyclic manner and writing or reading of drawing information is performed with respect to the reception buffer at the pointer position, when the input pointer is positioned immediately before the output pointer, reception is performed. Suppose the buffer is full.

This state corresponds to the positional relationship of the input / output pointers shown in FIG. 3A. In this case, the receiving buffer at the position of the input pointer is empty, but is input after writing to the receiving buffer at this position. It is avoided that if the pointer is advanced by one, the position of the output pointer is matched and the same state as when all the receiving buffers are empty is obtained.

For other positional relationships, it is determined that the receive buffer has a free space. For example, FIG. 3B shows a case where data is present in two reception buffers, and the input pointer is located at a position two positions after the output pointer. Also, FIG.
(C) shows the case where drawing data does not exist in all the reception buffers, and the input pointer is at the same position as the output pointer.

When the receiving buffer has a free space in the check process S1, the drawing information is stored in the receiving buffer at the position indicated by the input pointer (S2). At this time, the storage position is obtained from the information that specifies the storage area of the reception buffer of the management data 6.

It is checked whether or not the input pointer when the drawing information is stored in the empty reception buffer is located at the end of the reception buffer (S3). By this check, the host computer side determines the input pointer position as 1 depending on whether the input pointer position becomes the final position of the management data.
Determine whether to advance or return to the initial position.

When the input pointer is at the last reception buffer position, a cyclic process is performed to change the position of the input pointer to the position indicating the beginning of the reception buffer (S4). For example, as shown in FIG. 3D, the input pointer is at the final position,
After writing the drawing information at this position, the input pointer position is returned to the beginning position.

When the input pointer is not the last reception buffer position, the input pointer position is advanced by 1 (S5). For example, as shown in (e) of FIG. 3, when the input pointer position and the output pointer position match (all receiving buffers are empty), after drawing information is written in the receiving buffer at the input pointer position, the input pointer position Advance one step.

Therefore, in response to a request from the task, the host computer side checks whether or not the reception buffer at the input pointer position to be set is empty by checking the positional relationship of the input / output pointers, and if it is empty, the reception The process of writing the drawing information in the buffer and advancing the input pointer by one is sufficient.

FIG. 4 shows a flow chart for managing the reception buffer on the graphic controller side. When receiving the drawing processing completion notification from the firmware 4, the graphic controller side starts reading drawing information from the reception buffers 3 _{1 to} 3 _n . First, the management buffer 6
The current positions of the input pointer and the output pointer with respect to the data string are compared to check whether the input pointer is at the same position as the output pointer (S11).

This check determines whether or not the receiving buffers 3 _{1 to} 3 _n have drawing information. That is, since the input pointer and the output pointer are sequentially and cyclically positioned with respect to the data string of the management data and writing or reading of the drawing information with respect to the pointer position is performed,
When the output pointer position and the input pointer position match, it is assumed that there is no drawing information in the reception buffer.

This state has the positional relationship of the input / output pointers shown in FIG. 5A. In this case, it means that the output pointer position has been advanced to the input pointer position, and all the reception buffers are not yet stored. It is in use.

When there is drawing information in the receiving buffer in the check process S11, the drawing information is taken out from the receiving buffer at the position indicated by the output pointer (S12). At this time, the read position is obtained from the information for specifying the storage area of the reception buffer included in the management data 6.

The drawing information in the receiving buffer is taken out, and when the firmware 4 starts the drawing process, it is checked whether or not the output pointer is at the position indicating the end of the receiving buffer (S13). By this check, the graphic controller side determines whether to advance the output pointer position by one or return it to the first position depending on whether or not the output pointer position becomes the final position of the management data.

When the output pointer is at the last reception buffer position, the output pointer position is changed to the position indicating the beginning of the reception buffer (S14). For example, as shown in FIG. 5B, the output pointer is at the final position, the drawing information is read from the reception buffer at this position, and then the output pointer position is returned to the beginning position.

When the output pointer is not the last reception buffer position, the output pointer position is advanced by 1 (S15). For example, as shown in (c) of FIG. 5, after drawing information is read from the reception buffer at the output pointer position, the pointer position is advanced by one.

Therefore, when the graphic controller side receives the drawing processing completion notification of the firmware 4, it checks whether or not there is drawing information in the receiving buffer at the output pointer position to be set, based on the positional relationship of the input / output pointers. If there is data, the drawing information is read from the reception buffer and the output pointer is advanced by one.

[0036]

As described above, the present invention has the following effects.

On the host computer side, exclusive control of drawing requests from the task is unnecessary or reduced by the driver 2, the delay of processing due to waiting of the task is reduced, and the communication processing is simplified.

Further, the graphic controller side does not need to notify the host computer side of the completion of the drawing process by the firmware or the reception buffer ready by an interrupt, and the complicated process for accepting the interrupt from the driver of the host computer side is not necessary. become.

[Brief description of drawings]

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

FIG. 2 is a process on the side of a host computer in the embodiment.

FIG. 3 is a positional relationship of input / output pointers in transmission of drawing information.

FIG. 4 is a process on the side of a graphic controller in the embodiment.

FIG. 5 is a positional relationship of input / output pointers when receiving drawing information.

FIG. 6 is a configuration diagram of a conventional device.

[Explanation of symbols]

1 ₁ 1 _n Task 2 Driver 3 3 ₁ 3 _n Receive buffer 4 Firmware 5 CRT display 6 Receive buffer management data

Claims (1)

[Claims] 1. A computer transmits drawing commands and drawing data from a plurality of tasks to a graphic controller via a driver, the graphic controller receives the drawing data in a reception buffer, and receives the drawing data according to the drawing commands. In a graphics system for rendering and visualizing, a plurality of the reception buffers are provided, reception buffer management data having a data string that can identify each reception buffer in association with each reception buffer is provided, and the computer In response to the drawing request, the drawing data is stored in the reception buffer and the input pointer position is advanced by 1 if the reception buffer at the input pointer position that is cyclically set cyclically to the data string of the management data is free. A processing means is provided, and the graphic If there is data in the reception buffer at the output pointer position that is cyclically set to the data string of the management data in sequence, the trailer draws the drawing data in the reception buffer and advances the output pointer position by one. A graphics system characterized by being provided.