KR960002974B1 - Apparatus for extending windows using z-buffer memory - Google Patents

Abstract

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Description

Window Expansion Unit Using Z-Buffer Memory

1 is a block diagram illustrating an arrangement for providing multiple windows as disclosed in a pending patent application.

2 is a block diagram illustrating an arrangement in accordance with the present invention for increasing the number of windows available for display at the output of a computer system.

3 is a schematic explanatory diagram of an area in which a window extention system is arranged by storage of a window number in a window confirmation memory used in accordance with the present invention;

4 is a schematic explanatory diagram of an area in which a window extension system is disposed by storing window numbers in a Z buffer memory used in accordance with the present invention.

5 is a table of truth that can be used to understand the operation of the circuit of FIG.

6 is a diagram illustrating the bit size of a window and depth indication that may be stored together in a Z-buffer memory in one particular embodiment of the present invention.

The present invention relates to logic circuits, and more particularly to logic circuits that can be used to increase the number of windows that can be displayed by a computer system.

One common interface used for computer operation uses multiple “windows” displayed on the cathode ray tube to represent individual computer applications. In systems using Windows, more than one program at a time is placed in a portion of memory available for instant invocation. The text and graphics output of each such program is made to appear in a window (a boundary defined on a set of screens). Usually, a computer operator runs only one of these programs, but for many different reasons, switch to another program in another window (sometimes with a single keystroke), work with that program, call data from that program, Put data in the program. Each window can overlap another window with the "front window" that constitutes the active working file. You can add or delete information from the current window, add new terms to that window, recompile the window in another window, and generally, when there is no other window, you can perform any other action in the program in that window. Can be done.

It has been found that windowing the system is very useful for advanced computer operations. For example, experienced computer operators find that windowing of the system is very useful for providing fast movement between other programs and documents. On systems that do not use windowing, the operator usually has to close one program before calling the new program to work with the new program. This takes a lot of time. In addition, the main reason for switching between programs is to move data and graphical images between programs. Systems that do not use windowing usually do not easily move information between programs. Best of all, it made the computer run very fast, and the windowing of the system made it easy to move data between programs and documents that were designed.

Because of the complexity of the task, it is often desirable to have many windows running simultaneously, each with a separate program or document, just as a person has many individual documents on his desk for use in completing a particular task. However, windowing of more systems is not possible to provide more than a limited number of windows that can be called at a time. For example, a system called “apparatus for quickly erasing the output display of a computer system”, published in a pending patent application serial number filed by William Joy et al., Designated as the trustee of the present invention, has a total of 16 windows at once. Have a circuit to be used. Thus, even to a lesser extent, such systems still require the operator to switch between programs by closing one program before opening another program involving more than 16 programs or documents.

It is therefore an object of the present invention to provide a computer system comprising logic circuitry that defines a system windowing that allows selection of a substantially unlimited number of windows.

It is another object of the present invention to provide a computer system that can handle many programs or documents at one time.

It is a further object of the present invention to provide a logic circuit for a computer system that can optionally be used to increase the number of windows available at a time.

This and other objects of the present invention provide a display memory for storing information to be given to an output display, a window confirmation memory for storing information about a window position on the output display, and a window for displaying a window on which special data manipulation will appear. A window acknowledgment register to store the acknowledgment number, a window acknowledgment comparator to determine whether the number in the window acknowledgment register equals the window acknowledgment number at a particular pixel in the window acknowledgment register, and the depth of information to appear on the output display ( Z buffer memory for storing information indicating depth, Z buffer register for storing information indicating depth of each piece of information, and information in Z buffer register is equal to the depth of information stored in Z buffer memory, or Or Z to determine if it is small Per comparator, a window expansion register to store a larger window number than can be stored in the window confirmation register, a control register to cause the storage of the window confirmation number to Z buffer memory, a number and a window extension register stored in Z buffer memory Windows extended comparator and write enable circuits for comparing the numbers stored in the Windows check comparator, Z-buffer comparator, and window expand comparator (allow information to be written to the window check memory, Z-buffer memory, and display memory). Is performed in a computer system).

These and other features and advantages of the present invention will become apparent to those skilled in the art upon reading the following detailed description in conjunction with the various numbers in the figures.

Referring now to FIG. 1, there is shown a windowing of a system for use in a computer system, as described in the pending patent application with reference to the above designated as a trustee of the present patent application.

1 illustrates a window identification output system 10 used to provide an output signal to a cathode ray tube (CRT) 12 displaying another window.

To produce output on a computer output display, a screen full of images or text is displayed in a block of memory known as a "bit map". In its simplest form, each picture element (pixel) on the screen is represented by a memory bit. For example, if the display screen has 1024 × 1024 pixels, slightly more than one million bits of memory are needed to display each screen.

In order to produce color output, it is common to have many bits of memory for each pixel of the display memory. In a preferred embodiment, each display memory may include 24 bits of storage for storing color information at each pixel. This is referred to as a 24-bit RGB color value. To store these 24-bit RGB color values, the system 10 includes a pair of double buffered display memories 14 and 16 (each sufficiently including bitmapped memory) and a memory (A and a). It is said as B).

The system 10 also includes a window identification (WID) register 18 which stores four bits of information in the preferred embodiment and a full screen bit batch memory which also stores four bits of information for each pixel in the preferred embodiment. And a window identification (WID) memory 20 constituting the same.

The window identification (WID) comparator 22 receives output signals from the WID register 18 and the WID memory 20. The system 10 also includes write enable logic 26 to selectively enable writing of information to the multiplexer 24, cathode ray tube 12, display memory A and B, and window confirmation memory 20, respectively. And a control register 28 for controlling the operation of the system. In operation, the window is first selected by a value provided from the central processing unit (CPU). This value includes the window identification number and pixel address for each pixel contained within the window.

The window confirmation number is written to each corresponding pixel lying within the bounds of the particular window in the window confirmation memory.

When the first window is written to the window identification memory, each memory location within that window has a window identification number for that window. When the next window in front of the first window is written to the window identification memory, the portion of the second window that overlaps the first is written on top of the first overlapped memory location, and therefore automatically overwrites the first.

After all desired windows are stored in the window confirmation memory, the window confirmation memory stores the indication as shown in the display of the CRT of FIG. For example, the first window to be defined in the window identification memory is shown as a window (0) on the CRT, the second window (overlapping with the first) as the window 1, and the third window (foreground) ) Is shown as window 2.

When you want to write information to the display memory for a particular window, the information is written from the CPU to the selected display memory (A and B) via the data bus.

The information includes the pixel address (RGB color value described above) and the window identification number. The window confirmation number is stored in the window confirmation register 18 and compared with the window confirmation number previously stored for that pixel in the window confirmation memory 20.

If the window confirmation number stored in the window confirmation memory 20 is the same as that of the window confirmation register 18, the comparator circuit 22 causes the write enable logic 26 to display the display memory (the RGB information is selected). Allows writing to the addressed pixel of A or B).

If the comparator circuit 22 determines that the window confirmation number is not the same as the number stored for the pixel in the window confirmation memory 20, then the RGB information is not stored in the display memory. Thus, the signal for that window will be written only at the selected address in each particular window to which the information is addressed.

The signal written to the display memory is eventually transferred from the special display memory to the cathode ray tube 12 shown in FIG. 1 through the multiplexer controlled by the control register 28.

Since this uses only four bits for the storage of the window identification number, the system 10 described in FIG. 1 has information relating to only 16 windows (the entirety of the only binary number that can be represented by four bits). Can be stored. Clearly, such a system cannot be used to provide more than 16 windows at once without modification. In addition, it is much clearer that the provision of a much larger number of possible windows will make the computer system much more useful in many situations.

A pending patent application in connection with the above also discloses an arrangement for integrating a three-dimensional output display on a system output device.

The system incorporates a device for storing information indicative of the depth of each pixel to be provided as an output for a particular display on the cathode ray tube.

A special system adds a Z-buffer memory that stores Z or depth information values and a Z-buffer comparator circuit that compares the Z-buffer value stored in that Z-buffer memory to a new Z value for each particular pixel.

The Z buffer comparator looks at the old Z value at that pixel location in the Z buffer memory and compares it to the new Z value. If the Z-buffer comparison shows that the new Z number is less than or equal to that stored in memory, the new pixel is in the same plane or in front of the previously written pixel; The write enable logic is activated to write information about the pixel to the appropriate display memory and Z buffer memory.

Arrays are now designed to use the Zbuffer memory configuration as an extension of window identification memory, allowing essentially unlimited windows to be used at once, greatly improving the transition between different programs and documents and achieving this transition. Time can be greatly reduced.

A normal Z buffer memory is a full screen display memory that stores an indication of a particular location where a pixel is to be taken along the Z side at each location representing each pixel, such as the window and display memory discussed previously. In a preferred embodiment of the present invention, the Z buffer memory stores 24 bits for each pixel. It will be appreciated that the size of the memory can store individual numbers that sum up only unique numbers that can actually be stored in the window identification memory.

It will also be appreciated that no particular program or document can operate in the three-dimensional region, and therefore no Z-buffer memory circuitry is used for that operation.

Using the unused Z-buffer memory circuit can be used to extend the range of windows that the arrangement described in FIG. 2 can be used with the system. 2 shows display memory 14 and 16, WID memory 20, WID register 18, WID comparison circuit 22, control register 28, which were used in the system 10 already mentioned in FIG. And a write enable circuit 26 is described. The system 20 also includes a Z-buffer memory 42 and a Z-buffer comparison circuit 44.

In operation, the circuit of system 40 acts as follows. The following discussion assumes that the window check 20 and Z-buffer functions are enabled, and that the display memory (A or B) is selected by the CPU through setting the appropriate bits in the control register 28. System 40 first determines if the data is in a particular window and then determines if the data to be stored for that window is before the data already stored for that window. The first step in any operation is to store the window confirmation value of the window to be used in the window confirmation memory. This is accomplished by writing to the window confirmation memory 20 value from the CPU which defines each area of the window to be used.

When it is desirable to write a special pixel into the display memory after the window to be used is defined, the CPU provides the pixel address and color value along with the Z (depth) value. In the window check comparator circuit 22, the window number of the data is compared with the window check number stored in the window check memory 20, and if it is the same (i.e. information at that pixel is in the window), enable The signal is passed to the write enable logic 26.

Assuming that window comparison provides an enable signal, it is necessary to make a Z-buffer comparison to determine which pixel before this pixel is already stored. The Z buffer comparison circuit 44 compares the Z value previously stored in the Z buffer memory 42 with respect to the pixel with the Z value supplied by the CPU. If the Z value supplied by the CPU is less than or equal to that stored in the Z buffer memory 42, the new signal is in the same plane or in front of the data representing the currently stored pixel, and the signal causes the write enable logic 26 to It is provided to write the Z value to the Z buffer memory 42 and the color RGB value to the selected display memory 14 or 16.

Since the information in the particular program is not three-dimensional, Z buffer memory 42 can be used to expand the number of windows that can be used in the system, in situations where Z buffer memory 42 is not used. This is accomplished by the CPU writing an appropriate value to the control register 28 indicating that the window number expansion is required.

This allows control register 28 to enable Z buffer memory 42 for use as a memory to expand the number of available memories.

In such a case, unused memory available in Z buffer memory 42 is used to store the window number instead. Since the preferred Z-buffer memory 42 includes 24 bits of storage at each pixel, practically more windows can be stored.

In order to allow the Z buffer memory 42 to act as window memory, a window check extension comparator 46 and a window check extension register 48 are added to the system 20.

This works in a similar way to the WID register 18 and a WID comparator that compares the window number stored in the Z buffer memory with the expanded window number of the incoming value to determine if the incoming value is in the window to be written. If the entry is the same as the stored window number, the value is written to the display memory. If the values are not compared, the pixels are not in that window and are not written to the display memory. This arrangement allows very large window numbers to be stored so that many windows are available as a result without increasing the size of the window memory 20.

In a preferred embodiment of the arrangement, whenever it is desired to increase the number of windows beyond the normal number that can be stored in the window identification memory 20, the CPU writes an appropriate value into the control register 28 so that the window is windowed. It indicates that more than the confirmation memory 20 can handle.

Thereafter, the window confirmation value is displayed by the contents of the WID memory 20 and the Z buffer memory 42 and by the WID expansion register 48. Each window confirmation value contains 28 bits of information and is used to define the area occupied by the extended window in window confirmation memory 20 and Z-buffer memory 42. Each such value includes four bits of information for storage in the window identification memory 20 and 24 bits of information for storage in the Z buffer memory 42.

The portion of the value stored in the region defined for that window in window confirmation memory 20 defines that region as a window of zero number while the 24-bit portion of the signal stored in the Z buffer represents the actual window number in the same region. do.

In this way, an area with a four bit WID value of zero is placed by the system as indicated for the extended window number.

Then, when writing to the window with the extended number is required, the information includes 28 bits to define the window number with it. To determine whether this is written to the display memory, a 28-bit extended window identification number (four MSBs and zeros) for that pixel is sent to the WID extension register.

The window number in the WID extension register 48 is compared by the WID extension comparator 46 to the number stored in the WID memory 20 and the Z buffer memory 42 for the particular pixel. The WID memory 20 indicates that zero is stored for that pixel and if the Z buffer number is equal to the remainder of the extended window number in the WID extension register 48, the information is written to the selected display memory.

In this way, Z-buffer memory 42 is used to expand the number of windows that can be used with a very large number with the system.

3 illustrates an area arranged by the storage of the window number in the window identification memory 20 in which such a window expansion system is used. Such an area indicated with zero is an area where extended window numbers are stored in the Z buffer memory 42. 4 illustrates an area disposed for the expanded window in the Z buffer memory 42.

Expansion of the system 40 uses the window expansion mask 50. This circuit receives information from the CPU indicating the amount of Z buffer memory 42 to be used for the window expansion memory and the remaining portion of Z buffer memory 42 can be used for depth information.

The window extension mask 50 is a register that controls the comparator 46 by determining which of the 28 available bits is used for the WID extension comparator 46.

The replenishment of this mask, or the remaining bits of the total 28, define the bits to use for the Z-buffer comparator 44. For example, it may be desirable to have a smaller number of windows than may be stored in more than 16 but in 14 bits. The window expansion mask 50 can be used to select eight, twelve, sixteen or twenty bits of the Z buffer memory 42 for use as, for example, extended window memory.

For example, because eight bits of memory store enough window numbers in 256 windows, window extension mask 50 may be used to select eight bits from each pixel of Z-buffer memory 42 for the window extension number. Can be. Leave 16 bits remaining for storage of depth information.

FIG. 6 illustrates various options that can be used using the window expansion mask 50 in the system of FIG. In the first choice, window number extension is not used. In a second option, eight bits are used for window number extension and sixteen remain for depth indication storage. In the third example, 16 bits are used for window number extension while 8 bits remain for depth indication. In the last example, all bits are used to store depth information.

FIG. 5 is a table describing the signals that may exist in the system 40 shown in FIG. 2 and the response of the system 40 to such signals. The first row represents the signal provided to the control register by the CPU. In the first column, this signal is zero indicating that no window expansion is required. In this case, if the numbers in the window confirmation memory 20 and the window comparator 22 are not the same, nothing is written to the selected display memory and the Z buffer memory 42, regardless of the result of the window expansion comparison and the Z buffer comparison. Do not. The zero signal indicates no window number extension, but the WID comparator 22 shows the Z buffer memory 42 and Z buffer memory 42 in the next two columns of the table indicating that the window represented by the incoming pixel is the same as the window number stored at that location. The display memory 20 is written in accordance with the result determined by the Z buffer comparator 44.

In the next three columns of the table of FIG. 5, the control register 28 receives a signal indicating that the window number will be expanded. In such a situation, the results provided by the window confirmation comparator 22 do not affect the information to be written. If the window extension comparison shows unequal window numbers, nothing is written to the Z-buffer memory 42 and the display memory 20.

If the window extension comparison shows that the window number of the incoming signal is stored in the WID memory 20 and the Z buffer memory 42, the result of the Z buffer comparison determines that it is to be written. If the Z buffer comparison shows a Z buffer memory with the window extension number of the incoming signal, the information is written to the display memory. If the numbers are different, the information signal is written to the display memory.

Although the present invention has been described in the preferred embodiments, it will be appreciated that various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the present invention should be measured by the following claims.

Claims (17)

Display memory for storing information to be provided at a selected window position on an output display; A window confirmation memory for storing information of a first portion of a window confirmation number relating to a window position on an output display; A window acknowledgment register for storing a first portion of a window acknowledgment number indicating a window in which a particular portion of incoming data will appear; A window check comparator for determining whether the first portion of the number stored in the window check register is equal to the first portion of the window check number stored in a particular pixel in the window check memory; A Z-buffer memory for storing information indicative of the depth of information to appear on the output display; A Z-buffer register for storing information representing the depth of each portion of incoming data; A Z-buffer comparator to determine whether the information in the Z-buffer register is less than or equal to the depth of the information stored in the Z-buffer memory at depth; A window extension register for storing a second portion of a window identification number indicating a window in which a particular portion of incoming data will appear; A control register causing the Z buffer memory to store a second portion of the confirmation number for the window position on the output display; A window extension comparator for determining whether a second portion of the number stored in the window extension register is equal to a second portion of the window identification number stored in a specific pixel stored in the Z buffer memory; And a write enable circuit responsive to the window check comparator, the Z buffer comparator and the window extended comparator to cause information to be written to the window check memory, the Z buffer memory and the display memory. Display memory for storing information provided on an output display; A full screen bit layout window confirmation memory for storing information about the window position on the output display, the window confirmation memory capable of storing a first number of bits of information for each pixel of the output display; First means for storing a first number of bits of information about a window in which a particular portion of incoming data will appear; Z-buffer memory normally used to store information indicating the depth of information to appear on an output display, which is a full screen bit-located memory capable of storing the second number of bits of information for each pixel of the output display. ; A window extension register for storing a second number of bits of information for a window in which a particular portion of incoming data will appear; Means for selectively storing a first number of bits of information for the window portion of the output display in the window confirmation memory and a second number of bits of information for the window position on the output display in the Z buffer memory; And comparing the number of first bits of information stored in the window confirmation register with the number of first bits of information stored in the window confirmation memory, the number of second bits of information stored in the window extension register and the number of second bits of information stored in the Z buffer memory. And means for increasing the amount of information for the windows by increasing the total number of bits used to generate the window information. 3. The computer system of claim 2 further comprising means for enabling a selected number of bits at each location in a Z-buffer memory to store information about window locations on an output display. 4. The computer system of claim 3 wherein the means for enabling a selected number of bits at each location in the Z buffer memory comprises a window expansion mask. 3. The Z of claim 2, wherein means for selectively selecting, in the Z-buffer memory, a second number of bits of information about a window position on an output display, is normally used to store information indicating the depth of each portion of the incoming information. Buffer register; A Z-buffer comparator normally used to determine whether the information in the Z-buffer register is less than or equal to the depth of the information stored in the Z-buffer memory in depth; A control register for storing a second number of bits of information about a window position in a Z buffer memory; And a write enable circuit for causing information to be written to the window identification memory, the Z buffer memory and the display memory and responsive to the Z buffer comparator and comparison means. 6. The computer system of claim 5 including means for enabling a selected number of bits at each location in a Z-buffer memory to store information about window positions on an output display. 7. The computer system of claim 6 wherein the means for enabling a selected number of bits at each location in the Z buffer memory comprises a window expansion mask. Display memory for storing information to be provided on an output display; A full screen bit layout window confirmation memory for storing information about the window position on the output display, the window confirmation memory can store a first number of bits of information about each pixel of the output display; A second full screen bit layout memory normally used to store information indicating something other than a window position on the output display, the second memory being a second number of bits of information greater than a first number for each pixel of the output display; Full screen bit- layout memory for storing; Means for selectively storing the first number of bits of information on the window position of the output display and the second number of bits of information on the second memory; In order to determine in which window of the output display the incoming information should be selectively compared, the first bit number of the incoming information and the information stored in the window confirmation memory, and the second bit number of the incoming information and the information stored in the second memory. Computer system, characterized in that it comprises means for selectively comparing. 9. The computer system of claim 8 further comprising means for enabling a selected number of bits of each position of the second memory to store information about window positions on the output display. 10. The computer system of claim 9 wherein the means for enabling a selected number of bits of each location in the second memory comprises a window expansion mask. A first full screen bit layout memory for storing information to be provided on an output display; A second full screen bit layout memory for storing information about window positions on the output display, the second full screen bit layout memory having a limited number of bits to display each pixel of the output display; A first register for storing an input signal representing a window in which incoming data will appear; A first comparator for determining whether an input signal stored in the first register is equal to window position information stored in the second memory with respect to a particular pixel of the output display; A third full screen bit layout memory for normally storing information other than window position information to control the appearance of an output display, the third full screen bit layout memory having a substantially larger number of storage positions to display each pixel of the output display; A second register for storing an input signal for displaying information other than window position information; A second comparator for comparing the information in the second register with respect to the particular pixel in the output display to the information in the third memory; A third register for storing a portion of the number of windows larger than the maximum number of windows that can be stored in the first register; A control register for causing storage of a portion of the window confirmation number in the third memory; A window expansion comparator for comparing the number stored in the third register with the number stored in the third memory; And a write enable circuit responsive to the first comparator, the second comparator, and the window expand comparator to allow information to be written to the first memory, the second memory, and the display memory. 12. The computer system of claim 11, further comprising means for enabling a selected number of bits of each position of the third memory to store information about window positions on the output display. 13. The computer system of claim 12 wherein the means for enabling a selected number of bits in each location of the third memory comprises a window expansion mask. A first full screen bit layout memory for storing information to be provided to an output display; A second full screen bit layout memory for storing a first portion of information about a window position on an output display and having a first number of bits for displaying each pixel of the output display; Means for comparing each incoming signal with information stored in a second memory to determine whether to provide such information in a particular window of the output display; A third full screen bit layout memory for normally storing information to be displayed on an output display other than the window position information, and having a substantially larger number of storage locations than the second memory for displaying each pixel of the output display; Means for causing a second portion of the information about the window position on the output display to be stored in a third memory, each incoming signal being stored in the second and third memory to determine whether to provide such information in a particular window of the output display. Means for comparing with information; And means for responding to a comparison of the incoming information with the information in the second and third memories to cause information in the display memory to be written to the output display. 15. The apparatus of claim 14, wherein the means for comparing the incoming signal with information stored in the third memory comprises: a register for storing an input signal representing information other than window position information; A comparator for comparing the information in the register with the information at individual pixel locations in the third memory; A second register for storing a portion of the number of windows larger than the maximum number of windows that can be stored in the first register; A control register for causing storage of a portion of the window confirmation number in the second memory; A window expansion comparator for comparing the number stored in the third register with the number stored in the third memory; And a write enable circuit responsive to a first comparator, a second comparator and a window expand comparator for causing information to be written to the first memory, the second memory and the display memory. 15. The computer system of claim 14 further comprising means for enabling a selected number of bits of each position of the third memory to store information about window positions on the output display. 17. The computer system of claim 16 wherein the means for enabling a selected number of bits of each location in the third memory comprises a window expansion mask.

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